dap 101a-1105-1a

DAP 101A-1105-1A

PreliminaryAug 2017 (Iss 09)

AIR TRANSPORT OPERATIONS MANUAL

CARRIAGE OF CARGO BY HELICOPTERSGENERAL INFORAMTION

Issue No 10September 2017

Sponsored for use in theUnited Kingdom Ministry of Defenceand Armed Forces by ROYAL AIR FORCE – ACAS RTSA RW1

CONDITIONS OF RELEASE. This document is the property of Her Britannic Majesty’s Government. The information in this document (excluding the Departmental logo) may be reproduced for use by UK Government employees for Ministry of Defence business, providing it is reproduced accurately and not used in a misleading context. This document may be re-used under the terms of the Open Government Licence version 2.0, http://www.nationalarchives.gov.uk/doc/ open-government-licence/version/2/, and must be acknowledged in the following manner: ‘Air Transport Operations Manual, Carriage of Cargo by Helicopters, Underslung Load Clearances. MOD. © Crown copyright 2015’.

© Crown copyright 2015

Publication Authority: ACAS RTSA RW1

Prepared by JOINT AIR DELIVERY TEST AND EVALUATION UNIT

PUBLICATION AUTHORITY DETAILS. Service users should send their comments through the channel prescribed for the purpose by the publications Sponsor.

Ministryof Defence

DAP 101A-1105-1A


BOOK CHAPTERS

Preliminary material ................................................................................................................................3

ChaPter 1 .....................................................................................................................................................7ChaPter 1 - 1 .................................................................................................................................................8ChaPter 1 - 1: General information ....................................................................................................9ChaPter 1 - 2 ...............................................................................................................................................14ChaPter 1 - 2: heliCoPter UnDerSlUnG loaD eQUiPment (hUSle) anD itS manaGement ................................................................................................................................15

ChaPter 2 ...................................................................................................................................................17ChaPter 2 - 1 ...............................................................................................................................................18ChaPter 2 - 1: heliCoPter UnDerSlUnG loaD eQUiPment (hUSle) anD heliCoPter CarGo hooK ComPatibility ..................................................................................................................................19ChaPter 2 - 2 ...............................................................................................................................................22ChaPter 2 - 2: heliCoPter eXternal CarGo hooKS ......................................................................24ChaPter 2 - 3 ...............................................................................................................................................39ChaPter 2 - 3: heliCoPter eXtenSion StroPS.................................................................................42ChaPter 2 - 4 ...............................................................................................................................................70ChaPter 2 - 4: SUPPlementary SlinGinG eQUiPment .....................................................................73ChaPter 2 - 5 ...............................................................................................................................................99ChaPter 2 - 5: heliCoPter SlinGS - General ..................................................................................102ChaPter 2 - 6 .............................................................................................................................................123ChaPter 2 - 6: heliCoPter CarGo liftinG netS anD netteD loaDS ........................................127ChaPter 2 - 6 - 1: heliCoPter CarGo net ProteCtion PaD ........................................................129ChaPter 2 - 6 - 2: heliCoPter CarGo liftinG net - 5600 KG SWl ................................................130ChaPter 2 - 6 - 3: heliCoPter CarGo liftinG net - 5000 lb SWl.................................................141ChaPter 2 - 6 - 4: heliCoPter CarGo liftinG net - 7000 KG SWl ................................................150ChaPter 2 - 6 - 5: tyPiCal netteD loaDS...........................................................................................158ChaPter 2 - 6 - 6: SPeCifieD aUthoriSeD loaDS .............................................................................162ChaPter 2 - 7 .............................................................................................................................................167ChaPter 2 - 7: retainer breaKaWay aSSembly ..............................................................................168ChaPter 2 - 8 .............................................................................................................................................173ChaPter 2 - 8: CarGo reStraint reQUirementS for heliCoPter UnDerSlUnG loaDS ...175ChaPter 2 - 9 .............................................................................................................................................190ChaPter 2 - 9: baG - SinGle USe lift, SWl 1000 KG anD StroP, DiSPoSable, 2 m, SWl 2000 KG ........................................................................................................................................................................191

ChaPter 3 .................................................................................................................................................195ChaPter 3: StanDarD riGGinG PraCtiCe anD teChniQUeS ........................................................196

ChaPter 4 .................................................................................................................................................204ChaPter 4: PreParation of loaDS, StanDarD PraCtiCeS anD teChniQUeS ........................205

ChaPter 5 ..................................................................................................................................................213ChaPter 5: StatiC eleCtriCity anD DiSCharGerS ........................................................................214

DAP 101A-1105-1A


PRELIMINARY MATERIAL

CONTENTS

DAP ISSUE RECORD1 Updates ..................................................................................................................................................4ASOCIATED PUBLICATIONS2 air transport operations manuals (atomS) ..........................................................................................53 helicopter Underslung load equipment (hUSle) .................................................................................54 allied tactical Publications .....................................................................................................................55 Joint Doctrine Publication .......................................................................................................................56 Joint Service Publication ........................................................................................................................57 military aviation authority (maa) ............................................................................................................58 StanaGs ...............................................................................................................................................5INTRODUCTION9 General...................................................................................................................................................6HELICOPTER LOAD METHODS10 General...................................................................................................................................................611 method used...........................................................................................................................................6USING THIS DAP12 reference ...............................................................................................................................................613 DaP maintanance ..................................................................................................................................6

DAP 101A-1105-1A


DAP ISSUE RECORD

1 Updates

PREVIOUS UPDATESissue number Date issue number Date issue number Date

initial Jul 2006 6 Jun 2014

1 nov 2006 7 Jul 2014

2 may 2009 8 20150709

3 nov 2009

4 feb 2011

5 Jun 2012

LATEST UPDATEissue number Date Details of Change

09 aug 2017 Removed front Cover DaP record index Chapter 2-6-6

Inserted front Cover DaP record index Chapter 2-6-6

DAP 101A-1105-1A


ASOCIATED PUBLICATIONS

Publication Title DAP Reference

2 Air Transport Operations Manuals (ATOMS)Carriage of Cargo by helicopters, Underslung load Clearances 101a-1105-1bCarriage of Cargo by helicopters, Underslung load Clearances (aJo) 101a-1105-1b1

3 Helicopter Underslung Load Equipment (HUSLE)General orders and Special instructions 108G-0002-2(nar)1nets - General and technical information 108G-0002-1aStrops - General and technical information 108G-0002-1bSlings - General and technical information 108G-0002-1Cancillary equipment - General and technical information 108G-0002-1D

4 Allied Tactical PublicationsUse of helicopters in land operations Doctrine atP-49 (latest edition)

5 Joint Doctrine PublicationUse of helicopters in land operations (UK Supplement to atP-49) JDP 3-24.1

6 Joint Service PublicationDangerous Goods by air regulations JSP 800 Vol 4a

7 Military Aviation Authority (MAA)maa regulatory Publications (mrP)

8 STANAG’saircraft marshalling Signals (army Code 71444) 3117technical Criteria for the transport of Cargo by helicopter 3542technical Criteria for external Cargo Carrying Slings, nets and Strops/Pendants 2286aerial recovery equipment and techniques for helicopters 2970Criteria for the Clearance of helicopter Underslung load equipment (hUSle) and Underslung loads (USl)

2445

DAP 101A-1105-1A


INTRODUCTION

9 Generalin comparison with fixed wing tactical transport aircraft, helicopters have limited payload and range for the carriage of cargo. helicopters are ideal, however, for those tasks that cannot be undertaken by fixed wing aircraft due to the absence of airfields, weather limitations, difficulties of the terrain or difficulties operating at low level in forward areas of the battlefield. in such circumstances helicopters can transport cargo either internally or externally suspended from the aircraft cargo hook(s) by sling(s) or in nets.

HELICOPTER LOAD METHODS

10 Generalinternal cargo restraint systems are designed to reduce to a minimum the time and skill required to secure the load safely to the aircraft. Cargo carried externally can be delivered to a point on the ground and the load disconnected by the aircraft crew whilst the helicopter remains in the hover. both methods provide a commander with a flexible means of transport for cargo about the battlefield.

11 Method usedthe choice of which method is to be used will depend on the type of load, the availability of slinging equipment, the time and expertise available for the preparation of the load and the best utilisation and safety of the aircraft. both methods have advantages and disadvantages. normally a helicopter with internal cargo will be able to fly faster and further than one with an external load, but it will have to land and spend time on the ground to load or unload cargo, where it is more vulnerable to enemy action. on the other hand, external loads can be hooked up and unhooked from a helicopter very quickly but the aircraft may fly slower than with the cargo stowed internally due to the extra drag and in some cases instability of the load.

USING THIS DAP

12 Referencethis publication is for the use of all Services and contains comprehensive information concerning external loads that can be carried by helicopters. it provides a reference book for instructors for initial training and for helicopter handlers for continuation training at Unit level. Separate documentation is produced for the carriage of cargo internally within helicopters.

13 DAP Maintanancethis DaP is maintained by JaDteU, helicopter and training Section. Comments, queries or proposals relating to DaP 101a-1105-1a should be submitted to:

in writing: oC helicopter and training Section Joint air Delivery test and evaluation Unit brize norton Carterton oxon oX18 3lX

telephone: (Civ) 01993 896173 (mil) 95461 6173

e-mail: [email protected]

DAP 101A-1105-1A

Chapter 1 Aug 2017 (Iss 09)

CHAPTER 1

BOOK CHAPTERS

CHAPTER 1 - 1

ChaPter 1 - 1: General information ....................................................................................................9CHAPTER 1 - 2

ChaPter 1 - 2: heliCoPter UnDerSlUnG loaD eQUiPment (hUSle) anD itS manaGement ................................................................................................................................15

DAP 101A-1105-1A

Chapter 1Aug 2017 (Iss 09)

CONTENTS

CHAPTER 1 - 1: GENERAL INFORMATION

INTRODUCTION .................................................................................................................................... 91 General...............................................................................................................................................9CLEARANCE PROCEDURES ............................................................................................................... 92 aircraft clearance ...............................................................................................................................93 load Clearance ..................................................................................................................................94 the USlC document ..........................................................................................................................9LOAD CATEGORIES ............................................................................................................................. 95 load categories ..................................................................................................................................9CLEARED LOADS ................................................................................................................................. 96 Clearance documents ........................................................................................................................97 Clearance trials ..................................................................................................................................108 Promulgation of load flying characteristics and flying limitations .......................................................109 relating the clearance document to helicopter type ..........................................................................1010 load stability and attainable speed ....................................................................................................10AUTHORISED LOADS .......................................................................................................................... 1011 Definition ............................................................................................................................................1112 load stability and attainable speed ...................................................................................................11UNCLEARED LOADS ........................................................................................................................... 1113 restrictions.........................................................................................................................................1114 Preparing and rigging uncleared loads ..............................................................................................11DOWNED AIRCRAFT RECOVERY ....................................................................................................... 1115 recovery ............................................................................................................................................11CARRIAGE OF DANGEROUS GOODS (DG) ....................................................................................... 1216 General...............................................................................................................................................12HELICOPTER STATIC ELECTRICITY .................................................................................................. 1217 General...............................................................................................................................................12RESPONSIBILITIES OF UNITS AND PERSONNEL ............................................................................ 1218 General ..............................................................................................................................................1219 Preparation and handling of loads .....................................................................................................1220 Centre of gravity and other loading considerations ............................................................................1221 acceptance of a load for flight ............................................................................................................12REPORTING AND INVESTIGATION OF HELICOPTER EXTERNAL LOAD MALFUNCTIONS ......... 1322 Definition of external load ...................................................................................................................1323 reporting requirement........................................................................................................................13TRAINING COURSES AND FACILITIES ............................................................................................. 1324 Defence helicopter landing Site manager (DhlSm) and Defence helicopter handling intructor (Dhhi) ...........................................................................................................................................................13

CHAPTER 1 - 1

DAP 101A-1105-1A


CHAPTER 1 - 1: GENERAL INFORMATION

INTRODUCTION

1 Generalthis chapter provides general information on the carriage of external cargo by british Service helicopters, including the system of clearance for such cargo, generally referred to as slung or underslung loads (USls), and the responsibilities of both the ground user and the helicopter operator. Subsequent chapters include a description of the different types of british Service helicopter cargo hooks and full coverage of the practical aspects, correct usage and standard practices for the complete range of helicopter general purpose strops, slings, cargo lifting nets and allied equipment used in load preparation and rigging.

individual load preparation, rigging and slinging instructions for specifically cleared USls, of all types, are contained in DaP 101a-1105-1b.

CLEARANCE PROCEDURES

2 Aircraft clearancethe release to Service (rtS) is the release document for Service regulated flying; underpinned by the aircraft Safety Case, the rtS defines the operating envelope, conditions and limitations applicable to the aircraft to which it refers. With the exception of those items that can be properly classified as freight, all equipment authorised to be carried in or fitted to the aircraft is included in the rtS. Underslung loads are classed as freight and do not require a separate clearance within the rtS; however, items of helicopter Underslung load equipment (hUSle) that attach directly to the aircraft are required to be cleared within the rtS. those items of hUSle that form an integral part of an USl are cleared for use in accordance with its specific Underslung load Clearance (USlC).

note the range of hUSle cleared by the rtS varies by platform.

3 Load Clearanceloads that require regular transportation as an USl are to be formally assessed by the Joint air Delivery test and evaluation Unit (JaDteU) and an USlC produced. requests to task JaDteU should be submitted to the JaDteU task Co-ordination officer using a task inception form available on the JaDteU website. it should be noted that all tasks are to have a moD Sponsor.

4 The USLC documentthe JaDteU USlC documents contain detailed instructions and advice for each specific load. these instructions are issued after each load has undergone static rigging and lifting trials, has subsequently been test flown in each configuration required and has been proven acceptable for flight.

if a USlC is indicated as an aJo (available from JaDteU only) this is because it requires limited or controlled circulation and will not be distributed automatically. advice is to be sought from JaDteU regarding access to the clearance.

it is stressed that these published instructions constitute the Clearance for flight and must be fully adhered to. the rigging and load handling personnel must be directly supervised by a qualified Defence helicopter landing Site manager (DhlSm) or Defence helicopter handling instructor (Dhhi).

LOAD CATEGORIES

5 Load categorieshelicopter USls are divided into three distinct categories, namely: cleared loads, authorised loads and uncleared loads.

CLEARED LOADS

6 Clearance documentsCleared loads are loads for which detailed preparation, rigging and slinging instructions are drawn up and produced in the form of USlCs. in each case clearances will have been issued on the directions of

DAP 101A-1105-1A


a moD Sponsor, and are based on the Sponsor’s acceptance of the outcome of JaDteU trials. all but a few JaDteU clearances will be published for holding in DaP 101a-1105-1b, which in its opening chapters contains detailed information on the content, interpretation, general format and availability of clearance documents. the complete index of USlCs is contained in DaP 101a-1105-1b, Chapter 2-1.

7 Clearance trialsJaDteU helicopter and training Sect will normally take overall responsibility for the conduct of an USlC task. JaDteU engineering Sect will provide any necessary specialist knowledge and support.

JaDteU flight testing explores the safe speed and manoeuvre envelope in incremental stages with a thorough and progressive check of load manoeuvre performance at each speed increment. an extension strop with swivel hook is used to establish the flying characteristics of a single-point load. Strop length will normally be confined to the shortest length strop, unless the task Sponsor, or the nature of the load or the environment, demands otherwise.

trials helicopters are normally tasked by the Joint helicopter Command (JhC). the helicopter crew is provided by the rotary Wing test and evaluation Sqn (rWteS); a rWteS aircraft commander is the minimum requirement to conduct a flight trial. the helicopter crew receive a full briefing before flying commences and subsequently are accompanied by the JaDteU helicopter and training Sect trials officer who directs the trial during all phases of flight test. throughout the trial the aircraft commander and the crewman maintain their normal command function for safety and control of the helicopter.

8 Promulgation of load flying characteristics and flying limitationsCurrent clearances will state the maximum permitted airspeed, manoeuvre limitations and a statement of load flying characteristics within the clearance document

9 Relating the clearance document to helicopter typeas USlCs do not specify helicopter type, operators should check firstly that the clearance selected is suitable for the particular type of helicopter they plan to use, ie single or tandem hook clearance, helicopter lift capabilities and aircraft/hUSle compatibility. if the load has been cleared to a higher speed than that permitted by the aircraft type, then a lower speed must apply. for information on helicopter/equipment compatibility refer to the individual helicopter rtS, the compatibility matrix in Chapter 2, or the individual slinging equipment chapter. for information on the clearance read-across capability refer to aircrew advisory notes at Chapter 1-2 of DaP 101a-1105-1b.

10 Load stability and attainable speedthe maximum permitted speed at which a load is flown will depend upon one or more of the following factors:

10.1 the onset of load instability.

10.2 load motion which causes unacceptable stress on the helicopter or interference with control.

10.3 aircraft flight or power limits.

10.4 the drag of the load resulting in maximum safe trail angle limits being reached.

10.5 the natural resonance of tensioned sling/strop lengths combined with aerodynamic forces and aircraft vibration reaching unacceptable levels of sling leg flutter.

10.6 any other limitations in the rtS for the helicopter type being used, which prevents the carriage of the load at a higher speed.

AUTHORISED LOADS

a wide variety of loads made up from commonly used stores; supplies or equipment may be carried externally by helicopters. it is neither practicable, nor possible for JaDteU to raise separate clearances for each load of this nature. therefore certain loads not specifically cleared by JaDteU, defined as ‘authorised loads’, may be carried externally without reference to, or individual clearance from JaDteU, provided that there is compliance with the conditions and limitations that follow.

DAP 101A-1105-1A


11 Definitionauthorised loads are defined specifically as being loads carried in Service cargo lifting nets, comprising the 5000 lb net, 5600 kg net and 7000 kg net, loaded and generally prepared in accordance with the appropriate equipment chapters in this publication.

12 Load stability and attainable speed authorised loads may not be completely stable at all speeds. however, provided that the various authorised load equipments are used in the manner and with the type of load for which they were designed and cleared, the onset of any instability should be gradual, and will allow the pilot to determine a maximum speed for the prevailing conditions. Unless the pilot has previously flown an identical load or has a means of observing load behaviour, a crewman should be carried when authorised loads are being flown. the following important requirements must also be fulfilled:

12.1 an extension strop with swivel hook is to be used when carrying standard ordnance boxes to avoid wind-up and consequent damage to the slings.

12.2 a single net load may be carried without an extension strop and swivel hook, provided that the net lifting stirrup or device is in the form of a single item for attachment direct to the helicopter cargo hook. two or more nets must always be carried from a secondary hook.

12.3 an extension strop with swivel hook is to be used to give adequate clearance between the load and the aircraft if there is any doubt in the aerodynamic stability of an authorised load.

12.4 to employ any ‘authorised load equipment’ beyond its normal design usage or limitations is to enter the ‘uncleared load’ sphere.

12.5 Cargo nets are not to be flown empty.

UNCLEARED LOADS

loads that are neither cleared nor authorised are classified as ‘uncleared loads’ and therefore, specialist advice from JaDteU is to be obtained regarding the rigging and possible behaviours of such loads.

13 Restrictionsoperational circumstances may preclude the prior clearance of an USl by JaDteU and in such circumstances, the theatre Commander-in-Chief or equivalent may authorise the flight of an uncleared load. Should this occur, advice regarding the means of rigging unusual or one-off loads is to be obtained from JaDteU; this could involve the use of a JaDteU team to rig or supervise the preparation of the equipment. Under no circumstances will JaDteU authorise the carriage of an uncleared load. if it is impracticable for JaDteU to carry out the preparation, the ground handling personnel are to contact JaDteU and obtain the best possible advice available on rigging the load(s) in question. JaDteU will provide advice by any communicable means available. every effort should be made to seek an in-theatre engineering assessment of the structural integrity of the load and the chosen lifting points as stated in DaP 101a-1105-1b, Chapter 1-2, before any attempt is made to fly it.

it is essential that the commander of the helicopter carrying the load be informed that such loads are uncleared. this serves to forewarn that the load may affect the flying characteristics of the helicopter, as the behaviour of such loads in flight is completely unpredictable until they have been flown.

14 Preparing and rigging uncleared loadsother chapters in this book describe the equipment usage and standard practices to be followed when preparing and rigging USls. a study of these chapters and a study of USlCs for similar loads will enable a sensible approach to be made to the problems of rigging an uncleared load.

DOWNED AIRCRAFT RECOVERY

15 RecoveryWhere an aircraft requiring recovery is already the subject of a JaDteU USlC, and is substantially undamaged, it may be rigged and flown without further reference to JaDteU. however, if damage has been incurred and/or the aircraft is not cleared, JaDteU advice is to be sought. Such recoveries will normally

DAP 101A-1105-1A


be conducted by or under supervision of a JaDteU team. lifts will be in accordance with the provisions of StanaG 2970.

CARRIAGE OF DANGEROUS GOODS (DG)

16 Generalthe aircraft commander must be advised of any DG aspects relating to the load that he is tasked to undersling. the most common hazards are those associated with static electricity when carrying flammable or explosive natures, or raDhaZ where aircraft hf radio transmissions may affect electrical explosive devices (eeDs) or fuse mechanisms of weapons systems. for loads, which have a DG aspect, any necessary instructions or precautions will be contained in the relevant USlC, or reference will be made to the authoritative literature. in this respect, JaDteU is not a DG authority and any specialist DG information for inclusion in a clearance must be provided by the task Sponsor. Where a clearance applies to dummy or inert weapons only, operators must find out the full implications of carrying live versions prior to their carriage. finally, there is always the remote possibility of an irregular load release and any likely additional hazard posed by DG aspects must be considered prior to load pick-up.

HELICOPTER STATIC ELECTRICITY

17 Generalthe static discharge at load pick-up or landing is high, especially with the Sea King, merlin and Chinook helicopters. this is particularly important when considering the protection of ground handlers, and the dangers associated with inflammable materials or explosive devices.

further information can be found in Chapter 5.

RESPONSIBILITIES OF UNITS AND PERSONNEL

18 General for USl tasks it is the responsibility of the Service owning the helicopter to supply it equipped with the helicopter cargo hooks (primary hook) and any necessary extension strop with swivel hook (secondary hook).

19 Preparation and handling of loadsit is the user unit’s responsibility to provide slinging and load securing equipment, with the final means of hooking up to either the primary or secondary hook. it is also the user unit’s responsibility to provide suitably trained and qualified personnel for the purpose of load preparation, rigging, handling and marshalling at both the pick-up and load landing points in accordance with the published instructions. at the pick-up point, a load should be supported on level ground or be so disposed that its attitude in relation to the sling is the same as in flight. this will ensure that the load will not tilt or drag at the initial stages of the lift, but will remain in balance and so minimise the onset of oscillation in flight. When Joint helicopter Support Squadron (JhSS) personnel are tasked for operation they will take over all or some of the above responsibilities and provisioning, as necessary. Precise responsibilities will normally be included on the tasking signal. all personnel involved in the above duties should have access to the necessary publications and guidance literature to enable them to be fully conversant with their role.

20 Centre of gravity and other loading considerationsthe requirements for correct loading and centre of gravity (CoG) of a load are to be fulfilled by strict compliance with the detailed instructions for each specified cleared or authorised load as published in this publication and in DaP 101a-1105-1b. failure to comply with these instructions may result in the rejection of a load for flight or dangerous conditions developing once the helicopter is in flight.

21 Acceptance of a load for flightthe final responsibility for the acceptance of any load for flight rests with the commander of the helicopter concerned.

DAP 101A-1105-1A


the weights of USls are to be made available beforehand to the commander of the aircraft so that flight planning can be effected. the total weight of a USl is always to be determined accurately.

REPORTING AND INVESTIGATION OF HELICOPTER EXTERNAL LOAD MALFUNCTIONS

22 Definition of external loadthe term ‘external load’ includes the cargo and all items of USl equipment used to connect the cargo to the helicopter.

23 Reporting requirementall malfunctions of external loads observed or suspected, in flight, are to be reported in accordance with current regulations contained in the military aviation authority (maa) regulatory Publications (mrP). the report is to include any unusual behaviour exhibited by the USl that could have instigated the malfunction. Should ground based helicopter handling teams observe malfunctions during USl pick-up or delivery, or suspect that items of equipment are missing, an incident report is to be raised.

if the malfunction is suspected to have been caused by a failure of the hUSle or equipment being carried, it is the responsibility of JaDteU to conduct an investigation in to the circumstances. Should malfunctions of this nature occur JaDteU is to be informed as soon as possible and their assistance requested.

TRAINING COURSES AND FACILITIES

24 Defence Helicopter Landing Site Manager (DHLSM) and Defence Helicopter Handling Intructor (DHHI)training courses for DhlSm and Dhhi are held at JaDteU. Successful completion of the courses will enable the student to fulfil relevant responsibilities contained within Joint Doctrine Publication 3-24.1, Use of helicopters in land operations (UK Supplement to atP 49).

Details of available courses can be obtained from the JaDteU training Clerk.

DAP 101A-1105-1A


CONTENTS

CHAPTER 1 - 2: HELICOPTER UNDERSLUNG LOAD EQUIPMENT (HUSLE) AND ITS MANAGEMENT

INTRODUCTION .................................................................................................................................... 151 General...............................................................................................................................................15HUSLE ................................................................................................................................................... 152 hUSle definition ................................................................................................................................153 hUSle classified by Safe Working load (SWl) ................................................................................154 hUSle identification ..........................................................................................................................15MAINTENANCE SUPPORT LITERATURE ........................................................................................... 155 hUSle maintenance ..........................................................................................................................156 obtaining hUSle maintenance aPs ..................................................................................................15HUSLE EXAMINATION ......................................................................................................................... 157 introduction.........................................................................................................................................158 before and after-use ..........................................................................................................................169 routine ...............................................................................................................................................1610 hUSle life ..........................................................................................................................................16

CHAPTER 1 - 2

DAP 101A-1105-1A


CHAPTER 1 - 2: HELICOPTER UNDERSLUNG LOAD EQUIPMENT (HUSLE) AND ITS MANAGEMENT

INTRODUCTION

1 Generalthis chapter provides an introduction to the general purpose range of hUSle used by one or more of the three Services. the information that follows includes guidance on equipment management. reference to equipments and materials, together with the stores nomenclatures is to be found in the relevant hUSle maintenance aPs (paragraph 5 refers).

HUSLE

2 HUSLE definitionthe term ‘hUSle’ comprises nets, slings, strops and other ancillary items and refers to all load carrying equipment mounted between the helicopters cargo hook and the USl attachment points.

3 HUSLE classified by Safe Working Load (SWL)Service slinging equipment is classified by its ‘SWl’, and in all cases the manufacturer’s classification will be given in terms of SWl. the term SWl relates to the maximum static weight of load that may be suspended from a given item. the difference between the maximum allowable static load and the load that would be necessary to cause the item to fail (breaking load) is the safety factor. for helicopter slinging equipment, the safety factor must allow for the effective increase in load due to helicopter manoeuvre, and such factors as rotor downwash impinging on the suspended load, and inadvertent snatch loading during load pick-up. the slinging equipment must be able to sustain such treatment on a regular basis without any degradation. to cater for this, a minimum safety factor of 4.3 to 1 is applied (ie for hUSle with a SWl of 5000 kg the minimum breaking load is 21500 kg).

finally, for helicopter general purpose multiple leg slings, the SWl is further qualified by the maximum allowable included angle at which the sling legs may be used.

4 HUSLE identificationhUSle is identified by its equipment nomenclature (stores description) and stores reference numbers. the approved item name, together with the item nSn, should always be used for equipment demands.

MAINTENANCE SUPPORT LITERATURE

5 HUSLE maintenancethere is a Joint Service policy to which the three Services adopt common maintenance procedures. hUSle general orders and special instructions are published in aP 108G-0002-2(nar)1. the maintenance procedures for given equipment items are published in the following hUSle aPs: aP 108G-0002-1a - nets aP 108G-0002-1b - Strops aP 108G-0002-1C - Slings aP 108G-0002-1D - ancillary equipment

6 Obtaining HUSLE maintenance APsService users can access the aPs using the Design repository (Dr) which hosts the tech Docs on line (tDol) viewer (available at the this link tDol Viewer); alternatively requests for hardcopies can be addressed through the moD technical publication process.

HUSLE EXAMINATION

7 IntroductionDefence helicopter handling instructors (Dhhi), Defence helicopter landing Site managers (DhlSm), Defence landing Point Commanders (DlPC), helicopter crewmen and aircraft maintenance personnel can be authorised to carry out before and after-use examinations in accordance with aP 108G-0002-2(nar)1.

http://app-spvw034.ds.logis.r.mil.uk/tdol/

DAP 101A-1105-1A


8 Before and after-usea before and after-use examination is to be carried out on each item of hUSle as detailed in the equipment’s relevant hUSle maintenance aP.

9 Routinethe aP 108G-0002-2(nar)1 details the joint Service maintenance policy for hUSle. routine maintenance is only to be carried out by a qualified helicopter load Slinging equipment inspector (hlSei) who holds a valid hlSei certificate.

10 HUSLE lifethe life of hUSle components is given in the relevant hUSle maintenance aPs which should be consulted for up to date information. the component life expiry for major hUSle is given below as a guide.

10.1 all metalware (including wire slings, weak link assemblies, bV206 lifting frame and wire strops). Subject to condition, inspected for serviceability (not lifed).

10.2 helicopter Cargo lifting net – 7000 kg SWl, 5600 kg SWl and 5000 lb SWl. a finite life of 10 (ten) years with a maximum Service life of 4 (four) years.

10.3 net Cargo restraint, helicopter USl 1000 kg SWl. a finite life of 10 (ten) years with a maximum Service life of 4 (four) years.

10.4 textile roundsling for hD and mD Sling assemblies and Strops. a finite life of 10 (ten) years with a maximum Service life of 4 (four) years.

10.5 nylon redundant Sling (Chinook). a finite life of 10 (ten) years with a maximum Service life of 2 (two) years.

10.6 10000 kg Websling (belly-band). a finite life of 10 (ten) years with a maximum Service life of 2 (two) years.

10.7 bag-Single Use lift, SWl 1000 kg. a finite life of 10 (ten) years with a single use Service life. the SUlb must be used within 28 days following removal from the light proof packaging.

note ‘Single Use’ is defined as one load cycle.

10.8 Strop, Disposable, 2 m, SWl 2000 kg. a finite life of 10 (ten) years with a maximum Service life of 28 days following removal from the light proof packaging.

notwithstanding the lifing periods shown above and with exception to paragraph 10.8, all equipment is to be inspected by suitably qualified personnel, as stated in aP 108G-0002-2(nar)1 and to the requirements stated in the relevant hUSle maintenance aPs.

DAP 101A-1105-1A


CHAPTER 2

CONTETS

CHAPTER 2 - 1

ChaPter 2 - 1: heliCoPter UnDerSlUnG loaD eQUiPment (hUSle) anD heliCoPter CarGo hooK ComPatibility ..................................................................................................................................19

CHAPTER 2 - 2

ChaPter 2 - 2: heliCoPter eXternal CarGo hooKS ......................................................................24

CHAPTER 2 - 3

ChaPter 2 - 3: heliCoPter eXtenSion StroPS.................................................................................42

CHAPTER 2 - 4

ChaPter 2 - 4: SUPPlementary SlinGinG eQUiPment .....................................................................72

CHAPTER 2 - 5

ChaPter 2 - 5: heliCoPter SlinGS - General ..................................................................................101

CHAPTER 2 - 6

ChaPter 2 - 6: heliCoPter CarGo liftinG netS anD netteD loaDS ........................................126ChaPter 2 - 6 - 1: heliCoPter CarGo net ProteCtion PaD ........................................................128ChaPter 2 - 6 - 2: heliCoPter CarGo liftinG net - 5600 KG SWl ................................................129ChaPter 2 - 6 - 3: heliCoPter CarGo liftinG net - 5000 lb SWl.................................................140ChaPter 2 - 6 - 4: heliCoPter CarGo liftinG net - 7000 KG SWl ................................................149ChaPter 2 - 6 - 5: tyPiCal netteD loaDS...........................................................................................157ChaPter 2 - 6 - 6: SPeCifieD aUthoriSeD loaDS .............................................................................161

CHAPTER 2 - 7

ChaPter 2 - 7: retainer breaKaWay aSSembly ..............................................................................167

CHAPTER 2 - 8

ChaPter 2 - 8: CarGo reStraint reQUirementS for heliCoPter UnDerSlUnG loaDS ...174

CHAPTER 2 - 9

ChaPter 2 - 9: baG - SinGle USe lift, SWl 1000 KG anD StroP, DiSPoSable, 2 m, SWl 2000 KG ........................................................................................................................................190

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 1: HELICOPTER UNDERSLUNG LOAD EQUIPMENT (HUSLE) AND HELICOPTER CARGO HOOK COMPATIBILITY

INTRODUCTION .................................................................................................................................... 19COMPATIBILITY MATRICES ................................................................................................................. 191 introduction.........................................................................................................................................192 Using the compatibility matricies ........................................................................................................193 SaCrU compatability matrix ..............................................................................................................204 Connector’s and strops compatability matrix .....................................................................................21

CHAPTER 2 - 1

tablestable 1 - Slinging equipment ‘Compatability for helicopter type’ matrix .........................................................20table 2 - Slinging equipment ‘hook-up’ and ‘intercompatability’ matrix ...........................................................21

DAP 101A-1105-1A


CHAPTER 2 - 1: HELICOPTER UNDERSLUNG LOAD EQUIPMENT (HUSLE) AND HELICOPTER CARGO HOOK COMPATIBILITY

INTRODUCTION

the subsequent chapters in this publication describe individual items of hUSle and its usage. to assist Service users in helicopter USl operations the compatibility matrix consolidates the individual items to ensure correct application of hUSle to helicopter cargo hook type.

COMPATIBILITY MATRICES

1 IntroductionParticular items of hUSle may not appear on the compatibility matrix as these items may only be required for specific helicopter operations. in such cases the relevant hUSle and rigging/hook-up procedures will be contained on an USlC which is available from JaDteU only.

2 Using the compatibility matriciesthe SaCrU Compatibility matrix (table 1, page 20) is to be used to determine what equipment can be used on which aircraft SaCrU. the numbers and letters in each box will determine how many items can be attached to the aircraft’s SaCrU at any one time, and if additional items are required for the item to be used. if the box is empty that that particular item must not be used on that aircraft. the WARNING and Caution on page 20 must be adhered to.

the Connector’s and Strops Compatability matrix (table 2, page 21) is to be used to determine what equipment items can be attached to which connectors and strops. as with table 1 the letters and numbers in each box determine how many items can be attached to the connectors and strops listed, and if additional items are required for the item to be used.

DAP 101A-1105-1A


3 SACRU compatability matrix

SaCrU (see WARNING)IT

EM

No.

Key

incompatible

* not yet cleared

See Caution

a via item 12 or item 15

b via item 12

C via item 12 or item 13

D via item 14

e via item 15 or any compatible extension strop

f via item 13

G via item 14, 15 or any compatible extension strop

h via item 19

i via item 20

Cen

tre

fwd

& a

ft

tal

on h

C

no1

, mk3

Ch

47 f

/a h

ook

no

1, m

k3

no

1, m

k3

no

2,

mK

1

no

2, m

K1

no

2, m

k1

mk2

bre

eze

eas

tern

mk2

bre

eze

eas

tern

Ch

ino

oK

hC

mk3

, 4 &

6

Ch

ino

oK

hC

mk3

, 4 &

6

me

rli

n m

k3

me

rli

n m

k2 /

3a

me

rli

n m

k2 /

3a

Se

aK

inG

mk3

, 4 &

5

PU

ma

hC

mk2

Wil

DC

at (a

ll m

KS

)

lyn

X (a

ll m

KS

)

Ga

Zell

e (a

ll m

ks)

SQ

Uir

re

l h

t

Gr

iffi

n h

t m

k1 /

ha

r

STROPS1 2.7 m/5.7 m, SWl 11300 kg 1 1 1 1h 1 1h 1h 1f 1f 1f *2 2.5 m/5.5 m SWl, 5000 kg 1 1 1 1 1 1 1 1f 1f 1f 1 13 16 ft or 80 ft, SWl 6000 lb 1a 1a 1 1h 1h 1h 1h 1D 1D 1D * 1i

4 7 ft or 30 ft, SWl 1500 lb 1b 1b 1f 1 1h 1 1 1D 1D 1D 1 15 2 m Disposable extension Strop, SWl 2000 kg 1 1 1 1 1 1 1

SLINGS (see Caution)6 hD, SWl 5650 kg (2 leg) 1 1 1 1h 1 1h 1h 1f 1f 1f 17 HD, SWL 8475 kg (3 leg), SWL 11300 kg (4 leg (not Griffin)) 1 1 1 1h 1 1h 1h 1f 1f 1f 18 mD, SWl 2300 kg (2 leg), SWl 3450 kg (3 leg), SWl 4600 kg (4 leg) 1 1 1 1 1 1 1 1f 1f 1f 19 redundant Sling 1

10 4 leg, SWl 6000 lb 1a 1 1 1 1 1 1 1 1 1 1 111 Websling (belly-band), SWl 10000 kg

CONNECTORS, NETS AND SULB

12 16 mm masterlink assembly, SWl 7000 kg 1 1 1 1 1 1 1 1f 1f 1f *13 bow Shackle, SWl 1500 kg 1 1 1 1 1 1 1 1 * 114 Connector Sling, 10000 lb 1 1 1 1 1 1 1 * 115 masterlink & Swivel hook assembly, 11300 kg 1 1 1 1h 1h 1h 1h 1f 1f 1f *16 net Cargo lifting, SWl 7000 kg 1 117 net Cargo lifting, SWl 5600 kg 1 1 1 1 1 1 1 1 1 1 118 net Cargo lifting, SWl 5000 lb 1 1 1 1 1 1 1 1 1 1 1 119 Shackle, SWl 5 tonne, large bow * * 1 1 1 1 1 * * * 120 Shackle, SWl 3 tonne, large bow 121 Weak link assembly 6300 kg 122 Single Use lift bag (SUlb), SWl 1000 kg

table 1 - Slinging equipment ‘Compatability for helicopter type’ matrixWARNING:

ONLY ONE LIFTING RING/APEX DEVICE TO BE CARRIED ON LOAD BEAMS OF BRITISH SERVICE HELICOPTER CARGO HOOKS

Caution: Unless specified in a JADTEU clearance, all slings must be interfaced to helicopter primary hooks by masterlink and swivel aassembly or extension strop subject to compatibility

DAP 101A-1105-1A


4 Connectors and strops compatability matrix

ConneCtorS StroPSIT

EM

No.

Key

incompatible

* not yet cleared

a via item 12 or item 15

b via item 12

C via item 12 or item 13

D via item 14

e via item 15 or any compatible extension strop

f via item 13

G via item 14, 15 or any compatible extension strop

h via item 19

i via item 20 16 m

m m

aste

rlink

ass

embl

y S

Wl

7000

kg

(154

32 lb

)

bow

Sha

cle

SW

l 15

00 k

g

Con

nect

or S

ling

1000

0 lb

(453

6 kg

)

mas

terli

nk &

Sw

ivel

hoo

k a

ssem

bly

SW

l 11

300

kg (2

5000

lb)

2.7

m /

5.7

m P

olye

ster

& S

teel

SW

l 11

300

kg (2

5000

lb)

2.5

m /

5.5

m P

olye

ster

& S

teel

SW

l 50

00 k

g (1

1020

lb)

16 ft

or 8

0 ft

Ste

elS

Wl

6000

lb (2

724

kg)

7 ft

or 3

0 ft

Ste

elS

Wl

1500

lb (6

80 k

g)

2m D

ispo

sabl

e e

xten

sion

Stro

pS

Wl

2000

kg

STROPS1 2.7 m/5.7 m, SWl 11300 kg 1 1 2 2 1 1 1C

2 2.5 m/5.5 m SWl, 5000 kg 1 1 2 2 2 2 1f

3 16 ft or 80 ft, SWl 6000 lb 1 1 1 1b 1b 1b 1 14 7 ft or 30 ft, SWl 1500 lb 1 1 1 1b 1b 1b 1 15 2 m Disposable extension Strop, SWl 2000 kg

SLINGS (see Caution)6 hD, SWl 5650 kg (2 leg) 1 1 2 2 1 1 1C

7 HD, SWL 8475 kg (3 leg), SWL 11300 kg (4 leg (not Griffin)) 1 1 2 2 1 1 1C

8 mD, SWl 2300 kg (2 leg), SWl 3450 kg (3 leg), SWl 4600 kg (4 leg) 1 1 2 2 2 2 19 redundant Sling

10 4 leg, SWl 6000 lb 1 1 2 2 2 2 111 Websling (belly-band), SWl 10000 kg 1 1 1 1b 1b

CONNECTORS, NETS AND SULB

12 16 mm masterlink assembly, SWl 7000 kg 1 1 1 2 2 2 1f

13 bow Shackle, SWl 1500 kg 1 1 1 1 1 1 114 Connector Sling, 10000 lb

15 masterlink & Swivel hook assembly, 11300 kg 1 1 2 2 1 1 1C

16 net Cargo lifting, SWl 7000 kg 1 117 net Cargo lifting, SWl 5600 kg 1 1 2 2 2 1 118 net Cargo lifting, SWl 5000 lb 1 1 2 2 2 2 119 Shackle, SWl 5 tonne, large bow 1 1 1 1 1 120 Shackle, SWl 3 tonne, large bow

21 Weak link assembly 6300 kg

22 Single Use lift bag (SUlb), SWl 1000 kg 2 2 2 2

table 2 - Slinging equipment ‘hook-up’ and ‘intercompatability’ matrix

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 2: HELICOPTER EXTERNAL CARGO HOOKS

INTRODUCTION .................................................................................................................................... 24CARRIAGE OF EXTERNAL CARGO .................................................................................................... 241 Carriage of load from a single cargo hook .........................................................................................242 Carriage of load by means of two cargo hooks ..................................................................................24NATURE OF CARGO HOOKS .............................................................................................................. 243 function as cargo release units .........................................................................................................244 modes of release ................................................................................................................................24TYPES OF CARGO HOOK .................................................................................................................... 255 electro-magnetic type hooks ..............................................................................................................256 Chinook centre hook ..........................................................................................................................257 Use of term ‘primary hook’’ .................................................................................................................25MAXIMUM WEIGHT OF LOAD THAT CAN BE CARRIED ON HELICOPTER CARGO HOOKS ........ 258 load weight ........................................................................................................................................259 Payload available ...............................................................................................................................2510 maximum weight of external load .......................................................................................................26IMPORTANT RULES OF USAGE ......................................................................................................... 2611 restrictions and limitations for engagement of items on cargo hook load beams .............................2612 Static electricity discharge ..................................................................................................................2613 load hook-up/release procedures for ground handlers .....................................................................2614 load becoming detached during or after helicopter lift-off ................................................................2715 Close monitoring of load hook-up ......................................................................................................28

CHAPTER 2 - 2 - 1: TALON, SEMI-AUTOMATIC CARGO RELEASE UNIT (SACRU) 12000 LB

INTRODUCTION .................................................................................................................................... 3016 basic layout ........................................................................................................................................30MANUAL LOAD BEAM RELEASE ....................................................................................................... 3017 System of release...............................................................................................................................3018 Complete failure of the load beam to release ....................................................................................30HOOKING UP ........................................................................................................................................ 3019 hooking up procedure ........................................................................................................................30

CHAPTER 2 - 2 - 2: SEMI-AUTOMATIC CARGO RELEASE UNIT (SACRU) NO 1 MK3

INTRODUCTION .................................................................................................................................... 3120 Safe Working load .............................................................................................................................3121 baic layout ..........................................................................................................................................31MANUAL LOAD BEAM RELEASE ....................................................................................................... 3122 System of release...............................................................................................................................3123 Complete failure of the load beam to release ....................................................................................31HOOKING UP ........................................................................................................................................ 3124 hooking up procedure ........................................................................................................................31


INTRODUCTION .................................................................................................................................... 3325 basic layout ........................................................................................................................................33MANUAL LOAD BEAM RELEASE ....................................................................................................... 3326 System of release...............................................................................................................................3327 Complete failure of the load beam to release ....................................................................................33HOOKING-UP ........................................................................................................................................ 3328 hooking up procedure ........................................................................................................................33

CHAPTER 2 - 2

DAP 101A-1105-1A


CHAPTER 2 - 2 - 4: CHINOOK CARGO HOOKS

TRIPLE CARGO HOOK FACILITY ........................................................................................................ 3429 modes of employment ........................................................................................................................34CENTRE HOOK .................................................................................................................................3630 System of release...............................................................................................................................3631 Safe Working load (SWl) ..................................................................................................................36FORWARD AND AFT HOOKS ..........................................................................................................3632 System of release...............................................................................................................................3633 Safe Working load (SWl) ..................................................................................................................36JOINT CENTRE HOOK AND FORE AND AFT HOOK OPERATION ...............................................3634 inter-hook release ..............................................................................................................................3635 Complete failure of the load beam to release ....................................................................................36HOOKING-UP ....................................................................................................................................3636 Centre or fore and aft hooks hooking up procedure ...........................................................................36

CHAPTER 2 - 2 - 5: MERLIN MK2 AND MK3A, C160, CARGO HOOK

INTRODUCTION ................................................................................................................................38SYSTEM OF OPERATION .................................................................................................................3837 basic layout ........................................................................................................................................38MANUAL LOAD BEAM RELEASE ...................................................................................................3838 System of release...............................................................................................................................3839 Complete failure of the load beam to release ....................................................................................3840 hooking up procedure ........................................................................................................................38

figures

figure 2 - method of release if hook fails to release after load landing ...........................................................27figure 3 - incorrect and correct way of engaging lifting ring on load beam .....................................................28figure 4 - Steel wire rope strop overriding bill of SaCrU load beam..............................................................29figure 5 - Single hook operations....................................................................................................................34figure 6 - multiple hook operations .................................................................................................................34figure 7 - tandem hook operations with redundant rigging ............................................................................35figure 8 - tandem hook operations: long stropping ........................................................................................35

DAP 101A-1105-1A


CHAPTER 2 - 2: HELICOPTER EXTERNAL CARGO HOOKS

INTRODUCTION

the aim of this chapter is to provide ground handlers with a general background to the current range of british Service helicopter cargo hooks. the chapter also has applicability for helicopter aircrew inasmuch as it highlights important general rules of usage. each cargo hook is fully identified in Chapters 2-2-1 to 2-2-5 and describes relationships of hooks to helicopter typeand points of usage for ground handlers.

CARRIAGE OF EXTERNAL CARGO

the normal way of carrying external cargo by helicopter is to suspend it from underneath the helicopter by means of an external cargo hook. Depending upon the helicopter type, the cargo hook is either suspended by cables and/or a frame from the belly of the helicopter, or is attached to mountings on or to a connection panel within the belly of the helicopter. With the exception of the Chinook, all british Service helicopters operating in the USl role are designed with a single cargo hook facility.

1 Carriage of load from a single cargo hookthe system of employing a single cargo hook for suspending a load is known as ‘single hook suspension’, whereas the system of lifting a load from a single point on the load is known as single point lift. helicopters operating with a single cargo hook allow for a relatively simple load hook-up process, but once in flight the load is free to twist and orientate into positions of high drag, or commence spinning about its vertical axis or take on a swinging motion, the overall effects of which generally become more pronounced with increase in helicopter speed. for this reason single cargo hook helicopters are frequently unable to exploit their true speed capability when carrying external loads.

2 Carriage of load by means of two cargo hooksthe Chinook helicopter is equipped with a triple cargo hook facility. one of the important assets is the ability to suspend a load by means of two cargo hooks. this provides an immediate benefit of reducing the loads freedom of movement and additionally it enables the load to be hung so that it presents least drag surface to the airflow. as a result the load can be carried at higher airspeeds than would generally be attainable by single hook suspension. the load hook-up process will be more complex, however, and it will be necessary for ground handlers to maintain a high degree of proficiency and act as a thoroughly co-ordinated team. the use of the Chinook triple cargo hook system, including carriage of independent loads from each of the hooks, is discussed more fully in Chap 2-2-4.

NATURE OF CARGO HOOKS

3 Function as cargo release unitshelicopter cargo hooks are designed to function as ‘cargo release units’, allowing for release of an attached load by remote control, exercised by the pilot (sometimes the crewman) from within the helicopter.

4 Modes of releasea summary of the different modes of release for current british Service helicopter cargo hooks, together with any additional ground handler release facilities, are as follows:

4.1 Primary modes of release. all current british Service helicopter cargo hooks incorporate an electrically initiated hook release system as the primary means of achieving load release. Control is effected by a pilot push-button, or the like; in the Chinook the crewman has a similar control.

4.2 Standby/emergency hook release facilities within the helicopter. all existing Service cargo hooks incorporate a standby/emergency release system, which is mechanically and/or electrically operated from within the helicopter.

4.3 Ground handler release facility. With the exception of the Chinook centre cargo hook, all current cargo hooks have a mechanical/manual release facility located on the release unit body for use, where necessary, by ground handlers.

DAP 101A-1105-1A


TYPES OF CARGO HOOK

the different types of cargo hooks are illustrated in Chapters 2-2-1 to 2-2-5.

5 Electro-magnetic type hooksWith the exception of the Chinook centre cargo hook, all current british Service helicopter cargo hooks are of the ‘electro-magnetic’ type; also referred to as electro-mechanical release units. the hooks bear the designation ‘Semi-automatic Cargo release Unit’ (SaCrU); the Chinook forward and aft hooks bear the american designation ‘cargo hooks’.

although different in appearance, size and design all electro-magnetic type hooks follow the same basic principle of operation; a solenoid unit housed on the hook casing, which converts electrical force into mechanical movement, activates the internal mechanism of the release unit which opens an internal latch, allowing the load carrying beam of the hook (the ‘load beam’) to pivot downwards and release any attached extension strop, cargo net stirrup or any other connecting device.

the SaCrUs, especially the Chinook forward and aft hooks, have a distinct hook-like appearance; the load beam is pivoted to the unit casing at one end and tapers off to an open ended hook bill at the other end. the entrance onto and off the load carrying part of the load beam is protected by a spring-loaded keeper when the load beam is in the closed position. a lifting ring can be engaged onto SaCrU and Chinook hooks with the load beam in the closed/locked position. the SaCrU and Chinook forward and aft hook load beams automatically spring back to the closed position following hook opening and load release.

6 Chinook centre hookthe Chinook centre hook is unique, as it is powered to the open and closed position by a system which utilises hydraulic and/or pneumatic pressure; and the activation of the system is dependent upon an electrical command. the centre hook is similar in appearance to the forward and aft hooks, pivoted at one end and tapering to an open ended hook bill at the other, and protected by a spring loaded keeper when in the hook closed position. there is no ground handler release facility; see paragraph 13 for procedure.

7 Use of term ‘primary hook’’the helicopter cargo hook is generally referred to as the ‘primary hook’, which distinguishes it from the terminal hook fitting at the foot of an extension strop which is known as the ‘secondary hook’.

MAXIMUM WEIGHT OF LOAD THAT CAN BE CARRIED ON HELICOPTER CARGO HOOKS

8 Load weightthe maximum weight of load that can be suspended from the load beam of a SaCrU/ cargo hook is governed by the following:

8.1 the safe working load (SWl) of the SaCrU/cargo hook (see individual hook chapters).

8.2 the maximum allowable weight of an external load cleared for carriage by a given helicopter type; this may be less than the rated lifting capacity of the SaCrU/cargo hook with which it is fitted.

8.3 the SWl of the slinging equipment being used (see individual equipment chapters).

8.4 the payload available for a given sortie, and the need to keep within the cg envelope for the helicopter.

9 Payload availablethe actual payload that can be lifted (payload available) for any particular sortie is declared by the helicopter unit to the supported unit, and will depend upon the following factors:

9.1 required radius of action.

9.2 number of crew.

9.3 basic weight of the particular helicopter and role equipment installed.

DAP 101A-1105-1A


9.4 altitude at which operation is to take place, together with temperature and humidity in which the helicopter will operate.

9.5 full fuel plus reserves required for the sortie.

10 Maximum weight of external loadit is emphasised that the maximum external load weight figures cleared for helicopter type, as indicated in individual cargo hook chapters, are the absolute maximum under the most favourable conditions. they will almost certainly be reduced in Service owing to the factors detailed in paragraph 19. Users should contact helicopter command formations or helicopter units for accurate appraisals.

IMPORTANT RULES OF USAGE

11 Restrictions and limitations for engagement of items on cargo hook load beamsto ensure that the factor of safety of the load beam is not reduced and damage is not caused, either to the load beam itself or to such critical items as the load beam keeper or critical areas of the cargo hook casing, the following rules are to be strictly complied with:

11.1 all british Service helicopter cargo hooks are to be limited to the carriage of a single lifting ring or equipment apex device attached over the load beam. Where more than one lifting ring or apex device is to be carried, they are to be collectively engaged over an appropriate Service extension strop secondary hook or via another acceptable form of connector. See Chapter 2-3 on extension strop equipments and Chapter 2-4-1 on connectors.

11.2 Under no circumstances must chain be engaged over a cargo hook load beam. Where chain forms the apex of a lifting system it is always to be coupled via a suitable extension strop secondary hook, or any other suitable form of connector as may be called up in specific USlCs.

the suitability for engagement of an individual sling, cargo net or extension strop lifting ring or apex device to the current range of cargo hooks is covered in individual equipment chapters.

12 Static electricity dischargea helicopter in flight generates and stores a charge of static electricity. this constitutes a hazard for ground handler/hook-up personnel, to the extent of a ground handler receiving a very serious shock (and possibly burns) if the correct precautions are not carried out; this has considerably added emphasis with the Chinook helicopter.

for the purpose of engagement or disengagement of an item to and from the load beam of a helicopter primary or extension strop secondary hook, full static electricity discharge procedure must be carried out. this procedure applies to the helicopter in the hover or on the ground with rotors running. it also applies if, for any reason the ground handling party has to contact the load, before it has been lowered to the ground, or after it has been lowered to the ground and prior to carrying out discharge procedure at the helicopter primary or secondary hook.

for ground handlers who are required to assist with manoeuvring a load into position before load landing, the use of ropes (handling lines) in contact with the ground provides an added safeguard. full information on static electricity discharge, ground handler static probe equipment and standard procedures to be employed when earthing primary or secondary hooks, or suspended loads, is contained in Chapter 5.

13 Load hook-up/release procedures for ground handlersthe individual procedures for load hook-up and, when necessary, release of an engaged lifting ring by ground handlers, are covered in the individual chapters for each type of cargo hook. as a general procedure applicable to SaCrU series and Chinook type cargo hooks, the method of removing a lifting ring from the load beam, if the hook fails to open by any release mode, is illustrated at figure 2.

for load engagement and release procedures for extension strop secondary hooks, consult Chapter 2-3.

DAP 101A-1105-1A


KEEPER OPENED

AGAINST SPRING

STATIC PROBE

SLIDE OFF

LIFTING RING

figure 2 - method of release if hook fails to release after load landing

14 Load becoming detached during or after helicopter lift-offincidents have occurred over the years where a slung load has detached from the helicopter, either during the lift off stage, shortly afterwards or at some later stage in flight. Some of these incidents have been associated with suspect equipment or irregular rigging practice, and others with some form of irregular release from the primary hook. in the latter case, instances are generally associated with the slinging equipment lifting ring escaping from a serviceable and closed cargo hook of the SaCrU or Chinook type (ie designed with an open ended load beam protected by a spring loaded keeper).

Detachment can occur in the following ways:

14.1 failure to engage lifting item over the load beam during hook-up. figure 3a illustrates how a lifting ring can be engaged about the hook keeper instead of the load beam. When the helicopter takes strain on the load or at some stage soon after, when increasing speed or manoeuvring over the ground, the strain and direction of pull on the lifting ring is likely to cause the embraced keeper to open and thereby allow the ring and suspended load to drop free. figure 3b shows the correctly engaged position for the lifting ring, and ground handlers should where possible, adhere to the following procedure;

14.1.1 Upon engagement push/pull the ring firmly to the far end of the load beam.

14.1.2 Pull firmly downwards and into the heart of the hook to ensure that the lifting ring is actually engaged onto the load beam.

14.1.3 Check that the spring loaded keeper has returned to the fully closed position and is not embraced by the lifting ring.

DAP 101A-1105-1A


B CORRECT

A INCORRECT

figure 3 - incorrect and correct way of engaging lifting ring on load beam

14.2 item escaping off the load beam after correct engagement. this concerns lifting rings of apex devices which are sufficiently spacious in internal diameter or length, to be able to override the top of the load beam having been correctly engaged in the first place. looking at two aspects:

14.2.1 lifting ring in correct position. With such a lifting ring in a correct position (figure 3b); if the attendant sling is allowed to go slack prior to the helicopter taking strain on the load, it is possible for the ring to be inadvertently manoeuvred over the top of the load beam and assume the position shown in fig 3a, thereafter detachment from the cargo hook is likely to take place in the manner described in paragraph 14.1. it should be noted that the SaCrU no2 mk1, as a comparatively small cargo hook with relatively short hook bill, is likely to be more susceptible than most of this type of occurrence.

14.2.2 item overriding the bill. an item escaping by overriding the bill of the load beam at some stage after the slinging equipment has been lifted clear of the ground (figure 4). this is considered in a narrow and broad context as follows:

15 Close monitoring of load hook-upWhen a crewman is present they should ensure the lifting ring or apex device is correctly attached to the load beam before instructing the pilot to lift the load from the ground. the crewman and/or pilot must watch for the affirmative signal from the marshaller or hook-up team leader, who must in turn satisfy himself that the load is properly suspended before giving this signal.

DAP 101A-1105-1A


figure 4 - Steel wire rope strop overriding bill of SaCrU load beam

DAP 101A-1105-1A


CHAPTER 2 - 2 - 1: TALON, SEMI-AUTOMATIC CARGO RELEASE UNIT (SACRU) 12000 LB

INTRODUCTION

the talon, Semi-automatic Cargo release Unit (SaCrU) 12000 lb is an electro-magnetic type release unit. it is fitted as a single hook installation to the merlin mk3 helicopter. the release unit has a safe working load (SWl) of 12000 lb (5443 kg). the merlin mk3 is limited to a maximum of 9038 lb (4100 kg) all up weight carried from the release unit.

16 Basic layoutthe SaCrU is mounted underneath the helicopter in a fore and aft manner. it is suspended on a cross beam between two i-beams in the cargo hook bay below the cabin floor. When the hook is not in use it is raised manually by a lanyard into the cargo hook bay and secured in position by a retaining strap.

MANUAL LOAD BEAM RELEASE

17 System of releasethere is a manual release lever on the SaCrU casing which can be operated by a ground handler. Providing that there is a minimum of 15 lb (6.8 kg) on the load beam it will open, pivoting downwards to release the load. if there is no load on the load beam when operating the lever, the ground handler will have to apply a force of 15 lb (6.8 kg) to open the load beam. the load beam, being spring loaded, will close and lock automatically after release.

18 Complete failure of the load beam to releasefollowing load landing, with the helicopter in the hover, should the load beam fail to release then the ground handling party may achieve load disengagement by depressing the spring loaded keeper and sliding the engaged lifting ring/device off the load beam. See the CAUTION after paragraph 19.

HOOKING UP

WARNING ONLY ONE LIFTING RING/APEX DEVICE IS TO BE CARRIED ON THE LOAD BEAM OF THIS SACRU.

19 Hooking up procedure19.1 ensure that the white datum lines on the release lever assembly are in alignment.

19.2 only one lifting ring or lifting device may be suspended from the SaCrU load beam. engage the device over the bill of the load beam and push it fully past the keeper, onto the load carrying part of the beam. ensure that the keeper has returned to the fully closed position.

CAUTION See Chapter 5 concerning static electricity discharge and employment of a static electricity discharge probe for the hooking-up process, or any other allied ground handler functions described in foregoing paragraphs.

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INTRODUCTION

WARNING WHEN OPERATING WITH THE SACRU NO1 MK3, HOOK-UP PERSONNEL AND CREWMAN SHOULD PAY PARTICULAR ATTENTION TO MASTERLINK/ STIRRUP ATTACHMENT TO THE LOAD BEAM AS AN INCREASED RISK OF ROLL-OUT EXISTS.

the semi-automatic cargo release unit (SaCrU) no 1 mk3 is an electro-magnetic type release unit. the SaCrU no 1 mk3 is fitted with a modified (increased aperture) load beam and keeper to accord with the requirements of StanaG 3542. the SaCrU is fitted as a single hook installation to merlin, Sea King and Puma helicopters.

20 Safe Working Loadthe release unit has a Safe Working load (SWl) of 2724 kg which is within the cleared limits for Sea King helicopters. however, the all up weight of load carried from the release unit for the Puma is limited to a maximum of 2250 kg; the merlin mk 2 and 3a are limited to a maximum of 2272 kg.

note the merlin mk2 and 3a also operate with the Chinook C-160 hook connected to the hook carriage of an h-frame assembly, when in full VertreP role (see Chapter 2-2-5). this configuration allows for external load uplift of 3650 kg weight of load maximum.

21 Baic layoutthe SaCrU is mounted underneath the helicopter in a fore and aft manner on the merlin mk2 and 3a and Sea King helicopters and is suspended from the fuselage by means of four wire rope legs. on the Puma helicopter it is suspended from a pole (the ‘load pole’), which is attached to the main gearbox casing in the cabin roof and passes down to the floor hatch, and a shorter arm engages the SaCrU to the bottom of the load pole by means of a universal link.


22 System of releasethere is a manual release lever on the side of the SaCrU casing which can be operated by the ground handler. the manual release lever direction of movement is indicated by the word oPen and an arrow. Providing that there is a minimum load of 8lb on the load beam it will open, pivoting downwards to release the load. if there is no load on the load beam, the ground handler will have to apply a force of 8 lb to open the load beam against its spring.

23 Complete failure of the load beam to releaseShould the load beam fail to release following load landing and with the helicopter in the hover, then the ground handling party may achieve load disengagement by depressing the spring loaded keeper and sliding the engaged lifting ring/device off the load beam. See the CAUTION after paragraph 23.

HOOKING UP


24 Hooking up procedure24.1 ensure that the groove in the end of the manual release lever shaft and the reD engraved datum line on the release lever assembly cover are in alignment.


attention must be paid to the following CAUTION.

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CAUTION See Chapter 5 concerning static electricity discharge and employment of a static electricity discharge probe for the hooking-up process, or any other allied ground handler functions described in foregoing paragraphs.

DAP 101A-1105-1A



INTRODUCTION

WARNING WHEN OPERATING WITH THE SACRU NO2 MK1, HOOK-UP PERSONNEL AND CREWMAN SHOULD PAY PARTICULAR ATTENTION TO MASTERLINK/ STIRRUP ATTACHMENT TO THE LOAD BEAM AS THERE IS AN INCREASED RISK OF ROLL-OUT.

the semi-automatic cargo release unit (SaCrU) no 2 mk1 is an electro-magnetic type release unit. the SaCrU is fitted as a single hook installation to Wildcat, lynx and Gazelle helicopters. the release unit has a Safe Working load (SWl) of 1360 kg. lynx is cleared to lift to this capacity, however the maximum permitted external weight of load for Wildcat is 1000 kg,and 600 kg for Gazelle.

25 Basic layoutthe SaCrU is mounted underneath the Wildcat and lynx helicopter in a fore and aft manner. its fittings allow the release unit to swing fore and aft or from side to side. the release unit is mounted in an athwartships manner underneath Gazelle. it has similar freedom of movement about its fittings.


26 System of releasethere is a manual release knob on top of the SaCrU casing which can be operated by a ground handler. Providing that there is a minimum load of 10 lb (3.5 kg) on the load beam it will open, pivoting downwards to release the load. if there is no load on the load beam, when operating the manual release plunger, the ground handler will have to apply a force of 10 lb to open the load beam against its spring.

27 Complete failure of the load beam to releaseShould the load beam fail to release following load landing and with the helicopter in the hover, then the ground handling party may achieve load disengagement by depressing the spring loaded keeper and sliding the engaged lifting ring/device off the load beam. See the CAUTION after paragraph 27.

HOOKING-UP


28 Hooking up procedure28.1 before engaging the load onto the load beam, check that the flag in the release unit indicator window shows White.


CAUTION See Chapter 5 concerning static electricity discharge and employment of a static electricity discharge probe for the hooking-up process, or any other allied handler function described in foregoing paragraphs.

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CHAPTER 2 - 2 - 4: CHINOOK CARGO HOOKS

TRIPLE CARGO HOOK FACILITY

the Chinook has a triple cargo hook facility, allowing for the fitment of three releasable hooks spaced in tandem along the bottom centre-line of the fuselage. the hooks are referred individually as the ‘Centre hooK’ and the ‘forWarD and aft hooKS’. the centre hook is a different design to the forward and aft hooks, but the forward and aft hooks are identical to each other.

29 Modes of employmentthe Chinook triple cargo hook system allows for four modes of employment, as follows:

29.1 Single hook operations (Shos). this is where only one hook out of the three (the centre hook) is used for carrying the load, and can be likened to operations with single cargo hook helicopters (figure 5).

figure 5 - Single hook operations

29.2 multiple hook operations (mhos). this is where two or all three hooks are used simultaneously, each carrying an independent load (figure 6).

figure 6 - multiple hook operations

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29.3 tandem hook operations ‘redundant rigging’ (thorr). this is where a single load is suspended by means of the forward and aft hooks, with redundant rigging to the centre hook (figure 7).

figure 7 - tandem hook operations with redundant rigging

note redundant rigging calls for the use of an additional and special sling, designed solely for the purpose. in normal circumstances the legs of the redundant sling will remain slack/unused throughout the entire flight. however, the sling affords a safeguard against the possibility of an irregular release of either the forward or the aft hook or a failure of the primary sling legs at one end of the load. in such a situation, the redundant sling (suspended from the centre hook) will arrest the load drop at the relevant end, absorb the attendant shock loading in the process, and thereafter enable retrieval of the load. Without a redundant slinging system, an irregular hook release or sling leg failure, as described, could lead to severe structural damage of the airframe, due to shock loading. this would be accompanied by the risk of the load swinging in an arc, about the remaining cargo hook attachment point, leading to a possible fuselage or rotor strike before the crew could effect load jettison.

29.4 tandem hook operations ‘long stropping’ (tholS). this is where a single load is suspended employing slings, strops and weak link assemblies by means of the fore and aft hooks. the weak link enables the use of long stropping without the need for redundant rigging (figure 8).

USE OF WEAK

LINK ASSEMBLIES

figure 8 - tandem hook operations: long stropping

note the weak link assembly, with a specified breaking load, is fitted directly to the fore and aft hooks of the aircraft. in the event of a failure of the fore and aft hook/rigging, the remaining weak link will shear, protecting the aircraft structure from excessive forces.

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CENTRE HOOK

the centre hook is attached to a removable beam mounted in the centre floor hatch of the helicopter. the hook is free to move from side to side at its attachment point to the beam. the beam is free to swing forwards and aft.

30 System of releasethere is no externally mounted hook opening facility for ground handlers (see paragraph 35).

31 Safe Working Load (SWL)the maximum all up weight (aUW) that may be carried on the centre hook is 11300 kg, which is also the maximum aUW of external loads cleared for carriage under the Chinook helicopter.

FORWARD AND AFT HOOKS

the forward and aft hooks are identical, and are the electro-magnetic type release unit similar to the SaCrU range of hooks. the hooks are fitted in watertight compartments in the under fuselage, and the fittings allow the hooks to swing fore and aft or from side to side.

32 System of releasethere is a manual release knob on the cargo hook casing which can be operated by a ground handler. the knob has an arrow engraved on its face indicating the direction of operation (anti-clockwise). Providing that there is a minimum load of 9 kg on the load beam it will open, pivoting downwards to release the load. if there is no load on the load beam, when operating the manual release knob, the ground handler will have to apply a force of 9 kg to open the load beam against its return spring.

33 Safe Working Load (SWL)the maximum aUW of load that may be carried per hook is currently 5000 kg, providing that the aircraft remains within CoG limits. for tandem hook operations the maximum mass that may be carried is 10500 kg. the longitudinal CoG of the load must not result in a hook load distribution in excess of 40-60% (fwd-aft), 60-40% (fwd-aft).

JOINT CENTRE HOOK AND FORE AND AFT HOOK OPERATION

34 Inter-hook releasethe three hooks can be released individually or simultaneously by electrical command (normal mode). the electrical emergency release mode operates all three hooks simultaneously.

35 Complete failure of the load beam to releaseShould the beam fail to release following load landing with the helicopter in the hover the ground handler party may achieve load disengagement by depressing the spring loaded keeper and sliding the engaged lifting ring/device off the load beam. See ‘CAUTION’ after paragraph 35.

HOOKING-UP

WARNING ONLY ONE LIFTING RING/APEX DEVICE IS TO BE CARRIED ON THE LOAD BEAM OF THESE HOOKS.

36 Centre or fore and aft hooks hooking up procedureCarry out the following procedures:

36.1 With the forward and aft hook, check through the inspection window that the ‘hook locked’ indication is in accordance with the adjacent decal. Check the release knob reD/blaCK datum marks are in line. if the indicator shows the hook as being unlocked, manually open and close the hook. if the indicator still shows the hook as being unlocked then the hook is unserviceable.

36.2 in the case of all hooks, only one lifting ring or lifting device may be suspended from the hook load beam. engage the device over the bill of the load beam and push it fully past the keeper, onto the load carrying part of the beam. ensure that the keeper has returned to the fully closed position.

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DAP 101A-1105-1A


CHAPTER 2 - 2 - 5: MERLIN MK2 AND MK3A, C160, CARGO HOOK

INTRODUCTION

the C160, cargo hook is an electro-magnetic type release unit. it is fitted as a single hook installation to the merlin mk2 and mk3a helicopter, when in full VertreP role, and is limited to a maximum of 8046 lb all up weight carried from the release unit.

SYSTEM OF OPERATION

37 Basic layoutthe cargo hook is mounted underneath the helicopter in a fore and aft manner and used in conjunction with an ‘h’ frame. the frame is attached to strong-points on the lower fuselage with the cargo hook suspended from the centre of the frame.


38 System of releasethere is a manual release knob on the cargo hook casing which can be operated by a ground handler. the knob has an arrow engraved on its face indicating the direction of operation (anti-clockwise). Providing that there is a minimum load of 9 kg on the load beam it will open, pivoting downwards to release the load. if there is no load on the load beam, when operating the manual release knob, the ground handler will have to apply a force of 9 kg to open the load beam against its return spring.

39 Complete failure of the load beam to releaseShould the beam fail to release following load landing with the helicopter in the hover the ground handler party may achieve load disengagement by depressing the spring loaded keeper and sliding the engaged lifting ring/device off the load beam. See ‘CAUTION’ after paragraph 39.

HOOKING UP

WARNING ONLY ONE LIFTING RING/APEX DEVICE IS TO BE CARRIED ON THE LOAD BEAM OF THESE HOOKS.

40 Hooking up procedureCarry out the following procedures:

40.1 Check through the inspection window that the ‘hook locked’ indication is in accordance with the adjacent decal. Check the release knob reD/blaCK datum marks are in line. if the indicator shows the hook as being unlocked, manually open and close the hook. if the indicator still shows the hook as being unlocked then the hook is unserviceable.

40.2 only one lifting ring or lifting device may be suspended from the hook load beam. engage the device over the bill of the load beam and push it fully past the keeper, onto the load carrying part of the beam. ensure that the keeper has returned to the fully closed position.


DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 3: HELICOPTER EXTENSION STROPS

INTRODUCTION .................................................................................................................................... 421 nature of the equipment .....................................................................................................................422 Purpose of the equipment ..................................................................................................................423 additional facility of the polyester strop ..............................................................................................434 further application of extension strops ..............................................................................................43MATERIALS USED FOR STROP LEGS ............................................................................................... 445 Steel wire rope (SWr)........................................................................................................................446 textiles ...............................................................................................................................................44GENERAL PRINCIPLES OF STROP USAGE ...................................................................................... 447 Underslung load clearances (USlCs) ................................................................................................448 hooking up .........................................................................................................................................449 Chinook multiple hook operations. .....................................................................................................4510 Strop release ......................................................................................................................................4511 non-strop release operations .............................................................................................................4512 Strop recovery line .............................................................................................................................4513 Coupling of strops in series ................................................................................................................4614 factors affecting use of longer length strops .....................................................................................4615 further application of strop coupling ..................................................................................................46

CHAPTER 2 - 3 - 1: STROP, LIFTING, SINGLE LEG (11300 KG SWL)

INTRODUCTION .................................................................................................................................... 48EQUIPMENT DESCRIPTION ................................................................................................................. 4816 Standard assembly.............................................................................................................................4817 Use of masterlink lifting ring and swivel hook assembly connected direct .........................................4818 Safe working load (SWl)....................................................................................................................4919 life expiry of roundsling leg element ..................................................................................................49TECHNICAL SUPPORT LITERATURE ................................................................................................. 4920 hUSle publications ...........................................................................................................................49STROP USAGE ..................................................................................................................................... 4921 Suitability for engagement to current range of helicopter cargo hooks ..............................................4922 Coupling of 11300 kg strops ...............................................................................................................4923 Secondary hook engagement and accommodation limits ..................................................................51


INTRODUCTION .................................................................................................................................... 53EQUIPMENT DESCRIPTION ................................................................................................................. 5324 Standard assembly.............................................................................................................................5325 Safe working load (SWl)....................................................................................................................5326 life expiry of roundsling leg element ..................................................................................................5327 technical support literature ................................................................................................................53STROP USAGE ..................................................................................................................................... 5328 Suitability for engagement to current range of helicopter cargo hooks ..............................................5429 Coupling of 5000 kg strops ................................................................................................................5430 Secondary hook engagement and accommodation limits ..................................................................55

CHAPTER 2 - 3 - 3: STROP, LIFTING, SINGLE LEG (16 FT AND 80 FT (6000 LB SWL))

INTRODUCTION .................................................................................................................................... 58EQUIPMENT DESCRIPTION ................................................................................................................. 5831 Standard assembly.............................................................................................................................5832 Vinyl sleeve ........................................................................................................................................5833 metal tally ...........................................................................................................................................58

CHAPTER 2 - 3

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34 Safe working load (SWl)....................................................................................................................5835 technical support literature ................................................................................................................59STROP USAGE ..................................................................................................................................... 5936 Suitability for engagement to current range of helicopter cargo hooks ..............................................5937 SaCrU no 1 mk3, SaCrU no 2 mk1 and breeze eastern. ............................................................5938 mandatory use....................................................................................................................................5939 Coupling of 16 ft/80 ft strops ..............................................................................................................6040 Secondary hook engagement and accommodation limits ..................................................................61


INTRODUCTION .................................................................................................................................... 64EQUIPMENT DESCRIPTION ................................................................................................................. 6441 Standard assembly.............................................................................................................................6442 Vinyl sleeve ........................................................................................................................................6443 metal tally ...........................................................................................................................................6444 Safe WorKinG loaD.....................................................................................................................65TECHNICAL SUPPORT LITERATURE ................................................................................................. 65STROP USAGE ..................................................................................................................................... 6545 Suitability for engagement to current range of helicopter cargo hooks ..............................................6546 mandatory use....................................................................................................................................6547 Coupling of 7 ft/ 30 ft strops ...............................................................................................................6648 Secondary hook engagement and accommodation limits ..................................................................66

figures

figure 9 - british Service helicopter extension strops .....................................................................................43figure 10 - 11300 kg strop assemblies, branching two strops from one .........................................................47figure 11 - assembled strop ............................................................................................................................48figure 12 - masterlink and swivel ....................................................................................................................48figure 13 - typical arrangement showing method of connecting roundslings to produce an extended strop ..........................................................................................................................50figure 14 - 11300 kg strops, coupling complete assemblies together in series ..............................................51figure 15 - accommodation limits for the heavy duty strop secondary hook, engaging Sml 6000 lb SWl ............................................................................................................................51figure 16 - accommodation limits for the heavy duty strop secondary hook, engaging nets 5000 lb SWl or 5600 kg SWl ..................................................................................................52figure 17 - accommodation limits for 11300 kg SWl heavy duty strop secondary hook, engaging Sml 4600 kg SWl or Sml 11300 kg SWl ......................................................................................52figure 18 - assembled strop............................................................................................................................53figure 19 - typical arrangement showing method of connecting roundslings to produce an extended strop .54figure 20 - 5000 kg strops, coupling complete assemblies together in series ................................................55figure 21 - accommodation limits for the medium duty strop secondary hook engaging Sml 6000 lb SWl ...........................................................................................................................55figure 22 - accommodation limits for the medium duty strop secondary hook engaging nets cargo 5000 lb SWl or 5600 kg SWl ........................................................................................56figure 23 - accommodation limits for medium duty strop secondary hook engaging Sml 4600 kg SWl ..........................................................................................................................56figure 24 - accommodation limits for medium duty strop secondary hook engaging Sml 11300 kg SWl ........................................................................................................................57figure 25 - 16 ft / 80 ft strops (6000 lb SWl) ..................................................................................................58figure 26 - Using a ‘connector sling’ to connect lifting loop of 16 ft/80 ft strop to SaCrU no 2 mk1 and a 5 tonne SWl, bow shackle to connect lifting loop of 16 ft/80 ft strop to SaCrU no 1 mk3 ..................60figure 27 - 16 ft/80 ft strop coupling in series .................................................................................................60figure 28 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 6000 lb SWl ............................................................................................................................61 figure 29 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging nets engaging nets 5000 lb SWl .....................................................................................................62figure 30 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging nets engaging nets 5600 kg SWl ....................................................................................................62

DAP 101A-1105-1A


figure 31 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 4600 kg SWl ...........................................................................................................................63figure 32 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 11300 kg SWl .........................................................................................................................63figure 33 - 7 ft / 30 ft strops (1500 lb SWl) ....................................................................................................64figure 34 - Using a ‘sling connector’ to connect lifting loop of 7 ft/30 ft strop to SaCrU no 2 mk1 ...............65figure 35 - 7 ft / 30 ft strops coupling in series................................................................................................66figure 36 - accommodation limits for 7 ft/30 ft strop secondary hook engaging Sml 4600 kg SWl. .............67figure 37 - accommodation limits for 7 ft/30 ft strop secondary hook engaging Sml 6000 lb SWl ...............67figure 38 - accommodation limits for 7 ft/30 ft strop secondary hook engaging nets 5000 lb SWl ...............68figure 39 - accommodation limits for 7 ft/30 ft strop secondary hook engaging nets 5600 kg SWl ...............68figure 40 - accommodation limits for 7 ft/80 ft strop secondary hook engaging Sml 11300 kg SWl ............69

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CHAPTER 2 - 3: HELICOPTER EXTENSION STROPS

INTRODUCTION

helicopter extension strops are aircraft role equipment items and the purpose of this chapter is to cover the general aspects relating to the make up and use of british Service helicopter extension strops.

1 Nature of the equipmentthe current range of extension strops are shown in figure 9. each equipment is classified by its Safe Working load (SWl). equipments vary in length, with the legs being constructed from textile or steel wire rope (SWr). the top of the leg is either formed with a lifting loop or eye, or is fitted with a shackle or similar device for engagement onto the helicopter cargo hook or another strop hook. the bottom of the leg is fitted with a hook, known as the ‘secondary’ hook for reception of sling lifting ring, net stirrup or a similar device. the employment of a swivelling secondary hook is manDatory.

2 Purpose of the equipmentextension strops are normally associated in their use with loads suspended from a single helicopter cargo hook. in this context, british Service helicopter extension strops have a threefold function as described below:

2.1 increased vertical clearance

an extension strop enables a load to be underslung at an extended distance from the helicopter, serving the following purpose:

2.1.1 avoidance of load strike on helicopter. it provides a safe suspension distance for loads which, because of their size or flying characteristics, pose the risk of striking the helicopter in flight.

2.1.2 avoidance of surface obstacles. it affords a means of attaching or landing a load when the helicopter is unable to descend because of surface obstacles such as trees, buildings or ships rigging.

2.1.3 reduction of rotor downwash effect. it allows the helicopter to hover high enough for rotor downwash to be minimised, thus avoiding dust or snow disturbance, and damage to surrounding structures or loose items. it also reduces the possibility of objects or debris being drawn up into the helicopter rotors or engine intakes.

2.1.4 making hook-up of awkward shaped loads safer. it makes the process of load hook-up safer and simpler for the helicopter crew and for ground handlers operating with awkward shaped loads; avoiding the risk of helicopter wheel or skid strikes and, for the helicopter crew, removing the need for precise positioning over the load until the moment of the load uplift.

2.1.5 making hook-up under a particular helicopter type safer/simpler. it makes for safer and simpler load hook-up, when there is little room to spare for ground handlers between the cargo hook and surrounding wheels/skids or other items attached to the underside of the helicopter fuselage.

2.1.6 avoidance of load collisions in Chinook multiple cargo hook operations. it enables load suspension distances to be staggered in Chinook operations involving carriage of separate loads on two or all three of its cargo hooks, thus avoiding the risk of load collisions in flight.

2.2 Connector/coupling facility

the extension strop ‘secondary’ hook provides a means of connection for strops, slings or cargo lifting nets. the secondary hook also affords the means of coupling equipment lifting rings or apex devices in multiples. this is an important facility and is allied to current UK safety practice whereby only one lifting ring or apex device may be carried from the load beam of existing type british Service helicopter cargo hooks.

NOTE In certain instances, specified ‘connector devices’ can be used as an alternative means of connecting or coupling equipment to a helicopter cargo hook (see Chapter 2-4-1).

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2.3 Swivel facility

Certain loads have a tendency to rotate in flight, either intermittently or in the form of a sustained spin. Without a swivel device in the suspension system this would lead to a winding up of sling legs or strop, causing damage to these items and torsional strain on the helicopter cargo hook and/or its point of attachment to the helicopter. the end result could be loss of a load. the extension strop allows for the introduction of such a device.

SWL 11300 kg

(25000 lb)

SWL 5000 kg

(11020 lb)

2m or 5m LEG 2m LEGor 5m

POLYESTER ROUNDSLING LEGSTEEL WIRE ROPE (SWR) LEGS

7 ft LEG

30 ft LEG

16 ft LEG

80 ft LEG

SWL 6000 lb

(2724 kg)SWL 1500 lb

(680 kg)

SWL 6000 lb

(2724 kg)

SWL 1500 lb

(680 kg)

figure 9 - british Service helicopter extension strops

3 Additional facility of the polyester stropin certain situations it is advantageous for the swivel/connector/coupler facility, provided by the extension strop secondary hook, to be used without the increased load suspension distance afforded by the strop leg. the 11300 kg strop equipment caters for this, in its design which allows for easy removal of the polyester leg element and connection of the strop lifting ring (masterlink) direct to the swivel hook.

4 Further application of extension stropsmeans of improving or averting unfavourable load handling characteristics for a given helicopter. QinetiQ, ateC, boscombe Down clearance for a given helicopter type may make the use of an extension strop mandatory, outside of such requirements as simpler/safer hook-up facility for ground handlers (see paragraph 2.1.5) or specified needs for a strop when called for in JaDteU USlCs.

the mandatory requirement may be a general one, for carriage of any USl, because the use of a suitable strop can significantly enhance load handling characteristics of it under that helicopter type. the requirement may, however, be specific to carriage of one type of sling, for example, where the strop may overcome a problem of vertical bouncing of the load resulting from helicopter vibrational characteristics and the stretch characteristics of the particular sling. Such mandatory requirements for use of a strop will be laid down in the rtS document for the helicopter type (see Chapter 1).

DAP 101A-1105-1A


MATERIALS USED FOR STROP LEGS

5 Steel wire rope (SWR)longer length strops have traditionally been constructed from SWr. this is because the stretch in SWr is negligible when operating within its load range, thus posing no rebound hazard should the load detach from the strop secondary hook in flight. however, SWr is comparatively heavy, and not as pliant or easy to handle as textile equipment. Whilst the current range of SWr strops are of manageable weight and rope diameter, greater weight/ payload performance is achieved in the heavier duty range of equipment’s by the use of textile materials.

6 Textiles6.1 Polyester. the heavy duty polyester strop equipment is not limited in the length of assembly which may be used. this is because the stretch characteristics of polyester are negligible compared with nylon under similar load conditions. like nylon, polyester is a lightweight material, supple and easy to handle. however, unlike nylon, polyester is much less prone to deterioration as the result of regular exposure to sunlight (actinic degradation).

6.2 textile life. Polyester and nylon strop legs are ‘lifed’ items (see chapter 1-2, paragraph 10 or aP 108G-0002-1b: hUSle Strops).

GENERAL PRINCIPLES OF STROP USAGE

7 Underslung load clearances (USLCs)all USlCs published by JaDteU state clearly when an extension strop is required, amplified by a statement of flying characteristics for the loads concerned and specifying the strop equipment to be used. Clearances calling up 11300 kg strop equipment will also indicate whether a strop lifting ring (masterlink) may alternatively be connected to the swivel hook assembly without inclusion of the polyester roundsling leg. further information on USlCs and use of strops is contained in DaP 101a-1105-1b (chapter 1-3, paragraph 30 on aircrew advisory notes).

8 Hooking upnote

the number of equipment lifting rings or apex devices that can be accommodated by a given type of secondary hook will depend upon the size and nature of the apex device. Whilst these factors will automatically be catered for in USlCs, the standard accommodation limits for different types of strop hook are set down in the individual strop equipment chapters, for general information and to cater for ‘authorised loads’.

8.1 Static electricity discharge. if the extension strop is to be engaged to the cargo hook with the helicopter in the hover, or with the helicopter on the ground with rotors running, first carry out the static discharge procedure as described in Chap 5. engagement of items to the strop secondary hook will normally be carried out with the strop deployed from the helicopter in the hover, and with the same static discharge procedure being carried out.

8.2 engagement of strop to helicopter cargo hook. Consult chapter 2-2 for the process of engaging the strop lifting eye, ring or strop connector where applicable, onto the SaCrU and Chinook series of cargo hooks. Consult individual strop chapters for detailed points concerning each strop equipment.

8.3 engagement of items onto strop secondary hook. the current range of extension strop secondary hooks are broadly similar in appearance and all equipped with the same form of spring loaded keeper. having carried out static discharge procedures as required, it is normally necessary to grasp the secondary hook with one hand whilst pushing the sling lifting ring, net stirrup, or the like, past the spring loaded keeper fully onto the beam of the hook. Confirm that the spring loaded keeper has returned to its fully closed position and give a tug on the connected item to ensure correct and positive engagement. repeat this process for any further items to be engaged onto the secondary hook.

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9 Chinook multiple hook operations.the following points should be noted concerning Chinook multiple hook operations (see also Chapter 2-2-4):

WARNING HOOKING-UP MULTIPLE LOADS CAN BE HAZARDOUS TO GROUND PERSONNEL, PARTICULARLY IN POOR WEATHER. CLEAR COMMUNICATION IN THE FORM OF UNAMBIGUOUS SIGNALS BETWEEN MARSHALLERS, HOOK-UP TEAM AND THE HELICOPTER CREW IS ESSENTIAL.

9.1 When carrying a separate load on each of the three hooks, the preferred configuration is with the front load attached to a masterlink with swivel hook (11300 kg strop items), the centre load on a medium length 11300 kg strop and the rear load on a longer length 11300 kg strop. this combination may, however, be varied to suit operational circumstances.

9.2 there is no hooking-up sequence. however, it is usually easier to attach the load with the shortest suspension length first. horizontal load separation can be improved by attaching the densest load to the forward hook and the bulkiest load to the aft hook.

10 Strop releasefollowing load landing the helicopter crew will endeavour to release the strop to one side of the load, to avoid risk of damage. During this process, ground handler personnel must keep well clear of the release area and the attendant danger of being struck by the heavy and potentially lethal metal elements of a strop assembly. See chapter 2-3 for the methods of manually releasing the strop from the various types of helicopter cargo hook, should this be required of the ground handlers.

following strop release, the helicopter will normally land nearby to retrieve the strop. Where this is not possible, it is the responsibility of the ground unit to return the strop to the helicopter unit without delay.

11 Non-strop release operationsWARNING

TO AVOID CONFUSION AND POSSIBLE HAZARD TO GROUND HANDLER PERSONNEL IT IS IMPORTANT THAT THEY ARE FULLY BRIEFED ON THE HELICOPTER OPERATOR’S INTENT, INCLUDING THE VISUAL SIGNALS THAT ARE TO BE USED FOR UNDERLUNG LOAD OPERATIONS INVOLVING NON-STROP RELEASE.

for certain operations the helicopter crew may require disengagement of the load, following load landing, without releasing the strop from the helicopter cargo hook. a common practice is to use a strop recovery line, which enables the crewman to haul the free end of the strop up to the helicopter cabin, following disengagement of the load at the secondary hook. the following points concerning non-strop release operation are to be noted:

WARNING ALTHOUGH THE LOAD HAS BEEN LANDED, THE STATIC DISCHARGE PROCEDURE IS TO BE CARRIED OUT IN FULL BEFORE DISENGAGEMENT OF THE LOAD FROM THE STROP SECONDARY HOOK.

Disengagement involves depressing the spring loaded keeper, whilst removing the item(s) from the hook. throughout the process ground handlers must remain alert to the danger of inadvertent release from the helicopter cargo hook end, with the consequent falling of the strop assembly possibly fitted with heavy metal lifting ring.

12 Strop recovery linein order to recover a strop following completion of an external load lift without requiring the helicopter to land, or to facilitate swift transit speeds when conducting frequent short range load lifts, a recovery line may be fitted so that the strop may be drawn up into the helicopter when not in use.

information on the construction of the recovery line should be detailed in instructions pertinent to the aircraft type. the recovery line should have the following characteristics:

12.1 be fitted to the strop so as not to interfere with the use of the primary or secondary hooks.

12.2 be slightly longer than the strop; dependant on strop length.

12.3 Use of cord or rope that is easy to handle; this may include knots to assist grip.

DAP 101A-1105-1A


12.4 incorporate a weak link to allow detachment from the aircraft if the load is jettisoned from the primary hook.

a recovery line may be used to help stabilise a flailing strop.

13 Coupling of strops in seriesComplete strop assemblies from the same family (eg 16 ft and/or 80 ft SWr strops (SWl 6000 lb)) may be coupled to each other in series to make a longer assembly, providing the requirements of paragraph 14 below are adhered to. for further details consult individual strop chapters. in an extreme operational need, strops of mixed SWl and/or material (ie SWr and textile assemblies) may be coupled in series if compatible for connection to each other, as indicated in individual strop chapters.

in all cases the following rules are to be applied:

13.1 all secondary hooks in the coupled assembly are to be of the swivelling type.

13.2 the overall SWl of the assembly is to be determined by the strop(s) with the lowest SWl classification.

13.3 the total weight of equipment and terminal load suspended from any one secondary hook in series is not to exceed the SWl of that particular hook and parent strop leg. When calculating the weight of load suspended from any one secondary hook, the weight of all strops suspended below it must be taken into account.

note the 11300 kg and 5000 kg strop equipment’s also allows for connection in series of 2 m and/or 5 m roundsling elements, with a single lifting ring (masterlink) at the top of the assembly and a single swivel hook at the bottom. in these circumstances the SWl remains 11300 kg or 5000 kg, respectively, for any length of assembly within the operating capability of the helicopter type cleared to operate with this strop equipment.

14 Factors affecting use of longer length stropsGround units should note that any of the following factors may limit the extent to which longer length extension strops can be employed, either by a given helicopter type or in general terms:

14.1 individual helicopter performance limits at the high hover.

14.2 maximum allowable load suspension distance imposed for a given helicopter type.

14.3 operating conditions affording poor visibility, lack of visual clues or difficulty for the helicopter crew in accurate perception of distance to the ground.

15 Further application of strop couplingby coupling a pair of 11300 kg or 5000 kg extension strops to the secondary hook of an equivalent rated single extension strop, it is possible, for example, to carry a cluster of netted loads which would otherwise need lifting chains because there would be too many for direct suspension from or accommodation onto a single strop secondary hook; consult appropriate USlCs. figure 10 illustrates the system; a maximum of two masterlink lifting rings may be accommodated on the strop swivel hook.

DAP 101A-1105-1A


11300 kg 2.7 m LENGTH STROP

(ALTERNATIVELY THE ROUNDSLING

ELEMENT MAY BE OMITTED)

MAXIMUM ACCOMMODATION LIMIT OF

TWO 11300 kg STROP MASTERLINKS ON

11300 kg STROP SECONDARY HOOK

11300 kg 2.7 m

LENGTH STROP

figure 10 - 11300 kg strop assemblies, branching two strops from one

DAP 101A-1105-1A



INTRODUCTION

the 11300 kg extension strop, otherwise known as the ‘heavy Duty Strop’, is designed for easy dismantling and assembly by component parts. the equipment length assembled is either 2.7 m or 5.7 m. full nSn details and nomenclature for the equipment’s are contained in aP 108G-0002-1b: hUSle Strops.

the strop lifting ring and swivel hook, otherwise known as the ‘masterlink and Swivel’, may be connected one to the other direct if the added length of the roundsling leg element is not required. full nSn details for the equipment and nomenclature are contained in aP 108G-0002-1D: hUSle ancillary equipment.

EQUIPMENT DESCRIPTION

16 Standard assemblythe assembled strop incorporates a 2 m or 5 m length roundsling leg (see figure 11). a strop lifting ring (masterlink) is connected to one end of the strop and a swivel assembly with hoist hook (secondary hook) is connected to the other end. the strop is fitted with two identification labels, one external and one internal for fallback reference. each label contains the nSn, the SWl classification, the life expiry date of the roundsling leg and the assembly serial number.

ROUNDSLING OUTER

PROTECTIVE SLEEVE

SWIVEL

(HOIST)

HOOK

LOCKING SET

(RETAINING

PIN AND COLLAR)

ANTI-CHAFE

SLEEVE

EQUIPMENT

IDENTIFICATION/

LIFE EXPIRY LABELSWIVEL

ASSEMBLY

SPRING LOADED

KEEPER/LATCH

ANTI-CHAFE

SLEEVE

LOCKING SET

(RETAINING PIN

AND COLLAR)

ROUNDSLING

COUPLING

ROUNDSLING

COUPLING

STROP LIFTING RING

(CLOSED MASTERLINK)

PVC TAPE

PVC TAPE

figure 11 - assembled strop

17 Use of masterlink lifting ring and swivel hook assembly connected directthe masterlink lifting ring may be connected directly to the swivel hook assembly using a locking set. the ability to employ the equipment thus, without the inclusion of a roundsling leg, is of benefit when a swivel capability only is required. this is particularly useful for Chinook multiple hook operations (Chap 2-2-4 and Chap 2-3).

figure 12 - masterlink and swivel

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18 Safe working load (SWL)the SWl of the complete strop assembly, with masterlink lifting ring, single or interconnected roundsling legs and terminating swivel hook assembly is 11300 kg. the SWl remains the same for the masterlink and swivel hook assembly connected one to the other direct (paragraph 16).

19 Life expiry of roundsling leg elementthe roundsling leg element of the strop is a ‘lifed’ item, policy for which is laid down in the technical support literature for the equipment (as below and in chapter 1-2). the life expiry date is to be marked legibly and indelibly, with black permanent marker pen, on the strop identification label(s).

TECHNICAL SUPPORT LITERATURE

20 HUSLE publicationsfull technical supporting literature for the assembled 2.7 m or 5.7 m is published in aP108G-0002-1b, hUSle, Strops; full technical supporting literature for the masterlink and swivel hook is published in aP108G-0002-1D, hUSle ancillary equipment.

Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

STROP USAGE

Consult chapter 2-3 for the general principles applying to strop usage, hook-up, load release, etc.

21 Suitability for engagement to current range of helicopter cargo hooksfor details on attachment of the strop to the relevant aircraft SaCrU see Chapter 2-1 paragraph 3, paying particular attention to the WarninG and Caution.

22 Coupling of 11300 kg stropslonger length assemblies may be made up by joining 2 m and/or 5 m length roundslings end to end, using two roundsling couplings and a locking set at each interconnect point (figure 13). the assembly metalware is connected to the top and bottom of the overall roundsling assembly. refer to aP 108G-0002-1b: hUSle Strops, for roundsling couplings and locking sets nSn and nomenclature details.

DAP 101A-1105-1A


2 ROUNDSLING SHACKLES

AND LOCKING SET

11300 kg ROUNDSLINGS, 2 m

AND/OR 5 m AS REQUIRED

figure 13 - typical arrangement showing method of connecting roundslings to produce an extended strop

an alternative way of achieving longer strop lengths is by coupling strop assemblies together in series within the load suspension/performance limit for helicopter type. the coupling process simply involves engaging the masterlink lifting ring of one strop onto the swivel hook of the next strop (one lifting ring per secondary hook) until all strops have been linked. individual strop assemblies may include 2 m and/or 5 m length roundsling legs, and the masterlink, swivel hook assembly may also be included in the coupled series. in each case check that the hook keeper returns to the fully closed position after engagement of the lifting ring (figure 14).

DAP 101A-1105-1A


ANY ASSORTMENT OF LENGTHS

PERMISSABLE, AND OVERALL

LENGTH LIMITED ONLY BY

INDIVIDUAL HELICOPTER LIMITS

figure 14 - 11300 kg strops, coupling complete assemblies together in series

any number of 5000 kg, 16 ft, 80 ft, 7 ft or 30 ft strops may be included in a linked series of 11300 kg strops. in this respect, the masterlink lifting ring is suitable for engaging the swivel common to the 5000 kg, 16 ft and 80 ft strop but is too large to engage the smaller swivel hook of the 7 ft and 30 ft strops.

23 Secondary hook engagement and accommodation limitsfigures 15, 16 and 17 provide information on the suitability of the different types of sling and net for engagement to the secondary hook of the 11300 kg strop. Guidance is also given on the maximum number of equipment’s/apex devices that may be carried on the secondary hook, unless otherwise specified in individual USlCs.

WARNING: IN ALL CASES, THE MAXIMUM AUW OF EQUIPMENT AND LOAD SUSPENDED FROM THIS SECONDARY HOOK IS NOT TO EXCEED 11300 KG OR SUCH LOWER FIGURES AS MAY BE SET FOR THE HELICOPTER CARGO HOOK/HELICOPTER TYPE.

SUITABLE FOR DIRECT ENGAGEMENT TO THE HEAVY

DUTY STROP SECONDARY HOOK. MAXIMUM OF

TWO SLINGS FOR ACCOMMODATION ON THIS HOOK,

UNLESS SPECIFIED OTHERWISE IN INDIVIDUAL USLC’s.

SML 6000lb SWL.

figure 15 - accommodation limits for the heavy duty strop secondary hook, engaging Sml 6000 lb SWl

DAP 101A-1105-1A



DUTY STROP SECONDARY HOOK. AS AN ‘AUTHORISED

LOAD’, A MAXIMUM OF TWO NET STIRRUPS CAN BE

ACCOMMODATED ON THIS HOOK, UNLESS SPECIFIED

OTHERWISE IN INDIVIDUAL USLC’s.

NETS - 5000 lb SWL or 5600 kg SWL

figure 16 - accommodation limits for the heavy duty strop secondary hook, engaging nets 5000 lb SWl or 5600 kg SWl


DUTY STROP SECONDARY HOOK. A MAXIMUM OF

TWO SML 4600kg OR TWO SML 11300kg MASTERLINK

LIFTING RINGS ARE SUITABLE FOR ACCOMMODATION

ON THIS HOOK.

SML 4600 kg SWL

OR

SML 11300 kg SWL

figure 17 - accommodation limits for 11300 kg SWl heavy duty strop secondary hook, engaging Sml 4600 kg SWl or Sml 11300 kg SWl

DAP 101A-1105-1A



INTRODUCTION

the 5000 kg extension strop, otherwise known as the ‘medium Duty Strop’, is designed for easy dismantling/assembly by component parts. the assembled equipment length is either 2.5 m or 5.5 m. full nSn details and nomenclature for the equipment’s are contained in aP 108G-0002-1b: hUSle Strops.


24 Standard assemblythe assembled strop incorporates a 2 m or 5 m length roundsling leg (figure 18). a strop lifting ring (masterlink) is connected to one end of the strop and a swivel assembly with hoist hook (secondary hook) is connected to the other end. the strop is fitted with two identification labels, one external and one internal for fallback reference. each label contains the nSn, the SWl classification, the life expiry date of the roundsling leg and the assembly serial number.

25 Safe working load (SWL)the SWl of the complete strop assembly, with masterlink lifting ring, single or interconnected roundsling legs and terminating swivel hook assembly is 5000 kg.

ROUNDSLING OUTER

PROTECTIVE SLEEVE

SWIVEL

(HOIST)

HOOK

LOCKING SET

(RETAINING

PIN AND COLLAR)

ANTI-CHAFE

SLEEVE

EQUIPMENT

IDENTIFICATION/

LIFE EXPIRY LABELSWIVEL

ASSEMBLY

SPRING LOADED

KEEPER/LATCH

ANTI-CHAFE

SLEEVE

LOCKING SET

(RETAINING PIN

AND COLLAR)

ROUNDSLING

COUPLING

ROUNDSLING

COUPLING

STROP LIFTING RING

(CLOSED MASTERLINK)

PVC TAPE

PVC TAPE

figure 18 - assembled strop

26 Life expiry of roundsling leg elementthe roundsling leg element of the strop is a ‘lifed item’, the policy for which is laid down in the technical support literature for the equipment (see chapter 1-1). the life expiry date is to be marked legibly and indelibly, with black permanent marker pen, on the strop identification label(s).

27 Technical support literaturefull technical supporting literature for this equipment is published in aP 108G-0002-1b, hUSle Strops. chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

STROP USAGE

WARNING: IN ALL CASES, THE MAXIMUM AUW OF EQUIPMENT AND LOAD SUSPENDED FROM THIS SECONDARY HOOK IS NOT TO EXCEED 5000 KG OR SUCH LOWER FIGURES AS MAY BE SET FOR THE HELICOPTER CARGO HOOK/HELICOPTER TYPE.

DAP 101A-1105-1A


Consult Chapter 2-3 for the general principles applying to strop usage, hook up, load release, etc.


29 Coupling of 5000 kg stropslonger length assemblies may be made up by joining 2 m and/or 5 m length roundslings end to end, using two roundsling couplings and a locking set at each interconnect point (figure 19). the assembly metalware is connected to the top and bottom of the overall roundsling assembly. refer to aP 108G-0002-1b, hUSle Strops for roundsling couplings and locking sets.

2 ROUNDSLING SHACKLES

AND LOCKING SET

5000 kg ROUNDSLINGS

figure 19 - typical arrangement showing method of connecting roundslings to produce an extended strop

an alternative way of achieving longer strop lengths is by coupling strop assemblies together in series,

DAP 101A-1105-1A


within the load suspension/performance limit for the helicopter type. the coupling process simply involves engaging the masterlink lifting ring of one strop onto the swivel hook of the next strop (one lifting ring per secondary hook), until all strops have been linked. individual strop assemblies may include 2 m and/or 5m length roundsling legs in the coupled series. in each case check that the hook keeper returns to the fully closed position after the engagement of the lifting ring (figure 20).

ANY ASSORTMENT OF LENGTHS

PERMISSABLE, AND OVERALL

LENGTH LIMITED ONLY BY

INDIVIDUAL HELICOPTER LIMITS

figure 20 - 5000 kg strops, coupling complete assemblies together in series

any number of 11300 kg, 16 ft, 80 ft, 7 ft or 30 ft strops may be included in a linked series of 5000 kg strops. in this respect, the masterlink lifting ring is suitable for engaging the swivel hook common to the 11300 kg, 16 ft, 80 ft, 7 ft and 30 ft strops. in all cases, the maximum aUW of the equipment and the load suspended from this secondary hook is not to exceed 5000 kg, or such lower figure as may be set for the helicopter cargo hook, linked strop or helicopter type.

30 Secondary hook engagement and accommodation limitsfigures 21, 22, 23 and 24 provide information on the suitability of the different types of sling and net for engagement to the secondary hook of the 5000 kg strop. Guidance is also given on the maximum number of equipment’s/apex devices that may be carried on the secondary hook, unless otherwise specified in individual USlCs.

SUITABLE FOR DIRECT ENGAGEMENT TO THE MEDIUM

DUTY STROP SECONDARY HOOK. MAXIMUM OF

TWO SLINGS FOR ACCOMMODATION ON THIS HOOK,

UNLESS SPECIFIED OTHERWISE IN INDIVIDUAL USLC’s.

SML 6000lb SWL.

figure 21 - accommodation limits for the medium duty strop secondary hook engaging Sml 6000 lb SWl

DAP 101A-1105-1A



DUTY STROP SECONDARY HOOK. AS AN ‘AUTHORISED

LOAD’, A MAXIMUM OF TWO NET STIRRUPS CAN BE

ACCOMMODATED ON THIS HOOK, UNLESS SPECIFIED

OTHERWISE IN INDIVIDUAL USLC’s.

NETS - 5000 lb SWL or 5600 kg SWL

figure 22 - accommodation limits for the medium duty strop secondary hook engaging nets cargo 5000 lb SWl or 5600 kg SWl



TWO SML 4600kg SLING MASTERLINK LIFTING RINGS

ARE SUITABLE FOR ACCOMMODATION ON THIS HOOK.

SML 4600 kg SWL

figure 23 - accommodation limits for medium duty strop secondary hook engaging Sml 4600 kg SWl

DAP 101A-1105-1A




ONE SML 11300 kg SLING MASTERLINK LIFTING RING

IS SUITABLE FOR ACCOMMODATION ON THIS HOOK.

SML 11300 kg SWL

figure 24 - accommodation limits for medium duty strop secondary hook engaging Sml 11300 kg SWl

DAP 101A-1105-1A



INTRODUCTION

the 16 ft and 80 ft Steel Wire rope (SWr) extension strops are mainly associated with rn and raf helicopter units. there is no restriction on their use with any british Service helicopters; within the normal ambit of operating provisions for helicopter type, and subject to suitability for engagement by direct or by connector/coupling means, to the particular type of helicopter cargo hook. full nSn details for the equipment are contained in aP 108G-0002-1b: hUSle Strops.


31 Standard assemblythe 16 ft and 80 ft strops are identical in construction, differing only in length and/or weight. they derive their common usage titles from the respective length of wire rope leg. in each case the leg consists of a single length of SWr, each end formed into a loop. the upper loop which is oval in shape forms the ‘lifting loop’ for engagement onto a helicopter cargo hook, and is formed around a steel thimble. a smaller loop is formed at the bottom of the leg, to enclose a ‘deadeye’ to which is attached a secondary hook with spring loaded keeper (figure 25).

THIMBLE

SWIVEL

SECONDARY

HOOK

STEEL WIRE

ROPE LEG

TALLY

VINYL

SLEEVE

SPRING LOADED

KEEPER

‘DEAD EYE’

16 ft

OR

80 ft

17 ft

OR

81 ft

figure 25 - 16 ft / 80 ft strops (6000 lb SWl)

32 Vinyl sleevea vinyl sleeve is fitted the length of the strop leg for protective purposes and to make the strop easier to handle. Damage to the sleeve does not render the strop unusable, and the strop may continue to be used with the sleeve removed completely providing that the strop is serviceable in all other respects. a split sleeve may be taped, but a badly torn sleeve should be trimmed back or removed completely.

33 Metal tallya metal tally is attached to the strop leg, identifying the equipment and containing details of the nSn, equipment SWl, equipment serial number and date of ‘proof test’. if this tally is lost, the equipment is to be withdrawn from use immediately and back-loaded for technical inspection and further ‘proof test’.

34 Safe working load (SWL)the SWl for the complete strop assembly, with secondary hook, is 6000 lb.

DAP 101A-1105-1A


35 Technical support literaturefull technical supporting literature for this equipment is published in aP 108G-0002-1b, hUSle Strops. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

STROP USAGE

Consult chapter 2-3 for the general principles applying to strop usage, hook-up, load release etc.

36 Suitability for engagement to current range of helicopter cargo hooksfor details on attachment of the sling to the relevant aircraft SaCrU see Chapter 2-1 paragraph 3, paying particular attention to the WarninG and Caution.

37 SACRU No 1 Mk3, SACRU No 2 Mk1 and Breeze Eastern. the lifting loop of these strops will comfortably engage the load beams of SaCrU’s currently fitted to merlin mk2/3a, Sea King, Puma, Wildcat, lynx, Gazelle and Griffin helicopters. however, subsequent upwards movement or unusual orientation of the strop leg could cause the lifting loop to jam tight onto the widest section of the load beam or ride over the relatively short hook bill of these SaCrU’s and thereafter pull free from the keeper and detach from the SaCrU. Such an occurrence would normally be associated with events prior to engaging a load to the strop secondary hook or before the weight of the load is taken by the extension strop following load engagement.

two likely ways in which this could happen are as follows:

37.1 operations where the strop is pre-engaged to the helicopter cargo hook, with the secondary hook end of the strop held at the cabin door whilst in transit to or from a load, could lead to flexing of the strop leg and movement of the lifting loop in a way to override the bill of the SaCrU, or moving to the rear of the load beam of the SaCrU jamming tight.

37.2 operations where the load is being engaged to the secondary hook of the deployed strop, and vertical flexing of the strop leg occurs, due perhaps to inadvertent loss of height by the helicopter or due to movement with a seaborne load .the same issues of the strop lifting loop overriding the bill of the SaCrU or moving to the rear of the load beam of the SaCrU jamming tight could result.

38 Mandatory usein order to avoid any such risk it is mandatory to use one or the other of the following connection devices as the means of coupling the strop lifting loop to the SaCrU load beam (see figure 26):

38.1 a sling connector (SWl 10000 lb) for attachment to the SaCrU no 2 mk1 (figure 26).

38.2 a large bow shackle (5 tonne SWl) for attachment to the SaCrU no 1 mk3, or a large bow shackle (3 tonne SWl) for attachment to the breeze eastern.

WARNING WHEN OPERATING WITH THE SACRU NO 1 MK3, HOOK-UP PERSONNEL AND CREWMAN SHOULD PAY PARTICULAR ATTENTION TO SHACKLE ATTACHMENT TO THE LOAD BEAM AS AN INCREASED RISK OF ROLL-OUT EXISTS, CHAPTER 2-2-2 REFERS.

DAP 101A-1105-1A


SACRU No 2 Mk1 SACRU No 1 Mk3

SLING

CONNECTOR

LIFTING LOOP OF

16 ft / 80 ft STROP

5 TONNE SWL,

BOW SHACKLE

figure 26 - Using a ‘connector sling’ to connect lifting loop of 16 ft/80 ft strop to SaCrU no 2 mk1 and a 5 tonne SWl, bow shackle to connect lifting loop of 16 ft/80 ft strop to SaCrU no 1 mk3

the sling connector and bow shackle are described in Chapter 2-4-1.

39 Coupling of 16 ft/80 ft stropsthe 16 ft and 80 ft extension strops may be linked together in series to make a longer assembly. this may be conducted on the basis of ‘like with like’ or alternatively by a mix of 16 ft and 80 ft strops, two, three or more in number, within the load suspension/performance limit for helicopter types. the coupling process simply involves engaging the lifting loop of one strop onto the swivel hook of the next strop (one lifting loop per secondary hook), until all strops have been linked. in each case, check that the hook keeper returns to the fully closed position after engagement of the lifting loop (figure 3).

LIKE WITH LIKE LENGTH OR 16 ft STROP WITH

80 ft STROP. NO SET LIMIT ON NUMBER OF

THESE STROPS IN SERIES, PROVIDED WITHIN

INDIVIDUAL HELICOPTER LIMITS.

figure 27 - 16 ft/80 ft strop coupling in series

DAP 101A-1105-1A


the lifting loop of these strops may be connected, in the manner described above, to the swivel hook of the 11300 kg strop, the 5000 kg strop and the 7 ft/30 ft SWr strops, for which there is no limitation on numbers in making up an extended length assembly. the lifting loop is not however, suitable for engagement to the swivel hook of the 11300 kg or 5000 kg strops, although coupling via a 16 mm ‘open and closed masterlink assembly, would be possible.

for detailed rules which apply to strop coupling, mixing of strop types and assessment of SWl, consult chapter 2-3, paragraph’s 13 and 14.

40 Secondary hook engagement and accommodation limitsfigures 28, 29, 30, 31 and 32 provide information on the suitability of different types of sling and net for engagement to the secondary hook of the 16 ft and 80 ft strops. Guidance is also given on the maximum number of equipments/apex devices that may be carried on the secondary hook, unless otherwise specified in individual USlCs.

WARNING IN ALL CASES, THE MAXIMUM AUW OF EQUIPMENT AND LOAD SUSPENDED FROM THIS SECONDARY HOOK IS NOT TO EXCEED 6000 LB OR SUCH LOWER FIGURES AS MAY BE SET FOR THE HELICOPTER CARGO HOOK/HELICOPTER TYPE.

SUITABLE FOR DIRECT ENGAGEMENT TO THE

16 ft / 80 ft STROP SECONDARY HOOK. MAXIMUM

OF TWO SLINGS FOR ACCOMMODATION ON

THIS HOOK, UNLESS SPECIFIED OTHERWISE IN

INDIVIDUAL USLC’s.

figure 28 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 6000 lb SWl

DAP 101A-1105-1A



16 FT/ 80 FT STROP SECONDARY HOOK. AS AN

‘AUTHORISED LOAD’, A MAXIMUM OF TWO NET

STIRRUPS CAN BE ACCOMMODATED ON THIS

HOOK, UNLESS SPECIFIED OTHERWISE IN

INDIVIDUAL USLC’s.

NET - 5000 lb SWL

figure 29 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging nets engaging nets 5000 lb SWl


16 FT/ 80 FT STROP SECONDARY HOOK. ONLY

ONE OF THESE NETS WOULD BE CARRIED FROM

THESE STROPS, UNLESS SPECIFIED OTHERWISE

IN INDIVIDUAL USLC’s. HOWEVER TWO OF THESE

NET STIRRUPS WILL COMFORTABLY ENGAGE THE

SWIVEL HOOK.

NET - 5600 kg SWL

figure 30 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging nets engaging nets 5600 kg SWl

DAP 101A-1105-1A


SML 4600 kg SWL


16 FT/ 80 FT STROP SECONDARY HOOK. A

MAXIMUM OF TWO 4600 KG SLING MASTERLINK

LIFTING RINGS CAN BE ACCOMMODATED ON

THIS HOOK.

figure 31 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 4600 kg SWl

SML 11300 kg SWL


16 FT/ 80 FT STROP SECONDARY HOOK. A

MAXIMUM OF ONE 11300 KG SLING MASTERLINK

LIFTING RING CAN BE ACCOMMODATED ON

THIS HOOK.

figure 32 - accommodation limits for the 16 ft/80 ft strop secondary hook engaging Sml 11300 kg SWl

DAP 101A-1105-1A



INTRODUCTION

the 7 ft and 30 ft Steel Wire rope (SWr) extension strops are available to the 3 Services; the 30 ft strop, in particular, is used both by rn and raf helicopter units. there is no restriction on their use with any of the current british Service helicopter types, within the normal ambit of operating provisions for helicopter type, and subject to suitability for engagement, direct or by connector/coupling means, to the particular type of helicopter cargo hook. full nSn details for the equipment are contained in aP 108G-0002-1b, hUSle Strops.


41 Standard assemblythe 7 ft and 30 ft strops are identical in construction, differing only in length and/or weight. they derive their common usage titles from the respective length of wire rope leg (measured datum points as shown in figure 33. in each case the leg consists of a single length of SWr, each end formed into a loop. the upper loop, which is approximately egg shaped, forms the ‘lifting loop’ for engagement onto a helicopter cargo hook and is formed around a steel thimble. a smaller loop is formed at the bottom of the leg, to enclose a ‘deadeye’ to which is attached a 1500 lb SWl secondary hook with spring loaded keeper.

THIMBLE

STEEL WIRE

ROPE (SWR)

VINYL

SLEEVE

SPRING LOADED

KEEPER

‘DEAD EYE’

16 ft

OR

80 ft

7.5 in.

1.5 in.

figure 33 - 7 ft / 30 ft strops (1500 lb SWl)

42 Vinyl sleevea vinyl sleeve is fitted the length of the strop leg for protective purposes and to make the strop easier to handle. Damage to the sleeve does not render the strop unuseable, and the strop may continue to be used with the sleeve removed completely providing that the strop is serviceable in all other respects. a split sleeve may be taped, a badly torn sleeve should be trimmed back or removed completely.

43 Metal tallya metal tally is attached to the strop leg, identifying the equipment and containing details of the nSn, equipment SWl, equipment serial number and date of ‘proof test’. if this tally is lost, the equipment is to be withdrawn from use immediately and back-loaded for technical inspection and further ‘proof test’.

DAP 101A-1105-1A


44 SAFE WORKING LOADthe SWl for the complete strop assembly, including secondary hook, is 1500 lb.

TECHNICAL SUPPORT LITERATURE

full technical supporting literature for this equipment is published in aP 108G-0002-1b, hUSle Strops. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

STROP USAGE

Consult chapter 2-3 for the general principles applying to strop usage, hook-up, load release etc.


Use with SaCrU no 2 mk1. the lifting loop of these strops will comfortably engage the load beam of the SaCrU, currently fitted to Wildcat, lynx and Gazelle helicopters. however, subsequent upwards movement or unusual orientation of the strop leg could cause the lifting loop to ride over the relatively short hook bill of this SaCrU. Such an occurrence would normally be associated with events prior to engaging a load to the strop secondary hook, or before the weight of the load is taken by the extension strop following load engagement.

two likely ways in which this could happen are as follows:

45.1 operations where the strop is pre-engaged to the helicopter cargo hook, with the secondary hook end of the strop held at the cabin door whilst in transit to or from a load, could lead to flexing of the strop leg and movement of the lifting loop in a way to override the bill of the SaCrU.

45.2 in other circumstances, where the load is being engaged to the secondary hook of the deployed strop, and vertical flexing of the strop leg occurs, due perhaps to inadvertent loss of height by the helicopter or due to movement with a seaborne load, the same situation of the strop lifting loop overriding the bill of the SaCrU could result.

46 Mandatory usein order to avoid any such risk it is manDatory to use a Connector, sling (SWl 10000 lb) as the means of coupling the strop lifting loop to the SaCrU load beam (see figure 34). the sling connector is described in chapter 2-4-1.

SACRU No 2 Mk1

SLING

CONNECTOR

LIFTING LOOP OF

ft / 0 ft STROP7 3

figure 34 - Using a ‘sling connector’ to connect lifting loop of 7 ft/30 ft strop to SaCrU no 2 mk1

DAP 101A-1105-1A


46.1 Use with Chinook cargo hooks. the lifting loop of the 7 ft and 30 ft strop is not large enough however, to engage the Chinook cargo hooks. if these strops have to be employed with Chinook, a 16 mm ‘closed and open masterlink assembly’ would serve as a suitable connector for engagement to a Chinook hook. the strop lifting loop would be engaged onto the bottom of the ‘open’ masterlink. When employed with merlin mk2/3a cargo hook, in full VertreP role, a shackle, 5 tonne SWl, large bow is to be used as means of connecting the strop lifting loopto the SaCrU lifting beam. See Chap 2-3-1 for further details of use of 16 mm masterlink assembly and shackles as connectors.

46.2 Use with talon cargo hook. the lifting loop of these strops is not wide enough to sit comfortably on the talon cargo hook, fitted to the merlin mk3, due to two bevelled edges on the load beam. therefore to minimise damage which may occur to the lifting loop, a 1500 kg SWl bow shackle is suitable to use as a means of coupling the strop lifting loop to the load beam.

47 Coupling of 7 ft/ 30 ft stropsthe 7 ft and 30 ft extension strops may be linked together in series to make a longer assembly. this may be conducted on the basis of ‘like with like’ or alternatively by a mix of 7 ft and 30 ft strops, two, three or more in number, within the load suspension/performance limit for helicopter types. the coupling process simply involves engaging the lifting loop of one strop onto the swivel hook of the next strop (one lifting loop per secondary hook), until all strops have been linked. in each case, check that the hook keeper returns to the fully closed position after engagement of the lifting loop (figure 35).

the lifting loop of these strops may be connected, in the manner described above, to the larger swivel hook of the 16 ft and 80 ft SWr strops. the lifting loop is not suitable for engagement to the swivel hook of the 11300 kg strop or 5000 kg strop, coupling via a 16 mm ‘open and closed masterlink assembly’, is possible.

for detailed rules which apply to strop coupling, mixing of strop types and assessment of SWl, consult chapter 2-3, paragraph 13 and 14.

LIKE WITH LIKE LENGTH OR 7 ft STROP WITH

30 ft STROP. NO SET LIMIT ON NUMBER OF

THESE STROPS IN SERIES, PROVIDED WITHIN

INDIVIDUAL HELICOPTER LIMITS.

figure 35 - 7 ft / 30 ft strops coupling in series

48 Secondary hook engagement and accommodation limitsfigures 36, 37, 38, 39 and 40 provide information on the suitability of different types of sling and net for engagement to the secondary hook of the 7 ft and 30 ft strops. Guidance is also given on the maximum number of equipment’s/apex devices that may be carried on the secondary hook, unless otherwise specified in individual USlCs.

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WARNING IN ALL CASES, THE MAXIMUM AUW OF EQUIPMENT AND LOAD SUSPENDED FROM THIS SECONDARY HOOK IS NOT TO EXCEED 1500 LB OR SUCH LOWER FIGURES AS MAY BE SET FOR THE HELICOPTER CARGO HOOK/ HELICOPTER TYPE.

SML 4600 kg SWL

SUITABLE FOR DIRECT ENGAGEMENT

TO THE 7 FT/ 30 FT STROP SECONDARY

HOOK. A MAXIMUM OF ONE SLING FOR

ACCOMMODATION ON THIS HOOK.

figure 36 - accommodation limits for 7 ft/30 ft strop secondary hook engaging Sml 4600 kg SWl.

SML 6000 lb SWL

SUITABLE FOR DIRECT ENGAGEMENT

TO THE 7 ft / 30 ft STROP SECONDARY

HOOK. MAXIMUM OF ONE SLING FOR

ACCOMMODATION ON THIS HOOK.

figure 37 - accommodation limits for 7 ft/30 ft strop secondary hook engaging Sml 6000 lb SWl

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7 ft / 30 ft STROP SECONDARY HOOK. AS AN

‘AUTHORISED’ LOAD, ONLY ONE NET STIRRUP

CAN BE ACCOMMODATED ON THIS HOOK.

NET - 5000 lb SWL

figure 38 - accommodation limits for 7 ft/30 ft strop secondary hook engaging nets 5000 lb SWl


7 ft / 30 ft STROP SECONDARY HOOK. ONLY

ONE NET STIRRUP TO BE SUSPENDED FROM

THIS HOOK, IN UNLIKELY EVENT OF THIS NET

BEING EMPLOYED WITH THESE STROPS.

NET - 5600 kg SWL

figure 39 - accommodation limits for 7 ft/30 ft strop secondary hook engaging nets 5600 kg SWl

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SML 11300 kg SWL

BOW SHACKLE

1500 kg SWL

16 mm MASTERLINK

ASSEMBLY

figure 40 - accommodation limits for 7 ft/80 ft strop secondary hook engaging Sml 11300 kg SWl

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CONTENTS

CHAPTER 2 - 4: SUPPLEMENTARY SLINGING EQUIPMENT

INTRODUCTION .................................................................................................................................... 721 Supplementary slinging equipment ....................................................................................................722 rule of use as items of slinging equipment ........................................................................................723 Coverage in this publication ...............................................................................................................72ChaPter 2 - 4 - 1: ConneCtorS anD ShaCKleS ..................................................................................73SLING CONNECTOR ............................................................................................................................ 734 introduction.........................................................................................................................................735 equipment description ........................................................................................................................736 Safe Working load (SWl) ..................................................................................................................737 maintenance support literature ...........................................................................................................738 Usage .................................................................................................................................................739 Use with strops, lifting, single leg 1500 lb SWl and 6000 lb SWl .....................................................74SHACKLES ............................................................................................................................................ 7410 Safe Working load (SWl) ..................................................................................................................7411 maintenance support literature ...........................................................................................................75USE OF 16 MM MASTERLINK ASSEMBLY AS FALLBACK CONNECTOR ....................................... 7512 eequipment description ......................................................................................................................7513 Safe Working load (SWl) ..................................................................................................................75

CHAPTER 2 - 4 - 2: EXTENSION CHAIN ASSEMBLY

INTRODUCTION .................................................................................................................................... 76EQUIPMENT DESCRIPTION ................................................................................................................. 7614 Standard assembly.............................................................................................................................7615 Use of shortening clutches .................................................................................................................7616 maintenance support literature ...........................................................................................................7617 engaging the clutch ............................................................................................................................7718 extention chains .................................................................................................................................7919 Criteria when used with sling equipment ............................................................................................8020 Passage of chain through or about an object .....................................................................................8121 Used with Sling multiple leg (Sml) 11300 kg and its variants ...........................................................8122 Used with Sling multiple leg 4600 kg and its variants .......................................................................8223 Used with Sling multiple leg 6000 lb .................................................................................................8224 maximum allowable included angle of chain loop at closure of chain loop/chain assemblies ...........8325 an independent chain loop .................................................................................................................8326 taping clutches and loose chain ........................................................................................................84

CHAPTER 2 - 4 - 3: BV206 TRANSMISSION COUPLING LIFTING FRAME

INTRODUCTION .................................................................................................................................... 85EQUIPMENT DESCRIPTION ............................................................................................................... 8527 the bV206 .........................................................................................................................................8528 frame identification labels..................................................................................................................8529 frame classification............................................................................................................................8630 life expiry of equipment .....................................................................................................................8631 maintenance support literature ...........................................................................................................8632 equipment usage ...............................................................................................................................86

CHAPTER 2 - 4 - 4: WEAK LINK ASSEMBLY (6300 KG SWL)

INTRODUCTION .................................................................................................................................... 87EQUIPMENT DESCRIPTION ................................................................................................................. 8733 the weak link assemly .......................................................................................................................8734 assembly identification .......................................................................................................................87

CHAPTER 2 - 4

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35 Safe Working load (SWl) ..................................................................................................................8736 life expiry of assembly .......................................................................................................................8737 maintenance support literature ...........................................................................................................8838 assembly usage .................................................................................................................................88

CHAPTER 2 - 4 - 5: CHAIN CLAMP

INTRODUCTION .................................................................................................................................... 89EQUIPMENT DESCRIPTION ................................................................................................................. 8939 Standard assembly ............................................................................................................................8940 Clamp identification ............................................................................................................................8941 Clamp SWl ........................................................................................................................................8942 life expiry of equipment .....................................................................................................................8943 maintenance support literature ...........................................................................................................9044 equipment usage ...............................................................................................................................90

CHAPTER 2 - 4 - 6: SPREADER BARS

INTRODUCTION .................................................................................................................................... 91EQUIPMENT DESCRIPTION ................................................................................................................. 9145 Standard assembly.............................................................................................................................9146 end fitting ...........................................................................................................................................9147 Strut tubes ..........................................................................................................................................9248 Spreader bar identification .................................................................................................................9249 Spreader bar use................................................................................................................................9250 Spreader bar limitations .....................................................................................................................9251 life expiry of equipment .....................................................................................................................9352 maintenance support literature ...........................................................................................................9353 equipment usage ...............................................................................................................................93

CHAPTER 2 - 4 - 7: ADJUSTABLE SPREADER BARS (JADTEU USE ONLY)

INTRODUCTION .................................................................................................................................... 94EQUIPMENT DESCRIPTION ................................................................................................................. 9454 Standard assembly.............................................................................................................................9455 end fitting ...........................................................................................................................................9456 Strut tubes ..........................................................................................................................................9557 Spreader bar identification .................................................................................................................9558 Spreader bar use................................................................................................................................9559 limitations ..........................................................................................................................................9660 life expiry of equipment .....................................................................................................................9661 maintenace support literature .............................................................................................................9662 equipment usage ...............................................................................................................................96

figures

figure 41 - Sling connector .............................................................................................................................73figure 42 - Sling connector engaging lifting loop of 1500 lb SWl, and 6000 lb SWl extension strop to SaCrU no 2 mk1 ..................................................................................74figure 43 - Shackle:; bow shackle (left) and ‘D’ shackle (right) ......................................................................75figure 44 - open and closed masterlink assembly .........................................................................................75figure 45 - extension Chain assembly............................................................................................................76figure 46 - Chain locking lever ........................................................................................................................77figure 47 - engaging clutch to form a chain loop - correct method .................................................................78figure 48 - engaging clutch to form a chain loop - incorrect method ..............................................................79figure 49 - Correct method of engaging clutch ...............................................................................................80figure 50 - incorrect method of engaging clutch .............................................................................................80fig 51 - example taken from USlC 5324 ........................................................................................................81figure 52 - Chains used with 11300 kg sling ...................................................................................................82

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figure 53 - Chains used with 4600 kg sling.....................................................................................................82figure 54 - Chains used with 6000 lb sling......................................................................................................83figure 55 - maximum included angle of chain loop at closure of chain loop/chain assemblies ......................83figure 56 - extension chain used as independent chain loop .........................................................................84figure 57 - bV206 transmission coupling lifting frame ....................................................................................85figure 58 - Positioned bV206 transmission coupling lifting frame ..................................................................86figure 59 - Weak link assembly ......................................................................................................................87figure 60 - Chain clamp ..................................................................................................................................89figure 61 - Positioned chain clamp .................................................................................................................90figure 62 - Spreader bar .................................................................................................................................91figure 63 - Sling leg chain engaged into end-fitting ........................................................................................92figure 64 - Chain angle limits ..........................................................................................................................93figure 65 - djustable spreader bars.................................................................................................................94figure 66 - Sling leg chain engaged into end-fitting ........................................................................................95figure 67 - Chain angle limits ..........................................................................................................................96

DAP 101A-1105-1A


CHAPTER 2 - 4: SUPPLEMENTARY SLINGING EQUIPMENT

INTRODUCTION

to achieve the suspension of a load under a helicopter, it is often necessary to call upon supplementary items of slinging equipment, ie items in addition to the basic sling, cargo lifting net or extension strop equipment to be employed.

1 Supplementary slinging equipmentthese items generally serve the following purposes:

1.1 they provide the basic means or, in some cases, more secure retention of primary equipment at equipment attachment/engagement points, starting at the load itself and terminating at the helicopter cargo hook. thus shackles are often specified to provide a means of connecting the sling legs to load lifting points. Shackles or special connector devices may also be necessary for connection of slinging equipment to the helicopter cargo hook, and on occasion to extension strop secondary hooks.

1.2 in the case of extension chains, they provide the means of extending, when necessary, the leg length of general purpose wire rope or textile and chain leg slings. they also serve as ‘risers’/connectors from cargo net lifting stirrups to extension strop secondary hooks, used specifically if cargo nets are being carried in large clusters. it should be noted that chains are never to be engaged directly onto the load beam of a helicopter cargo hook (Chapter 2-2 refers).

occasionally a special role item may be introduced.

2 Rule of use as items of slinging equipmentmost items of supplementary slinging equipment are designed for use as items of load lifting equipment and are classified by their Safe Working load (SWl). Where equipment bears a manufacturer’s classification based on the items ultimate strength (ie the load or force under which the item can be expected to fail (breaking load)) then the Service(s) will specify the SWl for the item, when used as helicopter slinging equipment. this is discussed more fully in Chapter 1-2.

3 Coverage in this publicationChapters 2-4-1 and 2-4-2 describe supplementary slinging items which are commonly called into use for helicopter slinging operations and which are not necessarily restricted to use with one specific item of primary slinging equipment. items such as chain extension legs which are provisioned for use with specific equipment (eg extension legs for the heavy duty and medium duty slings) are described under the particular chapter for that equipment. occasionally USlCs will call up supplementary items of lifting equipment which are not covered by this publication, in which case all necessary information on the use of the item will be contained in the particular USlC.

DAP 101A-1105-1A


CHAPTER 2 - 4 - 1: CONNECTORS AND SHACKLES

SLING CONNECTOR

4 IntroductionCommonly known as the ‘sling connector’, this item provides a secure means of connection to the SaCrU no 2 mk1 cargo hook, fitted to the lynx, Wildcat and Gazelle helicopters, for a 1500 lb SWl or 6000 lb SWl extension strop. full nSn details for the equipment are contained in aP 108G-0002-1D, hUSle ancillary equipment.

5 Equipment descriptionthe sling connector (figure 41) consists of two parallel plates connected at the flat edged end by a welded pin. at the other end a detachable link pin, with spacer fitted, is locked in position by a sliding plate and locking plunger.

6 Safe Working Load (SWL)the SWl of the sling connector is 10000 lb, but is to conform to any lower figure as dictated by the equipment with which it is being employed which includes the helicopter cargo hook.

FIXED PIN MUST BE

AT TOP ON BEAM

LINK PIN

LOCKING

PLUNGER

SPACER

FLAT END AT TOP

OF SLIDE PLATES

LOCK PLATE

DEPRESS LOCKING PLUNGER

AND SLIDE LOCK PLATE UPWARD

TO REMOVE LINK PIN SPACER

figure 41 - Sling connector

7 Maintenance support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D: hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

8 Usagethe sling connector is too small to engage the Chinook cargo hooks, and is not suitable or intended for engagement to any existing extension strop secondary hooks.

to connect a strop to the sling connector (see figure 41), and subsequently the connector to load beams of specified helicopter hook, proceed as follows:

8.1 Depress the locking plunger and slide the lock plate over the plunger so that the link pin is free. remove the link pin and collect the spacer.

8.2 insert the eye of the strop between the side plates so that the link pin and its spacer can be inserted through the eye to close the open end of the connector.

8.3 insert the link pin with its spacer and slide the lock plate down to engage in the groove in the end of the link pin. ensure that the locking plunger is engaged in the hole formed in the lock plate.

DAP 101A-1105-1A


8.4 on hook up, place the sling connector over the beam, as shown in figure 42, so that its integral fixed pin rests on the beam and the strop hangs from the link pin. When engaging onto a SaCrU type load beam, ensure that the spring loaded keeper returns to the fully closed position having completed engagement.

figure 42 - Sling connector engaging lifting loop of 1500 lb SWl, and 6000 lb SWl extension strop to SaCrU no 2 mk1

9 Use with strops, lifting, single leg 1500 lb SWL and 6000 lb SWLthe sling connector provides a secure means of engagement for 1500 lb SWl and 6000 lb SWl extension strops, when they are being used with the SaCrU no 2 mk1 primary hook, fitted to lynx, Wildcat and Gazelle helicopters. Use of the connector overcomes the risk of the strop lifting loop inadvertently overriding the bill of the relatively short nosed load beam on this SaCrU. the lifting loop of the strop is engaged onto the sling connector as explained by the procedures set out in paragraph 8, which should be followed fully. for a more detailed background consult the individual strop chapters.

SHACKLES

Shackles are the most commonly called up items of supplementary slinging equipment. each shackle bears a unique serial number, on both body and pin, in permanent (stamped) characters. the body additionally carries the nSn, SWl and the legend ‘hUSle USe only’. there are two shapes of shackle commonly manufactured as shown in figure 43.

WARNING SHACKLE PINS ARE TO BE TIGHTENED BY HAND SUFFICIENTLY TO PREVENT THE PIN FROM BECOMING LOOSE DURING USE.

10 Safe Working Load (SWL)Shackles are used in various instances as a suitable interface for connecting specified equipments to helicopter cargo hooks or extension strop secondary hooks where the equipments, for one reason or another, are not suitable for direct engagement.

DAP 101A-1105-1A


the SWl of a shackle is to conform to any lower figure, as dictated by the equipment with which it is being employed, which includes the helicopter cargo hook or extension strop secondary hook.

BOW SHACKLE ‘D’ SHACKLE

figure 43 - Shackle:; bow shackle (left) and ‘D’ shackle (right)


USE OF 16 MM MASTERLINK ASSEMBLY AS FALLBACK CONNECTOR

12 Eequipment descriptionthe 16 mm ‘open and closed masterlink assembly’ (figure 44) is provisioned as part of the 4600 kg sling (Chapter 2-5-3) and 5000 kg strop (Chapter 2-3-2). however, it is compatible for engagement to the secondary hooks of all current british Service helicopter extension strops.

13 Safe Working Load (SWL)Used as a connector, the SWl of the 16 mm masterlink assembly is 7000 kg. however, it is to conform to any lower figure as dictated by the equipment with which it is being employed, which includes the helicopter cargo hook or extension strop secondary hook.

figure 44 - open and closed masterlink assembly

DAP 101A-1105-1A


CHAPTER 2 - 4 - 2: EXTENSION CHAIN ASSEMBLY

INTRODUCTION

heavy Duty (hD) and medium Duty (mD) extension chain assemblies are primarily supporting items of helicopter equipment used for extending sling leg lengths of the various helicopter slings, within the load path. alternatively the mD chains may be used as restraint equipment; refer to chapter 2-8-1 for USl restraint. full nSn details and nomenclature for the equipment’s are contained in aP 108G-0002-1D, hUSle ancillary equipment.


14 Standard assemblythe extension chain assembly consists of a welded link chain fitted with a shortening clutch at one or both ends. the chain link size is identical to that used on the fixed chain legs of the mD, hD and 6000 lb slings. the mD extension chains, available in 2 m and 4.5 m lengths, are fitted with a 7 mm clutch(es) and may be used to extend the sling legs of the mD sling, its variants and the 6000 lb sling. the hD extension chain, available in a 2 m length, is fitted with 10 mm clutch(es) and used to extend the sling legs of the hD sling, its variants and the redundant sling.

WARNING WHEN USED AS HELICOPTER SLINGING EQUIPMENT, EXTENSION CHAINS MUST ALWAYS BE USED IN ACCORDANCE WITH ITS STATED SWL. WHEN USED AS RESTRAINT EQUIPMENT AND USING THE 10000 LB QUICK RELEASE COUPLING (QRC), THE CHAINS ARE TO BE RATED AT 10000 LB MINIMUM ULTIMATE STRENGTH

CHAIN CLUTCH

figure 45 - extension Chain assembly

15 Use of shortening clutchesthe shortening clutch provides the means of engaging the chain back on itself to form a closed loop around a lifting point, or for engaging onto another chain of the same type and classification, for the purpose of extending sling leg lengths or for belly-banding. the clutch incorporates a chain locking lever (figure 46): should a locking lever become unserviceable the chain is to be declared unfit for use until the locking lever or entire clutch is replaced by a qualified hlSei. Correct and incorrect ways of engaging the clutch are shown in figures 47 and 48


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CHAIN POCKET OF

CLUTCH CLAW HOUSES

ENGAGED LINK

CHAIN LOCKING LEVER,

PIVOT PIN AND TORSION

SPRING.

LOCKING LEVER SHOWN

SPRING LOADED TO

CLOSED POSITION

CAM ON CHAIN LOCKING LEVER

ABUTS AGAINST LINK ANDA

PREVENTS THE CLUTCH FROM

DISENGAGING FROM ENGAGED LINK B

LINK A

LINK B

CHAIN LOCKING LEVER

(THUMBED OPEN AGAINST SPRING)

FOR CLUTCH ENGAGEMENT OR

DISENGAGEMENT

figure 46 - Chain locking lever

17 Engaging the clutchWhen forming a chain loop, the USlC will either call for a loop of so many links (e.g. a 25 link loop; which means the clutch is to be engaged on the 25th link as counted from the fixed end of the clutch), or alternatively that the clutch is to be engaged on a specified link as counted from the textile sling leg attachment point (e.g. engage the clutch on the 10th link from the sling leg attachment point). figures 47 and 48 show the correct and incorrect methods of clutch engagement respectively.

DAP 101A-1105-1A


WARNING HAVING ENGAGED THE CLUTCH ALWAYS PULL THE CHAIN TAUT TO ENSURE THAT THE CLUTCH HAS BEEN ENGAGED IN THE CORRECT MANNER (FIGURE 47) AND NOT IN THE INCORRECT MANNER (FIGURE 48). FINALLY CHECK VISUALLY OR BY FEEL THAT THE CHAIN LOCKING LEVER IS FULLY CLOSED ON THE CLUTCH.

DIRECTION OF PULL

PRE-SELECTED CHAINLINK

ENGAGED IN THE CHAIN POCKET

OF THE CLUTCH CLAWCLUTCH BODY ADOPTS

THE NATURAL LINE OF

THE CHAIN LOOP

MAXIMUM ALLOWABLE ANGLE

INCLUDING ANGLE OF CHAIN

LOOP, WITH CHAIN IN TENSION

IS 120 DEGREES

CHAIN POCKET FACES

INTO THE CHAIN LOOP

120 MAX0

BELLY OF CLUTCH

FACES TO THE INSIDE

OF THE CHAIN LOOP

figure 47 - engaging clutch to form a chain loop - correct method

WARNING LIFTING WHEN THE CLUTCH HAS BEEN ENGAGED IN THE INCORRECT MANNER AS SHOWN IN FIGURE 48 CAN CAUSE PREMATURE FAILURE OF THE CLUTCH.

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DIRECTION OF PULLBELLY OF CLUTCH

FACES TO THE SIDEOUT

OF THE CHAIN LOOP

CHAIN ‘DOG-LEGGED’

THROUGH CLUTCH CLAW

WHEN TAUT, THE FORCE

APPLIED THROUGH THE

ENGAGED LINK WILL TRY

TO PRISE OPEN THE

CLUTCH CLAW

figure 48 - engaging clutch to form a chain loop - incorrect method

18 Extention chainsindividual USlCs will outline in detail the form that the specific chain to chain connection is to take; requirement to do this is generally confined to USlCs which call for the use of extension chain assemblies. occasionally a USlC may call for one chain leg of a sling to be directly connected to a partner chain leg of the sling, for the purposes of forming a continuous loop under the load, e.g. the bellyband technique.

Primarily the extension chains are used to extend the sling leg length. however, specific USlCs may require the chains to be used as lifting loops, typically as riser/connectors for engaging cargo lifting net stirrups to an extension strop secondary hook for a large number of net cluster loads, using one looped chain per net.

When forming chain loops, count each link from the datum point given when engaging the chain clutch onto the pre-selected chain link of the chain that is to be engaged.

figures 49 and 50 show the correct and incorrect methods of engaging a clutch to a connection chain of the same type and classification.

CAUTION Having engaged the clutch always pull the chain taut to ensure the clutch has been engaged in the correct manner.

WARNING LIFTING WHEN THE CLUTCH HAS BEEN ENGAGED IN THE INCORRECT MANNER AS SHOWN IN FIGURE 50 CAN CAUSE PREMATURE FAILURE OF THE CLUTCH.

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EXTENSION CHAIN

THE PULL THE ENGAGED CHAINFROM

IS TAKEN THROUGH THE NOSE OF THE

D ,ENGAGE CLUTCH AND TAKES A

SYMMETRICAL LINE WITH THE BODY

OF THE CLUTCH.

PARENT CHAIN

ENGAGED CLUTCHENGAGED CHAIN

NON-ENGAGED

CLUTCH

figure 49 - Correct method of engaging clutch

THE PULL THE ENGAGEDFROM CHAIN

WILL TRY TO PRIZE OPEN THE CLUTCH CLAW

ND LIKE THE INCORRECTA EXAMPLE WITH THE

CHAIN LOOP THE DOG LEG EFFECT IS THERE.

ENGAGED CLUTCH ENGAGED CHAIN

figure 50 - incorrect method of engaging clutch

extension chains feature in many USlC’s and where the use of a particular length of chain is stipulated but not available it may be substituted using the other chain length i.e. 2 m/4.5 m (mD): but only for mD chains.

When a substitute is being used the distance between the sling leg attachment point and the clutch of the extension chain, which is attached to the lift point, must not be altered. the difference in weight must be taken into account when calculating the aUW.

to carry out a substitution the number of links per extension chain length are: 2 m (mD) is 94 links, and 4.5 m (mD) is 210 links.

Substitution example: to substitute the front 2 m chains of USlC 5324 (figure 51), with 4.5 m chains, proceed as follows:

18.1 Calculate the in use length of chain ie 94 links (total linkage of 2 m chain) minus 4 links (unused chain from free end) = 90 links (in use chain from clutch end)

18.2 Using the substitute 4.5 m extension chain form 40 link loops around the front lifting bracket. attach the sling leg clutch to the 90th link from the extension chain clutch end.

18.3 tape up all excess chain.

DAP 101A-1105-1A


19 Criteria when used with sling equipmentthe safe working load (SWl):

19.1 When used as sling chain(s)

19.1.1 independent of sling (acting along the line of the chain, at a factor of safety of 4.3 to 1) 2 m/4.5 m (mD) = SWl 1500 kg 2 m (hD) = SWl 3117.5 kg

19.2 as extension legs for specified slings.

19.2.1 SWl is in accordance with the single leg rating for the particular sling, operating up to the maximum leg angle from vertical as specified for the sling.

ENGAGE SLING LEG CLUTCH

ON 90th LINK FROM EXTENSION

CHAIN CLUTCH END

FRONT SLING CHAINS

40 LINK LOOPS AROUND

SPRING HANGER BRACKETS

fig 51 - example taken from USlC 5324

20 Passage of chain through or about an objectin all cases the following criteria applies when looping the extension chains through lifting points or around the load. the chain is not to be looped around:

20.1 a 2 m/4.5 m (mD) extension chain:

20.1.1 Circular sections of less than 13 mm diameter.

20.1.2 angular or flat sections with square or rounded edges whose thickness of section is less than 13 mm.

20.2 a 2 m (hD) extension chain:

20.2.1 Circular sections of less than 25 mm diameter.

20.2.2 angular or flat sections with square or rounded edges whose thickness of section is less than 25 mm.

21 Used with Sling Multiple Leg (SML) 11300 kg and its variantsWhen used with the Sml 11300 kg SWl and its variants, the SWl of the 2 m (hD) extension chain is to conform with the single leg rating for the sling i.e. 2825 kg applying to all angles from the vertical up to a

DAP 101A-1105-1A


maximum leg angle of 25° from the vertical and 2387 kg applying to all angles from the vertical up to a maximum leg angle of 40° from the vertical (figure 52). Chap 2-5-1 also refers.

SWL

SINGLE LEG MAX

ALLOWABLE LEG ANGLE

FROM VERTICALSINGLE LEG

VERTICAL

SWL

25°/40°

2825/2 87 kg3

2825/2 87 kg3

figure 52 - Chains used with 11300 kg sling

22 Used with Sling Multiple Leg 4600 kg and its variantsWhen used with the Sml 4600 kg SWl and its variants, the SWl of the 2 m/4.5 m (mD) extension chain is to conform with the single leg rating for the sling ie 1150 kg applying to all angles from the vertical up to a maximum leg angle of 40° (figure 53). Chap 2-5-3 also refers.

SWL

SINGLE LEG MAX

ALLOWABLE LEG ANGLE

FROM VERTICAL

SINGLE LEG

VERTICAL

SWL

40°

1150 kg

1150 kg

figure 53 - Chains used with 4600 kg sling

23 Used with Sling Multiple Leg 6000 lbWhen used with the Sml 6000 lb SWl, the SWl of the 2 m/4.5 m (mD) extension chain is to conform with the single leg rating for the sling ie 1500 lb applying to all angles from the vertical up to a maximum leg angle of 50° (figure 54). Chapter 2-5-4 also refers.

DAP 101A-1105-1A


SWL

SINGLE LEG MAX

ALLOWABLE LEG ANGLE

FROM VERTICALSINGLE LEG

VERTICAL

SWL

50°

1500 lb

1500 lb

figure 54 - Chains used with 6000 lb sling

24 Maximum allowable included angle of chain loop at closure of chain loop/chain assembliesWhen a loop is formed at the terminal end of a single or interconnected series of extension chains, the maximum allowable included angle of the chain loop at the point of connection of the chain clutch is 120° (figure 55).

LOAD

SWL IN ACCORDANCE WITH SINGLE LEG

RATING FOR SLING, OPERATING UP TO

MAXIMUM ALLOWABLE SLING LEG ANGLE

120°

LOAD

120°

MAXIMUM ALLOWABLE INCLUDED ANGLE

AT CLOSURE OF CHAIN LOOP CHAIN

ASSEMBLIES

figure 55 - maximum included angle of chain loop at closure of chain loop/chain assemblies

25 An independent chain loopWhen the chain is engaged back onto itself to form an independent loop ie engaged at the bottom of the loop to an equipment lifting ring, and at the top of the loop engaged over an extension strop secondary hook, the SWl of the independent loop is theoretically doubled i.e. 2 m (hD) extension chain SWl = 6235 kg and 2 m/4.5 m (mD) extension chain SWl = 3000 kg.

DAP 101A-1105-1A


note in practice allowance has to be made for additional stress on the links at the top and bottom ends of the chain loop, and the SWl for the chain loop is reduced to 70% of the theoretical, i.e. 2 m (hD) extension chain SWl = 4364.5 kg and 2 m/4.5 m (mD) extension chain SWl = 2100 kg (see figure 55).

STROP SECONDARY HOOK

CHAIN ASSEMBLY SINGLE LEG

SWL OF INDEPENDENT CHAIN LOOP

MD (1500 kg x 2) REDUCED TO 70% = 2100 kg

HD (3117.5 kg x 2) REDUCED TO 70% = 4364.5 kg

figure 56 - extension chain used as independent chain loop

26 Taping clutches and loose chainthe claws of an engaged clutch does not require taping, however to prevent inadvertent snagging on the load or with other parts of slinging equipment, non-engaged claws are to be taped, facing out, to indicate they are not in use. Similarly, all loose chain is to be taped to prevent snagging or possible flailing in flight. for further instructions and illustrations refer to Chapter 3.

DAP 101A-1105-1A


CHAPTER 2 - 4 - 3: BV206 TRANSMISSION COUPLING LIFTING FRAME

INTRODUCTION

the bV206 transmission lifting frame is a special item designed to be used with the Sling multiple leg (Sml) 11300 kg SWl, for the carriage of one hägglund bV206 articulated utility vehicle only. full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1D: hUSle ancillary equipment.

WARNING THE EQUIPMENT IS NOT TO BE USED FOR ANY PURPOSE OTHER THAN THAT SPECIFIED IN THIS CHAPTER.


27 The BV206the lifting frame (figure 57) consists of twin channel-section transverse link assemblies connected between two lifting yokes. the upper link is cushioned on its lower surface by nitrile rubber sheeting. the lower link is inverted, closed to a box section by a steel web welded between the flanges, and padded on its upper surface by a block of plywood shaped to fit the transmission coupling torsion member.

each lifting yoke is formed by two side plates joined at the top by a special shoulder bolt. the inner pair of sling legs are connected to these bolts between the two vehicle units, providing central support while the outer sling legs connect to the fore/aft ends of the combination using multiple extension chains. the lifting frame is finished in yellow paint indicating that it must be removed prior to operating the vehicle.

figure 57 - bV206 transmission coupling lifting frame

28 Frame identification labelsthe lifting frame has a manufacturer’s plate screwed to the reverse flange of the top link; which gives the equipment Part no, issue, Description, Serial no, SWl and Proof load.

DAP 101A-1105-1A


29 Frame classificationthe lifting frame has a fixed geometrical configuration, and a definitive load rating of SWl 4000 kg at the specified loading point.

30 Life expiry of equipmentthe lifting frame is not a ‘lifed’ item. the various items of padding are to be maintained in a good condition, and the manufacturer’s plate and all painted markings must remain legible at all times.

31 Maintenance support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D: hUSle ancillary equipment . Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

32 Equipment usagethe lifting frame is of fixed geometry. it is fitted by lowering the frame onto the transmission coupling with the bottom link removed. the link is refitted and the centre extension chains/clutches of the sling assembly are fed through the frame legs and around the lifting pins (figure 58).

figure 58 - Positioned bV206 transmission coupling lifting frame

WARNING WHEN REMOVING/REFITTING THE LINK SECURING PINS FOR INSTALLATION OF THE FRAME, OR WHEN REPLACING DEFECTIVE PINS DURING MAINTENANCE/REPAIR, THE UPPER PIN MUST NOT BE SUBSTITUTED FOR THE LOWER PIN, NOR MUST UNDERSIZE/ UNDERSTRENGTH REPLACEMENTS BE FITTED IN EITHER LINK.

DAP 101A-1105-1A


CHAPTER 2 - 4 - 4: WEAK LINK ASSEMBLY (6300 KG SWL)

INTRODUCTION

the 6300 kg weak link assembly was designed for tandem hook operations long Stropping (tholS) with the Chinook helicopter without the need for redundant rigging (Chapter 2-2-4 refers). full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1D: hUSle ancillary equipment.

WEAK LINK BODY

WEAK LINK BODY

COLLAR

SHEAR PIN

figure 59 - Weak link assembly


33 The weak link assemlythe weak link assembly (figure 59) has a specified breaking load and is attached to the fore and aft cargo hooks of the helicopters. in the event of a failure in the fore or aft cargo hooks/slinging equipment, the weak link in the remaining assembly will shear, protecting the aircraft structure from the excessive forces generated by the suspended load.

the assembly consists of two weak link bodies secured together by a shear pin and collar; attached to the outer end of one weak link body is a hoist hook and attached to the outer end of the other weak link body is a closed masterlink.

34 Assembly identificationthe weak link bodies are painted a distinctive red colour for identification.

35 Safe Working Load (SWL)the SWl for the weak link assembly is 6300 kg, based on 60% of the 10500 kg tandem hook maximum payload (chapter 2-2-4).

36 Life expiry of assemblythe weak link assembly has an indefinite life with the exception of the shear pin, the policy for which is laid down in the maintenance support literature for the equipment.

DAP 101A-1105-1A


37 Maintenance support literaturefull maintenance support literature is published in aP 108G-0002-1D: hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

38 Assembly usagethe assembly usage is only for tholS. in addition to the weak link assembly, the range of equipment that may be used for load suspension is as follows:

masterlink and swivel hook assembly, 11300 kg SWl 2.7 m or 5.7 m, h/D strop, 11300 kg SWl 5 m, soft eye strop, 5000 kg SWl Sml, 5650 kg SWl Soft eye Sml, 5438 kg SWl (rib bow and stern) 2 m, h/D extension chain

in the event of a Sml (SWl) 5650 kg being unavailable, an Sml (SWl) 11300 kg or Sml (SWl) 8475 kg may be used in lieu ensuring the rules for securing not in use legs are adhered to (chapter 3 refers).

DAP 101A-1105-1A


CHAPTER 2 - 4 - 5: CHAIN CLAMP

INTRODUCTION

the chain clamp is a special item primarily designed to be used, with Slings multiple leg (Sml) 4600 kg and 6000 lb, for the carriage of the 105 mm light gun. however, the clamp may also be used for similar applications providing the limitations in para 4 are not exceeded. full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1D: hUSle ancillary equipment.

figure 60 - Chain clamp

WARNING THE EQUIPMENT IS NOT TO BE USED FOR ANY PURPOSE OTHER THAN THAT SPECIFIED IN THIS CHAPTER.


39 Standard Assemblythe chain clamp (figure 60) consists of two identical steel links joined head-to-tail: one end is secured by a clevis pin that acts as the hinge; the corresponding position at the other end is occupied by a quick-release drop-nose pin. a sheathed steel wire lanyard attaches the quick-release pin to one of the links.

When closed, the clamp forms an elongated ring with a 9 mm central slot, which locks together two runs of chain by trapping adjacent in-line links. the clamp is used to retain the chain in a close loop around each wheel hub, to prevent disengagement when slack. the chain clamp will function only with chain of 7.1 mm wire diameter, as used on Sml 4600 kg and 6000 lb, and their respective extension chains. the chain clamp is finished in yellow paint indicating that it must be removed prior to disengaging the lifting equipment.

40 Clamp identificationthe clamp carries the same markings on both links; each upper face is marked the part number, serial number and nSn of the complete assembly, and each lengthwise outer edge is marked hUSle USe only. the equipment SWl is not marked as the capacity of the clamp, when used in accordance with paragraph 41, exceeds that of one Sml 4600 kg or 6000 lb sling leg.

41 Clamp SWLthe chain clamp is designed to be used with 7.1 mm chain, rated at 1500 kg SWl for the Sml 4600 kg and 1059 kg SWl for the Sml 6000 lb.

the following limitations apply: included angle of chain above clamp 0º (chain parallel) included angle of chain below clamp 90º max

42 Life expiry of equipmentthe chain clamp is not a ‘lifed’ item. all parts are to be maintained in a good condition, and all markings are to remain legible at all times.

DAP 101A-1105-1A


43 Maintenance support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D, hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

44 Equipment usagethe chain clamp is fitted after the chain loop has been formed around the wheel hub. the loop must be free of twists and snags, and held firmly in position to ensure that it will contain the correct number of links (as defined in the relevant USlC published in DaP 101a-1105-1b) when the clamp is in position. one link of the open clamp is then passed behind the two runs of chain, which must be necked together and held in alignment as the clamp is closed around the appropriate pair of chain links. the quick-release pin is then re-fitted to lock the clamp (figure 61). the clamp is removed by reversing the fitting procedures described above.

figure 61 - Positioned chain clamp

DAP 101A-1105-1A


CHAPTER 2 - 4 - 6: SPREADER BARS

INTRODUCTION

there are two categories of spreader bars that are available, medium Duty (mD) or heavy Duty (hD). the purpose of the spreader bars is to hold apart sling leg or extension chains that would otherwise foul or damage part of an Underslung load (USl). full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1D, hUSle ancillary equipment.


45 Standard assemblythe spreader bar (figure 62) consists of a strut tube with two identical end-fittings; mD and hD spreader bars are identical in their method of construction; the only difference is the physical size of the components and the range of available lengths.

figure 62 - Spreader bar

46 End fittingthe end-fitting plugs into the end of the strut tube with a close but free fit so compression is transmitted uniformly around the abutment flange. alignment of each end-fitting, and retention to the strut tube, is provided by a single capscrew. When positioned, the screw is recessed into a hole in the tube wall, such that its head acts as a locating spigot. a small clearance around the screw head ensures that it takes no load in normal operation. the sling leg or extension chains are located in specially-shaped pockets in the end-fittings and retained by quick-release pins (figure 63).

the pins are of the drop-nose type and are attached to the end-fitting by a steel wire lanyard. the chain is positioned such that the link to be captured lies flat against the loadbearing face of the end-fitting, between the lugs. the pin cannot be passed through the lugs of the end-fitting unless the chain is fully and correctly seated. Clearance channels are provided for the adjacent chain links; each channel allows for the maximum permitted chain angle, so that the assembled spreader bar can be used either way up.

DAP 101A-1105-1A


figure 63 - Sling leg chain engaged into end-fitting

47 Strut tubesthe mD and hD spreader bars use 3 in. and 4 in. oD tubing respectively. Strut tube length varies in 50 mm increments to give the following range of spreader bar effective lengths: mD spreader bar - 1.00 m - 2.90 m hD spreader bar - 1.20 m - 3.40 m

each complete assembly can be identified by its own nSn. the required assembly size and nSn for given loads can be found on the relevant USlCs published in DaP 101a-1105-1b.

48 Spreader bar identificationthe complete spreader assemblies are painted nato green. each assembly carries an identification (iD) plate at one end of the tube. the iD plate carries the manufacturer’s code, contract number, part number, serial number, the nSn of the assembly and the legend hUSle USe only. the equipment SWl is not stated as the capacity of the spreader bar, when used in accordance with figure 64 and paragraph 52, exceeds that of one pair of sling legs of the relevant type.

49 Spreader bar useWARNING

THE EQUIPMENT IS NOT TO BE USED FOR ANY PURPOSE OTHER THAN THAT SPECIFIED IN THIS CHAPTER.

the spreader bars have been designed to be used with the following Slings multiple leg (Sml):

49.1 mD spreader bar - used with Sml 4600 kg, 3450 kg, 2300 kg and 6000 lb

49.2 hD spreader bar - used with Sml 11300 kg, 8475 kg, 5650 kg and redundant

50 Spreader bar limitationsfigure 64 illustrates the following limitations.

50.1 angle of chain above spreader bar mD with Sml 4600 kg, 3450 kg and 2300 kg - 40° in from vertical (80° apex) mD with Sml 6000 lb - 50° in from vertical (100° apex) hD with Sml 11300 kg, 8475 kg, 5650 kg and redundant) - 25° in from vertical (50° apex)

50.2 angle of chain below spreader bar all Sml’s - 10° in from vertical

DAP 101A-1105-1A


40°/50° MAX (MD)

25° MAX (HD)

10° MAX

80°/100° MAX (MD)

50° MAX (HD)

figure 64 - Chain angle limits

51 Life expiry of equipmentthe spreader bar is not a ‘lifed’ item. all parts are to be maintained in a good condition, and all markings are to remain legible at all times.

52 Maintenance support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D, hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

53 Equipment usageWith the quick-release pins removed, the spreader bar is fitted between the appropriate chain links of the two adjacent legs (as defined in the relevant USlC), ensuring that there are no twists. the pins are then re-fitted to lock the bar in position. the spreader bar is removed by reversing the fitting procedures described above.

apart from detail contained in USlCs, a generalisation for the usage of both mD and hD spreader bars in differing modes of operation is as follows:

53.1 Sho. mD and hD spreader bars may be used with the Smls described in para 49 and subject to the chain angle limitations described in paragraph 50. the spreader bars may be attached either laterally or longitudinally between chain legs.

53.2 tholS. hD spreader bars are only to be used with Smls described in paragraph 49.2 (less redundant) and subject to the chain angle limitations described in paragraph 50. the spreader bars are to be attached laterally only.

53.3 thorr. hD spreader bars are only to be used with Sml 5650 kg and redundant described in para 49.2 and subject to the chain angle limitations described in para 50. Spreader bars used with the primary and redundant slings are to be positioned as close to the load as possible whilst still complying with the chain angle limitations. also, due care is to be taken when selecting the position of the spreader bar(s) to prevent interference with the top of the load during normal flight and a primary sling failure. the spreader bars are to be attached laterally only.

DAP 101A-1105-1A


CHAPTER 2 - 4 - 7: ADJUSTABLE SPREADER BARS (JADTEU USE ONLY)

INTRODUCTION

there are two types of adjustable spreader bars, used by JaDteU for the development of USlCs, that are items of helicopter Underslung load equipment (hUSle). the purpose of the spreader bars is to hold apart sling leg or extension chains that would otherwise foul or damage part of an Underslung load (USl). full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1D, hUSle ancillary equipment.


54 Standard assemblythe spreader bar (figure 65) consists of an aluminium outer tube and two aluminium inner tubes which are a sliding fit into the outer tube. Steel end-fittings are fitted to the outer end of each inner tube. the medium Duty (mD) and heavy Duty (hD) adjustable spreader bars are identical in their method of construction, the only differences being the physical size of components.

55 End fittingthe end-fitting plugs into the outer end of the spreader bar inner tube with a close, but free, fit such that compression is transmitted uniformly around the abutment flange. alignment of each end-fitting and retention to the strut tube, is provided by eight ¼ in. Unf pan head bolts and washers.

HD SPREADER BAR

END FITTING OF

MD SPREADER BAR

END FITTING OF

HD SPREADER BAR

figure 65 - djustable spreader bars

the sling leg or extension chains are located in specially shaped pockets in the end-fittings and retained by quick release pins (figure 66). the pins are of the drop-nose type and are attached to the end-fitting by a

DAP 101A-1105-1A


steel wire lanyard. the chain is positioned such that the link to be captured lies flat against the load bearing face of the end-fitting, between the lugs. the pin cannot be passed through the lugs of the end-fitting unless the chain is fully and correctly seated. Clearance channels are provided for the adjacent chain links; each channel allows for the maximum permitted chain angle, so that the assembled spreader bar can be used either way up.

figure 66 - Sling leg chain engaged into end-fitting

56 Strut tubesthe outer tube has two holes through each end, which allow four quick release pins (drop-nose pins for mD, pip pins for hD spreader bars) to be fitted. the quick release pins are secured by cable assemblies, which are secured to the outer tube.

the spreader bars offer the following effective lengths:

mD spreader bar - 1.70 m - 2.80 m

hD spreader bar - 1.93 m - 3.30 m

each inner tube is through drilled at 110 mm (mD) and 95 mm (hD) intervals to allow the quick release pins to lock the complete assembly at the length required. the mD inner tube has 7 bushes, equal in length to the diameter of the tube, inserted into the drilled holes and secured with loctite. these serve to prevent the drop-nose pins opening inside the tube.

the outer tube has a protective foam cover over its whole length with cut-outs around the four pin holes and the identification (iD) label. the protective cover is secured by a number of plastic ties.

57 Spreader bar identificationthe complete spreader assemblies are painted nato green. each assembly carries an iD label attached to one end of the outer tube. the iD label carries the manufacturer’s code, reference numbers, the nSn of the assembly and the legend hUSle USe only. the equipment SWl is not stated as the capacity of the spreader bar, when used in accordance with paras 10 and 14, exceeds that of one pair of sling legs of the relevant type.

WARNING THE EQUIPMENT IS NOT TO BE USED FOR ANY OTHER PURPOSE THAN THAT SPECIFIED IN THIS CHAPTER.

58 Spreader bar usethe spreader bars are designed to be used with the following Slings multiple leg (Sml):

DAP 101A-1105-1A


58.1 mD spreader bar - used with Sml 4600 kg, 3450 kg, 2300 kg and 6000 lb

58.2 hD spreader bar - used with Sml 11300 kg, 8475 kg, 5650 kg and redundant

59 Limitationsthe following limitations apply (figure 67):

59.1 angle of chain above spreader bar (mD with Sml 4600 kg, 3450 kg and 2300 kg) - 40° in from vertical (80° apex) (mD with Sml 6000 lb) - 50° in from vertical (100° apex) (hD with Sml 11300 kg, 8475 kg, 5650 kg and redundant) - 25° in from vertical (50° apex)

59.2 angle of chain below spreader bar all Sml’s - 10° in from vertical

40°/50° MAX (MD)

25° MAX (HD)

10° MAX

80°/100° MAX (MD)

50° MAX (HD)

figure 67 - Chain angle limits

60 Life expiry of equipmentthe adjustable spreader bar is not a ‘lifed’ item. all parts are to be maintained in a good condition, and all markings are to remain legible at all times.

61 Maintenace support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D: hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

62 Equipment usageWith the chain locking quick release pins removed, the pre-adjusted spreader bar is fitted between the appropriate chain links of two adjacent sling legs (as defined in the relevant USlC published in DaP 101a-1105-1b), ensuring that there are no twists. the pins are then re-fitted to lock the bar in position. the spreader bar is removed by reversing the fitting procedures described above.

apart from detail contained in USlCs, a generalisation for the usage of both mD and hD spreader bars in differing modes of operation is as follows:

62.1 Sho. mD and hD spreader bars may be used with the Smls described in paragraph 58 and subject to the chain angle limitations described in paragraph 59. the spreader bars may be attached either laterally or longitudinally between chain legs.

DAP 101A-1105-1A


62.2 tholS. hD spreader bars are only to be used with Smls described in paragraph 58.1 (less redundant) and subject to the chain angle limitations described in paragraph 59. the spreader bars are to be attached laterally only.

62.3 thorr. hD spreader bars are only to be used with Sml 5650 kg and redundant described in paragraph 58.1 and subject to the chain angle limitations described in paragraph 59. Spreader bars used with the primary and redundant slings are to be positioned as close to the load as possible whilst still complying with the chain angle limitations. also, due care is to be taken when selecting the position of the spreader bars to prevent interference with the top of the load during normal flight and a primary sling failure. the spreader bars are to be attached laterally only.

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 5: HELICOPTER SLINGS - GENERAL

INTRODUCTION .................................................................................................................................... 102HELICOPTER SLINGS .......................................................................................................................... 1021 General purpose slings ......................................................................................................................1022 Chinook redundant sling ....................................................................................................................1023 Sling classification ..............................................................................................................................1024 loading in sling legs ...........................................................................................................................1035 General rigging procedures ................................................................................................................1046 maintenance support literature ...........................................................................................................1047 load hook-up/release and static electricity discharge procedures ....................................................104

CHAPTER 2 - 5 - 1: SLING, MULTIPLE LEG, HEAVY DUTY (11300 KG SWL)

INTRODUCTION .................................................................................................................................... 105EQUIPMENT DESCRIPTION ................................................................................................................. 1058 Standard assembly.............................................................................................................................1059 textile legs..........................................................................................................................................10510 apex assembly ...................................................................................................................................10511 fixed chain legs .................................................................................................................................10612 Sling identification labels ....................................................................................................................10613 retainer breakaway ...........................................................................................................................106SUPPLEMENTARY EQUIPMENT ......................................................................................................... 10614 Chain extension legs ..........................................................................................................................10615 Sling classification ..............................................................................................................................10616 Safe working load (SWl)....................................................................................................................10717 maximum included angle....................................................................................................................10718 Chain extension legs ..........................................................................................................................10719 2 x Sml 5650 kg used as a Sml 11300 kg ........................................................................................10720 life expiry of roundsling legs ..............................................................................................................10821 maintenance support literature ...........................................................................................................108SLING USAGE ....................................................................................................................................... 10822 Use of shortening clutches .................................................................................................................10823 limits for passage of chain ................................................................................................................10824 Preparation of slings and general rigging techniques ........................................................................10825 Suitability for engagement to helicopter cargo hooks ........................................................................10826 Suitability for engagement to helicopter extension strop secondary hooks .......................................10827 Static electricity discharge procedure ................................................................................................108

CHAPTER 2 - 5 - 2: SLING MULTIPLE LEG (‘REDUNDANT SLING’) FOR CHINOOK TANDEM HOOK OPERATIONS (THO)

INTRODUCTION .................................................................................................................................... 109EQUIPMENT DESCRIPTION ................................................................................................................. 10928 Standard assembly.............................................................................................................................10929 textile leg ...........................................................................................................................................11030 apex assembly ...................................................................................................................................11031 fixed chain legs .................................................................................................................................11032 Sling identification labels ....................................................................................................................11033 Sling classification ..............................................................................................................................11034 life expiry of textile sling legs ............................................................................................................11035 maintenance support literature ...........................................................................................................110SLING USAGE ....................................................................................................................................... 11036 Use of shortening clutches .................................................................................................................11037 limits for passage of chain ................................................................................................................11038 Suitability for engagement to helicopter cargo hooks ........................................................................11139 Static electricity discharge procedure ................................................................................................111

CHAPTER 2 - 5

DAP 101A-1105-1A


CHAPTER 2 - 5 - 3: SLING, MULTIPLE LEG, MEDIUM DUTY (4600 KG SWL)

INTRODUCTION .................................................................................................................................... 112EQUIPMENT DESCRIPTION ................................................................................................................. 11240 Standard assembly.............................................................................................................................11241 textile legs..........................................................................................................................................11242 apex assembly ...................................................................................................................................11243 fixed chain legs .................................................................................................................................11344 Sling identification labels ....................................................................................................................11345 retainer breakaway ...........................................................................................................................113SUPPLEMENTARY EQUIPMENT ......................................................................................................... 11346 Chain extension legs ..........................................................................................................................113SLING CLASSIFICATION ...................................................................................................................... 11347 Sling multiple leg (Sml), medium duty (mD) ......................................................................................11348 Safe working load SWl ......................................................................................................................11349 maximum included angle....................................................................................................................11350 Chain extension legs ..........................................................................................................................11451 2 x Sml 2300 kg used as a Sml 4600 kg ..........................................................................................11452 life expiry of roundsling legs ..............................................................................................................11453 maintenance support literature ...........................................................................................................114SLING USAGE ....................................................................................................................................... 11454 Use of shortening clutches .................................................................................................................11455 limits for passage of chain ................................................................................................................11456 Preparation of slings and general rigging techniques ........................................................................11557 Suitability for engagement to helicopter cargo hooks ........................................................................11558 Suitability for engagement to helicopter extension strop secondary hooks .......................................11559 additional use of 16 mm ‘open and closed masterlink’ hardware ......................................................11560 Static electricity discharge procedure ................................................................................................115

CHAPTER 2 - 5 - 4: SLING, MULTIPLE LEG, 6000 LB SWL

INTRODUCTION .................................................................................................................................... 116EQUIPMENT DESCRIPTION ................................................................................................................. 11661 Stsndard assembly .............................................................................................................................11662 metal tally/identification plate .............................................................................................................117SUPPLEMENTARY EQUIPMENT ......................................................................................................... 11763 Chain extension legs ..........................................................................................................................11764 retainer breakaway ...........................................................................................................................118SLING CLASSIFICATION ...................................................................................................................... 11865 Safe working load (SWl)....................................................................................................................11866 maximum included angle....................................................................................................................11867 2 m and 4.5 m mD extension chains ..................................................................................................11868 maintenance support literature ...........................................................................................................119SLING USAGE ....................................................................................................................................... 11969 Use of shortening clutches .................................................................................................................11970 Preparation of slings and general rigging techniques ........................................................................11971 Suitability for engagement to helicopter cargo hooks ........................................................................11972 Suitability for engagement to helicopter extension strop secondary hooks .......................................12073 Static electricity discharge procedures ...............................................................................................120

CHAPTER 2 - 5 - 5: HUSLE, WEBSLING, LIFTING, SWL 10000 KG (JADTEU USE ONLY)

INTRODUCTION .................................................................................................................................... 121EQUIPMENT DESCRIPTION ................................................................................................................. 12174 the websling ......................................................................................................................................12175 Websling identification ........................................................................................................................12176 Safe working load ...............................................................................................................................12177 life expiry of 10000 kg websling ........................................................................................................12278 maintenance support literature ...........................................................................................................122

DAP 101A-1105-1A


figures

figure 68 - a theoretical 1000 lb SWl sling, max included angle 90° ..........................................................103figure 69 - loads in sling legs working at varying angles .............................................................................104figure 70 - Sling, multiple leg, heavy Duty together with chain extension legs ...........................................105figure 71 - two-part sling classification ........................................................................................................107figure 72 - Sml (redundant) ........................................................................................................................109figure 73 - Sling, multiple leg, medium Duty together with chain extension legs ........................................ 112figure 74 - two-part sling classification ........................................................................................................ 114figure 75 - Sml 6000 lb SWl with clutches attached ................................................................................... 116figure 76 - Sml 6000 lb SWl with hooks attached ....................................................................................... 117figure 77 - Sling classification ....................................................................................................................... 118figure 78 - maximum included angle of chain loop at terminus of leg when using 6000 lb sling with hooks or clutches attached........................................................................................................................................... 119figure 79 - 10000 kg Websling ......................................................................................................................121

EQUIPMENT USAGE ............................................................................................................................ 12279 tandem hook operations with redundant sling. ................................................................................12280 tandem hook operations ‘long stropping’. ........................................................................................12281 Single hook operations. ....................................................................................................................122

DAP 101A-1105-1A


CHAPTER 2 - 5: HELICOPTER SLINGS - GENERAL

INTRODUCTION

this chapter deals with helicopter slings; there are three general purpose slings and a ‘redundant sling’ specific to the Chinook’s tandem hook operations (tho).

HELICOPTER SLINGS

1 General purpose slingsthe SWr (steel wire rope) sling is a four legged Sml 6000 lb; the Sml (sling multiple leg) heavy Duty (hD) and Sml medium Duty (mD) are available as four, three or two legged variants, and are equipped with polyester roundsling upper legs. all terminate with chain leg assemblies.

the chain legs of the SWr 6000 lb terminate with either chain shortening clutches or hooks; by engagement back onto its parent leg, the chain clutch/hook allows for a lifting loop to be formed about a load lifting point, by engaging the clutch/hook further up or down the leg, the leg length may be varied to suit the geometry of the lift. the chain clutch/hook also allows for engagement onto an adjacent chain leg or to a 2 m/4.5 m mD extension chain assembly.

the chain leg assemblies of the Sml hD and Sml mD terminate in chain shortening clutches; extension chain assemblies are also provisioned, specific to each sling and are generally used with a shortening clutch fitted to one end. the shortening clutch, unlike the hook, is equipped with a spring loaded locking lever for retaining it in position when engaged back onto its parent chain leg or onto another chain.

2 Chinook redundant slingthe Chinook redundant sling has four nylon legs and employs the same apex and terminal chain leg assembly as the Sml hD (see Chapter 2-2-4 for concept of thos). full nSn details and nomenclature for the equipment are contained in aP 108G-0002-1C: hUSle Slings.

WARNING THE REDUNDANT SLING MUST ONLY BE USED FOR ITS PRIMARY FUNCTION: THE CHINOOK TANDEM HOOK OPERATIONS (THO).

3 Sling classificationWith the exception of the redundant sling all Service helicopter slings are classified by SWl; with the three general purpose slings further classified by the maximum included angle at which the sling legs may operate. the following points should be noted with regard to the system of sling classification:

3.1 Safe Working load (SWl) the SWl classification relates to all legs of the sling being in use and, unless clearly specified otherwise, taking an equal share of the load. it is therefore necessary to divide the specified SWl by the total number of legs on the sling to ascertain the SWl for each leg: e.g. if a four-legged sling is classified with a SWl of 1000 lb, the SWl for each leg will be 250 lb. When only some of the legs on a sling are used to achieve a load lift, then the SWl of the sling is reduced to the combined SWl of the legs in use; e.g. if only three legs of the sling are being used to lift the load then the SWl of the sling is reduced to 3 x 250 lb which equals 750 lb.

3.2 maximum included angle the three general purpose slings are further classified by a ‘maximum included angle’ which is taken at the apex of the sling: this is measured between diametrically opposed sling legs, with each leg taking an equal share of the load (up to the SWl limit for the legs). thus the sling may be used to lift a load not in excess of its SWl classification (and number of legs in use), with the legs working at any angle from vertical up to the specified maximum included leg angle for the sling. this is illustrated in figure 68, using the example of a 1000 lb SWl four-legged sling (quoted in paragraph 3.1) which is classified with a maximum included angle of 90°.

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figure 68 - a theoretical 1000 lb SWl sling, max included angle 90°

3.3 maximum working angle for individual sling legs figure 68 also illustrates that the maximum included angle when halved gives the maximum allowable working angle for any one sling leg, i.e. the angle as measured between the line of the sling leg and the true vertical running down from the apex of the sling through the loads centre of gravity (CoG). in practice this angle together with the SWl limit for an individual leg are the important factors to relate to, and they are immediately derived from the sling classification. the reason for their importance is simply because in many cases the CoG of the load is not evenly distanced from available load lifting points. therefore sling legs are working at different angles, and bearing differing shares of the load in relationship to each other. also, with a four-legged sling for example, where only three of the legs are being used to lift a load, there are no diametrically opposed legs and it is necessary to relate to the maximum allowable working angle for an individual leg.

4 Loading in sling legsin most cases the legs of a sling are working at an angle; the general principle applying to use of helicopter slings being that loads should be suspended from points as far from and above the CoG position of the load as possible. this makes for better all-round stability of the load, for initial lifting, subsequent carriage and subsequent load landing.

it is important to bear in mind that for a given weight of load being suspended, the tension or loading along the line of the sling legs will be greater when the legs are working at an angle to the vertical - the greater the leg angle the greater the tension or loading in the legs (see figure 69).

it also follows that, whatever the leg angle, the tension or loading in the sling legs will increase if the weight of the suspended load is increased. these various factors are automatically catered for in USlCs, providing that the instructions in the clearance are followed in every respect - which includes taking note of the maximum aUW of load stipulated for a given rigging scheme.

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figure 69 - loads in sling legs working at varying angles

5 General rigging proceduresUSlCs are specific rigging schemes for specified USls. there are certain standard rules and practices which apply to the use of slings and allied equipment; these are fully covered in Chapter 3. any points of usage particular to a given sling will be highlighted in the individual equipment chapter for that sling.

6 Maintenance support literaturefull maintenance support literature for each sling is published in aP 108G-0002-1C, hUSle Slings. Chapter 1-2 gives general advice on obtaining hUSle maintenance aP’s.

7 Load hook-up/release and static electricity discharge proceduresGeneral procedures for load hook-up and release are contained in the chapters covering helicopter hooks (Chapters 2-3 to 2-3-5) and helicopter extension strops (Chapters 2-4 to 2-4-5), and any points specific to a given sling are highlighted in the appropriate sling equipment chapter.

Users should also consult Chapter 5 for full information on static electricity discharge, ground handler static probe equipment and standard procedures to be employed when earthing helicopter primary or secondary hooks, or suspended loads.

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CHAPTER 2 - 5 - 1: SLING, MULTIPLE LEG, HEAVY DUTY (11300 KG SWL)

INTRODUCTION

the heavy Duty (hD) sling was introduced for the Chinook helicopter and is designed for easy dismantling/assembly by component parts.

the sling is configured more commonly with four legs; however three and two leg variants may also be used when called for on certain Underslung load Clearances (USlCs). full nSn details for the equipment are contained in aP108G-0002-1C: hUSle slings.


8 Standard assemblythe sling legs, each consist of an upper textile element and a lower/terminal chain leg element, and at their apex, the textile legs are attached to a masterlink assembly (figure 70).

figure 70 - Sling, multiple leg, heavy Duty together with chain extension legs

9 Textile legsthe inner part of each textile leg consists of a polyester fibre roundsling in a continuous textile sleeve, which is then further sleeved in textile so that the roundsling forms a single leg terminating in a loop at each end. all sleeving to this stage is known as the inner sleeving.

each end loop is then fitted with a protective leather anti-chafe sleeve, and replacement roundslings are issued thus assembled.

When issued intact with a complete sling assembly, each roundsling leg is further protected by an outer protective textile sleeve (which for replacement purposes is demanded under its own nSn). the outer sleeve is retained in position at each end by nylon cord and PVC adhesive tape wrapping which leave the extremities of the anti-chafe sleeve and roundsling loop ends exposed.

10 Apex assemblythe upper end loops of the roundsling legs are engaged to an ‘open masterlink’, which in turn is connected to a ‘closed masterlink’ to form the lifting ring assembly.

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11 Fixed chain legsattached to the lower end loop of each roundsling by means of a roundsling shackle and half link shackle, is a 2 m length of 10.3 mm diameter chain. attached to the bottom end of each chain leg is a shortening clutch, stores description ‘Clutch, Chain Shortening (10 mm)’.

the clutch in its simplest use provides the means of coupling the chain back onto itself to form a closed loop about a lifting point; the leg length may be varied depending on the position along the chain that the clutch is engaged. the clutch may also be used as the means of engaging and thereby coupling to another 10.3 mm diameter chain.

the clutch incorporates a chain locking lever. the locking lever prevents the clutch from inadvertent detachment from an engaged position, when the chain is slack, e.g. prior to load hook-up and the helicopter taking tension on the load. Chapter 2-4-2 details workings of the chain locking lever and basic principles of clutch usage.

12 Sling identification labelseach leg has two identification labels; one over the exterior of the outer protective sleeving, the other attached directly to the roundsling inside the outer protective sleeve. the inner label provides fallback reference in case the outer label becomes illegible or lost. each label contains the nSn of the equipment, the equipment SWl classification and the life expiry date of the textile leg.

13 Retainer breakawaythe retainer breakaway is a single textile leg which is attached along the polyester section of one of the sling legs, and has a number of velcro cross straps; and is fully described in chapter 2-7. the velcro straps allow for the sling legs to be retained together, either for storage or to prevent sling leg snagging during initial load lift. in the lprevention of snagging as tension is taken on the load the cross straps will pull open allowing the sling legs to deploy naturally.

SUPPLEMENTARY EQUIPMENT

14 Chain extension legsfor certain loads it will be necessary to have the facility for lengthening the sling legs. extension chain assemblies are used for this purpose. these chains also allow the chain clutches to be engaged back onto its parent chain to form a lifting loop about a load lifting point, or to be engaged onto a further extension chain.

the chain lengths can be varied: by engaging the clutch higher up or lower down the sling leg or extension chain leg, with the final aim of achieving equilibrium of the load. the chains are fully described in chapter 2-4-2; full nSn details for the equipment are contained in aP108G-0002-1D: hUSle ancilliary equipment.

Masterlink/hook assembly

for certain loads it will be necessary to have the facility to employ the use of a masterlink/hook assembly, more commonly known as a ’Speedhook’. the assembly is attached to the sling via the sling chain or an extension chain, and consists of an ‘open masterlink’ and ’13 mm hook’ secured together using a locking set. these are demanded as individual items; full nSn details for the equipment are contained in aP108G-0002-1D: hUSle ancilliary equipment.

15 Sling classificationthe sling has a two part classification to cater for the use of the sling at included angles in excess of 50°, up to a maximum included angle of 80°, but at a reduced working load rating. the sling classification is therefore summarised as follows (see also general notes in chapter 2-5):

15.1 Sml, hD (four legs) SWl 11300 kg up to 50° maximum included angle SWl 9550 kg up to 80° maximum included angle

15.2 Sml, hD (three legs) SWl 8475 kg up to 50° maximum included angle SWl 7165 kg up to 80° maximum included angle

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15.3 Sml, hD (two legs) SWl 5650 kg up to 50° maximum included angle SWl 4775 kg up to 80° maximum included angle

16 Safe working load (SWL)the SWl rating relates to all legs of the particular sling being used, and all legs taking an equal share of the load. thus, taking the 11300 kg rating, the SWl for any one sling leg is 2825 kg, taking the 9550 kg rating, the SWl for any one sling leg is 2387 kg. it follows that if less than four legs of the sling are being employed to lift a load, then the sling SWl is reduced accordingly.

17 Maximum included angleWith both parts of the sling classification the sling SWl rating is related to a maximum included angle. taken at the apex of the sling, this is the maximum allowable angle measured between diametrically opposed sling legs, with each leg taking an equal share of the load up to the SWl limit for the 50° or 80° angle rating.

figure 71 shows that the maximum included angle when halved gives the maximum allowable working angle for any one sling leg; i.e. the angle as measured between the line of the sling leg and the true vertical running down from the apex of the sling through the load CoG.

18 Chain extension legsthe chain extension legs conform to the sling leg rating for the sling; i.e. 2825 kg SWl per chain leg operating up to a maximum leg angle of 25° from vertical; and 2387 kg SWl per chain leg operating up to a maximum angle of 40° from vertical.

19 2 x SML 5650 kg used as a SML 11300 kgalthough uncommon, 2 x Smls 5650 kg may be used to form a four-legged sling configuration with an 11300 kg classification for a single point lift; but this configuration is only to be connected to a helicopter extension strop secondary hook.

figure 71 - two-part sling classification

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20 Life expiry of roundsling legsthe roundsling elements of the sling legs (excluding the outer protection sleeves) are ‘lifed’ items, the policy for which is laid down in the technical support literature for the sling (paragraph 22). equipment holders are to ensure that the life expiry date for each roundsling is marked legibly and indelibly (by black permanent marker pen) on the individual leg identification labels.

21 Maintenance support literaturefull details are published in aP108G-0002-1C: hUSle Slings.

SLING USAGE

22 Use of shortening clutchesinformation on the use of chain shortening clutches, as fitted to the hD sling, including its variants and associated chain extension legs is contained in chapter 2-4-2.

23 Limits for passage of chainthe following limits for passage of chain through lifting points or around the load, apply to the fixed chain legs and chain extension legs of the hD sling.

23.1 the chain is not to be looped around:

23.1.1 Circular sections of less than 25 mm (1 in.) diameter.

23.1.2 angular or flat sections with square or rounded edges whose thickness of section is less than 25 mm (1 in.).

24 Preparation of slings and general rigging techniquesConsult Chapter 3 for standard rigging practice and techniques.

25 Suitability for engagement to helicopter cargo hooksthe masterlink lifting ring of the hD sling is suitable for direct engagement onto all cargo hooks of the Chinook helicopter. Consult the chapter 2-2 series for full details of Chinook cargo hooks and allied hook-up and load release procedures.

note the compatibility matrix, chapter 2, figure 2.1, states the ‘non Standard Usage’ of sling direct to cargo hook. it is now common practice to use an extension strop, with swivel hook, as an interface between cargo hook and USl unless otherwise specified in an USlC.

26 Suitability for engagement to helicopter extension strop secondary hooksthe masterlink lifting ring of this sling is suitable for direct engagement onto the secondary hooks of all british Service helicopter extension strops when used with Chinook, with the exception of the 7 ft or 30 ft SWr strops, SWl 1500 lb. in the event that the sling ever had to be carried from a 7 ft or 30 ft 1500 lb SWl strop, then a shackle, 1500 lb SWl, or alternatively a 16 mm ‘open and closed masterlink assembly’ would provide a suitable means of connecting the masterlink lifting ring of the sling to the 1500 lb SWl secondary hook; this is illustrated in chapter 2-3-4.

27 Static electricity discharge procedureChapter 5 gives full details on helicopter static electricity discharge procedures and associated items of ground handler equipment.

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CHAPTER 2 - 5 - 2: SLING MULTIPLE LEG (‘REDUNDANT SLING’) FOR CHINOOK TANDEM HOOK OPERATIONS (THO)

INTRODUCTION

the redundant Sml is a special multiple-leg slingset for the Chinook helicopter; it is an emergency equipment only, ensuring retention of the load if an irregular release of a cargo hook occurs during Chinook thos. full nSn details for the equipment are contained in aP108G-002-1: husle Slings.


28 Standard assemblythe sling (figure 72) has four legs, each consisting of an upper textile element and a lower chain leg element. at their apex, the textile legs are attached to a masterlink assembly.

figure 72 - Sml (redundant)

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29 Textile legthe inner part of each textile leg consists of flat nylon webbing made from a single length formed into three concentric loops, stitched through at the overlap. the resulting single loop is held together as a compact bundle by tape wrapped around at regular intervals, to form a nominal length of 5.2 m. this construction is known as the ‘Strap’. a label is taped to one end of the strap and is the ‘internal label’. for replacement purposes, straps are demanded under a separate nSn.

the strap is fitted with a protective tubular sleeve secured at each end by tape. the sleeve is red in colour and carries prominent black identification markings. as a non-loadbearing element, the protective sleeve is considerably longer than the strap to allow for stretch in the latter when under load. this construction is known as the ‘Strap assembly’, and carries a second identical label (the ‘external’ label) taped to the same end as the internal label. for replacement purposes, protective sleeves are demanded under a separate nSn.

two strap assemblies are joined by binding their upper end loops together with tape, forming a ‘Double Strap assembly’; one redundant sling contains two such assemblies.

30 Apex assemblythe upper end loops of the two double strap assemblies are engaged to an ‘open masterlink’, which in turn is connected to a ‘closed masterlink’ to form the steel lifting ring assembly.

31 Fixed chain legsattached to the lower end loop of each textile leg, by means of a roundsling shackle and half link shackle, is a 2 m length of 10.3 mm diameter chain. attached to the bottom end of each chain leg is a shortening clutch, which in its simplest use provides the means of coupling the chain back onto itself to form a closed loop about a lifting point; the leg length may be varied depending upon the position along the chain at which the clutch is engaged. the clutch incorporates a chain locking lever which prevents inadvertent detachment of the clutch from an engaged position, when the chain is slack, eg prior to the load hook-up and the helicopter taking tension on the load. Chapter 2-4-2 details the workings of chain locking levers and basic principles of clutch usage.

32 Sling identification labelseach sling leg carries two identification labels; one fitted over the outer protective sleeving, the other attached directly to the strap within. the inner label provides fallback reference in case the outer label becomes illegible or lost. each label contains the nSn of the equipment and the life expiry date of the textile leg. an additional iD label, stamped with the assembly part number, is strapped to the masterlink.

33 Sling classificationthe redundant sling is an item of emergency equipment and is not classified for use as a conventional sling.

34 Life expiry of textile sling legsthe inner textile elements of the sling legs (excluding the outer protection sleeves) are ‘lifed’ items, the policy for which is laid down in the maintenance support literature for the sling (paragraph 35). equipment holders are to ensure that the life expiry date for each strap is marked legibly and indelibly, by black permanent ink, on the associated inner and outer iD labels.

35 Maintenance support literaturefull maintenance supporting literature is published in aP108G-0002-1C. Chapter 1-2 gives general advice on obtaining aeSPs.

SLING USAGE

36 Use of shortening clutchesinformation on the use of chain shortening clutches, as fitted to the redundant sling, is described in Chapter 2-4-2, paragraph 15.

37 Limits for passage of chainthe following limits for passage of chain through lifting points, or around the load, apply to the chain legs of the redundant sling. the chain is not to be looped around:

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Circular sections of less than 25 mm diameter.

angular or flat sections with square or rounded edges whose thickness of section is less than 25 mm.

the chain legs of the redundant sling must not connect to any part of the main lifting sling, ie the redundant sling must be connected directly to the load.

38 Suitability for engagement to helicopter cargo hooksthe masterlink lifting ring of the redundant sling is intended for direct engagement onto the centre cargo hook of the Chinook helicopter. Consult the Chapter 2 series for full details of Chinook cargo hooks and allied hook-up and load release procedures.

WARNING THE REDUNDANT SLING IS NOT TO BE ATTACHED TO AN EXTENSION STROP, OR TO ANY LIFTING POINT OTHER THAN AS DESCRIBED ABOVE.

39 Static electricity discharge procedureConsult Chapter 5 for full details of helicopter static electricity discharge procedures and associated items of ground handler equipment.

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CHAPTER 2 - 5 - 3: SLING, MULTIPLE LEG, MEDIUM DUTY (4600 KG SWL)

INTRODUCTION

the medium Duty (mD) sling was introduced for the Chinook helicopter and is a scaled down version of the heavy Duty (hD) sling. it is designed for easy dismantling/assembly by component parts. the sling is configured more commonly with four legs, butthree leg and two leg variants may also be used when called for on certain Underslung load Clearances (USlCs). full nSn details for the equipment are contained in aP108G-0002-1C: hUSle Slings.


40 Standard assemblythe sling legs, each consist of an upper textile element and a lower/terminal chain leg element. at their apex, the textile legs are attached to a masterlink assembly (figure 73).

LOCKING

SET

OPEN

MASTERLINK PVC TAPE

PVC TAPE

RETAINER, BREAKAWAY

(ATTACHED TO ONE LEG)

OUTER PROTECTIVE

SLEEVEIDENTIFICATION LABEL

CHAIN SHORTENING

CLUTCH

2 m or 4.5 m EXTENSION CHAIN

(AS REQUIRED)

ROUNDSLING SHACKLE

HALF LINK SHACKLE

AND LOCKING SET

JOINER

LINK

ANTI-CHAFE

SLEEVE

CLOSED MASTERLINK

(LIFTING RING)

figure 73 - Sling, multiple leg, medium Duty together with chain extension legs

41 Textile legsthe inner part of each textile leg consists of a polyester fibre roundsling in a continuous textile sleeve, which is then further sleeved in textile so that the roundsling forms a single leg terminating in a loop at each end. all sleeving to this stage is known as the inner sleeving. each end loop is then fitted with a protective leather anti-chafe sleeve. replacement roundslings are issued thus assembled. When issued intact with a complete sling assembly, each roundsling leg is further protected by an outer protective textile sleeve (which for replacement purposes is demanded under its own nSn). the outer sleeve is retained in position at each end by nylon cord and PVC adhesive tape wrapping, so as to leave the extremities of the anti-chafe sleeve and roundsling loop ends exposed.

42 Apex assemblythe upper end loops of the roundsling legs are engaged to an ‘open masterlink’, which in turn is connected to a ‘closed masterlink’ to form the steel lifting ring assembly.

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43 Fixed chain legsattached to the lower end loop of each roundsling, by means of a roundsling shackle and half link shackle, is a 2 m length of 7.1 mm diameter chain (which incorporates a ‘joiner link’ for connection to the half link shackle). attached to the bottom end of each chain leg is a shortening clutch; in its simplest use provides the means of coupling the chain back onto itself to form a closed loop about a lifting point, and the leg length may be varied depending on the position along the chain that the clutch is engaged. the clutch may also be used as the means of engaging and thereby coupling to another 7.1 mm diameter chain. the clutch incorporates a chain locking lever, which prevents the clutch from inadvertent detachment from an engaged position when the chain is slack, e.g. prior to load hook-up and the helicopter taking tension on the load. Chapter 2-5 details workings of the chain locking lever and basic principles of clutch usage.

44 Sling identification labelseach leg has two identification labels; one over the exterior of the outer protective sleeving, the other attached directly to the roundsling inside the outer protective sleeve. the inner label provides fallback reference in case the outer label becomes illegible or lost. each label contains the nSn of the equipment, the equipment SWl classification and the life expiry date of the textile leg.

45 Retainer breakawaythe retainer breakaway is of textile construction and consists of a single leg which is attached along the polyester section of one of the sling legs, and has a number of velcro cross straps. the velcro straps allow for the sling legs to be retained together, either for storage or to prevent sling leg snagging during initial load lift. in the latter case, as the tension is taken on the load the cross straps will pull open allowing the sling legs to deploy naturally. it is fully described in Chapter 2-7.


46 Chain extension legsfor certain loads it will be necessary to have the facility for lengthening the sling legs. extension chain assemblies, 2 m or 4.5 m with terminal chain clutches, are used for this purpose. these chains serve the same function as a chain leg, allowing for the chain clutches to be engaged back onto its parent chain, to form a lifting loop about a load lifting point, or to be engaged onto a further extension chain. leg length can be varied, by engaging the clutch higher up or lower down the sling leg or extension chain leg, with the final aim of achieving equilibrium of the load. the chains are fully described in Chap 2-4-2 and full nSn details for the equipment are contained in aP108G-0002-1D: hUSle ancilliary equipment

SLING CLASSIFICATION

47 Sling multiple leg (SML), medium duty (MD)the sling has a single classification to cater for the use of the sling at a maximum included angle of 80°. the sling classification is therefore summarised as follows (see also general notes in Chapter 2-5):

Sml, mD (four legs), SWl 4600 kg up to 80° maximum included angle

Sml, mD (three legs), SWl 3450 kg up to 80° maximum included angle

Sml, mD (two legs), SWl 2300 kg up to 80° maximum included angle

48 Safe working load SWLthe SWl rating relates to all legs of the particular sling being used and each leg taking an equal share of the load; thus the SWl for any one sling leg is 1150 kg. it follows that if less than four legs are being employed to lift a load, then the sling SWl is reduced accordingly.

49 Maximum included anglethe sling SWl classification is also related to a maximum included angle of 80°. taken at the apex of the sling this is the maximum allowable angle measured between diametrically opposed sling legs, with each leg taking an equal share of the load up to the SWl limit for the legs. figure 74 shows that the maximum included angle when halved gives the maximum allowable working angle for any one sling leg, i.e. the angle as measured between the line of the sling leg and the true vertical running down from the apex of the sling through the load CoG.

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80o

80o

40o

MAX

SWL 1150 kg

MAX PER LEG

SWL 1150 kg

MAX PER LEG

SWL 1150 kg

MAX PER LEG

VERTICAL FROM SLING APEX

THROUGH LOAD C OF G

ANY ONE LEG RELATED TO VERTICAL

THROUGH LOAD C OF G

MAXIMUM INCLUDED

ANGLE

figure 74 - two-part sling classification

50 Chain extension legsthe chain extension legs conform to the sling leg rating for the sling, ie 1150 kg SWl per chain leg, operating up to a maximum angle of 40° from vertical.

51 2 x SML 2300 kg used as a SML 4600 kgalthough uncommon, 2 x Smls 2300 kg may be used to form a four-legged sling configuration with a 4600 kg classification for a single point lift. however, it is to be noted that this configuration is only to be connected to a helicopter extension strop secondary hook.

52 Life expiry of roundsling legsthe roundsling elements of the sling legs (excluding the outer protection sleeves) are ‘lifed’ items, the policy for which is laid down in the maintenance support literature for the sling (paragraph 53). equipment holders are to ensure that the life expiry date for each roundsling is marked legibly and indelibly (by black permanent marker pen) on the individual leg identification labels.

53 Maintenance support literaturefull maintenance supporting literature for this equipment, including before and after use examination, general care, unit repairs and fitment instructions for component parts technical inspection procedures and any Service modification action or other changes, is published in aeSP 1670-h-100. Chap 1-1 gives general advice on obtaining aeSPs.

SLING USAGE

54 Use of shortening clutchesinformation on the use of chain shortening clutches, as fitted to the mD sling (incl variants) and associated chain extension legs, is described in Chap 2-3-2, para 3.

55 Limits for passage of chainthe following limits for passage of chain through lifting points, or around the load, apply to the fixed chain legs and chain extension legs of the mD sling. the chain is not to be looped around:

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Circular sections of less than 13 mm (½ in.) diameter.

angular or flat sections with square or rounded edges whose thickness of section is less than 13 mm (½ in.).

56 Preparation of slings and general rigging techniquesConsult Chap 3 for standard rigging practice and techniques.

57 Suitability for engagement to helicopter cargo hooksthe masterlink lifting ring of the mD sling is suitable for direct engagement onto all cargo hooks of the Chinook helicopter. Consult the chapter 2-2 series for full details of Chinook cargo hooks and allied hook-up and load release procedures.

note the compatibility matrix in chapter 2-1 states the ‘non Standard Usage’ of sling direct to cargo hook. it is now common practice to use an extension strop, with swivel hook, as an interface between cargo hook and USl, unless otherwise specified in an USlC.

58 Suitability for engagement to helicopter extension strop secondary hooksthe masterlink lifting ring of this sling is suitable for direct engagement onto the secondary hooks of all british Service helicopter extension strops when used with Chinook. Consult the Chapter 2-3 series for full details of the current range of british Service helicopter extension strop equipments, and allied hook-up and load release procedures.

59 Additional use of 16 mm ‘open and closed masterlink’ hardwarethe 16 mm ‘open and closed’ masterlink assembly, forming the apex of the mD sling, can also be used as a fallback connector for older range equipments that are not compatible for engagement onto Chinook cargo hooks or the 11300 kg strop. the use of the apex hardware in this manner is discussed in Chapter 2-4-1.

60 Static electricity discharge procedureConsult Chapter 5 for full details of helicopter static electricity discharge procedures and associated items of ground handler equipment.

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CHAPTER 2 - 5 - 4: SLING, MULTIPLE LEG, 6000 LB SWL

INTRODUCTION

the Sml 6000 lb is a general purpose helicopter sling, traditionally used by the royal fleet auxilliary and the royal marines. full nSn details for the equipment are contained in aP108G-0002-1C: hUSle Slings.


61 Standard assemblythe sling consists of four steel wire rope (SWr) and four chain legs attached to an oval shaped steel connecting ring at the apex (figures 75 and 76). the upper portion of each leg comprises a 6 ft (1.83 m) length of SWr, the upper end of which is formed into a loop encircling the lifting ring.

the loop is formed about a thimble, with the free end of the wire rope secured back (swaged) to the parent leg by means of a ‘talurit’ ferrule. the lower end of each leg terminates in a swaged loop, with the free end of wire rope similarly secured back to the parent leg by means of a ‘talurit’ ferrule, and each lower loop houses a ‘deadeye’.

the wire rope legs are protected over their length, between ferrules, by a translucent vinyl sleeve.

LIFTING RING

‘TALURIT’

FERRULE

DEAD EYE

THIMBLE

TALLY

WIRE ROPE

VINYL SLEEVE

LINK PLATES BOLTED

AND SPLIT-PINNED

figure 75 - Sml 6000 lb SWl with clutches attached

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LIFTING RING

‘TALURIT’

FERRULE

DEAD EYE

THIMBLE

TALLY

WIRE ROPE

VINYL SLEEVE

LINK PLATES BOLTED

AND SPLIT-PINNED

figure 76 - Sml 6000 lb SWl with hooks attached

the lower part of each sling leg consists of a standard 7.1 mm diameter chain, 5 ft 6 in. (1.68 m) in length and terminating in a chain clutch (figure 75) or hook (figure 76). each chain leg is secured to the foot of its wire rope leg by means of ‘link plates’ bolted at one end of the terminal ‘deadeye’ of the wire rope leg and at the other end to the top link of the chain.

62 Metal tally/identification platea brass plate (tally) is attached to one of the sling legs, and contains the sling description, nSn, SWl, manufacturer and date of ‘proof test’. if the tally is lost, the equipment is to be withdrawn from use immediately.


63 Chain extension legsfor certain loads it will be necessary to have the facility for lengthening the sling legs. extension chain assemblies, 2 m or 4.5 m with terminal chain clutches, are used for this purpose. these chains serve the same function as a chain leg, allowing for the chain clutches to be engaged back onto its parent chain, to form a lifting loop about a load lifting point, or to be engaged onto a further extension chain.

leg length can be varied, by engaging the clutch higher up or lower down the sling leg or extension chain leg, with the final aim of achieving equilibrium of the load. the chains are fully described in Chap 2-4-2 and full nSn details for the equipment are contained aP108G-0002-1C: hUSle Slings.

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64 Retainer breakawaythe retainer breakaway is of textile construction and consists of a single leg which is attached to the upper/non-chain element of a sling leg and has a number of velcro cross straps. the velcro straps allow for the sling legs to be held together, either for storage or to prevent sling leg snagging during initial load lift e.g. as tension is taken on the load the cross straps will open allowing for the sling legs to deploy naturally.

the retainer breakaway may be adapted for use with the Sml 6000 lb and the item is fully described in chapter 2-7 (which includes an example of its installation on this sling). the item is readily replaceable and full nSn details for the equipment are contained in aP108G-0002-1C:hUSle Slings

SLING CLASSIFICATION

the sling is classified as ‘Sling, multiple leg, 6000 lb SWl up to 100° maximum included angle’. the classification is considered as follows (see also general notes in Chap 2-5):

65 Safe working load (SWL)the SWl classification of 6000 lb relates to all four legs of the sling with each leg taking an equal share of the load. thus the SWl for each leg is 1500 lb. it follows that if only three of the four legs are being employed to lift a load the sling SWl is reduced to 4500 lb; if only two of the legs are being employed to lift a load the sling SWl is reduced to 3000 lb.

66 Maximum included anglethe sling SWl classification is also related to a maximum included angle of 100°; taken at the apex of the sling, it is the maximum allowable angle measured between diametrically opposed sling legs, with each leg taking an equal share of the load up to the SWl limit for the legs. figure 77 shows that the maximum included angle when halved gives the maximum allowable working angle for any one sling leg, i.e. the angle as measured between the line of the sling leg and the true vertical running down from the apex of the sling through the load CoG.

figure 77 - Sling classification

67 2 m and 4.5 m MD extension chainsWhen used as extension chain legs for this sling, 2 m and 4.5 m mD extension chains (Chap 2-4-2) conform to the single leg rating for the sling; i.e. 1500 lb SWl per chain leg operating up to a maximum leg angle of 50° from vertical.

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68 Maintenance support literaturefull maintenance supporting literature for this equipment is published in aP108G-0002-1C: hUSle Slings. Chapter 1-2 gives general advice on obtaining hUSle maintenance aP’s.

SLING USAGE

69 Use of shortening clutchesinformation on the use of chain shortening clutches, as fitted to the 6000 lb sling and associated chain extension legs, is described in chapter 2-4-2.

note for a 6000 lb sling leg terminating with a chain hook or shortening clutch the maximum allowable included angle at closure of chain loop is 90° and 120° respectively (figure 78).

120°

CHAIN HOOK SHORTENING CLUTCH

90°

figure 78 - maximum included angle of chain loop at terminus of leg when using 6000 lb sling with hooks or clutches attached

the following limits for passage of chain through lifting points, or around the load, apply to the fixed chain legs of the 6000 lb sling. the chain is not to be looped around:

Circular sections of less than 13 mm diameter.

angular or flat sections with square or rounded edges whose thickness of section is less than 13 mm.

70 Preparation of slings and general rigging techniquesConsult chapter 3 for standard rigging practice and techniques.

71 Suitability for engagement to helicopter cargo hooksthe lifting ring of this sling is suitable for direct engagement onto any of the SaCrU series of cargo hooks currently fitted to british Service helicopters. the lifting ring is also suitable for direct engagement onto the forward and aft hooks of the Chinook helicopter, but not onto the centre hook; the lifting ring is suitable, for engagement onto the secondary hook of the Chinook 11300 kg extension strop. alternatively it could be engaged to the Chinook centre hook by means of a 16 mm ‘open and closed’ masterlink assembly (see Chap 2-4-1).

note the compatibility matrix in chapter 2-1 states the ‘non Standard Usage’ of sling direct to cargo hook. it is now common practice to use an extension strop, with swivel hook, as an interface between cargo hook and USl, unless otherwise specified in an USlC.

Consult the Chapter 2-3 series for full details of current british Service helicopter cargo hooks, and allied hook-up and load release procedures.

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72 Suitability for engagement to helicopter extension strop secondary hooksthe lifting ring of this sling is suitable for direct engagement onto the secondary hooks of all current british Service helicopter extension strops. Consult the chapter 2-3 series for full details of the current range of british Service helicopter extension strop equipments, and allied hook-up and load release procedures.

73 Static electricity discharge proceduresConsult chapter 5 for full details of helicopter static electricity discharge procedures and associated items of ground handler equipment.

DAP 101A-1105-1A


CHAPTER 2 - 5 - 5: HUSLE, WEBSLING, LIFTING, SWL 10000 KG (JADTEU USE ONLY)

INTRODUCTION

the 10000 kg websling (more commonly known as a belly-band) has been designed a to provide an alternative and versatile method of lifting unusual and fragile loads that have no suitable lifting points. full nSn details for the equipment are contained in aP108G-0002-1C: hUSle Slings.


74 The webslingthe websling (figure 79) is 14 m long and manufactured from 2 ply 100% polyester webbing. Stitched loops at each end provide a means of attachment to appropriate in-service hUSle. Protective sleeves, manufactured from 100% polyester, are used to prevent damage to the Websling when lifting loads with sharp or abrasive edges. the SWl of the equipment is 10000 kg.

F AOR J TEU SE ONLYU 001356128

SpanSet 10000KG

Info labelrmation

Lifting loop

Lifting loop

Protective sleeve

Websling

figure 79 - 10000 kg Websling

75 Websling identificationthe websling has two sewn on labels: one with the manufacturers name and SWl, the other with equipment description, nSn, drawing number, serial number, date of manufacture, life expiry and the legend ‘for JaDteU USe only’. the serial number and legend ‘for JateU USe only’ are also stencilled on the websling.

76 Safe working loadthe SWl of the websling is 10000 kg, but is to conform to any lower figure as dictated by the equipment with which it is being employed by the helicopter.

DAP 101A-1105-1A


77 Life expiry of 10000 kg webslingthe websling is a ‘lifed’ item the policy for which is laid down in the maintenance support literature for the sling (paragraph 78). equipment holders are to ensure that the life expiry date is entered onto the equipment log card. the protective sleeves are not ‘lifed’ but are replaced on condition.

78 Maintenance support literaturefull maintenance supporting literature for this equipment is published in aP108G-0002-1C: hUSle Slings. Chapter 1-2 gives general advice on obtaining hUSle maintenance aP’s.

EQUIPMENT USAGE

the Websling provides an alternative method to low speed crane lifts of unusual loads which can be used with various helicopter types, subject to limitations in their respective release to Service. the websling can be used in the following configurations:

79 Tandem hook operations with redundant sling. although the use of a redundant sling with webslings is cleared for use, this method is not deemed to be normal practice. however, it may be used when operationally essential.

80 Tandem hook operations ‘long stropping’. the preferred method of use, using extension strops and weak links, are to be used to prevent damage occurring to the aircraft or webslings. the hook of a hD extension strop will accommodate two websling lifting loops, however, it is recommended that a 16 mm ‘open and closed master link assembly’ (chapter 2-4-1) is used as a connector for ease of attachment and disengagement.

81 Single hook operations. a hD extension strop is to be used for single hook operations. the use of a 16 mm ‘open and closed master link assembly’ (chapter 2-4-1) is recommended as a connector between the websling and extension strop secondary hook.

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 6: HELICOPTER CARGO LIFTING NETS AND NETTED LOADS

INTRODUCTION .................................................................................................................................... 127NET PROTECTION ................................................................................................................................ 1271 General...............................................................................................................................................127LOADS ................................................................................................................................................... 1272 the securing of items .........................................................................................................................1273 netted loads .......................................................................................................................................1274 authorised loads.................................................................................................................................1275 Specified authorised loads ................................................................................................................1286 two net cluster load ...........................................................................................................................128GROUND OR DECK TRANSPORTATION ............................................................................................ 1287 General...............................................................................................................................................1288 flat bed vehicles ................................................................................................................................1289 fork lift trucks .....................................................................................................................................12810 nets with baseboards .........................................................................................................................12811 nets without baseboards ....................................................................................................................128

CHAPTER 2 - 6 - 1: HELICOPTER CARGO NET PROTECTION PAD

INTRODUCTION .................................................................................................................................... 129EQUIPMENT DESCRIPTION ................................................................................................................. 12912 Protection pads ..................................................................................................................................12913 maintenance support literature ...........................................................................................................12914 General usage ....................................................................................................................................129

CHAPTER 2 - 6 - 2: HELICOPTER CARGO LIFTING NET - 5600 KG SWL

INTRODUCTION .................................................................................................................................... 130EQUIPMENT DESCRIPTION ................................................................................................................. 13015 the 5600 kg net .................................................................................................................................13016 net lifting strop assemblies ................................................................................................................13117 net stirrup ...........................................................................................................................................132ASSOCIATED EQUIPMENT .................................................................................................................. 13318 retainer breakaway ...........................................................................................................................13319 Pad, protection, helicopter cargo net .................................................................................................13320 life expiry of net .................................................................................................................................13321 net storage .........................................................................................................................................13322 technical support literature ................................................................................................................133PREPARATION OF NET FOR CARRIAGE OF NATO PALLETS ......................................................... 13323 net handlers .......................................................................................................................................13324 laying out the net ...............................................................................................................................13325 Setting up a two-net cluster load ........................................................................................................13326 Preparing the second net ...................................................................................................................134LOADING OF NATO PALLET LOADS AND NET SECURING ............................................................. 13427 General...............................................................................................................................................13428 even loading.......................................................................................................................................13529 Sharp edged loads .............................................................................................................................13530 low density items ...............................................................................................................................13531 Securing cord ties...............................................................................................................................13532 loading schemes ...............................................................................................................................13533 net protection pads ............................................................................................................................13634 like loads ...........................................................................................................................................13735 net loading process - single net uplifts ..............................................................................................137

CHAPTER 2 - 6

DAP 101A-1105-1A


36 fork lift operation................................................................................................................................13737 Securing net pads around load ..........................................................................................................137CLOSING AND SECURING THE NET AND NET STROP ASSEMBLIES ............................................ 13738 Side wall netting .................................................................................................................................13739 Connecting-up to net stirrup ...............................................................................................................13840 Securing net strop assembly legs ......................................................................................................138HELICOPTER HOOK-UP AND LANDING ............................................................................................ 13841 hooking-up single net loads ...............................................................................................................13942 hooking-up a two-net cluster load ......................................................................................................13943 Precautions during initial lift ...............................................................................................................14044 Precautions during net release ..........................................................................................................14045 net dragging during load pick-up and landing ....................................................................................140FLYING LIMITATIONS ........................................................................................................................... 14046 the 5600 kg net ................................................................................................................................14047 Weight ................................................................................................................................................14048 Cluster loads ......................................................................................................................................140

CHAPTER 2 - 6 - 3: HELICOPTER CARGO LIFTING NET - 5000 LB SWL

INTRODUCTION .................................................................................................................................... 141EQUIPMENT DESCRIPTION ................................................................................................................. 14149 the 5000 lb net ..................................................................................................................................14150 lifting strops .......................................................................................................................................14251 Stirrup and hooks ...............................................................................................................................14252 retainer breakaway ...........................................................................................................................143ASSOCIATED EQUIPMENT .................................................................................................................. 14353 net protection pad ..............................................................................................................................14354 net life expiry......................................................................................................................................14355 maintenance support literature ...........................................................................................................143PREPARATION OF NET ....................................................................................................................... 14356 General ..............................................................................................................................................14357 Use of net pads ..................................................................................................................................14358 laying out the net ...............................................................................................................................143LOADING OF NET ................................................................................................................................. 14359 even loading.......................................................................................................................................14360 Uneven loading ..................................................................................................................................14461 low density items ...............................................................................................................................14462 fragile stores......................................................................................................................................14563 Sharp or rough edged loads ...............................................................................................................14564 flat sheets of metal ............................................................................................................................14565 Securing cord ties...............................................................................................................................14566 batteries and battery electrolyte .........................................................................................................14567 baseboards ........................................................................................................................................14568 Side wall netting .................................................................................................................................14669 Connecting-up to net stirrup ...............................................................................................................14770 Securing net lifting strops ...................................................................................................................147HELICOPTER HOOK-UP AND LANDING ............................................................................................ 14771 Checks before hook-up ......................................................................................................................14772 hooking-up .........................................................................................................................................14873 Single netted load ..............................................................................................................................14874 two-net cluster load ...........................................................................................................................14875 Precautions during initial lift ...............................................................................................................14976 Precautions during release ................................................................................................................149FLYING LIMITATIONS ........................................................................................................................... 149


INTRODUCTION .................................................................................................................................... 150EQUIPMENT DESCRIPTION ................................................................................................................. 150

DAP 101A-1105-1A


77 the 7000 kg net .................................................................................................................................15078 lifting strops .......................................................................................................................................15079 Stirrup and hooks ...............................................................................................................................15080 retainer breakaway ...........................................................................................................................151ASSOCIATED EQUIPMENT .................................................................................................................. 15181 net protection pad ..............................................................................................................................15182 net life expiry......................................................................................................................................15183 maintenance support literature ...........................................................................................................152PREPARATION OF NET ....................................................................................................................... 15284 General ..............................................................................................................................................15285 Use of net pads ..................................................................................................................................15286 laying out the net ...............................................................................................................................152LOADING OF NET ................................................................................................................................. 15287 even loading.......................................................................................................................................15288 Uneven loading ..................................................................................................................................15289 low density items ...............................................................................................................................15290 fragile stores......................................................................................................................................15391 Sharp or rough edged loads ...............................................................................................................15392 flat sheets of metal ............................................................................................................................15493 Securing cord ties...............................................................................................................................15494 batteries and battery electrolyte .........................................................................................................15495 baseboards ........................................................................................................................................15496 Side wall netting .................................................................................................................................15497 Connecting-up to net stirrup ...............................................................................................................15598 Securing net lifting strops ...................................................................................................................155HELICOPTER HOOK-UP AND LANDING ............................................................................................ 15599 Checks before hook-up ......................................................................................................................155100 hooking-up .........................................................................................................................................156101 Single netted load ..............................................................................................................................156102 two-net cluster load ...........................................................................................................................156103 Precautions during initial lift ...............................................................................................................157104 Precautions during release ................................................................................................................157FLYING LIMITATIONS ........................................................................................................................... 157

CHAPTER 2 - 6 - 5: TYPICAL NETTED LOADS

TYPICAL NETTED LOADS ................................................................................................................... 158105 Composite ration packs ......................................................................................................................158106 Jerricans .............................................................................................................................................158107 45 gallon drum....................................................................................................................................159108 to prepare a load of seven drums ......................................................................................................160109 Carriage of single nato pallet loads .................................................................................................161

CHAPTER 2 - 6 - 6: SPECIFIED AUTHORISED LOADS

INTRODUCTION .................................................................................................................................... 162APFC’S .................................................................................................................................................. 162110 load preparation ................................................................................................................................162111 rigging ...............................................................................................................................................162CLASS 30 AND 60 TRACKWAY ........................................................................................................... 163112 load preparation ................................................................................................................................163113 rigging ...............................................................................................................................................163114 Second load .......................................................................................................................................163VEHICLES AND TRAILERS .................................................................................................................. 164115 load preparation ................................................................................................................................164116 rigging ...............................................................................................................................................164117 initial lift ..............................................................................................................................................164118 flying limitations .................................................................................................................................165

DAP 101A-1105-1A


METAL TRACKED OR STUDDED/WHEEL CHAINED VEHICLES AND USE OF DUNNAGE ........... 165119 Selection of dunnage .........................................................................................................................165120 Preparation and loading ....................................................................................................................165

figures

figure 80 - net protection pad - for use with 5600 kg net and 5000 lb net ...................................................128figure 81 - 5600 kg net basic layout .............................................................................................................129figure 82 - net suspended ............................................................................................................................130figure 83 - net lifting strop assemblies ........................................................................................................130figure 84 - Stirrup with net strop assembly lifting hooks engaged ................................................................131figure 85 - loading second net of two-net cluster ........................................................................................133figure 86 - net end wall formation with full and short loads ..........................................................................134figure 87 - nato pallet loading schemes .....................................................................................................135figure 88 - Cross-sectional view of load showing net side wall ‘holding tie’ .................................................137figure 89 - Stirrup engagement.....................................................................................................................138figure 97 - 5000 lb cargo lifting net ...............................................................................................................140figure 98 - Stirrup with all four hooks engaged .............................................................................................141figure 99 - typical netted load ......................................................................................................................143figure 100 - recommended design of baseboard ........................................................................................145figure 101 - Cross sectional view showing net side wall ‘holding tie’ ...........................................................146figure 102 - hooking-up single netted load...................................................................................................147figure 103 - 7000 kg net basic layout ...........................................................................................................149figure 104 - Stirrup with all four hooks engaged ...........................................................................................150figure 105 - typical netted load in flight ........................................................................................................152figure 107 - Cross sectional view showing net side wall ‘holding tie’ ...........................................................154figure 108 - hooking-up single netted load...................................................................................................155figure 109 - arrangement of composite ration pack load ..............................................................................157figure 110 - arrangement of maximum 89 jerrican load ................................................................................158figure 111 - arrangement of seven x 45 gallon drums ..................................................................................159figure 112 - Positioning of airportable fuel Containers (aPfCs) .................................................................161figure 113 - airportable fuel Containers (aPfCs) suspended in 5600 kg net ..............................................162figure 114 - Class 30 and Class 60 trackway in 5600 kg net ........................................................................162figure 115 - land rover (lr) in 5600 kg net ................................................................................................164figure 116 - Dunnage with boards abutting and overlapping ........................................................................165figure 117 - Dunnage with boards in foreground ..........................................................................................165

DAP 101A-1105-1A


CHAPTER 2 - 6: HELICOPTER CARGO LIFTING NETS AND NETTED LOADS

INTRODUCTION

this series of chapters deals with helicopter cargo lifting nets and their loads. there are currently three cargo lifting nets; 5000 lb, 5600 kg and 7000 kg. Purpose made net protection pads are also described at Chap 2-6-1.

NET PROTECTION

1 Generalthe cargo net is to be protected from damage the load may cause; this is achieved by the use of net Protection Pads (Chapter 2-6-1). felt, and other packing materials may also be used to prevent the net snagging on load protrusions, but is to be secured to the load such that it does not fall from the net in flight.

LOADS

2 The securing of itemsall loads that are contained and carried in any of the 5000 lb, 5600 kg and 7000 kg cargo nets must be secured so they are not able to fall from the net in flight.

Small items are to be secured within a suitable container within the cargo net and prevented from falling through the net mesh e.g. a wooden or metal box, a new mail bag or a new cargo lifting bag.

When using the cargo restraint net described in Chapter 2-8 to secure items, the net is not to be attached directly to the underslung cargo net, but is to be secured to the load pallet (if being used) or a suitable restraint point on the load.

WARNING ATTACHMENT OF THE RESTRAINT NET DIRECT TO THE UNDERSLUNG CARGO NET MAY LEAD TO NET OVERLOAD AND ULTIMATELY NET FALIURE.

3 Netted loadsloads carried in cargo lifting nets are commonly known as ‘netted loads’, and this method of carrying external cargo has certain advantages which are as follows:

most loads are fairly simple to prepare.

a wide variety of loads can be carried including mixed load items that can be lifted as a single unit. the 5600 kg and 7000 kg nets also have the capability of carrying certain types of vehicles, where slinging by other means may prove difficult in terms of finding suitable lifting points.

both high and low density loads can generally be lifted without affecting the flying characteristics of the helicopter.

4 Authorised loadson the basis of paragraph 1.3, it is normally unnecessary for netted loads to be specially cleared or test flown at JaDteU. as a result, cargo lifting nets are normally categorised as ‘authorised load’ equipments. the rules for ‘authorised loads’, together with the identification of loads/load carrying equipments which come into the category, are set out in Chapter 1; with regards to cargo nets, it is worth reiterating the following:

loads carried in specified cargo net equipments are treated as authorised loads providing that they conform with the type of load for which the equipment was designed. on this basis, flying characteristics can be reasonably guaranteed based on original trials. typical loads and loading schemes or loading parameters, are given in individual net chapters.

With such loads, although it cannot be guaranteed that they will remain stable at all speeds, providing the helicopter crew exhibits the normal caution that they would show for any new load, then they are unlikely to be confronted with the type of load which with little or no warning enters a severely unstable condition of flight.

DAP 101A-1105-1A


Cargo nets must not be flown empty. the minimum acceptable loads are discussed in each chapter referring to the particular equipment.

5 Specified Authorised Loadsthe 5600 kg net has been specifically designed for the carriage of nato pallets, JaDteU trials have confirmed that the net is suitable for the carriage of certain other specified equipments and vehicles, examples of which are given in Chapter 2-6-6.

6 Two net cluster loadtwo net cluster loads are not to be attached to a helicopter cargo hook. these loads are only to be lifted on the secondary swivel hook of an extension strop or masterlink assembly.

the stirrups of the two nets are not to be secured or tied together in any way as spinning of a two net cluster load leads to net separation which can cause the two stirrups to open like butterfly wings pivoting at the stirrup to stirrup tie. this action can force one stirrup past the hook keeper and off the hook.

Stirrups should be held together by hand, or attached to the secondary hook one stirrup at a time. alternatively, a single turn of 2 in. adhesive tape may be used to secure together the lifting strops of both nets just below the two stirrups.

GROUND OR DECK TRANSPORTATION

7 Generalloaded nets are very awkward to move on the ground or on a deck. ideally the net should be loaded at the pick-up point and the load broken down at the dropping point, but this is not always either practical or desirable. if a loaded net has to be moved flat bed vehicles or forklift trucks can be used.

8 Flat bed vehiclesthe net can be laid out on the flat bed of a truck or trailer, and once the load is complete the vehicle and the loaded net moved to the pick-up point. the net will then be picked up by the helicopter from the back of the vehicle. the helicopter lowers the net on to the vehicle and the vehicle is then moved to the unloading point.

9 Fork lift trucksif this method is being used then a baseboard (inside or outside the net) or a suitable pallet is essential.

10 Nets with baseboardsif the load is to be mounted on a baseboard for flight, the load should be prepared in the usual manner with the net well stretched out on the ground, the baseboard placed on the net and the load built up and secured, where necessary to the baseboard. the net is then to be well stretched around the complete load and the net strops taped to keep the net taut.

the complete assembly can then be picked up by a fork lift truck, by inserting the truck forks through the net immediately below the board and over the bottom part of the net; care must be taken to avoid the forks damaging the net.

When unloading (if the load has been secured to the board) it is usually more convenient to unhook the net and throw the sides clear of the load, then pick up the baseboard and its load leaving the net at the dropping point.

11 Nets without baseboardsthe net may be placed centrally over a baseboard or a pallet before being loaded, and the baseboard with the loaded net on top is then picked up and moved to the pick-up point. after pick-up the baseboard must be returned to the distribution point.

DAP 101A-1105-1A


CHAPTER 2 - 6 - 1: HELICOPTER CARGO NET PROTECTION PAD

INTRODUCTION

the helicopter cargo net protection pad’ (figure 80) is a custom made item, introduced for use with the 5600 kg cargo lifting net and also suitable for the smaller 5000 lb cargo lifting net. also available is a larger net protection pad specifically introduced into service for use with the 7000 kg net. the purpose of the pads is to prevent damage to helicopter cargo nets caused by sharp edges or protrusions on loads, and also to reduce damage to the load caused by net snagging. full nSn details for the equipment are contained in aP 108G-0002-1D: hUSle ancillary equipment.


12 Protection padsthe pads, are manufactured from PVC covered polyester fabric sheet (‘transilon’). eyeletted holes are spaced at intervals near the edges, allowing for the pad to be tied in position on the load (not to the net) and also for pads to be tied together. Pads are not issued with nets so should be demanded as separate items.

13 Maintenance support literaturemaintenance support literature for this equipment is published in aP 108G-0002-1D, hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

14 General usageUse of the pads is basically self-explanatory but the following points should be noted:

Pads should normally be used under the load as well as around the load. the method of use for the 5600 kg net is detailed in Chap 2-6-2.

inadequately secured pads are likely to be disrupted once the helicopter positions for load pick-up, and as a result could fail to provide the protection intended, and could also become detached and end up in the helicopter rotors. it is vitally important to ensure that the pads are well secured, held down firmly by the load and, where possible, tied securely to or about the load but never the net.

loose pads must never be left lying about in the vicinity of a helicopter pick-up/landing point as they could end up in a helicopters rotors.

figure 80 - net protection pad - for use with 5600 kg net and 5000 lb net

DAP 101A-1105-1A



INTRODUCTION

the 5600 kg helicopter cargo net is especially suitable for the carriage of nato pallet loads in multiples and for box shape container type loads. the net can also be used for the carriage of other specified loads and certain types of vehicles. the net is cleared for carriage under all current Service helicopters, except the Gazelle (all mks), Squirrel ht mk2 and subject to the limitations laid down in paragraph 15 to 17.


15 The 5600 kg netthe 5600 kg helicopter cargo net, square in shape, measuring 6.25 m x 6.25 m (20.5 ft x 20.5 ft) is constructed from 3569 kg (break strength) black nylon braid formed into a 200 mm (8 in.) knotless mesh.

RED CENTRELINE MARKERS

YELLOW CENTREMARKERSQUARE

STIRRUPRETAINING CORD

NET LOADING AXIS

NET LIFTING STROP ASSEMBLYWITH LIFTING HOOK

NET BORDER CORD

STIRRUP

figure 81 - 5600 kg net basic layout

the periphery of the net is fitted with a border cord, forming an integral part of the net and constructed from twin nylon braid. as an aid to correct alignment when loading the net, the net centre lines (running between opposite net edges) are identified by red nylon cord following the ‘zig-zag’ lines of the mesh, with the centre box indicated by yellow nylon cord.

a small metal plate, giving the life expiry date of the textile elements of the net, is attached to the mesh section

four composite lifting strop assemblies (each culminating at its upper end in a metal lifting hook) are attached to the net border cord, two assemblies each on the two net sides in question. the four lifting hooks of the combined net strop assemblies attach to a stirrup. the stirrup forms the connection between the net assembly and the load beam of the helicopter cargo hook or the secondary hook of a helicopter extension strop, and is attached to the apex of one of the net lifting strop assemblies by a nylon retaining cord.

the net is suspended from two of its four sides, folding about one centre axis, known as the loading axis as shown in figure 82.

DAP 101A-1105-1A


SIDE LOADING OF NETBEARING AGAINST LOAD

NET BORDER CORD FORMING ACONTINUOUS RUN AROUND THEFOUR SIDES OF THE NET

NET LOADINGAXIS

FORM TAKEN BY NETENDS END WALLING

figure 82 - net suspended

16 Net lifting strop assemblieseach of the four composite net lifting strop assemblies is made up as follows:

an inner and outer lifting member (both constructed from 45 mm width nylon webbing, folded and stitched for greater aerodynamic stability) are reeved through the eye of a parent lifting hook, to form four legs (figure 83).

ATTACHMENT OF STROP LEGAT BORDER CORD

LIFTING MEMBERFOLDED BACK ANDSTITCHED

STROP ASSEMBLY APEX

STROP ASSEMBLYLIFTING HOOK

RUBBING STRIP

KEEPER

figure 83 - net lifting strop assemblies

at their lower end the four legs are spaced out and formed into loops, each leg loop encircling the net border cord and stitched back onto itself.

at the apex of each strop assembly a length of nylon strap is stitched to the inside face of the inner lifting member (serving as an anti-chafe pad where the inner member bears against the lower rim of the lifting hook eye). a small piece of webbing is stitched across the apex of the loop to position the hook centrally on the lifting members.

DAP 101A-1105-1A


17 Net stirrupfor helicopter single point suspension operations, all four net strop assembly lifting hooks are attached to one stirrup only. the 5600 kg net stirrup is oval in shape and is manufactured from a one piece steel forging, which incorporates a crossbar dividing the stirrup into two approximately equal parts, referred to as the upper part and lower part. the frame and crossbar of the stirrup are predominately of the same circular cross section and thickness. the upper part of the stirrup accommodates the load beam of the helicopter cargo hook or the hook of a secondary extension strop.

engagement/disengagement of associated assembly lifting hooks is as follows (figure 84):

the lower part of the stirrup accommodates all four assembly lifting hooks. it is necessary for the hooks to be detached from the stirrup to allow the net to be laid flat with all four lifting strop assemblies lying clear of the mesh for the purpose of loading and unloading and to enable a thorough pre-flight and after use inspection of hook engagement/ disengagement.

the mouth of a serviceable net strop hook will not pass over any part of a serviceable stirrup structure other than at one intentionally ‘waisted’ section located on the lower part of the stirrup on one side frame, immediately below the stirrup crossbar.

a robust spring loaded metal safety latch, hinged to the crossbar, provides a close contact guard on the inside face of the ‘waisted’ section of the stirrup frame.

the safety latch is formed with a trigger shaped lever, which when depressed opens the latch against its spring. this enables the mouth of a net strop lifting hook to pass over the ‘waisted’ section, allowing the (larger) hook eye to pass onto the stirrup frame and to slide down captive to the base of the stirrup. Upon release, the spring loaded safety latch returns to its safe position at the ‘waisted’ section of the stirrup frame.

note figure 84 shows the ‘bills’ of the assembly lifting hooks all facing uniformly in one direction in their engaged position on the stirrup. this is not essential. the main criterion is that the lifting legs of the individual assemblies, are not twisted 360°, at the moment of engaging the hooks onto the stirrup.

for disengagement, the lifting hooks are slid up the frame to the ‘waisted’ section and with the safety latch depressed to the open position, are removed from the stirrup.

€30WAISTED€31 SECTION

SAFETY LATCH WITHTRIGGER

LOWER PART ACCOMMODATINGASSEMBLY LIFTING HOOKS

UPPER PART FOR ENGAGEMENT ONTOHELICOPTER CARGO HOOK OR ASECONDARY EXTENSION STROP

STIRRUPRETAINING CORD

figure 84 - Stirrup with net strop assembly lifting hooks engaged

WARNING IT IS DANGEROUS FOR THE LOWER PART OF THE STIRRUP TO BE USED AS THE MEANS OF ENGAGING A HELICOPTER CARGO HOOK OR THE SECONDARY HOOK OF A HELICOPTER EXTENSION STROP.

DAP 101A-1105-1A


ASSOCIATED EQUIPMENT

18 Retainer breakawaythe retainer breakaway assembly is fully described in Chapter 2-7 and comes pre-fitted to a net lifting member. the 5600 kg net lifting members are retained together in a compact and manageable form, prior to hook-up to the helicopter.

19 Pad, protection, helicopter cargo nethelicopter net protection pad equipment is an issue item for the 5600 kg net and is fully described in Chapter 2-6-1. the pads protect the net from damage which may be caused by sharp edges and protrusions on the load snagging in the net, and also provides a measure of protection for the load. full nSn details for the equipment are contained in aP 108G-0002-1a.

20 Life expiry of netthe 5600 kg net is fitted with a label which is attached to the net mesh. the label records the net life expiry date: all nets are to be taken out of Service when reaching their life expiry date and action taken in accordance with the procedures laid down in hUSle aP’s.

21 Net storageStorage instructions for the 5600 kg net are contained in aeSP 1670-h-100.

WARNING THE NET MAY BE SUBJECT TO SNATCH LOADING OR DRAGGING ALONG THE SURFACE DURING LOAD LIFTING OR LOAD LANDING OPERATIONS. DELAYING THE REPAIR OR REPLACEMENT OF FAULTY EQUIPMENT COULD RESULT IN SERIOUS INJURY TO PERSONNEL OR SERIOUS DAMAGE TO EQUIPMENT.

22 Technical support literaturefull technical supporting literature for this equipment, including before and after use examination, general care, unit repairs and fitment instructions for component parts, technical inspection procedures and any Service modification action or other changes, is published in aP 108G-0002-1a. Chapter 1-2 gives general advice on obtaining aeSPs.

PREPARATION OF NET FOR CARRIAGE OF NATO PALLETS

23 Net handlersthe 5600 kg net is large, heavy and difficult to manage without an adequate net handler team. experience has shown that a team of six men is the ideal, allowing for hooking-up to the helicopter and for subsequent load lifting.

24 Laying out the netWhen operating in a Chinook uplift area do not lay out nets and net protection pads until the loads are assembled. empty nets and protection pads could be blown away creating the added danger that loose protection pads could be drawn up into a helicopter’s rotors.

When ready, stretch the net out flat on the ground with all four strop assemblies pulled out into an untangled form, ensuring they are uncrossed and clear of the net. Do not leave the net strop assembly lifting hooks engaged on the net stirrup. to reduce wear and tear, a reasonably firm and flat grass surface is preferable to hardstanding.

before laying out the net protection pads pull the net into a square, ensuring the net mesh is not in an elongated diamond form.

25 Setting up a two-net cluster loadWhen preparing a two-net cluster load complete the laying out, loading and securing process on the first net before laying out and loading the second net; allowing the second net to be prepared in close formation to the first, resulting in both nets presenting a compact load for lifting. this allows an easier hook-up operation and prevents unnecessary damage to the nets and loads caused by the nets dragging in towards each other as the helicopter lifts them clear of the ground (see paragraph 22).

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26 Preparing the second netWith the first net loaded and secured ready for lifting, the second net of a two-net cluster load is built immediately alongside the first (see paragraph 21) with the loading axis/lifting sides of both nets aligned as shown (figure 85).

FIRST PALLET OF

FOUR PALLET LOAD

IN SECOND NET

LOADING AXIS OF SECOND

NET WILL LIE CLOSER TO SIDE

OF FIRST NET LOAD FOR A

SINGLE ROW OF PALLETS

LOADING AXIS OF BOTH

NETS LYING PARALLEL

FIRST NET WITH A

SIX PALLET LOAD

LIFTING STROP ASSEMBLIES

OF SECOND NET DRAPED

OVER FIRST NETTED LOAD

figure 85 - loading second net of two-net cluster

With the second net of the cluster laid out, carry out the remaining net preparation, loading, net pad and net side wall securing procedures.

Secure the assembled net lifting strop assemblies on the second net, using the net retainer breakaway. the lifting strop assemblies of both nets should be held together, to the side of the combined load, in readiness for hooking-up.

note: trials have shown that, with a maximum load variation of six laden pallets in one net and a single laden pallet in the other, flying characteristics remain unaffected.

LOADING OF NATO PALLET LOADS AND NET SECURING

27 Generalloads should be evenly distributed about and along the line of the loading axis, with the longest sides or (for cylindrical items) rolling axes running parallel to the loading axis (unless specific load clearance shows otherwise). heaviest items should be as close to the centre of the net as possible.

When fitted the net must provide end restraint for the assembled load in the form of a mesh wall. for normal length loads, the net only provides a limited depth of end walling; this is satisfactory for pallet or container loads in a single layer where the load is secured at its base within the end net walling.

in the case of free layered or free stacked loads where they rise clear of the end walling, net side wall pressure may provide a useful ‘binding’ effect on the load.

With certain types of load suitable load lashing schemes for end restraint are required. With shorter length loads end sections of the net will form into large vertical folds (figure 86).

the safe practices covered under load preparation for the 5000 lb octagonal cargo lifting net (Chapter 2-6-3) have a similar application for the 5600 kg net.

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SHOWING NET END WALL ANDBORDER CORD FORMATION WITHFULL LOAD LENGTH OF PALLETS

SHORTER LOAD SHOWING LOOSEFOLDS OF NET END WALLS

figure 86 - net end wall formation with full and short loads

28 Even loadingthe safety of the net depends upon the load weight being reasonably distributed in terms of mesh loading across the net. Uneven loading could, if significantly disproportionate, be dangerous at higher laden weights, particularly if the net is lifting the load at snagging points where mesh severance or failure could easily occur with a risk of the failure spreading.

29 Sharp edged loadsCarriage of such loads without suitable net protection can result in severe damage to the net, particularly at potential load snagging points. the resulting damage could lead to an in-flight hazard (see Chapter 2-6-1 concerning net protection pads).

30 Low density itemsUnless adequately secured there is always the danger that airflow may propel low density load items out of the net (this has a particular bearing in relation to the end restraint factor for the 5600 kg net): under certain conditions such unsecured items could hazard the aircraft.

31 Securing cord tiesUnless a specific load clearance states otherwise or a specific practice is highlighted in this chapter, do not use the net mesh or net border as anchoring points for ‘securing-cord ties’. they may interfere with the natural position that the net mesh or net border cord should adopt as it comes into tension about the load. although the ‘securing-cord tie’ may snap the net braid may also sustain damage, including heat searing, as a result.

32 Loading schemesthe correct layout of laden nato pallets in the 5600 kg net is shown in figure 86; 1, 2, 3, 4 and 6 (max) pallet loads can be carried in a netted load. all loads on pallets must be securely restrained to the parent pallets by ‘banding’ or restraint lashings.

the total assembled weight of the load for carriage in the net is not to be less than 450 kg, with the total assembled weight of the load for carriage in the net is not to exceed 5600 kg. ideally pallet loads should be of uniform weight for any one net load.

if there is no alternative, then the maximum difference in weight not exceeding 450 kg may be accepted between the heaviest and lightest laden pallet in the loads. When dealing with 3 or 6 pallet loads, place the heaviest pallet in the centre.

the loading schemes do not allow stacking of pallets in two layers, or the carriage of 5 laden pallets in a net; 5 pallets do not allow a balanced load, causing pallet crushing and a misshapen net when the load is suspended. nato pallets are to be loaded in the net with their longer sides running parallel to the loading axis.

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33 Net protection padsthere is to be one protection pad per pallet and they are to be laid out with their longer sides running parallel to the net loading axis. When working in multiples, the net pads are to be set end to end, or side to side in the case of two pallet rows, and are to be secured to the load and not to the net.

the centre axis of the total net pad assembly should straddle the centre axis of the net and the loaded pallets are to be placed squarely on top of the assembled net pads.

2 x NATO PALLETS1 x NATO PALLETS

3 x NATO PALLETS 4 x NATO PALLETS

6 x NATO PALLETS

NET LOADING AXIS

figure 87 - nato pallet loading schemes

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34 Like loadsthe clearance for nato pallet loads extends to the carriage of box shape container loads with minimum base dimensions approximately equal to nato pallets. the same loading principles are to be adhered to, and the container(s) must be loaded as a single layer load. When assembled in the net the load must not exceed the maximum length and breadth dimensions of an assembled load of six nato pallets with a maximum height from floor of net of 70 in. refer to paragraph 16 for weight information.

note Certain types of box container may not be suitable for movement by fork lift and another form of ground handling aid will be necessary; the requirement to avoid damaging the net in any way during load placement or removal remains paramount.

35 Net loading process - single net upliftsfork lift the pallets onto their allocated positions on the net. fork lift vehicles and load handlers will tend to ‘ruck’ the net. Keep the net pulled out evenly as loading progresses.

net centre line markers play an important part and are to be kept in good order and replaced as necessary.

CAUTION Erratic handling of the fork lift can result in serious damage to the net border cord or mesh. Avoid wheel spin or unnecessary turning on the net and ensure the forks are raised when departing the net.

36 Fork lift operationit is recommended that a fork lift approaches from the net lifting strop side with pallets forked broadside-on. this allows greater accuracy of the load placement. When approaching from this direction, the net lifting strop assemblies are opened out as far as possible. When passing over any section of strop leg, fork lift drivers are to avoid the apex of strop assemblies where strop lifting hooks and restrictor buckles are located. this also applies when reversing off the net.

37 Securing net pads around loadSecure the outlying stretches of net pad up and around the walls of the loads. Join the edges of the pad together using cord ties. Secure the padding firmly in position against the side and end walls of the load using cord ties directly to the load or over-the-load to the opposite net pad. Upon completion the bottom outer corners of the assembled load should be firmly contained within the net protection padding.

CLOSING AND SECURING THE NET AND NET STROP ASSEMBLIES

38 Side wall nettingWhen loading and protection pad securing is complete, the lifting sides of the net are to be pulled up against the side walls of the load, ensuring they are firm and even along their length. hold the net side walls in position against the load using up and over-the-load 1200 lb ‘holding-ties’ to secure opposite sides of the net around the load side walls (figure 88).

this will reduce the work load on the net handling team during the initial stage of the helicopter lifting process and as an aspect of load preparation should help reveal snagging points and the need for extra protective padding (which will have to be secured to the load). When lifted, the netted load is under tension and the net side wall ‘holding ties’ will automatically slacken off until the load is returned to the ground and tension removed.

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LIFTING SIDE OF NETLIFTING SIDE OF NET

NET SIDE WALL 1200 lb NBC €30HOLDINGTIE€31(SECURED TO INNER FACE OF NET MESH EACH SIDE OF LOAD,

ABOUT ONE FOOT DOWN IN RELATION TO TOP OF LOAD SIDE WALLS)

NET PROTECTION PAD

figure 88 - Cross-sectional view of load showing net side wall ‘holding tie’

39 Connecting-up to net stirruplocate the net lifting strop assembly, to which the net stirrup is secured. engage the assembly lifting hook onto the stirrup lower part by depressing the stirrup safety latch lever and engaging the hook at the ‘waisted’ section of the stirrup side frame. Check that the legs of the connected assembly are not twisted through 360° or more.

taking a clockwise or anti-clockwise order of precedence (related to strop assembly mounting points around the net border cord) engage the remaining strop assembly lifting hooks onto the lower part of the stirrup. Check that the individual assemblies are not twisted through 360° or more before engaging their hooks. it is not mandatory for the mouths of the lifting hooks to point uniformly when engaged on the stirrup. When all hooks have been engaged ensure the safety latch has returned to the fully closed position.

40 Securing net strop assembly legsto make net lifting strop assemblies more manageable for helicopter hook-up and during initial stage of lift, secure the legs together using the retainer breakaway assembly starting at the stirrup. if the retainer breakaway assembly is not fitted, secure by taping the legs together at intervals along their length starting from the top.

HELICOPTER HOOK-UP AND LANDING

WARNING A HAZARD EXISTS FROM STATIC ELECTRICITY. BEFORE THE HOOKING-UP PROCESS OF AN EXTERNAL LOAD AND OTHER ALLIED FUNCTIONS, STATIC ELECTRICITY MUST BE DISCHARGED BY THE USE OF A STATIC ELECTRICITY DISCHARGE PROBE (SEE CHAPTER 5).

WARNING IT IS DANGEROUS FOR THE LOWER PART OF A STIRRUP TO BE USED AS THE MEANS OF ENGAGING A HELICOPTER CARGO HOOK OR THE SECONDARY HOOK OF A HELICOPTER EXTENSION STROP.

WARNING THERE IS A DANGER TO PERSONNEL OF SLIPPING OR GETTING ENMESHED IN A BILLOWING NET IF HELICOPTER HOOK-UP IS CONDUCTED FROM THE TOP OF A NETTED LOAD. WHENEVER POSSIBLE HOOK-UP IS TO BE CARRIED OUT TO ONE SIDE OF THE NETTED LOAD.

CAUTION When employing the 5600 kg net for helicopter single point suspension operations, all four net lifting strop assembly hooks must be connected to one net lifting stirrup.

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CAUTION For single net uplifts the net stirrup may be attached either directly to the helicopter cargo hook or to the secondary hook of a helicopter extension strop. A cluster of two 5600 kg net loads must always be suspended from the secondary hook of a helicopter extension strop or by such other means as a specific JADTEU clearance may allow.

41 Hooking-up single net loadsthe 5600 kg stirrup is a heavy item and, whilst it may be attached to the helicopter cargo hook or extension strop hook using one hand, most people will probably find it easier to use two hands.

ensure that the combined assembly of net lifting legs is not twisted along its run by 360° or more. Grasp the lower half of the stirrup side frame, so that the fingers are above the engaged net strop hooks and below the stirrup crossbar (figure 89). Visually check that the stirrup safety latch is fully closed at the ‘waisted’ section of the side frame.

to hook up, place the upper half of the stirrup firmly over the helicopter cargo hook or, if being used, the secondary hook of the helicopter extension strop. With the stirrup fully engaged on the helicopter cargo hook or the extension strop hook, check that the hook keeper has returned to the fully closed position.

STATIC PROBE

GLOVES

HOOK KEEPER

figure 89 - Stirrup engagement

42 Hooking-up a two-net cluster loadWith a two-net cluster load full of pallets, it is still possible to conduct the helicopter hook-up operation from the side of the combined load.

avoid hooking-up with substantial twists in the assembled legs of each net as the twists may not be removed by the loads freedom to rotate beneath the helicopter on the extension strop swivel hook.

When engaging the stirrup of each net personnel may be able to hold both stirrups together and engage them onto the helicopter extension strop hook in one operation, although it is easier to engage one stirrup at a time. engage the stirrups onto the extension strop swivel hook in the order that the nets lie with reference to the helicopter’s likely departure path. more significantly this is a means of avoiding wear on the net lifting strop assemblies and ensure the lifting legs on the individual nets are not badly twisted.

the checks and correct manner of engagement for each stirrup, on the helicopter extension strop hook are stated in paragraph 30.

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43 Precautions during initial liftthere must always be sufficient ground handlers to manage any loose netting and to prevent snagging during the initial stage of load pick-up. the 5600 kg net is a large net to handle and in addition to the need for good load preparation techniques, a team of four men is fully employed during the initial stage of lift with a large load. the success, or otherwise, of loading and net protection measures will not become evident until helicopter uplift. at any stage, where poor loading or bad net snagging becomes evident, the load must be returned to the ground and released if necessary, to enable re-preparation.

WARNING TO AVOID THE DANGER OF BEING STRUCK BY THE POTENTIALLY LETHAL METAL ELEMENT OF A STIRRUP OR EXTENSION STROP ASSEMBLY, GROUND PERSONNEL ARE TO KEEP CLEAR OF THE LOAD RELEASE AREA DURING NET RELEASE.

44 Precautions during net releasefollowing net landing the helicopter crewman will attempt to release the net stirrup (and helicopter extension strop if employed) clear of the load to avoid possible damage to the load.

if the net stirrup is to be manually disengaged from an extension strop, whilst the strop remains attached to the helicopter, it is important that reference is made to Chapter 2-3.

45 Net dragging during load pick-up and landingthe helicopter crew, ground marshallers and load preparation team (when dealing with the cluster loads), should ensure that the netted load(s) are not dragged along the ground during lift-off or landing. Wear or serious damage can result particularly with heavy loads, and it is important if dragging has occurred, that the net(s) receive a thorough and early after-flight inspection.

FLYING LIMITATIONS

46 The 5600 kg net the 5600 kg net is not to be underslung unladen: an empty net deploys rapidly towards the horizontal at a speed as low as 30 kts, with the subsequent danger that it may be drawn up into the helicopter rotors.

47 Weightthe weight of cargo should not be less than 450 kg (1000 lb) in total, and this in turn should be related to the drag profile presented by a normally stacked single nato pallet load. for loads of the same weight but with a larger surface area, the stability characteristics may prove less predictable than the standard nato pallet load.

Certain low drag, high density loads with a total cargo weight lower than 450 kg, may prove acceptable. Ultimately, the safe carriage of any ultra-low density/ultra-lightweight load will depend on the speed at which maximum allowable trail angles are attained and the speed at which any deterioration in load handling characteristics takes place.

48 Cluster loadsWith two nets in cluster loads net separation can occur at the higher speed range, so the speed at which the load is carried must be limited by the onset of this phenomenon.

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CHAPTER 2 - 6 - 3: HELICOPTER CARGO LIFTING NET - 5000 LB SWL

INTRODUCTION

the 5000 lb cargo lifting net is designed to contain and lift external cargo loads up to a maximum weight of 5000 lb, suspended from the load beam of a helicopter cargo hook or extension strop secondary hook. it can be used on all current british helicopters and is in use with the three Services.


49 The 5000 lb Netthe complete net assembly (figure 97) consists of an octagonal-shaped net made from nylon braided Cord (nbC) to which are attached four, four-legged nylon webbing lifting strops each with a steel hook attached. the eye of one of these strops is permanently connected by a nylon cord grommet to a steel stirrup or loading ring, to which the four hooks can be attached for net closure and lifting. the dry weight of the net is 45 lb.

YELLOWMARKER

RED CENTRELINE MARKER

HOOK ANDSTIRRUP

HOOK

OUTER LIFTINGMEMBER

INNERLIFTING MEMBER

BORDER CORD

figure 97 - 5000 lb cargo lifting net

the nbC is coreless, with a minimum breaking strain of 3500 lb, and is interlaced to form a net mesh of approximately 6 in. the periphery of the net is fitted with a border cord (corresponding to the headrope of a conventional net) which forms an integral part of the net; it is coreless braided nylon, with a minimum breaking strain of 7000 lb.

owing to the construction of the net and to changes in dimensions that may occur in use it is impossible to

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give the exact dimensions but, when laid out flat, there will be a distance of between 14 ft 9 in. and 15 ft 5 in. between the opposing flats of its octagonal perimeter.

During manufacture, the nylon cord is given an anti-abrasive treatment which can cause some stiffness of the cord, but this effect diminishes through use and does not affect the strength or handling qualities of the net to any material extent.

50 Lifting stropseach of the four strops is formed from two lengths of nylon webbing both passed through the eye in its hook. a small piece of webbing is stitched across the apex of the loop to position the hook centrally on the lifting members.

the four ends of each lifting member are attached to the border cord by folding back and stitching so that the four hooks can suspend the net from 16 points around the perimeter.

51 Stirrup and hooksthe stirrup forms the connection between the net and the load beam of the helicopter cargo hook or extension strop secondary hook. it is constructed from one piece of steel, which incorporates a cross bar dividing the stirrup into two approximately equal parts: the upper part and the lower part (figure 98). the frame and the crossbar are of a circular cross section.

the stirrup upper part engages the load beam of a cargo hook or extension strop secondary hook. the lower part accommodates the four hooks.

figure 98 - Stirrup with all four hooks engaged

the stirrup is fitted with a robust spring loaded metal safety latch which is hinged to the crossbar, with a ‘waisted’ area positioned on the stirrup side frame immediately adjacent to the safety latch. the safety latch is formed with a trigger shaped lever, which when depressed opens the latch and enables engagement or disengagement of the strop hooks.

each of the four hooks is made from flat steel plate. the hooks can be readily detached from or attached to the stirrup when required. the removal of the hooks from the stirrup allows the net to be laid out flat for loading purposes with all four strops clear of the net, but all hooks must be attached to the stirrup before the net is lifted.

the lower portion of the stirrup is of sufficient size to allow it to be held by hand with the fingers clear of the hooks and below the crossbar so that hook-up can be effected without trapping or pinching the fingers. it is normally easier to use two hands to engage the stirrup.

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the mouth of a serviceable/non-defective net hook will not pass over any part of its associated stirrup structure (assuming that item is serviceable) other than via the ‘waisted’ section.

it is not essential that the stirrup hooks are facing uniformally in one direction; the most important consideration is that the net lifting strop legs are not twisted in a complete 360° turn about themselves when the hook is engaged to the stirrup.

52 Retainer breakawaythe retainer breakaway assembly is fully described in Chapter 2-7 to ensure the 5000 lb net lifting strops are retained together in a compact and manageable form, prior to hook-up to the helicopter.


53 Net protection padhelicopter net protection pad equipment is an issue item for the 5600 kg net and is fully described in Chapter 2-6-1. the pads protect the net from damage which may be caused by sharp edges and protrusions on the load snagging in the net, and also provides a measure of protection for the load. full nSn details for the equipment are contained in aP 108G-0002-1a.

54 Net life expirythe 5000 lb net is fitted with a metal label which is woven into the net mesh: the label records the net life expiry date. all nets are to be taken out of Service when reaching their life expiry date and action taken in accordance with the procedures laid down in aeSP’s.

55 Maintenance support literaturefull maintenance supporting literature for this equipment is published in aP108G-0002-1a: hUSle nets. Chapter 1-2 gives general advice on obtaining aeSP’s.

PREPARATION OF NET

56 General although one of the advantages of the net is that loads are easily and relatively quickly prepared, this does not mean that the load items can simply be piled into the net: for safety reasons and to obtain maximum life from the net, some basic principles must be followed when preparing the netted loads.

these principles, together with notes on general load items, use of baseboards and the transportation of a loaded net on the ground, are covered in the following paragraphs and some typical netted loads, with instructions on loading, are also shown in this chapter.

57 Use of net padsWhenever possible net pads should be used; the practical use of these items is shown in Chap 2-6-2 (5600 kg net), and also in USlC 3052: nato Palletised loads in Clusters in DaP101a-1105-1b.

58 Laying out the netthree hooks should be detached from the stirrup and the net stretched out flat on the ground with all four lifting strops clear of the net. the net must be kept stretched during loading; with multi-item loads, it should be pulled taut at intervals as loading progresses. When loading is complete the net, when lifted by its lifting strops, must encompass the outer corners of the load items such no part of the load contacts the strops.

note Users will have to use their best judgement as to how to assemble a pair of net loads for uplift (paragraph 73). See paragraphs 69 and 73 and Chapter 2-6-2 provides some worthwhile considerations when making up two nets alongside each other for direct uplift as a pair by the helicopter.

LOADING OF NET

59 Even loadingload items should be evenly stacked around the centre of the net in a near circular pattern to accord with the

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octagonal shape of the net (if possible). if items of varying height are to be carried, the higher items should be in the centre of the net load.

60 Uneven loadingif the net is loaded unevenly when lifted some portions of the net will be taking more weight than others, which will result in some lifting strops and some portions of the net taking unequal shares of the load; this is particularly dangerous when near or at the maximum load of 5000 lb. to mitigate this place heavier items near the centre of the net.

Uneven loading may not be obvious until the helicopter starts to lift when it becomes immediately apparent by the over-tautness of some cords with comparative slackness in others. Pulling the net tightly away from the load during the initial lift will help reduce the bad effects but the only certain cure is to rearrange the load.

note the safety of the net depends upon the weight being evenly distributed over the net as a whole; if this is disregarded, a failure at one point could lead to failure of the whole net.

61 Low density itemsWhen a net is correctly loaded with a large number of small items it adopts a deep inverted saucer-like shape in flight (figure 99). Provided that the individual load items are tightly packed against each other, and the outer edges of the net enclose the outer packages, there is little danger of spillage. in fact, the outer edges of the net (being pulled inwards) help to hold the whole load together as a solid mass.

figure 99 - typical netted load

With low density items such as empty jerricans, empty drums or similar items of comparatively large size and little weight, there is a real danger that the airflow will force them out of the open top of the net.

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it is essential that such loads be lashed together but not tied to the net, or the qantity reduced so that the top of the net effectively encloses them. alternatively they can be wrapped in net protection pads, tarpaulins, or or hessian, provided they are securely parcelled and tied.

62 Fragile storesfragile stores can easily be crushed by the net and so damaged. in this case, ‘fragile’ or ‘flimsy’ applies to such items as fresh rations, thin-walled plastic fuel or water containers, or equipment that has delicate protrusions such as radio aerials etc.

apart from packaging such items in protective containers, crushing can be prevented by placing them on a locally manufactured circular baseboard or pallet and tying them to the base; a suitable baseboard is described in paragraph 65.

63 Sharp or rough edged loadsSharp or rough edges of load items will cut the nylon cord/mesh of the net; ammunition boxes are common offenders. all sharp edges of items must be encompassed within net pads or be padded with felt, sandbags, or other suitable material to avoid damage to the net when the load is lifted and in transit under the helicopter. Padding can be kept in place by the use of masking tape; net pads are manufactured with eyeletted holes around the edges, allowing for the pad to be tied in position on the load (not to the net) and also for pads to be tied together.

64 Flat sheets of metalflat thin sheets of metal such as corrugated iron sheets and similar material are not to be loaded into nets unless:

64.1 the sheets are tightly lashed or banded to form one dense load.

64.2 all sharp edges, particularly the corners, are padded.

64.3 the total weight of the load exceeds 500 lb.

65 Securing cord tiesUnless a specific load clearance states otherwise, or a specifically highlighted in this chapter, do not use the mesh or net border cord as anchoring points for ‘securing cord ties’; they may interfere with the natural position the net mesh or net border cord should adopt as it comes into tension about the load. although the ‘securing cord tie’ may simply snap (no longer serving the purpose for which it was possibly intended) the net braid may also sustain damage including heat searing as a result.

66 Batteries and battery electrolytemost acids will rapidly rot the net and must not be allowed to come into contact with it. the net material is particularly susceptible to sulphuric acid and net failures are known to have occurred due to contamination by this acid, probably arising from contact with battery electrolyte.

Wet batteries (acid or alkali) and containers of battery electrolyte must be prepared for lift in accordance with current instructions for air transportation of Dangerous Cargo.

67 Baseboardsa circular wooden baseboard that can be placed inside the net is shown in figure 100, which provides sufficient information for its local manufacture. this baseboard can advantageously be used for:

67.1 Crushable loads.

67.2 Delicate loads.

67.3 awkward or difficult-to-load loads such as engines, flexible fuel tanks, batteries, radios, etc.

Using a baseboard imposes a weight penalty that must be taken into account. figure 100 gives the maximum permissible outside diameter compatible with normal load containment and smaller (and lighter) baseboards can be constructed when required. other wood can be used, but to gain strength equivalent to that of plywood will usually impose a greater weight penalty.

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the essentials are:

Sufficient strength to carry the load when supported by its edges alone.

Sufficient holes to allow adequate lashing down of load items.

12 in.

6 in.

4 in.

A

B

C D E

CONSTRUCTION

A & B - TWO 5/8 in. PLYWOOD SHEETS 8 ft X 4ft STANDARDSIZE CUT TO TWO 6 ft DIAMETER HALF CIRCLES

C & D - 3 1/2 in. X 2 in. HARDWOOD BEARERS POSITIONEDUNDERNEATH BASEBOARD TO HOLD THE TWO HALVESTOGETHER AND GIVE CLEARANCE FOR THE FORKS OF AFORK LIFT TRUCK

E - 1 in. DIAMETER HOLES DRILLED 4 in. IN FROM EDGE OFBASEBOARD APPROXIMATELY 12 in. BETWEEN PAIRS AND6 in. BETWEEN HOLES

figure 100 - recommended design of baseboard

if fork lifting is envisaged, the height of the cross-members must be sufficient to allow the forks of the fork lift truck to pass under the board and clear of the net. the height of the cross-member shown in figure 100 is the absolute minimum for this purpose.

note it is essential that the net is well stretched under the baseboard before starting to build the load up on the baseboard.

68 Side wall nettingWhen loading and protection pad securing is complete, the lifting sides of the net are to be pulled up against the side walls of the load ensuring it is firm and even along its length.

hold the net side walls in position against the load by using up and over-the-load ‘holding ties’ to secure opposite sides of the net about the load side walls (figure 101). this will reduce the work load on the net handling team during the initial stage of the helicopter lifting process and as an aspect of load preparation should help reveal possible snagging points and the need for extra protective padding (which will have to be secured to the load).

When lifted, the netted load is under tension and the net side wall ‘holding ties’ will automatically slacken off until the load is returned to the ground and helicopter lifting tension removed.

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figure 101 - Cross sectional view showing net side wall ‘holding tie’

69 Connecting-up to net stirruplocate the net lifting strop to which the net stirrup is secured. engage the lifting hook onto the stirrup lower part by depressing the stirrup safety lever and engaging the hook at the ‘waisted’ section of the stirrup side frame. Check that the lifting members of the connected lifting hook are not twisted through 360° or more. taking a clockwise or counter clockwise order of precedence (related to lifting strop mounting points around the net border cord) engage the remaining lifting hooks onto the lower part of the stirrup. Check that the individual lifting members are not twisted through 360° or more, before engaging their hooks.

it is not mandatory for the mouths of the lifting hooks to point uniformly when engaged on the stirrup. When all hooks have been engaged ensure the stirrup safety latch has returned to the fully closed position.

70 Securing net lifting stropsto make net lifting strops more manageable for helicopter hook-up and during the initial stage of lift, secure their legs together in combined form using the retainer breakaway starting at the stirrup end. if a retainer breakaway is not fitted, secure by taping the legs together, at intervals along their length, starting from the top.


the following paragraphs 74 to 80 deal with those precautions to be observed before and during hook-up, flying and release.

71 Checks before hook-upimmediately before hook-up the following items must be checked.

71.1 the net is serviceable.

71.2 the all Up Weight (aUW) is known; this is the total weight of all items plus the weight of the net.

71.3 no exposed sharp edges can damage the net.

71.4 any items of comparatively large volume and light weight, ie low density items such as empty jerricans or empty drums, are positively secured in the net.

71.5 net lifting strops are taped together, or held by a retainer breakaway so that they cannot catch on any projecting portions of the load during the initial stages of lift.

71.6 the net is as evenly loaded as possible.

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it is permissible to lift clusters of two or more nets at once. each net is to weigh approximately the same, and the load in each net is to be of approximately the same bulk, ie the loads should be of approximately equal density and weight. refer to USlC 3052: nato Palletised loads in Clusters in DaP101a-1105-1b for details.

however, in order to safely accommodate the net stirrups of a two or more net cluster the use of an extension strop with swivel hook is manDatory.

72 Hooking-upa hazard exists from static electricity.

WARNING ALWAYS USE A STATIC PROBE PRIOR TO HOOK-UP OR BEFORE HANDLING A SUSPENDED LOAD.

73 Single netted loadhold the stirrup so that the operators fingers are above the hooks and below the crossbar, slide the upper part of the stirrup over the extended forward portion of the load beam of the cargo hook, then slide it aft past the spring-loaded hook keeper latch: to confirm that the stirrup is engaged correctly pull back the stirrup and ensure it does not disengage (figure 102).

note the load beam is never to be engaged in the lower portion of the stirrup.

figure 102 - hooking-up single netted load

74 Two-net cluster loadavoid hooking-up with substantial twists in the lifting strops of each net, as the twists may not be entirely removed as the result of the loads freedom to rotate on the helicopter extension strop swivel hook.

When engaging the stirrup of each net it may be able to hold both stirrups together and engage them onto the helicopter extension strop hook in one operation, but could be easier to engage one stirrup at a time.

engage the stirrups on to the extension strop swivel hook, in the order that the nets lie with reference to the helicopters likely departure path, and by ensuring the lifting stropes on the individual nets are not badly twisted this avoids wear on the net lifting member.

the checks and correct manner of engagement for each stirrup on the helicopter extension strop hook are as stated in paragraph 74.

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75 Precautions during initial liftCare must be taken that the lifting strops of the net do not catch or snag on any projection of the load. taping the lifting strops will assist in keeping them clear but it may be necessary for personnel to assist by holding the lifting strops and the upper portion of the net tight and clear of the load as the helicopter takes the weight.

With some loads it is difficult to prevent individual parts of the net from being overloaded but every effort must be made to prevent this. ideally each cord length should be of equal tension, but this is impossible to achieve exactly in practice. if one or two cords in any one area of the net are taut while adjacent cords are comparatively slack, the net must be adjusted to equalise the tension as far as possible.

marshallers, crewman and pilots must ensure that the helicopter cargo hook is central over the loaded net before the helicopter starts to lift; if it is not the load will be dragged along the ground with consequent wear and even breakage of the net where it rubs on the ground.

76 Precautions during releasemarshallers, crewman and pilots must ensure that the helicopter is stationary in relation to the ground before release and that the net is lowered gently to the ground, otherwise, the net will drag and wear will be caused: if the load is dropped the net may be cut by edges or corners of the load items.


following net landing, the helicopter crewman will attempt to release the net stirrup and helicopter extension strop (if used) clear of the load to avoid possible damage to the load.

if the stirrup is to be manually disengaged from an extension strop whilst the strop remains attached to the helicopter, it is important that the static electricity discharge procedure be carried out (Chaper 5).

FLYING LIMITATIONS

WARNING THE 5000 LB NET IS NOT TO BE UNDERSLUNG UNLADEN. THE EMPTY NET DEPLOYS RAPIDLY TOWARDS THE HORIZONTAL AT A SPEED AS LOW AS 30 KTS, WITH THE SUBSEQUENT DANGER THAT IT MAY BE DRAWN UP INTO THE HELICOPTER ROTORS.

the weight of cargo should not be less than 227 kg in total, and this in turn should be related to the drag profile presented by a normally stacked single nato pallet load.

for loads of the same weight but with a larger surface area, the stability characteristics may prove less predictable than the standard nato pallet load. Certain low drag, high density loads, with a total cargo weight lower than 227 kg, may prove acceptable.

Ultimately, the safe carriage of any ultra-low density/ultra-lightweight load will depend on the speed at which maximum allowable trail angles are attained and the speed at which any deterioration in load handling characteristics takes place.

With two nets in cluster loads, net separation can occur at the higher speed range and the speed at which the load is carried, must be limited by the onset of this phenomenon.

DAP 101A-1105-1A



INTRODUCTION

the 7000 kg helicopter cargo net is designed to carry cargo for carriage by helicopter as an Underslung load to a maximum gross weight of 7000 kg.


77 The 7000 kg netthe 7000 kg helicopter cargo net, square in shape, measuring 7.64 m x 7.64 m is constructed from black nylon and is formed in a knotless configuration.

figure 103 - 7000 kg net basic layout

four lifting loops are attached to the main body with a hook at the end if each lifting loop, there is a Stirrup loosely attached to one of the lifting loops. an ident label is attached to the main body of the net. the red marker cord on the main body of the net identifies the centre of the net, and the yellow cord identifies the minimum cargo footprint of the net.

78 Lifting stropseach of the four strops is formed from two lengths of nylon webbing both passed through the eye in its hook. a small piece of webbing is stitched across the apex of the loop to position the hook centrally on the lifting members.

the four ends of each lifting member are attached to the border cord by folding back and stitching so that the four hooks can suspend the net from 16 points around the perimeter.

79 Stirrup and hooksthe stirrup forms the connection between the net and the load beam of the helicopter cargo hook or extension strop secondary hook. it is constructed from one piece of steel, which incorporates a cross bar dividing the stirrup into two approximately equal parts: the upper part and the lower part (figure 104). the frame and the crossbar are of a circular cross section.

the stirrup upper part engages the load beam of a cargo hook or extension strop secondary hook. the lower part accommodates the four hooks.

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figure 104 - Stirrup with all four hooks engaged

the stirrup is fitted with a robust spring loaded metal safety latch which is hinged to the crossbar, with a ‘waisted’ area positioned on the stirrup side frame immediately adjacent to the safety latch. the safety latch is formed with a trigger shaped lever, which when depressed opens the latch and enables engagement or disengagement of the strop hooks.

each of the four hooks is made from flat steel plate. the hooks can be readily detached from or attached to the stirrup when required. the removal of the hooks from the stirrup allows the net to be laid out flat for loading purposes with all four strops clear of the net, but all hooks must be attached to the stirrup before the net is lifted.

the lower portion of the stirrup is of sufficient size to allow it to be held by hand with the fingers clear of the hooks and below the crossbar so that hook-up can be effected without trapping or pinching the fingers. it is normally easier to use two hands to engage the stirrup.

the mouth of a serviceable/non-defective net hook will not pass over any part of its associated stirrup structure (assuming that item is serviceable) other than via the ‘waisted’ section.

the stirrup hooks are to face uniformally in one direction; the most important consideration is that the net lifting strop legs are not twisted in a complete 360° turn about themselves when the hook is engaged to the stirrup.

80 Retainer breakawaythe retainer breakaway assembly is fully described in Chapter 2-7 to ensure the 7000 kg net lifting strops are retained together in a compact and manageable form, prior to hook-up to the helicopter.


81 Net protection padhelicopter net protection pad equipment is an issue item for the 7000 kg net and is fully described in Chapter 2-6-1. the pads protect the net from damage which may be caused by sharp edges and protrusions on the load snagging in the net, and also provides a measure of protection for the load. full nSn details for the equipment are contained in aP 108G-0002-1a.

82 Net life expirythe 7000 kg net is fitted with a metal label which is woven into the net mesh: the label records the net life expiry date. all nets are to be taken out of Service when reaching their life expiry date and action taken in accordance with the procedures laid down in aP’s.

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83 Maintenance support literaturefull maintenance supporting literature for this equipment is published in aP108G-0002-1a: hUSle nets. Chapter 1-2 gives general advice on obtaining aP’s.

PREPARATION OF NET

84 General although one of the advantages of the net is that loads are easily and relatively quickly prepared, this does not mean that the load items can simply be piled into the net: for safety reasons and to obtain maximum life from the net, some basic principles must be followed when preparing the netted loads.

these principles, together with notes on general load items, use of baseboards and the transportation of a loaded net on the ground, are covered in the following paragraphs and some typical netted loads, with instructions on loading, are also shown in this chapter.

85 Use of net padsWhenever possible net pads should be used; the practical use of these items is shown in Chap 2-6-2 (5600 kg net), and also in USlC 3052: nato Palletised loads in Clusters in DaP101a-1105-1b.

86 Laying out the netthree hooks should be detached from the stirrup and the net stretched out flat on the ground with all four lifting strops clear of the net. the net must be kept stretched during loading; with multi-item loads, it should be pulled taut at intervals as loading progresses. When loading is complete the net, when lifted by its lifting strops, must encompass the outer corners of the load items such no part of the load contacts the strops.

note Users will have to use their best judgement as to how to assemble a pair of net loads for uplift; Chapter 2 paragraphs 7 and 11, and Chapter 2-6-2 provide some worthwhile considerations when making up two nets alongside each other for direct uplift as a pair by the helicopter.

LOADING OF NET

87 Even loadingthe safety of the net depends upon the load weight being reasonably distributed in terms of mesh loading across the net. Uneven loading could, if significantly disproportionate, be dangerous at higher laden weights, particularly if the net is lifting the load at snagging points where mesh severance or failure could easily occur with a risk of the failure spreading.

88 Uneven loadingif the net is loaded unevenly when lifted some portions of the net will be taking more weight than others, which will result in some lifting strops and some portions of the net taking unequal shares of the load; this is particularly dangerous when near or at the maximum load of 7000 kg. to mitigate this place heavier items near the centre of the net.

Uneven loading may not be obvious until the helicopter starts to lift when it becomes immediately apparent by the over-tautness of some cords with comparative slackness in others. Pulling the net tightly away from the load during the initial lift will help reduce the bad effects but the only certain cure is to rearrange the load.

note the safety of the net depends upon the weight being evenly distributed over the net as a whole; if this is disregarded, a failure at one point could lead to failure of the whole net.

89 Low density itemsWhen a net is correctly loaded with a large number of small items it adopts a deep inverted saucer-like shape in flight (figure 105). Provided that the individual load items are tightly packed against each other, and the outer edges of the net enclose the outer packages, there is little danger of spillage. in fact, the outer edges of the net (being pulled inwards) help to hold the whole load together as a solid mass.

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figure 105 - typical netted load in flight

With low density items such as empty jerricans, empty drums or similar items of comparatively large size and little weight, there is a real danger that the airflow will force them out of the open top of the net.

it is essential that such loads be lashed together but not tied to the net, or the qantity reduced so that the top of the net effectively encloses them. alternatively they can be wrapped in net protection pads, tarpaulins, or hessian, provided they are securely parcelled and tied.

90 Fragile storesfragile stores can easily be crushed by the net and so damaged. in this case, ‘fragile’ or ‘flimsy’ applies to such items as fresh rations, thin-walled plastic fuel or water containers, or equipment that has delicate protrusions such as radio aerials etc.

apart from packaging such items in protective containers, crushing can be prevented by placing them on a locally manufactured baseboard or pallet and tying them to the base; a suitable baseboard is described in paragraph 95.

91 Sharp or rough edged loadsSharp or rough edges of load items will cut the nylon cord/mesh of the net; ammunition boxes are common offenders. all sharp edges of items must be encompassed within net pads or be padded with felt, sandbags, or other suitable material to avoid damage to the net when the load is lifted and in transit under the helicopter. Padding can be kept in place by the use of masking tape; net pads are manufactured with eyeletted holes around the edges, allowing for the pad to be tied in position on the load (not to the net) and also for pads to be tied together.

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92 Flat sheets of metalflat thin sheets of metal such as corrugated iron sheets and similar material are not to be loaded into nets unless:

92.1 the sheets are tightly lashed or banded to form one dense load.

92.2 all sharp edges, particularly the corners, are padded.

92.3 the total weight of the load exceeds 700 kg.

93 Securing cord tiesUnless a specific load clearance states otherwise, or a specifically highlighted in this chapter, do not use the mesh or net border cord as anchoring points for ‘securing cord ties’; they may interfere with the natural position the net mesh or net border cord should adopt as it comes into tension about the load. although the ‘securing cord tie’ may simply snap (no longer serving the purpose for which it was possibly intended) the net braid may also sustain damage including heat searing as a result.

94 Batteries and battery electrolytemost acids will rapidly rot the net and must not be allowed to come into contact with it. the net material is particularly susceptible to sulphuric acid and net failures are known to have occurred due to contamination by this acid, probably arising from contact with battery electrolyte.

Wet batteries (acid or alkali) and containers of battery electrolyte must be prepared for lift in accordance with current instructions for air transportation of Dangerous Cargo.

95 Baseboardsa wooden baseboard can be placed inside the net, and can advantageously be used for:

95.1 Crushable loads.

95.2 Delicate loads.

95.3 awkward or difficult-to-load loads such as engines, flexible fuel tanks, batteries, radios, etc.

Using a baseboard imposes a weight penalty that must be taken into account: other wood can be used, but to gain strength equivalent to that of plywood will usually impose a greater weight penalty.

the essentials are:

Sufficient strength to carry the load when supported by its edges alone.

Sufficient holes to allow adequate lashing down of load items.

if fork lifting is envisaged, the height of the cross-members must be sufficient to allow the forks of the fork lift truck to pass under the board and clear of the net. for further details on baseboard construction refer to Chapter 2-6-3 paragraph 67.

note it is essential that the net is well stretched under the baseboard before starting to build the load up on the baseboard.

96 Side wall nettingWhen loading and protection pad securing is complete, the lifting sides of the net are to be pulled up against the side walls of the load ensuring it is firm and even along its length.

hold the net side walls in position against the load by using up and over-the-load ‘holding ties’ to secure opposite sides of the net about the load side walls (figure 107). this will reduce the work load on the net handling team during the initial stage of the helicopter lifting process and as an aspect of load preparation should help reveal possible snagging points and the need for extra protective padding (which will have to be secured to the load).

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When lifted, the netted load is under tension and the net side wall ‘holding ties’ will automatically slacken off until the load is returned to the ground and helicopter lifting tension removed.

figure 107 - Cross sectional view showing net side wall ‘holding tie’

97 Connecting-up to net stirruplocate the net lifting strop to which the net stirrup is secured. engage the lifting hook onto the stirrup lower part by depressing the stirrup safety lever and engaging the hook at the ‘waisted’ section of the stirrup side frame. Check that the lifting members of the connected lifting hook are not twisted through 360° or more. taking a clockwise or counter clockwise order of precedence (related to lifting strop mounting points around the net border cord) engage the remaining lifting hooks onto the lower part of the stirrup. Check that the individual lifting members are not twisted through 360° or more, before engaging their hooks.

the stirrup hooks are to face uniformally in one direction. When all hooks have been engaged ensure the stirrup safety latch has returned to the fully closed position.

98 Securing net lifting stropsto make net lifting strops more manageable for helicopter hook-up and during the initial stage of lift, secure their legs together in combined form using the retainer breakaway starting at the stirrup end. if a retainer breakaway is not fitted, secure by taping the legs together, at intervals along their length, starting from the top.


the following paragraphs 99 to 104 deal with those precautions to be observed before and during hook-up, flying and release.

99 Checks before hook-upimmediately before hook-up the following items must be checked.

99.1 the net is serviceable.

99.2 the all Up Weight (aUW) is known; this is the total weight of all items plus the weight of the net.

99.3 no exposed sharp edges can damage the net.

99.4 any items of comparatively large volume and light weight, ie low density items such as empty jerricans or empty drums, are positively secured in the net.

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99.5 net lifting strops are taped together, or held by a retainer breakaway so that they cannot catch on any projecting portions of the load during the initial stages of lift.

99.6 the net is as evenly loaded as possible.

it is permissible to lift clusters of two or more nets at once. each net is to weigh approximately the same, and the load in each net is to be of approximately the same bulk, ie the loads should be of approximately equal density and weight. refer to USlC 3052: nato Palletised loads in Clusters in DaP101a-1105-1b for details.

however, in order to safely accommodate the net stirrups of a two or more net cluster the use of an extension strop with swivel hook is manDatory.

100 Hooking-upa hazard exists from static electricity.

WARNING ALWAYS USE A STATIC PROBE PRIOR TO HOOK-UP OR BEFORE HANDLING A SUSPENDED LOAD.

101 Single netted loadhold the stirrup so that the operators fingers are above the hooks and below the crossbar, slide the upper part of the stirrup over the extended forward portion of the load beam of the cargo hook, then slide it aft past the spring-loaded hook keeper latch: to confirm that the stirrup is engaged correctly pull back the stirrup and ensure it does not disengage (figure 108).

note the load beam is never to be engaged in the lower portion of the stirrup.

figure 108 - hooking-up single netted load

102 Two-net cluster loadavoid hooking-up with substantial twists in the lifting strops of each net, as the twists may not be entirely removed as the result of the loads freedom to rotate on the helicopter extension strop swivel hook.

When engaging the stirrup of each net it may be able to hold both stirrups together and engage them onto the helicopter extension strop hook in one operation, but could be easier to engage one stirrup at a time.

engage the stirrups on to the extension strop swivel hook, in the order that the nets lie with reference to

DAP 101A-1105-1A


the helicopters likely departure path, and by ensuring the lifting stropes on the individual nets are not badly twisted this avoids wear on the net lifting member.

the checks and correct manner of engagement for each stirrup on the helicopter extension strop hook are as stated in paragraph 101.

103 Precautions during initial liftCare must be taken that the lifting strops of the net do not catch or snag on any projection of the load. taping the lifting strops will assist in keeping them clear but it may be necessary for personnel to assist by holding the lifting strops and the upper portion of the net tight and clear of the load as the helicopter takes the weight.

With some loads it is difficult to prevent individual parts of the net from being overloaded but every effort must be made to prevent this. ideally each cord length should be of equal tension, but this is impossible to achieve exactly in practice. if one or two cords in any one area of the net are taut while adjacent cords are comparatively slack, the net must be adjusted to equalise the tension as far as possible.

marshallers, crewman and pilots must ensure that the helicopter cargo hook is central over the loaded net before the helicopter starts to lift; if it is not the load will be dragged along the ground with consequent wear and even breakage of the net where it rubs on the ground.

104 Precautions during releasemarshallers, crewman and pilots must ensure that the helicopter is stationary in relation to the ground before release and that the net is lowered gently to the ground, otherwise, the net will drag and wear will be caused: if the load is dropped the net may be cut by edges or corners of the load items.


following net landing, the helicopter crewman will attempt to release the net stirrup and helicopter extension strop (if used) clear of the load to avoid possible damage to the load.

if the stirrup is to be manually disengaged from an extension strop whilst the strop remains attached to the helicopter, it is important that the static electricity discharge procedure be carried out (Chaper 5).

FLYING LIMITATIONS

WARNING THE 7000 KG NET IS NOT TO BE UNDERSLUNG UNLADEN. THE EMPTY NET DEPLOYS RAPIDLY TOWARDS THE HORIZONTAL AT A SPEED AS LOW AS 30 KTS, WITH THE SUBSEQUENT DANGER THAT IT MAY BE DRAWN UP INTO THE HELICOPTER ROTORS.

the weight of cargo should not be less than 700 kg in total, and this in turn should be related to the drag profile presented by a normally stacked single nato pallet load.

for loads of the same weight but with a larger surface area, the stability characteristics may prove less predictable than the standard nato pallet load. Certain low drag, high density loads, with a total cargo weight lower than 700 kg, may prove acceptable.

Ultimately, the safe carriage of any ultra-low density/ultra-lightweight load will depend on the speed at which maximum allowable trail angles are attained and the speed at which any deterioration in load handling characteristics takes place.

With two nets in cluster loads, net separation can occur at the higher speed range and the speed at which the load is carried, must be limited by the onset of this phenomenon.

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CHAPTER 2 - 6 - 5: TYPICAL NETTED LOADS

TYPICAL NETTED LOADS

105 Composite ration packseighty-five 10 man composite ration packs can be carried, arranged in a single layer as shown in figure 109.

figure 109 - arrangement of composite ration pack load

the packs are stacked on their ends so that their 16 in. lengths are vertical. the weights of composite packs vary so it is essential that the aUW is checked before lifting.

the net must be kept reasonably tight during the stacking of the packs so that the loaded net, when lifted by its lifting strops, completely covers the outer corners of the packs.

106 Jerricanseighty-nine filled jerricans of fuel or water, can be carried in a net (figure 110): the outer jerricans must be positioned with their filler caps inward so that the lifting strops or the cords of the net do not catch on the projections of the filler caps and their locking devices as the net is lifted.

note old cans may occupy a greater area than is illustrated.

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3 PACKS

3 PACKS

3 PA

CK

S

3 PA

CK

S

LINE OF 6 PACKS

LINE OF 6 PACKS

LIN

E O

F 6

PAC

KS

LIN

E O

F 6

PAC

KS

LIN

E O

F 7

PAC

KS

3 CANS

ROW OF 9 JERRICANS

ROW OF 11 JERRICANS

ROW OF 11 JERRICANS

3 ROWS OF 13 JERRICANS

3 CANS

2 C

AN

S

2 C

AN

S OUTER CANS MUST HAVEFILLERCAPS INWARDS

figure 110 - arrangement of maximum 89 jerrican load

it is essential that when the net is lifted by its lifting strops, the net completely covers the outer corners of the assembled load. empty jerricans carried in this manner must be lashed together, but not to the net: this may be done by passing rope or 1200 lb nbC through the handles until the jerricans are all laced together, either as a single entity or in clutches of 15 to 20 cans.

When passing cord through cans on the periphery of the load, some slack in the cord should be allowed to cater for these outer cans rising when the side walling of the net is brought into tension about the load.

alternatively, empty cans may be parcelled and tied in net pads, tarpaulin or the like, to form an enveloped load within the net. if such securing measures cannot be taken, then the carriage of empty jerricans within the net must be limited to the number which allow for the net side walling effectively to close over the load with a smaller base area taken up by the load.

a certain amount of double stacking of jerricans may prove possible whilst still remaining well enclosed by the net walls.

Plastic type metal typeempty 4.5 lb (2 kg) empty 10 lb (4.5 kg)filled with 4-5 gallons Water

55 lb (25 kg) filled with 4-5 gallonsCivgas 46 lb (21 kg)Diesel 50 lb (22.7 kg)Kerosene 55 lb (25 kg)

table 1 - Jerricans typical weight (each)107 45 gallon drumSeven filled 45 gallon drums can be carried in a net. the weight of one to seven drums with their more common contents are given in table 2.

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Contents (lb per gallon)

aUW (lb) including drums1 drum 2 drums 3 drums 4 drums 5 drums 6 drums 7 drums

Water (10.0 lb) 503 1006 1509 2012 2515 3017 3520aVtUr (8.0 lb) 423 826 1239 1652 2065 2477 2890aVtaG (7.7 lb) 399 798 1197 1596 1995 2393 2792aVGaS (7.2 lb) 377 754 1131 1508 1885 2261 2638lubricating oil (9.1 lb average) 463 926 1389 1852 2315 2777 3240

table 2 - all up weight (aUW) of filled 45 gallon drums

1 ROW OF 3 DRUMS ON TOP1ROW OF 4 DRUMS ON BASE

figure 111 - arrangement of seven x 45 gallon drums

108 To prepare a load of seven drums108.1 lay out the net with the lifting strops clear of the net. lay net pads (para 15 and 19) if available.

108.2 Join together two sets of two web lashings. lay parallel to each other about 3 ft apart across the net so that they are equally disposed about the centre of the net.

108.3 Position four drums, on their sides, over the web lashings so that the sides of the drums are at right angles to the lashings and the whole assembly forms a rectangle centred in the net (see figure 105). refers.

108.4 Check all the drums against outward movement, with chocks, and position the remaining drums so that they lie naturally in the ‘valleys’ formed by the lower drums.

108.5 tighten each web lashing with a ratchet tensioner and then remove the chocks.

108.6 if using net pads, draw them up and secure in position about the outer edges of the drums using cord. in the absence of net pads, use felt, sacking, sandbags or the like to pad the outer edges of the

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drums where the net will be pulled tight over the edges; secure the padding in place with masking tape.

108.7 finally, pull the net tightly up and around the load, so that when lifted the net will completely encompass the drums. Secure the net in the ‘ready for lift’ position by means of up and over ‘holding ties’ (para 37).

108.8 empty drums can also be carried in this manner but in this instance the web lashings must be tied to the net so that there is no danger of the drums being blown out of the net (para 26 refers).

109 Carriage of single NATO pallet loadsSee USlC 3052: nato Palletised loads in Clusters in DaP101a-1105-1b for carriage of single nato pallet loads in 5000 lb nets; either as a single net load, or in cluster, using Chinook heavy duty extension strop and assorted net suspension methods.

DaP 101a-1105-1a

Chapter 2Sep 2017 (iss 10)

CHAPTER 2 - 6 - 6: SPECIFIED AUTHORISED LOADS

INTRODUCTION

While carrying items in a net may well be a short term expedient when time is at a premium there is always the attendant risk, particularly in the case of vehicles, that damage to the load and/or the net may result.

note although trials have shown other vehicles and equipment can be carried in the 5600 kg net, if there a slinging scheme published in the DaP 101a-1105-1b this will always be the recommended method of carriage if time permits and the required slinging equipment is available.

APFC’S

a maximum of two full aPfC’s can be carried in the 5600 kg net, giving a maximum lift of four containers carried in a two-net cluster.

110 Load preparationCarry out the standard serviceability checks on the aPfC’s. ensure that the fuel filler valve protection cap is fitted and that the air pressure valve is tight; the air pressure in a full aPfC should not exceed 5lb/in².

Position the two aPfC’s end to end in the centre of the net along the net loading axis (figure 112), ensuring that adequate suitable padding is placed between them (figure 113).

if only one aPfC is being carried it is unnecessary to pad the ends of the container as the net is not drawn up around the end plates.

PADDING

NET LOADING AXIS

figure 112 - Positioning of airportable fuel Containers (aPfCs)

111 RiggingPull the net around the aPfCs ensuring that the mesh does not snag on any part of the load. retain the net side-walls in position against the load using up and over ties of 1200 lb nbC.

attach the net lifting strop hooks to the lower part of the stirrup, checking for twists in the strops. ensure that the stirrup safety latch is fully closed.

a second load, with two aPfCs, can be prepared in the same manner but ensure that it is built up immediately alongside and parallel with the first to minimise dragging the nets on the ground during pick-up.

DaP 101a-1105-1a


PADDING

figure 113 - airportable fuel Containers (aPfCs) suspended in 5600 kg net

CLASS 30 AND 60 TRACKWAY

rolls of Class 30 and 60 trackway can be carried either singly or in pairs as a single or two-net clustered load (figure 114). one spooled 45.7 m roll of Class 30 trackway weighs 3300 kg and one spooled 15.2 m roll of Class 60 weighs 2400 kg (clean weights).

figure 114 - Class 30 and Class 60 trackway in 5600 kg net

112 Load preparationthere is no special load preparation required prior to placing the trackway in the net.

113 RiggingPlace or roll the trackway in the net so that it is positioned centrally and parallel to the loading axis. ensure that ample padding is placed around the ends of the load to protect the net mesh and retain the net side-walls in position against the load with 1200 lb nbC up and over ties. attach the net lifting strop hooks to the lower part of the stirrup, checking for twists in the strops, and ensure that the stirrup safety latch is fully closed.

114 Second loada second load can be prepared in the same manner to form a two-net cluster if required (aircraft payload permitting) but ensure that it is built up immediately alongside the first to minimise dragging the nets on the ground during pick-up.

DaP 101a-1105-1a


VEHICLES AND TRAILERS

trials have been conducted at JateU with the ½ ton, ¾ ton and 1 tonne land rover’s (hard and soft top variants) underslung in the 5600 kg net. experience has shown that, while this method of underslinging vehicles or trailers in the field may offer a more convenient tactical alternative to the primary method of using slings, it is very likely that minor damage to both the vehicle and net will be sustained.

the decision as to whether this damage is acceptable or not, rests with the local ground unit commander whose vehicles are being moved.

115 Load preparationthe normal vehicle preparation actions (excluding securing the doors together and securing the spare wheel with additional nylon cord) should be taken as per the appropriate clearances.

Particular attention should be paid to removing or folding in all items such as radio antennae and wing mirrors, which could snag on the net mesh during load pick-up. if vehicle canvas covers are left on they must be serviceable and fully secured.

laden vehicle/ trailer contents must be secured to prevent possible loss during flight. it should also be remembered that, in many cases, laden vehicle/trailer weights will be more difficult to determine.

116 Rigginghaving laid out the net on flat ground drive the vehicle/trailer carefully onto the centre of the net along the loading axis. it is important that the load is placed accurately in the centre of the net so that the vehicle/trailer does not tip sideways on lifting. Secure ample padding around sharp edges of bumpers, wheel hubs, towbars etc. Draw the net up around the load, ensuring that the mesh does not snag on any part, and secure the net walls in position against the load by using 1200 lb nbC up and over ties (see figure 87 of Chapter 2-6-2).

attach the net lifting strop hooks to the lower part of the stirrup checking for twists in the strops. ensure that the stirrup safety latch is fully closed. Where possible employ a retainer breakaway assembly to gather the net strops and lay the net stirrup to one side of the load ready for hook up.

WARNING A HAZARD EXISTS FROM STATIC ELECTRICITY. BEFORE HOOKING-UP AN EXTERNAL LOAD AND OTHER ALLIED FUNCTIONS IS COMMENCED, STATIC ELECTRICITY MUST BE DISCHARGED BY THE USE OF A STATIC ELECTRICITY DISCHARGE PROBE.

WARNING IT IS DANGEROUS FOR THE LOWER PART OF A STIRRUP TO BE USED AS THE MEANS OF ENGAGING A HELICOPTER CARGO HOOK OR THE SECONDARY HOOK OF A HELICOPTER EXTENSION STROP.

WARNING THERE IS A DANGER TO PERSONNEL OF SLIPPING OR GETTING ENMESHED IN A BILLOWING NET IF HELICOPTER HOOK-UP IS CONDUCTED FROM THE TOP OF A NETTED LOAD. WHENEVER POSSIBLE HOOK-UP IS TO BE CARRIED OUT TO ONE SIDE OF THE NETTED LOAD.

117 Initial liftDuring the lifting process ground personnel should continually monitor the net to ensure that no snagging has occurred and that the vehicle hangs square in the net (figure 115). if it leans excessively one way or the other damage to the vehicle canopy struts could occur and therefore the load should be set down and re-rigged.

DaP 101a-1105-1a


figure 115 - land rover (lr) in 5600 kg net

118 Flying limitationsno limiting speeds can be predicted for netted vehicle/trailer loads but gradual incremental speed changes should be made with careful continuous monitoring of canvas covers, windscreens, vehicle contents etc for any signs of deterioration or coming loose.

METAL TRACKED OR STUDDED/WHEEL CHAINED VEHICLES AND USE OF DUNNAGE

operationally it may prove necessary to uplift metal tracked or studded/wheel chained vehicles in the 5600 kg net. Without appropriate protection the net would almost certainly sustain critical damage during vehicle loading, and thereafter. net protection pads on their own would be an inadequate safeguard and the use of ‘dunnage’ would be necessary.

119 Selection of dunnageSuitable sheets of durable wood (e.g. plywood) should be selected of ½ in. minimum thickness and measuring up to the length and width of the vehicle. a single sheet is not necessary and overlapping of several sheets where the material cannot be cut to size, is acceptable.

the area of dunnage should not exceed the vehicle track length/wheelbase; dunnage trackways will also be required to allow the vehicle to be driven onto the net.

120 Preparation and loading Proceed as follows:

120.1 fully stretch out the net in accordance with practice.

120.2 Position net protection pads.

DaP 101a-1105-1a


120.3 Place the primary dunnage on the pads spanning the vehicle carrying location in the net (figure 116).

NET LOADINGAXIS

NET LOADINGAXIS

5600 kg. NET 5600 kg. NET

PROTECTION PADSPROTECTION PADS

DUNNAGE DUNNAGE

DUNNAGE WITH BOARDS ABUTTING DUNNAGE WITH BOARDS OVERLAPPINGfigure 116 - Dunnage with boards abutting and overlapping

lay down lead-in dunnage (figure 117). Carefully drive the vehicle onto its central location in the net, travelling across the lead-in dunnage; when the vehicle is satisfactorily located on the primary dunnage remove lead-in dunnage and associated net pads around net border.

NET LOADINGAXIS

5600 kg. NET

PROTECTION PADSDUNNAGE

figure 117 - Dunnage with boards in foreground

fold primary net padding about ends of vehicle track sections or wheels. Secure padding, and then continue with net securing and preparation for uplift in accordance with procedures in this chapter.

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 7: RETAINER BREAKAWAY ASSEMBLY

INTRODUCTION .................................................................................................................................... 168EQUIPMENT DESCRIPTION ................................................................................................................. 1681 the retainer breakaway......................................................................................................................1682 attachment .........................................................................................................................................1693 further information .............................................................................................................................169

figures

figure 118 - General details of retainer breakaway assembly ......................................................................168figure 119 - retainer fitted to helicopter cargo nets ......................................................................................170figure 120 - retainer fitted to textile slings ...................................................................................................171figure 121 - retainer fitted to Sml 6000 lb ...................................................................................................172

CHAPTER 2 - 7

DAP 101A-1105-1A


CHAPTER 2 - 7: RETAINER BREAKAWAY ASSEMBLY

INTRODUCTION

for helicopter USls employing slings or cargo nets with multiple lifting legs it is necessary, as the final part of the rigging process, to secure together the sling set or net lifting members. this is to reduce the chance of their snagging on the load during the hook-up process, or as the helicopter takes strain on the load, prior to lifting it to the hover.

the retainer breakaway assembly has been designed as a re-usable and reliable method of temporarily securing sling or net legs together, until hook-up has been effected and the load brought to tension under the helicopter; the retainer can also be used for sling stowage.


1 The retainer breakawaythe retainer breakaway is manufactured from nylon webbing and consists of a longitudinal strap to which (in the case of the master assembly) nine cross straps are sewn. Velcro straps are attached to each leg of the cross straps, providing the means of closure about the assembled legs of a sling or lifting members of a cargo net.

FOLD OVEREND

TYPE B

TYPE A

VELCRO ON EACHCROSS STRAP

SECONDARYLOOP

LOOP END

TYPE C

TYPE A

TYPE A - SML 6000 lb SWLNET CARGO LIFTING 5000 lb SWL

TYPE C - SML 11300 kg SWL & VARIANTSNET CARGO LIFTING 5600 kg SWLNET CARGO LIFTING 7000 kg SWL

TYPE B - SML 4600 kg SWL

figure 118 - General details of retainer breakaway assembly

DAP 101A-1105-1A


the full/master length retainer is employed on the 5600 kg helicopter cargo net and the 11300 kg sling. the retainer may be cut to shorter lengths, to allow for its wider employment with other specified sling or net equipments. for instructions and individual fitment procedures for specified sling and cargo net equipments, consult army equipment Support Publication (aeSP) 1670-h-100.

2 Attachmentthe retainer breakaway assembly is attached to a specified leg of the given sling or cargo net equipment.

a loop is provided at the lower end of the longitudinal strap, which is secured with a double loop nylon cord tie to a specified point at the lower end of the parent sling or net leg.

a further loop is provided at the approximate mid-point of the retainer longitudinal strap (mid-point related to full/master length assembly) so that the strap can be cut into two ‘type a’ lengths (figure 118).

note reinforcing patches are attached to the longitudinal strap adjacent to all cutting positions.

the retainer longitudinal strap is secured along the remainder of the parent sling or net lifting member by encircling wraps of adhesive tape, placed at both sides of each cross strap (tape wraps three full turns).

in the case of the full/master length retainer, an additional nylon cord tie is likely to be introduced at the top end of the longitudinal strap when the assembly is employed with the 5600 kg helicopter cargo net.

3 Further informationadditional information for this equipment can be found in the illustrated Parts list in aP108G-0002-1C, the nSn is currently 1670-99-977-3351.

DAP 101A-1105-1A


RETAINERBREAKAWAY

HOOK

HOOK

OUTER STROP

NET BORDER

OUTER LIFTINGMEMBER (STROP)

INNER LIFTINGMEMBER (STROP)

INNER STROP

INDIVIDUAL CROSSSTRAP WITHVELCRO STRIP

RETAINER LOOP

REINFORCING PATCHOR FOLDED END

STIRRUP

RETAINER TO STROPSECURING TAPE(EACH SIDE OF EACHCROSS STRAP)

DOUBLE LOOPNYLON CORD

NET BORDERCORD

HOOKS (FOUR)

NOTE

With a well bulked out net itmay not be possible to securethe lower cross strap

RETAINER LOCATION

RETAINER FITMENT DETAIL ASSEMBLED STROPS

figure 119 - retainer fitted to helicopter cargo nets

DAP 101A-1105-1A


RETAINERBREAKAWAY

RETAINER LOCATION

RETAINER FITMENT DETAIL

LIFTING RING(CLOSED MASTER LINK)

ROUNDSLING OUTERPROTECTIVE SLEEVE

SLING LEGS

VELCRO STRIP

RETAINER LOOP

REINFORCING PATCH(TYPE 'B' LENGTH)ORFOLDED END(TYPE 'D' LENGTH)

RETAINER TO SLINGLEG SECURING TAPE(EACH SIDE OF EACHCROSS STRAP)


ROUNDSLINGSHACKLE

ASSEMBLED SLING

figure 120 - retainer fitted to textile slings

DAP 101A-1105-1A


RETAINERBREAKAWAY

RETAINER LOCATION

LIFTING RING

SLING LEG

SLING LEGS

VELCRO STRIPON UNDERSIDE

VELCRO STRIP

LIFTING RING

RETAININGCROSS STRAPS

REINFORCING PATCH

TAPE EACH SIDE OFEACH CROSS STRAP


DEAD EYE

RETAINER FITTING DETAIL

RETAINER LOOP

ASSEMBLED FOURLEGGED SLING

figure 121 - retainer fitted to Sml 6000 lb

DAP 101A-1105-1A


CONTENTS

CHAPTER 2 - 8: CARGO RESTRAINT REQUIREMENTS FOR HELICOPTER UNDERSLUNG LOADS

INTRODUCTION .................................................................................................................................... 175THE BASIS OF RESTRAINT ................................................................................................................. 1751 restraint for helicopter Underslung loads (USl’s) ............................................................................1752 Directional restraint ............................................................................................................................1753 location of loose items/freight ...........................................................................................................1764 range of restraint equipment and securing materials ........................................................................176LOAD CATEGORIES ............................................................................................................................. 1765 load categories and restraint equipment rating .................................................................................1766 aerodynamic load...............................................................................................................................1767 non-aerodynamic load .......................................................................................................................1778 restraint equipment rating .................................................................................................................178DETERMINATION OF RESTRAINT ...................................................................................................... 1789 Determine restraint requirement.........................................................................................................17810 estimate the number of lashings required ..........................................................................................17811 optimum restraint ...............................................................................................................................179

CHAPTER 2 - 8 - 1: RESTRAINT CHAINS AND COUPLING TENSIONERS

2 M OR 4.5 M, MEDIUM DUTY (MD) EXTENSION CHAINS USED AS RESTRAINT CHAINS ........... 18012 limits for passage of chains around tie-down rings or parts of the load ............................................18013 Quick release Coupling (QrC), 10000 lb. ........................................................................................18014 Classification of equipment and rating ...............................................................................................18215 taping praction ...................................................................................................................................18216 technical support literature ................................................................................................................182

CHAPTER 2 - 8 - 2: NYLON CORD

INTRODUCTION .................................................................................................................................... 183FEATURES OF NYLON CORD ............................................................................................................. 18317 General...............................................................................................................................................18318 Knots ..................................................................................................................................................18319 ties .....................................................................................................................................................18320 types of securing ties.........................................................................................................................18421 Practical strength of ties .....................................................................................................................18622 Strength criteria ..................................................................................................................................18623 Use of alternatives when 1200 lb nbC is not available ......................................................................186

CHAPTER 2 - 8 - 3: NET CARGO, THROW-OVER RESTRAINT FOR HUSLE SWL 1000 KG

INTRODUCTION .................................................................................................................................... 187EQUIPMENT DESCRIPTION ................................................................................................................. 18724 hooks .................................................................................................................................................18725 net identification label ........................................................................................................................188ASSOCIATED EQUIPMENT ............................................................................................................18826 Pad protection, helicopter cargo net ..................................................................................................18827 net life expiry......................................................................................................................................18828 net storage .........................................................................................................................................18829 maintenance support literature ...........................................................................................................188INSTRUCTIONS FOR USE ..............................................................................................................18830 General...............................................................................................................................................18831 Preparation to vehicles/trailers ...........................................................................................................18832 attachment to vehicles .......................................................................................................................188

CHAPTER 2 - 8

DAP 101A-1105-1A


figures

figure 122 - Palletised load ...........................................................................................................................175figure 123 - Combined use of load structure and lashings to provide restraint/securement against movement of loose items ................................................................................................................................................176figure 124 - aerodynamic load on a vehicle flatbed or pallet ........................................................................176figure 125 - aerodynamic load in trailer ........................................................................................................177figure 126 - non-aerodynamic load ..............................................................................................................177figure 127 - Partially exposed non-aerodynamic load ..................................................................................178figure 128 - Quick release coupling (QrC), 10000 lb...................................................................................180figure 129 - 2 m or 4.5 m mD extension chain assembly and QrC with chain engaged in chain anchor housing.......................................................................................................................................................................180figure 130 - QrC, jaws in ‘open’ position .....................................................................................................181figure 131 - QrC, jaws in ‘closed’ position ...................................................................................................181figure 132 - 2 m or 4.5 m mD extension chain and QrC, example of ‘claws to attachment point ...............181figure 133 - 2 m or 4.5 m mD extension chain and QrC, examples of ‘claws to chain loop’ engagement ..182figure 134 - tying a bowline, round turn and two half hitches ......................................................................183figure 135 - tying various useful knots .........................................................................................................184figure 136 - single and double ties ...............................................................................................................185figure 137 - Parcel tie ...................................................................................................................................185figure 138 - Vantage strop ............................................................................................................................186figure 139 - net cargo, thrower-over restraint for hUSle SWl 1000 kg ......................................................187

33 attachment to trailers .........................................................................................................................18834 net tensioning ....................................................................................................................................18935 net attachment ...................................................................................................................................189

DAP 101A-1105-1A


CHAPTER 2 - 8: CARGO RESTRAINT REQUIREMENTS FOR HELICOPTER UNDERSLUNG LOADS

INTRODUCTION

Underslung load restraint equipment is used to secure those parts of a load which might otherwise be free to shift their position or detach from the load at any stage from helicopter load hook-up, to load landing of the load at its destination. the load must be capable of remaining intact when subjected to rotor downwash, airflow effect and any load oscillations induced during flight.

movement of part of the load could cause imbalance and undue strain being placed on part of the slinging system, and would cause damage to or severance of parts of the slinging equipment. this could result in the load entering an unstable condition which might culminate in the crew having to jettison the load. items detaching from the load pose a threat to the safety of the helicopter, as well as to persons or property on the ground.

THE BASIS OF RESTRAINT

to restrain any load it is necessary to identify the direction and magnitude of forces that are likely to be applied to the load. the restraint equipment must be used inside the margin of its ultimate strength/breaking point to cater for the normal forces, which are likely to affect the load.

identification of normal and likely extreme forces is relatively straightforward for the purpose of aircraft internal load restraint, and the criteria allow for a margin of safety between normal operating conditions and the restraint equipment reaching its breaking point.

1 Restraint for Helicopter Underslung Loads (USL’s)to identify the magnitude and direction of forces, which are likely to affect the security of individual parts of an USl, is extremely difficult. this is particularly so with loads suspended from a single cargo hook, where the load may display random tendencies to turn, or spin and even enter violent forms of oscillation.

to allow for the various forces that will affect different types of USl’s, the rating of restraint equipment used will vary according to the category of the load being restrained (paragraphs 5 to 8 deal with the different load categories and the rating of restraint equipment).

note it is important to remember that the overall rating of a restraint system is no higher than that of its weakest link.

2 Directional restraintloose items or freight, making up or forming part of an USl, require to be secured against movement of individual items (best illustrated by banding of palletised loads, figure 122).

RESTRAINT STRAPS

figure 122 - Palletised load

Where container, vehicle or trailer walls, flooring or similar, provide adequate restraint in given directions, lashing requirements are reduced to securing against movement in those directions not covered by immediately surrounding structure (figure 123).

DAP 101A-1105-1A


RESTRAINT STRAPS

figure 123 - Combined use of load structure and lashings to provide restraint/securement against movement of loose items

Where the structure is all enclosing, as in a trailer, it is sufficient to restrain the items by means of the trailer canopy and a load restraint net.

3 Location of loose items/freightin deciding upon the position of loose freight or other items, there must be suitable means or facilities for securing them in location. it is vitally important that loose items and associated lashing equipment do not come into contact with deployed sling legs or associated items of slinging equipment. Positioning of loose items/freight must avoid upsetting the balance of the load with the result that any one sling leg may become overloaded. Where these requirements cannot be met, Underslung load Clearances (USlC’s) will only cover carriage of vehicles in the unladen state.

4 Range of restraint equipment and securing materialsthe current range of tie-down chains, tensioner equipment and cargo restraint nets provisioned for the USl restraint role is covered in Chapters 2-8-1 and 2-8-4. Chapter 2-8-3 discusses the use of nylon cord which, along with adhesive tape, serve as additional securing materials commonly called up in USlC’s.

LOAD CATEGORIES

5 Load categories and restraint equipment ratingto determine the restraint equipment rating, the load weight and category must first be established. loads, regardless of their shape, can be categorised as aerodynamic or non-aerodynamic: the difference between these two categories is explained in paragraphs 6 and 7.

6 Aerodynamic loadan aerodynamic load is a load which is exposed on its sides to the airflow; e.g. a load on a flatbed vehicle or pallet (figure 124) or a load which does not completely fill and protrudes above the sides of the cargo compartment of a vehicle/trailer or container (figure 125).

LOAD

LOAD SIDES EXPOSEDTO THE AIRFLOW

VEHICLE FLATBEDOR PALLET

DIRECTIONOF AIRFLOW

figure 124 - aerodynamic load on a vehicle flatbed or pallet

DAP 101A-1105-1A


LOAD PROTRUDING ABOVEAND NOT SUPPORTED BYTHE TRAILER SIDES

HEAVY LOADS MUST BEPLACED CENTRALLY WITHINTHE CARGO COMPARTMENT

DIRECTIONOF AIRFLOW

figure 125 - aerodynamic load in trailer

7 Non-aerodynamic loada non-aerodynamic load is a load will be one of the following:

7.1 a load that is not exposed on any of its sides to the airflow (figure 126).

LOAD

HIGH SIDED VEHICLE,TRAILER OR CONTAINER

DIRECTIONOF AIRFLOW

LOAD SIDES PROTECTEDFROM THE AIRFLOW

LOADS MAY COMPLETELY OR PARTIALLY FILLTHE CARGO COMPARTMENT. HEAVY LOADSMUST BE PLACES CENTRALLY

THE LOADMUST NOTPROTRUDEABOVE THE

SIDES

figure 126 - non-aerodynamic load

7.2 a load that is partially exposed to the airflow on one or more sides, ie the load height does not exceed 25% of the sideboard height of the vehicle, trailer or container etc (figure 127).

7.3 a load that is fully exposed to the airflow on one side only, eg a load in a vehicle without a tailboard which may also be partially exposed on its other sides as descirbed above.

if a load that is partially or fully exposed exceeds the limits stated, it is to be classified as aerodynamic.

DAP 101A-1105-1A


LOAD

MAX HEIGHT THAT THE LOAD MAYPROTRUDE ABOVE THE VEHICLE/TRAILER/CONTAINER SIDEBOARDAND BE EXPOSED TO THE AIRFLOWIS 25% OF THE MEASUREDSIDEBOARD HEIGHT (X)

DIRECTIONOF AIRFLOW

SIDEBOARDHEIGHT = (x)

THE LOAD MUST FILL THE CARGO COMPARTMENTAND BE FULLY SUPPORTED BY THE VEHICLE/TRAILER/CONTAINER SIDEBOARDS

figure 127 - Partially exposed non-aerodynamic load

8 Restraint equipment ratingthe forces acting on aerodynamic and non-aerodynamic of load are different, therefore the amount of restraint required will also differ. the simple rule of thumb to be applied is to use the Ultimate tensile Strength (UTS) of the total restraint system for non-aerodynamic loads and to use ⅔ of the UTS for aerodynamic loads, e.g. a non-aerodynamic load of 1000 lb would require a minimum restraint of 1000 lb and an aerodynamic load of 1000 lb would require a minimum of 1500 lb.

for individual UtS ratings, refer to Chap 2-8-1 to 2-8-4 for hUSle and to the respective vehicle or equipment handbook for vehicle or equipment tie-down rings.

DETERMINATION OF RESTRAINT

the following instructions should be used to ensure that items of load are adequately restrained.

9 Determine restraint requirementthe restraint required in each direction is to be determined by multiplying the all up weight (aUW) of the load by the directional restraint factor (1G in all directions), the restraint required for example for a load weighing 1000 lb is:

forward 1000 times 1000 lbaft 1000 times 1000 lbVertical 1000 times 1000 lbSide 1000 times 1000 lb

10 Estimate the number of lashings requiredthe approximate number of lashings required to adequately restrain a load can be estimated by applying the following rule of thumb: for forward and aft restraint multiply the aUW of the load by the G factor and divide by the rated strength of the lashing, e.g.:

For an aerodynamic load of 4000 lb using 5000 lb web lashing with a ⅔ UTS rating of 3333 lb you would calculate as follows:

load Wt 4000 lb x 1G 1.2 2 lashings forward and 2 lashings aft. lashing rating 3333 lb

if all lashings are attached to the load at angles of between 30° and 45° (both to the cargo compartment floor and the centre line) adequate vertical and lateral restraint will be achieved.

DAP 101A-1105-1A


11 Optimum restraintto achieve optimum load restraint the following basic principles should be applied whenever possible:

11.1 all lashings should be used in pairs and be arranged to provide restraint in three directions (see figure 113).

11.2 all lashings should be of equal length and strength and be attached to the load at equal angles.

DAP 101A-1105-1A


CHAPTER 2 - 8 - 1: RESTRAINT CHAINS AND COUPLING TENSIONERS

2 M OR 4.5 M, MEDIUM DUTY (MD) EXTENSION CHAINS USED AS RESTRAINT CHAINS

2m or 4.5 m mD extension chain assemblies can also be used as items of restraint equipment. their basic description, together with the correct method of engaging the chain shortening clutch, is given in Chapter 2-4-2.

When called up as items of USl restraint equipment, the chains are used with the 10000 lb QrC. Chain and QrC equipment is particularly useful for providing anti-jack knife restraint with vehicle and trailer type combination loads when carried externally by helicopter. instructions relating to the particular methods used for specific vehicle/trailer type combinations are contained in the relevant USlCs.

12 Limits for passage of chains around tie-down rings or parts of the loadfor use as items of restraint equipment the following limits apply for passage of 2 m or 4.5 m mD extension chains around tie-down rings or parts of the load.

the chain is not to be looped around:

12.1 Circular sections of less than 13 mm.

12.2 angular or flat sections with square or rounded edges whose thickness of section is less than 13 mm.

13 Quick Release Coupling (QRC), 10000 lb.a QrC is a device that allows for connected chains to be hand tensioned, thereby removing any final element of slack in the length of the chain which would otherwise be difficult to eliminate. a description and its method of operation is given:

13.1 the QrC consists of a central turnbuckle barrel with a quick release claw fitting at one end and chain anchor housing at the other (figure 128).

CLAWS

TURNBUCKLE BARREL

TURNBUCKLE COVER TENSIONING RINGfigure 128 - Quick release coupling (QrC), 10000 lb

FREE END OF CHAIN

CLUTCH ASSEMBLY

figure 129 - 2 m or 4.5 m mD extension chain assembly and QrC with chain engaged in chain anchor housing

DAP 101A-1105-1A


13.2 the turnbuckle barrel can be rotated by an external tensioning ring to extend or retract the overall length of the coupling, thus slackening or tightening an attached length of chain.

13.3 the chain anchor housing is slotted to accommodate a 2 m or 4.5 m m/D chain which is retained by a locking ring. this ring is also slotted to permit entry of the chain which is locked by a half turn of the locking ring (figures 128 and 129).

13.4 the quick release claws are opened and closed by a quarter turn of a knurled claw operating ring (figs 128, 130 and 131). the tensioners have a red dot engraved on the turnbuckle cover and on the claw operating ring. it is essential that the two red dots be aligned before the claws can be considered as being positively locked (figure 131).

CLAW OPERATING RING

figure 130 - QrC, jaws in ‘open’ position

RED DOTS IN ALIGNMENT

figure 131 - QrC, jaws in ‘closed’ position

13.5 in use, the QrC claws lock the coupling to a tie down/load securing ring or to an extension chain loop (figure 132 and 133). the maximum tension applied via the QrC must not exceed that which can be applied by hand, ie tools are never to be used as an aid to tensioning.

figure 132 - 2 m or 4.5 m mD extension chain and QrC, example of ‘claws to attachment point

DAP 101A-1105-1A


FREE ENDOF CHAIN

FREE ENDOF CHAIN

FREE ENDOF CHAIN

FREE ENDOF CHAIN

QRC TO CHAIN LOOP, SINGLE CHAIN CIRCUIT

QRC TO CHAIN LOOP, TWO CHAIN CIRCUIT

QRC TO CHAIN LOOP, TWO INDEPENDENT CHAINS

figure 133 - 2 m or 4.5 m mD extension chain and QrC, examples of ‘claws to chain loop’ engagement

14 Classification of equipment and ratingthe extension chain assemblies and QrC are classified by ‘ultimate strength’ (breaking load). in this case the extension chains have a far greater breaking load than the QrC which ultimately becomes the weak link and would be expected to fail before the extension chains.

therefore the QrC can be expected to fail under a force or load in excess of 10000 lb (taken along the line of the chain/tensioner). the rating of the QrC is dependent on the category of load being restrained (Chapter 2-8 refers) and are as follows:

non-aerodynamic loads 10000 lb ratingaerodynamic loads 6666 lb rating

15 Taping practiceSee Chapter 3 for examples of taping practice.

16 Technical support literaturefull maintenance support literature for this equipment is published in aP 108G-0002-1D: hUSle ancillary equipment. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

DAP 101A-1105-1A


CHAPTER 2 - 8 - 2: NYLON CORD

INTRODUCTION

nylon cord is used extensively in USl preparation and is suitable for restraining or securing lightweight items, where chains or web lashings and their associated tensioners cannot be used. this chapter highlights some general and important points concerning the practical use of nylon cord: for practical applications of nbC see Chapter 4.

FEATURES OF NYLON CORD

17 Generalin general cords that are commonly called up in USlCs, have a high strength/weight ratio with a high degree of strength before breakage. being pliable, nylon cord is relatively tolerant of passage around acute corners providing there are no sharp or jagged edges. nylon cord is normally classified by minimum breaking strength (min bS), which equates to breaking load, but this figure does not include the degrading effect of knotting.

18 Knotsthe effect which makes a knot hold securely is friction; the more tension on the cord the more tightly the knot should bind together. nevertheless, with smoothly finished material such as nylon braided cord (nbC), it is sound practice to apply ‘stop’ knots (thumb knots) having completed the main knot. Stop knots prevent the cord ends from slipping back through the main knot and will also help to prevent fraying of the cord ends.

a more permanent means of preventing fraying is to fuze the end filaments of the cord by directing a soft flame for a few seconds across the end of the cord. this practice is normally called upon for the purposes of USl’s and may be debarred by the nature of the load, eg flammable materials.

figures 134 and 135 illustrate various types of knot which have a useful application for securing items, or parts of the load, in preparation for helicopter underslinging.

BOWLINE

ROUND TURN AND TWO HALF HITCHES

1 2 3 4

figure 134 - tying a bowline, round turn and two half hitches

19 Tiesthe purpose of a securing tie is that it will hold one item to another in a sufficiently and robust manner to ensure that the items remain secured together for the duration intended. for a helicopter USl this includes all phases of the operation, from ground transit to the helicopter hook-up point to eventual landing of the load at its destination.

DAP 101A-1105-1A


OVERHAND OR THUMB KNOT

REEF OR SQUARE KNOT

REEF STOPPED WITH THUMB KNOT

CLOVE HITCH

TWO HALF HITCHESHALF HITCH

figure 135 - tying various useful knots

20 Types of securing tiesthe following information details various types of securing ties which feature regularly in USlC’s:

20.1 Single tie (figure 136) a single tie connects two items, with a single thickness of cord.

20.2 Double tie (figure 136) a double tie connects two items, with two thicknesses of cord.

20.3 Single loop tie (figure 136) a single loop tie connects or secures two or more items together with two thicknesses of cord.

DAP 101A-1105-1A


20.4 Double loop tie (figure 136) a double loop tie connects or secures two or more items together with four thicknesses of cord.

20.5 Double running loop tie (figure 136) a double loop tie connects or secures two or more items together with four thicknesses of cord. a single part of cord is passed twice around the items and the two single cord ends tied together with a reef knot and two stop knots.

figure 136 - single and double ties

20.6 Parcel tie (figure 137) a parcel tie is made with a bowline knot, a round turn and two half hitches. this tie is useful when two or more items are to be secured tightly together, and is made in the fashion of the first tie around a postal parcel. the bowline knot is used to form a loop or eye in one end of the cord and the cord is passed around the items to be tied, with the end passing through the bowline loop. the end is then tightened and pinched with the fingers in a bight at the bowline loop to maintain the tension of the tie, while securing with the round turn and two half hitches. the main benefits with this tie are that a mechanical advantage of two is offered (neglecting friction) when the end is being hauled through the loop, and the tension obtained can be maintained whilst making fast the tie.

figure 137 - Parcel tie

20.7 Vantage strop (figure 138) this tie is very useful where two items need to be drawn powerfully towards each other and secured. the tie can be made to perform the function of a tie-down or lashing. Viewing the strop as depicted it offers a mechanical advantage of two if the upper end moves, and three if the lower end moves (neglecting friction). if the main consideration is for the maximum pulling force, the tie should be made so that the pull exerted by the operator (indicated by the black arrow in figure 126) is away from the moving end of the system. Where the maximum of force is not the main consideration, the tie may be made in a way the operator finds convenient.

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figure 138 - Vantage strop

21 Practical strength of tiesin practice, the efficiency and strength of a tie is affected by the following:

21.1 Stretching - it has to be accepted that under sufficient load, nylon cord will stretch and allow a certain amount of movement of the item restrained. Providing the stretch is not too great, and limited movement of the item is not critical, this should not prove a problem with most USl’s.

21.2 Knots - the reduction of strength of cord by the inclusion of knots affects ties of all types; as a general rule, the use of knots effectively reduces the breaking strength of a cord to half of the rated figure. although knots reduce the strength of the cord, it is seldom that the knot itself breaks under load; failure usually occurs at or near the point where the standing part of the cord enters the knot.

21.3 Sharp edges or corners - Sharp edges or corners cut into the cord when a load is imposed; they should be avoided, or if they cannot be avoided then they must be padded to protect the cord.

22 Strength criteriathe strength criteria to be applied when using nylon cord (or similar materials) for securing items on USl’s and the following rules are to apply:

22.1 Practical strength to provide a safe working tolerance for unforeseen load forces, including allowance for knots and for the possibility of the cord operating at acute angles and round acute bends, the practical strength of the cord is to be reckoned as being one third of its rated breaking strength, e.g. 1200 lb nbC is to have the capability of restraining a load or force not in excess of 400 lb.

22.2 Working strength as a general rule the ‘working’ strength of the cord may be multiplied by the number of parts of the cord passing between the items tied, e.g. a 1200 lb nbC ‘double tie’ (figure 136), having two parts of the cord passing between the items, may be considered to have a working strength of 800 lb (400 lb x 2).

23 Use of alternatives when 1200 lb NBC is not availablethe use of alternative lower strength nbC to 1200 lb nbC is permitted provided multiple ties are used to give an equivalent or greater strength than 1200 lb.

nbC: 1200 / (150 x 2) = 4 4 + (4 x ⅓) = 5.333 therefore 6 complete turns are required.

note If continuous running ties are used to replace single ties the NBC is degraded and an additional ⅓ more turns must be made to compensate, e.g. to replace a single 1200 lb nbC tie with a running tie of 150 lb.

DAP 101A-1105-1A


CHAPTER 2 - 8 - 3: NET CARGO, THROW-OVER RESTRAINT FOR HUSLE SWL 1000 KG

INTRODUCTION

the throw-over restraint cargo net has been designed to restrain cargo loads loaded in a vehicle or trailer, up to 1000 kg, when carried as a helicopter underslung load. full nSn details and nomenclature for the equipment are contained in aP108G-0002-1a: hUSle nets.


the net (figure 137), measures 3.25 m x 2.44 m, is constructed in knotless intersections to a one piece rectangular shape, with diamond meshes. a continuous peripheral border cord forms an integral part of the net assembly. a ‘marker row’ (red) is attached to the mesh row adjacent to the border cord on one narrow side; the marker row therefore identifies one narrow side of the net. lashing lines used for final net tensioning are attached to the net, four meshes in from each corner. the dry weight of the net is 10 kg.

HOOK

NET BODYBORDER CORD LASHING LINE

MARKER ROW

IDENTIFICATION LABEL

figure 139 - net cargo, thrower-over restraint for hUSle SWl 1000 kg

24 Hookstwenty-two hooks are permanently attached around the net periphery; these are used to attach the net to a vehicle or trailer. a further fourteen hooks are permanently attached to the net mesh and are equally spaced 3.5 or 4 meshes inboard from the net periphery; these hooks are used for initial tensioning of the net.

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25 Net identification labelthe net has an identification label located near the centre of the net and provides the details of the net, as shown in figure 139. the rear of the ident label is used to record the net life expiry date.


26 Pad protection, helicopter cargo netnet protection pads are described fully in Chap 2-6-1, and are used to protect the net from damage which may be caused by sharp edges and protrusions in the load, they also provide a measure of protection for the load or its fittings. full nSn details and nomenclature for this equipment are contained in aP108G-0002-1D: hUSle ancillary equipment.

27 Net life expirythe net is a ‘lifed item’ (the policy for which is laid down in the maintenance support literature for the equipment) and users must ensure that the life expiry date is recorded on the rear of the ident label with either a permanent black/blue marker pen or a metal etching tool.

28 Net storageStorage instructions for the cargo net are contained in aP108G-0002-1a: hUSle nets.

29 Maintenance support literaturefull maintenance support literature for this equipment is published in aP108G-0002-1a: hUSle nets. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

INSTRUCTIONS FOR USE

30 Generalall items with sharp edges within the load must be padded to prevent damage to the net. the load should be covered with a canvas to restrain small items: chapter 2-9 and chapter 4 describe fully the restraint of equipment within a vehicle or trailer.

before attaching to the load, lay out the net on a dry flat surface, free off any hooks that may have tangled in the meshes and untangle the lashing lines.

31 Preparation to vehicles/trailersif the load is small and not expected to project beyond the rear of the vehicle or above the sides, action must be taken to provide the means of securing the net. this can be achieved by tying double lengths of braided nylon cord laterally and longitudinally to the vehicle or trailer internal restraint brackets, tying the cord with stop knots.

action before loading is not required if the load is in excess of that described above; in which case the net will be secured by using the external canopy lugs.

32 Attachment to vehiclesDrape the net over the load ensuring that the red marker row is at either the front or the rear of the vehicle, and there is an equal amount of netting hanging down each side of the load.

32.1 Small load. Pass the hooks located on the border cord around the length of the braided nylon cord and then engage them back on to the net mesh.

32.2 large load. engage the net border cord on the external canopy securing lugs on each side of the vehicle and engage the hooks located on the border cord back on to the net mesh.

tension the net by using the hooks located in the net mesh and also the lashing lines (see paragraph 34).

33 Attachment to trailersDrape the net over the load ensuring that the red marker row is at either the front or rear of the trailer, and there is an equal amount of netting hanging down each side of the load.

DAP 101A-1105-1A


engage the net border cord on the cover securing lugs on each side of the trailer and engage the hooks located on the border cord back on to the net mesh.

tension the net by using the hooks located in the net mesh and also the lashing lines (see paragraph 34).

34 Net tensioningthe method of tensioning the net is the same for both vehicles and trailers; the net is tensioned, on completion of attachment, by using the hooks and lashing lines located in the mesh, ideally with equal tension over the whole of the net surface.

initial tensioning is achieved by pulling on each hook in turn towards the net centre, taking up some slack in the net and attaching the hooks to convenient mesh legs; this is repeated until the net is equally tensioned over the net surface.

final tensioning is achieved by reeving each lashing line in turn, in and out of the net meshes pulling it tight then tying off with double stop knots.

35 Net attachmentthe cargo restraint net is not to be attached directly to the underslung cargo net, but is to be secured to the load pallet (if being used) or a suitable restraint point on the load.

warning attachment of the restraint net direct to the underslung load net may lead to net overload and ultimately net failure.

further detail on cargo lifting nets can be found in Chapter 2-6.

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CONTENTS

CHAPTER 2 - 9: BAG - SINGLE USE LIFT, SWL 1000 KG AND STROP, DISPOSABLE, 2 M, SWL 2000 KG

SINGLE USE LIFT BAG (SULB) ........................................................................................................... 1911 introduction.........................................................................................................................................1912 equipment description ........................................................................................................................1913 Single use lift bag identification ..........................................................................................................1914 liife expiry of the single use lift bag ...................................................................................................1915 technical support literature ................................................................................................................1926 equipment usage ...............................................................................................................................192STROP, DISPOSABLE, 2 M .................................................................................................................. 1927 introduction.........................................................................................................................................1928 equipment description ........................................................................................................................1929 Strop identification label .....................................................................................................................19210 life expiry of the disposable strop ......................................................................................................19211 technical support literature ................................................................................................................19212 equipment usage ...............................................................................................................................19313 Suitability for engagement to current range of helicopter cargo hooks ..............................................194

figures

figure 138 - Single Use lift bag, showing user advice and identification details .........................................191figure 139 - Strop, Disposable, 2 m ..............................................................................................................193figure 140 - Disposable Strop connecting to 2 SUlbs to helicopter cargo hook ..........................................194

CHAPTER 2 - 9

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CHAPTER 2 - 9: BAG - SINGLE USE LIFT, SWL 1000 KG AND STROP, DISPOSABLE, 2 M, SWL 2000 KG

SINGLE USE LIFT BAG (SULB)

1 Introductionthe Single Use lift bag (SUlb) has been introduced into Service as a disposable item of hUSle to enable small items of stores and equipment to be carried by helicopter. further details and full nSn details for the equipment are contained in aP108G-002-1D: ancilliary equipment

2 Equipment descriptionthe SUlb (figure 138) is manufactured from polypropylene and available in 4 colours, Sand, olive Drab, Snow and red. four lifting loops are fitted to the bag, one to each corner. the two adjacent loops are connected via Stevedore harnesses to provide a single point lift. the top of the bag is secured by means of a draw-corded skirt. the SUlb safe working load is:

minimum SWl 250 kgmaximum SWl 1000 kg

3 Single use lift bag identificationthe bags are stencilled with various identification details.

DRAWCORD

SKIRT

LOOP

STEVEDORE HARNESS

figure 138 - Single Use lift bag, showing user advice and identification details

4 LIife expiry of the single use lift bagthe SUlb is a ‘lifed’ item the policy for which is laid down in the technical support literature, paragraph 5 and also described in chapter 1-2.

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on removal from its protective packaging, equipment holders must record the removal date legibly and indelibly with black permanent marker pen on the front of the SUlb (figure 138).

5 Technical support literaturethere is no technical supporting literature for the SUlb apart from operating information and nSn details which are published in aP108G-002-1D: ancilliaty items. Chapter 1-2 gives general advice on obtaining hUSle aP’s.

6 Equipment usageWARNING

THE SULB IS FOR ONE SORTIE PER BAG ONLY.

the SUlb allows for miscellaneous items of equipment and general cargo to be carried as authorised loads within the given SWl. items with sharp edges/corners are to be prepared accordingly to minimise the risk of splitting/tearing the SUlb. a skirt, sewn around the top edges of the bag with a draw-cord incorporated (figure 138), enables items to be contained securely within the bag.

if there is a requirement to carry equipment with a Dangerous air Cargo (DaC) aspect, it is to be prepared in accordance with current instructions for air transportation of DaC. the bag is resistant to most solvents, oils and greases, however it may be vulnerable to corrosive substances such as battery acid that may cause structural failure of the bag.

the SUlb has a tendency to twist in flight and therefore is not to be attached direct to the aircraft cargo hook but to either an extension strop with swivel hook assembly or to a 2 m Disposable Strop. When a strop is being used to lift the SUlb it must not be flown individually but as a pair: as the characteristics of a failed single SUlb are unacceptable. a maximum of 2 SUlbs can be attached direct to an extension strop secondary hook or 2 m Disposable Strop, with a minimum of 250 kg SWl in each SUlb.

multiple SUlbs may be carried with the appropriate multi-legged sling; the SUlb is to be prepared, rigged and flown in accordance with DaP101a-1105-1b, USlC 3030.

STROP, DISPOSABLE, 2 M

7 Introductionthe Disposable Strop (figure 139) has been introduced into Service as an alternative method of lifting 2 SUlbs from a helicopter cargo hook. the equipment has the nato description of ‘Strop, Disposable, 2 m, SWl 2000 kg’ and full nSn details for the equipment are contained in aP108G-002-1D: ancilliaty items

8 Equipment descriptionthe Disposable Strop is constructed from braid into an endless 4 m loop, with a protection sleeve to interface with the Stevedore harnesses of the SUlb. Soft eyes are formed at each end of the strop as a method of attachment to a helicopter cargo hook. the strop can only be used in a ‘parallel basket hitch’ configuration giving an effective working length of 2 m. the SWl of the Disposable Strop is 2000 kg.

9 Strop identification labelthe Disposable Strop has an identification label attached over one leg and is taped in position, and the label details are shown in figure 127.

10 Life expiry of the disposable stropthe Disposable Strop is a ‘lifed’ item the policy for which is laid down in the technical support literature, paragraph 11 and also described in chapter 1-2. on removal from its protective packaging, equipment holders must mark the removal date legibly and indelibly with black permanent marker pen on the strop identification label.

11 Technical support literaturefull technical supporting literature for this equipment including before and after use examination and general care is published in aP108G-002-1D: ancilliaty items. Chapter 1-2 gives general advice on obtaining aP’s.

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D.A. PARTNUMBER: HU20-0266300 NSN: 1670-99-573-1519 SERIALNO.VVVVVVD.O.M:VVVVVV

E.W.L. 2m S.W.L. 2000kg

SUPPLIED BY:AmSafe Bridport K2429

MAX SERVICE LIFE 28 DAYS FROM REMOVALOF PROTECTIVE PA

CKAGING DATE OF REMOVAL:

92785/1-038102/09

D.A. PART NUMBER: HU20-0266300NSN: 1670-99-573-1519

SERIAL NO.VVVVVVD.O.M:VVVVVV

E.W.L. 2m S.W.L. 2000kg

SUPPLIED BY: AmSafe Bridport K2429

M AX SERVICE LIFE 28 DAYS FROMREM OVAL OF PROTECTIVE PACKAGING

DATE OF REM OVAL:

92785/1-038102/09

IDENTIFICATION LABEL

PROTECTIVE SLEEVE

SOFT EYES

ADHESIVE TAPE

figure 139 - Strop, Disposable, 2 m

12 Equipment usagethe Disposable Strop allows for 2 SUlbs to be attached to a helicopter hook and delivered to a Drop-off-Point without the need for a ground handling team. the Disposable Strop may be used several times, within its 28 day service life, subject to its serviceability.

CAUTION The design of the Disposable Strop includes a protective sleeve onto which the SULB Stevedore harnesses are to be placed. Should the Stevedore harnesses make direct contact with the unprotected braid of the strop, significant chafing may result in failure of the strop.

one soft eye end of the Disposable Strop is looped through both Stevedore harnesses on each SUlb to create a ‘parallel basket hitch’ configuration (figure 140). the Stevedore harnesses are to be centralised

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on the Disposable Strop and placed over the protective sleeve; a failure of the strop may occur should the Stevedore harnesses be positioned directly around the unprotected braid. the Disposable Strop is to be taped just above the ends of the protective sleeve and at the soft eye ends to reduce incorrect attachment of the Disposable Strop to a helicopter cargo hook.

SOFT EYES

ADHESIVE TAPE

STROP CENTRALISED THROUGHSTEVEDORE HARNESSESPROTECTIVE SLEEVE

figure 140 - Disposable Strop connecting to 2 SUlbs to helicopter cargo hook

Chapter 2-2 paragraph 11, states only one lifting ring/apex device is to be carried on the load beams of british Service helicopter cargo hooks. however as the Disposable Strop can only be used in the ‘parallel basket hitch’ configuration, 2 soft eye ends need to be attached to the helicopter cargo hook. When connecting the Disposable Strop to the helicopter cargo hook, ground personnel are to ensure that both soft eye ends of the strop are attached correctly to the cargo hook load beam.

Consult Chapter 2-1 paragraph 3 (compatibility matrix) and DaP101a-1105-1b, USlC 3030 for application of the Disposable Strop to helicopter cargo hook.

13 Suitability for engagement to current range of helicopter cargo hooksthe current range of applicable helicopter cargo hooks are described in Chapters 2-2-1 to 2-2-5.

DAP 101A-1105-1A


CHAPTER 3

CONTENTS

CHAPTER 3: STANDARD RIGGING PRACTICE AND TECHNIQUES

INTRODUCTION .................................................................................................................................... 196STANDARD RIGGING PRACTICES AND TECHNIQUES .................................................................... 1961 basic rules for slings and cargo lifting nets ........................................................................................1962 Use of nbC ........................................................................................................................................1993 Use of tape .........................................................................................................................................201SYSTEMS FOR CHAIN LEG MEASUREMENT IN USLCS .................................................................. 2014 Chain loops ........................................................................................................................................2015 Chain to chain ....................................................................................................................................2026 forming chain lifting loops around vehicle spring hangar brackets ...................................................202

figures

figure 1 - Securing loose chain and not in use sling legs .............................................................................196figure 2 - taping loose chain and chain hooks .............................................................................................197figure 3 - Use of extension chain leg supporting ties....................................................................................198figure 4 - retainer breakaway assembly, or tape, securing lifting strops/sling legs after rigging .................199figure 5 - Correct use of a sling leg support tie.............................................................................................200figure 6 - incorrect use of a sling leg support tie ..........................................................................................200figure 7 - methods of connecting chains.......................................................................................................201figure 8 - methods of connecting chains.......................................................................................................202figure 9 - Chain loops above vehicle spring hanger brackets.......................................................................202

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CHAPTER 3: STANDARD RIGGING PRACTICE AND TECHNIQUES

INTRODUCTION

Chapter 2 described individual items of hUSle in detail, and rigging instructions in the USlC’s in DaP101a-1105-1b will give precise instructions for employment of items of equipment when they are called into use for a specific load.

USlC’s assume a thorough knowledge of standard practice on the part of personnel using the rigging scheme, however they will aim to provide maximum guidance by use of pictorial presentation. it is implicit that personnel using a USlC have been trained, are in current practice with the slinging equipment called up, or are directly supervised by authorised personnel. the purpose of this chapter is to ensure that all personnel understand what constitutes standard rigging practice, together with applicable techniques.

STANDARD RIGGING PRACTICES AND TECHNIQUES

1 Basic rules for slings and cargo lifting netsthe following basic rules apply to slings and, where applicable, cargo lifting nets:

1.1 Sling legs are to be arranged about the load in a symmetrical manner; eg with a four legged sling, the two outer legs are led to one end of the load and the two inner legs led to the other.

1.2 it is very important to ensure that sling legs are not crossed at the stage of attaching them to the load. the same principle applies to the lifting strops on nets at the stage of engaging lifting hooks to the net stirrups. it is also important to ensure that individual net lifting members are not twisted along their own length.

1.3 When the sling legs are in full lifting attitude, with the load suspended, the steel wire rope and textile element of the sling legs are to be clear of the load.

1.4 With four legged slings, if less than four legs are being used to lift the load, the legs not in use must be securely taped to the legs in use (figure 1). this is to prevent snagging of the unused legs during initial load lift and any possibility of flailing in flight.

figure 1 - Securing loose chain and not in use sling legs

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1.5 loose chain must be taped back securely onto the standing part of the chain, or secured in such other manner as may be called for in individual USlCs (figure 2). the mouths of all chain hooks are to be taped after their engagement onto a chain, to prevent inadvertent detachment prior to load lift or at any time when the chain is slack. Similarly, to prevent snagging, shortening clutch claws must be taped. Chain shortening clutches are fitted with chain locking levers and do not require taping in their ‘chain engaged’ position (Chap 2-5-1).

figure 2 - taping loose chain and chain hooks

1.6 there is a correct and incorrect method of engaging chain hooks and chain shortening clutches. the included angle of chain loops are limited and dependent upon the type of chain, minimum diameters or thickness of section around which the chain may pass, are also limited.

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1.7 after the sling has been attached to the load, the final stage of rigging involves steering the sling legs (or net lifting strops) clear of potential snagging points on the load and securing them in this position using nbC, the retainer breakaway or turns of adhesive tape.

1.7.1 nbC is used to support the sling legs to prevent them dropping down below the load attachment points and becoming trapped or twisted on lift or to prevent them from snagging on load protrusions (figure 3).

figure 3 - Use of extension chain leg supporting ties

1.7.2 the retainer breakaway or adhesive tape is used to secure the sling legs/net lifting strops together at intervals just above the load (figure 4). When the sling legs/net lifting strops

DAP 101A-1105-1A


come under tension the Velcro fasteners or turns of tape will break and the legs take up their natural line of lift. at this stage the nbC support ties will become loose or break. the retainer breakaway (chapter 2-7) is used with all available slings, the 5000 lb and 5600 kg nets.

figure 4 - retainer breakaway assembly, or tape, securing lifting strops/sling legs after rigging

2 Use of NBCWhen applying nbC leg support ties, unless otherwise specified on the USlC, a single tie of 150 lb nbC is to be used. the incorrect use of support ties could lead to serious problems.

figure 5 shows the correct use with the tie fully supporting the sling leg.

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figure 5 - Correct use of a sling leg support tie

figure 6 shows the incorrect use, the tie being tied off to the sling leg above the attachment point on the load.

figure 6 - incorrect use of a sling leg support tie

if tied incorrectly the sling leg will slacken off before the load is lifted allowing the attachment loop to drop down below the spring hanger bracket where it could become trapped or twisted and shorten the length of the sling leg. the shortened leg would then take a greater proportion of the load weight which could overload the leg causing a breakaway or alter the load attitude, both of which could seriously effect its flying characteristics.

the incorrect strength of nbC used as supporting ties could also cause the same problems.

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3 Use of tapeWhen securing hook mouths, loose chain or shortening clutches to a standing chain, there must be a minimum of three full turns of tape around the item being secured (2 in. tape is normally used). this rule also applies when securing not in use sling legs to those in use. for the final securing of an assembled sling or net prior to load lift, one and a half turns of 2 in. tape must be used.

WARNING DO NOT EXCEED TAPING PRACTICE ON PARTS OF SLINGING EQUIPMENT WHICH EXTENDS BEYOND THE PRACTICE STATED HERE, IN ANY OF THE HUSLE CHAPTERS IN THIS BOOK OR IN INDIVIDUAL USLC’S. IF THERE IS CONCERN IN ANY AREA THEN THIS CONTACT JADTEU.

SYSTEMS FOR CHAIN LEG MEASUREMENT IN USLCS

4 Chain loopsChain loops are normally related to the number of links forming the loop, as counted from the fixed end of the chain hook or shortening clutch. in a 24 link loop, link no 1 is the link which is attached to the tail of the chain hook or clutch (whether or not this link is a special joiner or out-sized link). Counting along the links from that start point, the chain hook or clutch is engaged onto the 24th link (figure 7).

figure 7 - methods of connecting chains

for larger chain loops, the chain hook or clutch engagement point may be related to the far end of the chain, ie the point where the chain is fixed to the end of the wire rope or textile element of the sling. to engage the chain hook or clutch onto the 8th link from the sling leg fixture point, link no 1 is the link attached to the fixture at the end of the wire rope or textile leg element (whether or not this link is a special joiner or out-sized link). Counting along from link no 1, the chain hook or clutch would be engaged onto the 8th link from the start point (figure 8).

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figure 8 - methods of connecting chains

5 Chain to chainfor engagement of a chain clutch, of one chain onto another like chain, eg chain extension leg, the link for engagement will normally be identified as a numbered link, counting from a specified end of the chain, for engagement (figure 8).

6 Forming chain lifting loops around vehicle spring hangar bracketsthe typical method for forming a chain lifting loop, about the spring hanger brackets on a vehicle, is shown in figure 9.

figure 9 - Chain loops above vehicle spring hanger brackets

noteS

1 - Unless a specific USlC calls for loose chain to be taped, or otherwise secured to the load itself, the standard practice is for loose chain, assembled into folds, to be taped to its parent chain as illustrated

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2 - the length of chain folds will be dictated by the routing and available length of the ‘working’ section of the parent chain; four thicknesses of chain is the normal manageable number of folds,

3 - Do not pull the loose chain tightly back on the engaged chain hook or clutch, allow slack in the ‘U’ turn.

4 - the claw of a non-engaged clutch is taped, facing out, to indicate it is not in use.

5 - the claw of an engaged clutch does not require taping, though if non-engaged it must be taped.

6 - an engaged chain hook must be taped and the mouth of a non-engaged chain hook must also be taped.

DAP 101A-1105-1A


CHAPTER 4

CONTENTS

CHAPTER 4: PREPARATION OF LOADS, STANDARD PRACTICES AND TECHNIQUES

INTRODUCTION .................................................................................................................................... 205GENERAL HANDLING OF RESTRAINT OR SECURING EQUIPMENT .............................................. 2051 taping practice ...................................................................................................................................2052 Use of nylon braided cord ..................................................................................................................206VEHICLES AND TRAILERS .................................................................................................................. 2063 Securing typical land rover load .....................................................................................................2064 Securing typical trailer load ................................................................................................................210

figures

figure 1 - method of interconnecting and taping single web lashing ............................................................205figure 2 - method of interconnecting and taping two ratchet assemblies .....................................................205figure 3 - method of interconnecting and taping two web lashings connections ..........................................206figure 5 -Securing soft top vehicle canopy using net cargo restraint ............................................................207figure 6 - Securing bonnet catches...............................................................................................................207figure 7 - Securing doors of soft/hard top land rovers................................................................................208figure 8 - Securing seats, ignition key, fire extinguisher and vehicle tool kit .................................................209figure 9 - typical anti-jack-knife chain configuration .....................................................................................210figure 10 - trailer restraint using net cargo restraint..................................................................................... 211figure 11 - routing of web lashings and ratchet assemblies ........................................................................ 211

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CHAPTER 4: PREPARATION OF LOADS, STANDARD PRACTICES AND TECHNIQUES

INTRODUCTION

many of the practices and techniques for the preparation of a load follow a common pattern, particularly in the case of vehicle loads. the aim of this chapter is to provide illustrations of those practices or techniques for securing items on loads which have a wide application. in this chapter the emphasis is upon general features of land rover vehicle and trailer preparation.

GENERAL HANDLING OF RESTRAINT OR SECURING EQUIPMENT

Chapter 2-8 covers current items of restraint equipment and materials provisioned for the USl role, and also lay down the rules of usage.

1 Taping practicein general the taping practices which apply to the use of chains, in the slinging role (chapter 3) should be followed for the purpose of load restraint. loose chain should be secured and the mouths of chain hooks should be taped. Similarly, loose strap with web lashings should be neatly secured together with tape. the aim is to avoid the risk of snagging, particularly with sling legs or the like, and any chance of flailing or subsequent catching on items of slinging equipment during flight. Chapter 3, figure 2 gives examples of taping loose chain; figures 1, 2 and 3 (below) gives examples of connecting and taping ratchet assemblies and web lashings.

SINGLE WEB LASHING AND RATCHET ASSEMBLY

CONNECTED TO SINGLE ATTACHMENT POINTS EITHER END

figure 1 - method of interconnecting and taping single web lashing

TWO RATCHET ASSEMBLIES INTERCONNECTED WITH

WEB LASHINGS CONNECTED TO SINGLE ATTACHMENT POINTS EITHER END

figure 2 - method of interconnecting and taping two ratchet assemblies

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TWO WEB LASHINGS INTERCONNECTED WITH LOOSE

ENDS CONNECTED TO TWO RATCHET ASSEMBLIES.

RATCHET ASSEMBLIES CONNECTED TO SINGLE

ATTACHMENT POINTS EITHER END

TWO WEB LASHINGS INTERCONNECTED WITH LOOSE ENDS

CONNECTED TO TWO INTERCONNECTED RATCHET ASSEMBLIES.

METHOD USED FOR ENCIRCLING LOADS

figure 3 - method of interconnecting and taping two web lashings connections

2 Use of nylon braided cord (NBC)nylon braided cord (nbC) is probably the most used material for general/lightweight securing purposes, and the securing ties illustrated in chapter 2-8-2 provide a useful basis for tackling various types of securing required with helicopter USl’s.

VEHICLES AND TRAILERS

the following figures cover general points of preparation for vehicles and trailers.

3 Securing typical Land Rover load figures 4 to 9 illustrate the typical preparation for a land rover, which can be applied to other vehicles.

figure 4 - Securing canopy and equipment into vehicles

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SECURE NET TO PROVISIONED CLEATS.

SURPLUS NET MUST BE PULLED TIGHT

AND SECURED BACK TO THE MAIN BODY

OF THE NET USING THE PROVISIONED HOOKS

1200 lb NBC LACING TIE TO

SECURE LOOSE EDGES OF

RESTRAINT NET AT REAR

figure 5 -Securing soft top vehicle canopy using net cargo restraint

150 lb NBC

figure 6 - Securing bonnet catches

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HARD TOP

VANTAGE STROP 1200 lb NBC

3 COMPLETE TURNS

1200 lb NBC

SOFT TOP

(CANOPY REMOVED)

figure 7 - Securing doors of soft/hard top land rovers

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150 lb NBC SECURELY TIED AROUND STEERING COLUMN

MUST BE LONG ENOUGH TO REACH IGNITION SWITCH

MASKING TAPE

MASKING TAPE

FIRE EXTINGUISHER SECURED

IN DESIGNATED CLAMP

TOOLS LOCATED IN

DESIGNATED FIXINGS

1200 lb NBC SECURING SEATS

(DOUBLE HITCH WITH THUMB KNOT)

1200 lb NBC SECURING

CUSHION SEATS

figure 8 - Securing seats, ignition key, fire extinguisher and vehicle tool kit

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RESTRAINT CHAINS WITH HOOKS OR

EXTENSION CHAINS WITH CLUTCHES

MAY BE USED AS ANTI JACK-KNIFE CHAINS-

figure 9 - typical anti-jack-knife chain configuration

4 Securing typical trailer loadthere are two methods of restraining loads within a trailer:

4.1 Using trailer canvas and net cargo restraint, helicopter USl: the new and more common method is the use of the trailer canvas cover and net cargo restraint, helicopter USl (figure 10). loose stores or equipment in the trailer must be fully secured against movement, utilising the lashing rings, and securing with vehicle ratchet assembly and web lashings prior to fitment of canvas and net. Stores or equipment, which totally fill the trailer compartment and abuts the trailer sides, may be restrained by the canvas and net only (chapter 2-8, paragraph 5 refers).

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figure 10 - trailer restraint using net cargo restraint

4.2 Using trailer canvas and duck-board the stores or equipment in the trailer must be fully secured against movement, utilising the trailer lashing rings (figure 11).

¾ TONNE WIDE TRACK TRAILER

figure 11 - routing of web lashings and ratchet assemblies

4.3 the rings are used in conjunction with web lashings and ratchet assemblies. the sequence of operations is as follows:

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4.3.1 remove the canvas and duck-board.

4.3.2 attach a web lashing or ratchet assembly to the side lashing rings, as required.

4.3.3 Pack the stores or equipment in the trailer, ensuring that the load does not project beyond the top edge. Place the cam net (if carried) and canvas cover evenly over the load tucking it inside the trailer. Position the duck-board on top of the canvas cover.

4.3.4 ensure the web lashings are routed under the outer edges of the duck-board. attach web lashings to the ratchet assemblies.

4.3.5 tighten web lashings with the ratchet assemblies. lock ratchet assemblies and tape loose ends of web lashings.

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CHAPTER 5

CONTENTS

CHAPTER 5: STATIC ELECTRICITY AND DISCHARGERS

INTRODUCTION .................................................................................................................................... 214MAINTENANCE SUPPORT LITERATURE ........................................................................................... 214ELECTROSTATIC DISCHARGE POLE (‘STATIC PROBE’) ................................................................. 2141 mk1 and mk2 Static Probes ...............................................................................................................2142 the vertep earthing pole ....................................................................................................................2153 life expiry policy .................................................................................................................................215THE DISSIPATION OF STATIC ELECTRICITY ..................................................................................... 2154 responsibility .....................................................................................................................................2165 method of use.....................................................................................................................................2166 ammunition, explosives and missiles .................................................................................................2167 flammable liquids ..............................................................................................................................2178 Static electricity in dry and cold conditions .........................................................................................2179 operations during thundery conditions ..............................................................................................217

figures

figure 1 - mk1 Static discharge probe...........................................................................................................214figure 2 - mk2 Static discharge probe...........................................................................................................215figure 3 - rn earthing pole ...........................................................................................................................215

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CHAPTER 5: STATIC ELECTRICITY AND DISCHARGERS

INTRODUCTION

the electrostatic discharge pole, commonly known as a ‘static probe’, is a manufactured item that provides a means of dissipating static electricity from a hovering helicopter safely.

MAINTENANCE SUPPORT LITERATURE

full maintenance support literature for this equipment is published in aP 108G-0002-1D: hUSle ancillary equipment, along with full nSn details and nomenclature. Chapter 1-2 gives general advice on obtaining hUSle maintenance aPs.

ELECTROSTATIC DISCHARGE POLE (‘STATIC PROBE’)

1 Mk1 and Mk2 Static Probestwo static probes (mk1 and mk2) are available and similarly assembled with several components (figure 1 and figure 2). one end of a length of wire rope, double insulated on the mk2 probe, is passed through the end link of a length of chain, looped back and secured using a wire grip. an interface is used to connect the other end of the wire rope with the hook. the handle is secured around the interface and encloses the end of the hook and wire rope. the handle is insulated and designed with a wasted area, marked ‘Grip here’ on the mk2 probe, for the user to hold.

the mk1 and mk2 static probes are not authorised for use in the maritime environment.

figure 1 - mk1 Static discharge probe

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figure 2 - mk2 Static discharge probe

2 The VERTREP earthing polethe rn VertreP earthing pole (figure 3) is authorised for use in the marine environment and is available from naval stores. it is to be serviced to current rn regulations.

figure 3 - rn earthing pole

3 Life expiry policyall static probes are not subject to an in-service or finite life and is to be rejected only on condition.

THE DISSIPATION OF STATIC ELECTRICITY

the structure of a helicopter can become charged with static electricity during flight and this charge can be a hazard when hooking-up external loads. in most instances, if a member of a hooking-up team were to grasp a primary/secondary hook before applying a probe/pole hook, it is unlikely that a fatal electric shock would result.

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4 Responsibilitythe helicopter load handling team is responsible for the discharge of static electricity from an aircraft. instructions on helicopter load handling procedures will include the methods of dissipation to be used by load handling teams.

5 Method of useGloves must be worn when handling the static probe. ensuring that the wire grip and wire rope is properly earthed, hold the probe/pole by the insulated handle. When the helicopter is correctly positioned in the hover at the loading point, the probe/pole hook, is to be placed firmly over the load beam of either the primary or secondary hook.

note Static electricity is discharged at the point where the wire grip and wire loop touch the ground. the chain acts as a weight only and will not discharge static electricity.

hook-up the load to the primary or secondary hook and then remove the probe/pole hook (in that order).

note a lapse of two or three seconds, without the earthing device being in contact with the aircraft and the ground, is long enough for an appreciable further charge to build up in the aircraft.

it is not necessary to follow the earthing drill when releasing external loads except when the load is dangerous goods (paragraph 6). any induced charge in the helicopter and its load will be dissipated through the load as soon as the load touches the ground; this may be a hazard to dangerous goods. obviously, the load should not be touched by hand until it is grounded.

6 Ammunition, explosives and missilesirrespective of weather conditions or the type of helicopter concerned, it must always be assumed that a discharge arc will occur when an external load is earthed by contact with the ground.

the possibility exists and is of particular concern with external loads of ammunition or live missiles (especially those electrically detonated) or highly volatile flammable liquids such as fuels or liquid oxygen.

the following information concerns the carriage of ammunition, explosives and missiles as USls.

6.1 items not containing electro explosive Devices (eeDs) are safe to carry as USls, providing they are packed in their authorised outer container.

6.2 ammunition or explosives etc, containing eeDs packed as follows, are safe USls:

6.3 Packed in authorised metal outer containers with any type of authorised inner container.

6.4 Packed in authorised non-metal containers with authorised metal inner containers.

6.5 items covered by paragraphs 6.1 and 6.2 can be carried safely in cargo nets. During delivery, it is safe to earth the helicopter through the load if this is necessary.

6.6 the hazard to personnel during pick-up or delivery of the load is minimal for items covered by paras 6.1, 6.2 and 6.3 providing:

6.6.1 During pick-up, the normal earthing procedures in force are carried out using either a probe/pole hook before hUSle is engaged on to primary or secondary hooks.

6.6.2 During delivery, neither the helicopter nor the load is touched by personnel before it is earthed, either through the load touching the ground, or via the probe/ pole hook.

6.7 Unpacked ammunition or explosives etc, containing eeDs are not safe, because discharge may occur through the open, unprotected casing of the store.

6.8 Packed ammunition or explosives etc, other than those described in paragraph 6.2, are not safe irrespective of the method of carriage.

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7 Flammable liquidsflammable liquids, carried in cargo nets, are to be earthed through a suitable chain attached to the metal fuel container and suspended at least 9 ft below the load. the main hazard with flammable liquids is ignition of the vapour: this is minimised by the chain maintaining a safe distance between the load and any possible spark, providing there is no leakage from the containers.

8 Static electricity in dry and cold conditionsthe build-up of static electricity is very rapid in dry and cold conditions, and it is not unusual for personnel to receive a noticeable shock when they touch a well-earthed object. Static electricity dischargers are essential when external load operations are in progress.

before operating in dry and cold conditions, all personnel must be aware:

8.1 there is increased build-up of static electricity in dry and cold conditions.

8.2 Static electricity dischargers must be used for all external load operations.

9 Operations during thundery conditionsVertical replenishment operations during thundery conditions should be avoided when operationally possible. not only do such conditions increase the electrostatic hazards by reason of the high ambient charged atmosphere, in addition the configuration of a hovering helicopter with external load is susceptible to lightning strike.

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