aerospace control & guidance systems committee rev b, 10/08/08 shawn donley acgsc meeting 102 1...

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Aerospace Control & Guidance Systems Committee

Rev B, 10/08/08

Shawn DonleyACGSC Meeting 102

SAE A-6 Project A-6A3-08-1

Aerospace Recommended Practice - ARP94910

Aerospace- Flight Control Systems - Design, Installation and Test of, Military Unmanned Aerial

Vehicles, Specification Guide

ACGSC Meeting 10215-17 Oct 2008

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ARP94910 Origins – Project Definition & Approval

• In 2007 the A-6 Systems panel completed AS94900 – Aerospace Standard for FCS for Military Manned Aircraft

• Spec released July 6, 2007 adopted by DoD to replace MIL-F-9490 November 5, 2007

• Version of the AS for UA’s suggested and informally polled in industry to mixed results

• The US Navy, Army and Air Force expressed support which justified initiating the project

• May 2008, A-6 Steering Council approved project– But as an Aerospace Recommended Practice, not an Aerospace Standard– Explicitly confined to vehicle subsystem (ground station and data links not

included)– Targeting late 2009 for a draft ARP


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• A-6A3 “Systems” Panel Officers– Ian Halley, Chairman and Co Sponsor

• Boeing Phantom Works

– Dave Flavell, Vice Chairman and Co Sponsor • Moog Inc

– Floyd Fazi, Secretary and ASD Liason• Lockheed Aeronautics

Project Sponsored by the SAE A-6A3 Flight and Utility Control Systems Panel


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Moving Forward with the ARP

• AS94900 is written for manned military aircraft. Implicit premise that total loss-of-control should an exceedingly rare event rather than an occasionally acceptable event.

• At least for some UAS’s to date, occasional losses seem to be acceptable in today’s climate. Some would claim even frequent losses are acceptable in certain circumstances.

• AS94900 may serve as a basis for developing the ARP, but clearly not all requirements in AS94900 are applicable to all UA’s. Some UA requirements are missing all together.

• If manned aircraft loss-of-control criteria are not technically or economically achievable for some classes of UA’s, what should our expectations be?

Thoughts which follow are VERY preliminary and subject to change.Your feedback encouraged !

[email protected] [email protected]


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Data Spans 5 Orders of Magnitu

de !

Unclear What P

ercentage of Losses are Due to

Flight C

ontrols

From Weibel & Hansman, MIT, May 2005(with F-18 data added)

Unmanned Aircraft1 Accidents/ 100,000 hr–Global Hawk (4 accidents)* 168–RQ-2A Pioneer 363–RQ-2B Pioneer 139–Predator RQ-1A* 43–Predator RQ-1B* 31

Manned Military Aircraft1,3

–F-16 3.5–F-18 2.8

Manned Civil/ Commercial Aircraft Accident Rates (2003)2

–General Aviation 6.7–General Aviation (Fatal) 1.4–Part 121 Scheduled & Unscheduled 0.313–Part 121 Scheduled & Unscheduled (Fatal) 0.012

Sources:1.) National Defense Magazine, May 20032.) NTSB Press Release, March 22, 20043.) NAVAIR System Safety, August 2008

*Total Operational Hours < 100,000 : Predator (65,000 hr); Global Hawk (2,500 hr)


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What Does the Customer Expect a UA to Do After a FCS Failure ?

• Need to answer this question before we can generate a useful ARP.

• Answer depends on the characteristics of the UA (size, cost, range), its mission and its operating area.

• Perhaps trying to answer this question provides a framework for linking ARP flight control recommendations to UA behavioral expectations.– Applicability of an ARP paragraph would depend upon expectations for

post-failure behavior.


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Proposal

Develop a Concept of “Types” of UA FCS Post-Failure Behavior

• Applicability of an ARP paragraph would depend upon FCS Type

• If “Type” is the wrong name, pick another one

• Brute-force redundancy may not be the best or only answer– for smaller UA’s, it may be impossible or cost prohibitive

• Definitions of behavior and comments are very preliminary

• Have purposely avoided trying to assign a PLOC number to each Type since I don’t trust these numbers, and because management focuses on them as absolutes when they are not

• If PLOC numbers become unavoidable, recommend considering “Probability of Containment” requirement to augment PLOC

– Probability of containment is the probability that the UA will not stray outside pre-defined geographical coordinates


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Type Acceptable Behavior After First FCS Failure

Comments Acceptable Behavior

After Second Failure

0 Immediate loss of attitude, altitude or speed control, resulting in immediate loss of flight path control and eventual or immediate uncontrollable impact with terrain/obstructions.

Characterized by a single thread system with no analytical redundancy or control reconfiguration features.

N/A

1 Degraded control of attitude, altitude or speed. Vehicle unable to complete the original mission. Vehicle able to maintain safe altitude and airspeed in some cases. Sufficient flight path control to maintain a pre-defined fail-safe heading that minimizes risks to third parties.

Type 0 system where special efforts are made to keep the processors and their power sources alive. If data link is available, ground control could provide vector to alternate recovery area. Controllable landing may not be possible.

Type 0

2 Degraded control of attitude, altitude or speed. Vehicle unable to complete the original mission or a modified mission without risk of loss. Vehicle attempts to estimate if it can reach the recovery point of original intent or an alternate for a controllable but possibly degraded recovery. If not, vehicle attempts to reach a pre-defined geographical coordinate and terminate flight.

Characterized by very high integrity simplex digital processors and processor power supplies/sources, or at least duplex redundancy in these components . Servos may be simplex but designed to minimize probability of hardover failures. Analytical redundancy and control reconfiguration used to provide sufficient control and navigation to safely reach a recovery point for degraded landing, or a pre-defined flight termination coordinate.

Type 1

How Should the Vehicle Respond After a Flight Control Failure(For purposes of this table, FCS includes Nav Sensors such as GPS/INS, but not data links)


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FCS “Type” Continued

Type Acceptable Behavior After First FCS Failure

Comments Acceptable Behavior After Second Failure

3 Partial degradation of attitude, altitude or speed control. Vehicle may be unable to complete the mission without risk of loss unless mission parameters are modified. Vehicle still capable of reaching recovery point of original intent or an alternate for a controllable but possibly degraded recovery.

Characterized by at least duplex or higher levels of redundancy in control & guidance processing and power sources. Analytical redundancy, control reconfiguration or sensor/actuator physical redundancy used to mitigate failure effects.

Type 2

4 No degradation of attitude, altitude or speed control, or degradation not severe enough to warrant termination of the mission. Vehicle capable of returning to recovery point of original intent or a pre-defined alternate for safe recovery.

Characterized by at least triplex or higher levels of redundancy in control & guidance processing, sensors and actuator control paths. Flight control actuators physically redundant or use redundant surfaces. Analytical redundancy and control reconfiguration may be used to further mitigate failure effects.

Type 3


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What Sets Required FCS Type

• Required “Type” is some function of: Vehicle + Payload Cost, Mission, Operating Area, Kinetic Energy,

Weapons carriage ?

– Change any parameter and the required “FCS Type” may change– Operating Area may be bigger driver than Mission (although related)

• Need some definitions of “Operating Area”• Not strictly an airspace classification

– Change the Operating Area and the FCS may no longer be suitable

• Need to adopt a taxonomy for UA Categories– Use 2007 DoD UAV Roadmap ?

• Make “mission creep” difficult without reconsideration of FCS applicability and safety.

• Break the habit of assuming “small = throw-away”– Even an insect will try to save itself when injured


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UA Categories From DoD 2007 UAV Roadmaphttp://www.acq.osd.mil/usd/Unmanned%20Systems%20Roadmap.2007-2032.pdf

Current System Attributes

JUAS CategoriesOperational Altitude (ft)

Typical Payload

Launch Method Weight (lbs)Airspeed (kts)

Endurance (hrs)

Radius (nm)

Current Systems (Projected by 2014)

1

T1 - Tactical 1 Special Operations Forces (SOF) Team Small Unit Company

& below

≤ 1,000

Primarily EO/IR or Comm Relay

Hand launched ≤ 20 ≤ 60 < 4< 10

Hornet, BATCAM, Raven, Dragon Eye, FPASS, Pointer,

Wasp, BUSTER (rail-launched), MAV

2T2 - Tactical 2

Battalion/Brigade Regiment SOF

Group/Flight

≤ 5,000 Mobile launched 20 - 450 ≤ 100 < 24 < 100Neptune, Tern, Mako, OAV-II,

Shadow, Silver Fox, ScanEagle, Aerosonde

3T3 - Tactical 3 Division/Corps MEF/Squadron/

Strike Group

≤ 10,000Above, plus

SAR, SIGINT, Moving Target

Indicator (MTI), or WPNS

Conventional or Vertical Take-off

and Landing (VTOL)

450 – 5,000≤ 250

< 36

< 2,000

Maverick, Pioneer, Hunter, Snow Goose, I-Gnat-ER,

ER/MP, Dragonfly, Eagle Eye, Firescout, BAMS,

Hummingbird, Onyx

≤ 40,000

Conventional

≤ 15,000

> 250

Predator, N-UCAS, Reaper4 O – Operational JTF

5 S – Strategic National

> 40,000Above, plus

RADAR> 15,000

Theater wide

Global Hawk


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Operating Area/Mission Considerations

Preliminary Definitions of Operating AreasNote: No attempt (yet) to marry these up with NAS definitions or FAA Notice 07-01

Op Area Definition1 UA’s intended to operate only in Restricted and Warning

Areas under controlled and supervised conditions, or in combat areas with few no-combatants present.

2 UA’s intend to regularly operate in areas of low population density, and/or in Restricted and Warning Areas, and/or in a maritime environment, and/or in combat zones.

3 UA’s that are intended to regularly operate a majority of the time over densely populated urban areas where uncontrolled loss of the UA may cause injury/fatalities to civilian population or damage to property.

4 UA’s that intend to regularly operate in all classes of airspace including those outside of Restricted/Warning Areas and combat zones.


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Notional Relationship of FCS Type to UA Category and Operating Area

FCS Type UA Category

Cat 1 Cat 2 Cat 3 Cat 4 Cat 5

OpArea

1 0 1 2 3 4

2 0 1 2 3 4

3 1 3 4 4 4

4 2 3 4 4 4

Op Area Definition

1 UAS intended to operate only in Restricted and Warning Areas under controlled and supervised conditions, or in combat areas with few no-combatants present.

2 UAS intend to regularly operate over areas of low population density, and/or in Restricted and Warning Areas, and/or in a maritime environment, and/or in combat zones.

3 UAS that are intended to regularly operate a majority of the time in densely populated urban areas where uncontrolled loss of the UA may cause injury/fatalities to civilian population or damage to property.

4 UAS that intend to regularly operate in all classes of airspace including those outside of Restricted/Warning Areas and combat zones.

Baseline FCS Type Could be Adjusted Up for:

1. Shipboard operations2. Aerial refueling capability3. Weapons carriage4. Payload classification5. Active structural load control6. Swarming ops (multiple UA’s in same

airspace)


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Summary

• Aerospace Recommended Practice rather than a Spec

• Challenge of accepting some vehicle losses without compromising safety to people and property

• Challenge of encompassing large range of UA sizes, cost, missions, etc

• Smaller UA’s may be able to utilize flight control failure accommodation strategies that are considered too risky, immature or unconventional for manned aircraft

• Volunteers needed to help develop the ARP

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Aerospace Control & Guidance Systems Committee

Rev B, 10/08/08

Shawn DonleyACGSC Meeting 102

Backup Charts


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Definition of a UAV

• UAV

• An aircraft which is designed to operate with no human pilot on board and which does not carry personnel.

• Moreover a UAV :– Is capable of sustained flight by aerodynamic means,

• Comment: Is jet lift considered “by aerodynamic means?”– Is remotely piloted or automatically flies a pre- programmed flight profile,– Is reusable,– Is not classified as a guided weapon or similar one shot device designed for

the delivery of munitions.

From STANAG 4671


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ARP94910 Origins – SAE A-6 and Panel A-6A3

• Systems Panel Place in A-6

Committee A-6Aerospace Actuation, Control &

Fluid Power Systems

Subcommittee A6ASystems/Subsystems

Integration

Subcommittee A6BActuation and Control

Subcommittee A6CFluid Power Generation

and Distribution

Panel A6A1Commercial Aircraft

Panel A6A2Military Aircraft Panel A6B2

EHA/IAPPanel A6C2

Seals

Panel A6C3Fluids

Panel A6C4Tubing

Panel A6C5Components

Panel A6C6Power Sources

Panel A6A3Flight & Utility

Control Systems

Panel A6B1Servovalve and

Actuation

Panel A6C1Contamination and

Filtration

Panel A6B3Mechanical and EMActuation Systems

Systems Panel membership: 47 total8 Government Agencies, remainderhalf Prime Contractors, half Suppliers


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ARP vs AS

• Aerospace Recommended Practice rather than an Aerospace Standard because, “although the FCS technology employed for UAs is mature, the application is not”

• Definitions from the SAE “Aerospace Council Organization and Operating Guide, 6th Revision, February 2006

• AS - Aerospace Standard - These Technical Reports contain specific performance requirements and are used for: (1) design standards, (2) parts standards, (3) minimum performance standards, (4) quality, and (5) other areas conforming to broadly accepted engineering practices or specifications for a material, product, process, procedure, or test method.

• ARP - Aerospace Recommended Practice - These Aerospace Technical Reports are documentations of practice, procedures, and technology that are intended as guides to standard engineering practices. Their content may be of a more general nature, or they may propound data that have not yet gained broad acceptance.


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Revised Approved Scope

• Approved by SAE A-6 Steering Council, May 2008; – Revised by “Customer TOR” Meeting Sept 3, 4, Warrendale, PA– “This document will provide a comprehensive guide to the

specification of the general performance, design, test, development and quality assurance requirements for the Flight Control System (FCS) of a military Unmanned Aircraft (UA). It will recognize the levels of FCS capability required for UAs of differing size, function and operational strategy. (Prior emphasis on categorization removed) Specific focus areas will include flight safety and the integration of the FCS with other systems and subsystems, such as the electrical and hydraulic systems. (reference to “See and Avoid” removed) It will address the integration with the up-link and down-link of the command loop but not the specification of these links or the design of the associated Control Station, both of which will customarily be separately specified by the procuring activity. It will be similar in structure to the new standard for manned military aircraft, AS94900.”


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Draft Terms of Reference for Working Group

• WG Mission– Produce an aerospace standard that provides recommended

practices for the specification of the Flight Control System (FCS)of a military Unmanned Aircraft (UA). The document will be titled “ARP94910 Aerospace- Flight Control Systems - Design, Installation and Test of, Military Unmanned Aerial Vehicles, Specification Guide”.

• Document to be Based on:– The document shall be closely related to the new standard for the

FCS of manned military aircraft, AS94900. That Aerospace Standard (AS) takes the form of a specification whereas ARP94910 will be a guide to the writing of a specification.


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Draft Terms of Reference for Working Group (Cont’d)

• Document Structure and Scope– The document shall be:

• An ARP rather than an AS• A guide to the specification of the FCS for the UA and not for the entire UAS • Applicable to the FCS capability required for the range of UAs covered by figure

A.4 in the DOD 2007 roadmap. There will be a limit to the smallest size covered to be decided on kinetic energy and other grounds.

• A comprehensive guide to the specification of the general performance, design, test, development and quality assurance requirements of the FCS.

• Similar in structure, scope and depth to AS94900.• Performance oriented:

– guiding the specification of the FCS performance requirements, the design of the FCS and its subsystems, and of its integration with the vehicle, and not specific architectural approaches.

• A guide to the specification of the design and manufacture of the FCS components.

• A guide to the documentation, testing, verification, validation and other quality assurance requirements of the FCS.


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• Document Emphases– The ARP will pay particular attention to:

• The definition of a UA flight control system.

• The definition of a range of FCS capability. (Ref. to UA categories deleted)

• Flight safety, including the definition of minimum acceptable capability following failure and the associated probability.

• Integration of the FCS with other systems and subsystems within the UAS.

• (Ref. to impact of “Detect, Sense and Avoid” deleted.)


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• Requirements Assessment– Many national and international bodies are currently working to

define suitable airworthiness requirements to allow the certification of UASs for flight within the non-segregated, controlled national airspaces of participating countries. In support of these efforts, several Standards Development Organizations (SDOs) are producing aerospace standards, currently mostly for UASs rather than for UAs. The WG will track these airworthiness and standards efforts and the ARP will incorporate the relevant portions of the UA flight control requirements and recommendations that result from them. References for these requirements and recommendations will be cited. (See Appendix to the TOR document - Documents of Interest.)


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What Constitutes a UAV Flight Control System ?

• Flight control system• The flight control system comprises sensors, actuators, computers and all

those elements of the UAV System, necessary to control the attitude, speed and flightpath (trajectory) of the UAV.

– Comment: Navigation sensors (GPS, INS, other) are part of FCS for ARP94910 purposes– Comment: Data Links are not part of FCS for our purposes

• The flight control system can be divided into 2 parts:• Flight control computer – A programmable electronic system that

operates the flight controls in order to carry out the intended inputs.• Flight controls – sensors, actuators and all those elements of the UAV

System (except the flight control computer), necessary to control the attitude, speed and flightpath of the UAV.

– Comment: Not sure we need to make this distinction for the APR

• Flight controls can further be defined as:• Primary flight control – Primary flight controls are those used in the UAV

by the flight control system for the immediate control of pitch, roll, yaw and speed.

• Secondary flight control - Secondary controls are those controls other than primary flight controls, such as wheel brakes, spoilers and tab controls.

– Comment: Useful definitions for the ARP

From STANAG 4671


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• Requirements Assessment– Many national and international bodies are currently working to

define suitable airworthiness requirements to allow the certification of UASs for flight within the non-segregated, controlled national airspaces of participating countries. In support of these efforts, several Standards Development Organizations (SDOs) are producing aerospace standards, currently mostly for UASs rather than for UAs. The WG will track these airworthiness and standards efforts and the ARP will incorporate the relevant portions of the UA flight control requirements and recommendations that result from them. References for these requirements and recommendations will be cited. (See Appendix to the TOR document - Documents of Interest.)


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Table A.1 Alignment of UAS Categories with FAA RegulationsCertified Aircraft /

UAS (Cat III )

Nonstandard Aircraft /

UAS (Cat II)

RC Model Aircraft

/ UAS (Cat I)

FAA Regulation 14 CFR 91 14 CFR 91, 101, and 103 None (AC 91-57)

Airspace Usage All Class E, G, &

non-joint-use Class D

Class G

(<1200 ft AGL)

Airspeed Limit, KIAS None NTE 250 (proposed) 100 (proposed)

Example Types

Manned Airliners Light-Sport None

Unmanned Predator, Global Hawk Shadow Dragon Eye, Raven

UAS (Cat III). Capable of flying throughout all categories of airspace and conforms to Part 91 (i.e., all the things a regulated manned aircraft must do including the ability to S&A). Airworthiness certification and operator qualification are required. UASs are generally built for beyond LOS operations. Examples: Global Hawk, PredatorUAS (Cat II). Nonstandard aircraft that perform special purpose operations. Operators must provide evidence of airworthiness and operator qualification. Cat II UASs may perform routine operations within a specific set of restrictions. Example: ShadowUAS (Cat I). Analogous to RC models as covered in AC 91-57. Operators must provide evidence of airworthiness and operator qualification. Small UASs are generally limited to visual LOS operations. Examples: Raven, Dragon Eye.

The JUAS COE has since further divided these three categories into six categories, as shown in Figure A.4.

Tech – Categories- Roadmap Table A.1


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Domestic Use UAS “Levels” From DoD UAV 2007 Roadmap


Domestic Use UAS Levels

Airspeed (kts)

Weight (lbs)

Operating Altitude (ft)

Current Systems (Projected by 2014) Description UAS Examples

Level 0

≤250

≤2 ≤1,200 Hornet, BATCAM, WaspSystems under 2 lbs, within LOS control, operating in unregulated airspace

Level 1 2 – 20 ≤3,000Raven, Dragon Eye, FPASS, Pointer, BUSTER, MAV

Systems under 20 lbs, operating below VFR airspace

Level 221 – 1,320

< 18,000

Silver Fox, FINDER, Aerosonde, MARTS ScanEagle, Neptune, OAV-II, Tern, Mako, Shadow, Pioneer, REAP, RAID, TARS, JLENS, Killer Bee

Systems under 1,320 lbs fall under light sport aircraft standards

Level 31,321 – 12,500

Maverick, Snow Goose, Dragonfly, Hunter A, Hunter B, Onyx, I-Gnat-ER, Eagle Eye, ER/MP, Firescout, BAMS, Hummingbird, Predator

Systems over 1,320 lbs, operating below Class A airspace

Level 4 250 ≤12,500Currently no DOD UAS fall in this category. Example system is Killer Bee concept UAS

Systems operating below 10,000 ft MSL with max airspeeds that exceed the limit of 250 kts

Level 5 Any > 12,500 ≥18,000Reaper, Global Hawk N-UCAS, HAA, NSMV

Systems operating at or above 18,000 ft MSL fall under Class A airspace standards


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Combination, Courtesy of Mr. R. Burton

Domestic Use UAS Levels

DoDRoadmap

(2005)

FAARegulation


Airspeed (kts)

Weight (lbs)OperatingAltitude (ft)

Current Systems(Projected by 2014)

Description

Level 0

Category I

None(Advisory Circular91-57)

≤ 250

≤ 2 ≤ 1,200 Hornet, BATCAM, WaspSystems under 2 lbs, within line-of-sight control, operating in unregulated airspace

Level 1 2 - 20 ≤ 3,000Raven, Dragon Eye, FPASS, Pointer, BUSTER, MAV

Systems under 20 lbs, operating below Visual Flight Rules (VFR) airspace

Level 2 Category II14 CFRParts

91/101/10321 – 1,320

< 18,000

Silver Fox, Aerosonde, Scan Eagle, Neptune, OAV-II, Tern, Mako, Shadow, Pioneer, REAP, RAID, MARTS, TARS, JLENS

Systems under 1,320 lbs fall under light sport aircraft standards

Level 3

Category III14 CFRPart 91

1,321 – 12,500

Maverick, Snow Goose, Dragonfly, Hunter A, Hunter B, Onyx, I-Gnat-ER, Eagle Eye, Warrior, Firescout, Hummingbird, Predator

Systems over 1,320 lbs, operating below Class A airspace

Level 4 > 250 ≤ 12,500Currently no DoD UAS fall in this category. Example system is Killer Bee concept.

Systems operating below 10,000 ft Mean Sea Level (MSL) with max airspeeds that exceed the limit of 250 kts.

Level 5 Any > 12,500 ≥ 18,000Reaper, Global Hawk, N-UCAS, HAA, NSMV

Systems operating at or above 18,000 ft MSL fall under Class A airspace standards


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UAS Stds and Airworth. – Stds Devel Orgs (SDOs)

– SDOs from DoD roadmap 2007 & UAV Forum, see updated Table below

– Also, in Europe, EUROCAE and ETSI are working standards

Category of InformationSDO

AIAA ASTM RTCA SAE

Certification ANSI ANSI/ISO ANSI

UAS Committee(s) UAV/ROA CoS F38 SC-203 AS-4, G-10, A-6

Formed Oct 2002 Jul 2003 Dec 2004 Aug2004

No. of Members ~15 209 ~200 ~120

SDO Staff Manager Craig Day Dan Schultz Rudy Ruana Becky Lemon

No. of Standards:

- Produced (Total) 60 15,000 152 8,300

- On Aviation 7 200+ 152 4,000+

- Adopted by DoD 3 2,572 0 3,240

- Recommended by FAA 0 30+ 152 numerous

- Produced on UAS 1 11 0 8

- In Work on UAS 0 12 3 1


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UAS Stds and Airworth. – Stds Released & in Work

• RTCA– 3 MASPS in work – top level and not duplicative

• ASTM– 11 released, 12 in work– 5 of these 23 are relevant but not duplicative

• SAE ASD AS-4 & GPD G-10– 8 released – top level or training and not duplicative

• AIAA– 1 released – terminology, superseded by ASTM spec

• EUROCONTROL– 1 released – list of UAS standards needed, of interest but not

duplicative


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UAS Stnds and Airworth. – Airworthiness Bodies & Docs

• NATO FINAS USAR– STANAG 4671 Airworthiness – draft form but highly relevant (See 4.)

• NATO NNAG & JAPCC– Two released STANAGs, one in work, one flight plan – of interest but not believed to

be relevant• FAA

– Two released procedural cert. docs - Controlling UAS cert through CoA and Exp Certificate

• ICAO– Study Group Report – Guidance for state UAS regulation

• EASA– Certification policy doc

• DoD– MIL-HDBK-516 –Rev B includes UASs– relevant check lists but no numbers

• US Army– UAV Airworthiness procedural document

• UK MoD– Design & airworthiness DEF STAN doc. – relevant but overtaken by STANAG?


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UAS Stnds and Airworth. - Summary

• Two released ASTM standards and three in work are relevant– But not duplicative

• Two regulatory docs relevant– STANAG 4671 (See next agenda section)– DEF STAN 00970 Part 9 (Rel. 2006. Emphasis now on the

STANAG?)


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NATO Airworthiness – Draft STANAG 4671

• DRAFT STANAG 4671 - UNMANNED AERIAL VEHICLE SYSTEMS - AIRWORTHINESS REQUIREMENTS (USAR)

• “This document contains a set of technical airworthiness requirements intended primarily for the airworthiness certification of fixed-wing military UAV Systems with a maximum take-off weight between 150 and 20,000 kg that intend to regularly operate in non-segregated airspace. Certifying Authorities may apply these certification requirements outside these limits where appropriate.”

• General. If a National Certifying Authority states that a UAV System airworthiness is compliant with STANAG 4671 (and any appropriate national reservations), then, from an airworthiness perspective, that UAV System should have streamlined approval to fly in the airspace of other NATO countries, if those countries have also ratified this STANAG.


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Structure of ARP94910

• AS94900 Structure appears to be adequate for new ARP• Many updates needed to content of various sections

– Need to incorporate guidance and navigation recommendations.– Need to incorporate contingency management recommendations.– Many references to pilot and crew station that need to be cleaned up– Many references to pilot controls that are no longer applicable or that

need to be reworked to remotely piloted vehicle requirements.– Many references to other specifications (i.e. MIL-STD-1797, ADS-

33E-PRF, MIL-F-83300) that may not support UAV requirements– Includes transient and ride quality requirements, do these need to be

retained to cover the potential of carrying passengers?• Combat MEDVAC


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1. SCOPE

2. REFERENCES

3. REQUIREMENTS3.1 General System Requirements

Applicable.3.1.1 Safety and Operability Considerations

Probably applicable but will require a re-write to remove references to pilot and AFCF.3.1.2 Reliability Considerations

May need to consider new vehicle classification.3.1.3 Redundancy Considerations

Probably applicable but may need to be rewritten to consider new vehicle classification3.1.4 Maintainability Considerations

Mostly applicable but needs rework to reference ground station, maintenance concepts and also needs to consider Contingency Management

3.1.5 Survivability RequirementsApplicable but may need to consider new vehicle classifications.

3.1.6 Electromagnetic Interference (EMI) LimitsApplicable


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3.2 System Performance Requirements3.2.1 General FCS Performance Requirement

Needs to be reworked, includes references to other specifications that may not support UAV’s.

3.2.2 Primary FCS RequirementsApplicable

3.2.3 Secondary FCS (SFCS)Applicable

3.2.4 Automatic Flight Control Function (AFCF) Performance RequirementsNot applicable, need to consider how to include performance requirements related to navigation and guidance.

3.3 System Testability Requirements Mostly applicable but needs rework to reference ground station, maintenance concepts and also needs to consider Contingency Management

3.4 System Design RequirementsMostly applicable except section 3.4.5, Electrical FCS Design may need updating dependent on vehicle classification and mission.

3.5 Subsystem Design RequirementsApplicable except section 3.5.8, Display and Annunciator Subsystem needs to be re-written to refer to the ground station operation.


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3.6 Component Design and Fabrication RequirementsAll sections applicable except 3.6.7, Specific Component Requirements is not applicable, related to pilot controls

4. QUALITY ASSURANCE PROVISIONS 4.1 General Requirements

Applicable4.2 Analysis Requirements

Applicable4.3 Software Verification

Applicable4.4 Test Requirement

Mostly applicable but may need updating dependent on vehicle classification and mission.4.5 Qualification (Preproduction) Tests

Mostly applicable but may need updating dependent on vehicle classification and mission.4.6 Documentation

Mostly applicable but may need updating dependent on vehicle classification and mission.