cfm56 7 b borescope inspection manual vol 1

CFMI Proprietary InformationCFM7BSI4V2

PRELIMINARY ISSUE

CFM56-7B

Borescope Inspection

Training Manual

Customer Training ServicesAugust 2000

CFM56-7BBORESCOPE INSPECTION

Volume 1 Course Textbook

Document: CFM2BSI4V1Revised: Aug. 2000Published by CFMI

CFMI Customer Training Center Snecma (RXEF)

Direction de l’Après-Vente CivileMELUN-MONTEREAU

Aérodrome de Villaroche B.P. 193677019 - MELUN-MONTEREAU Cedex

FRANCE

CFMI Customer Training ServicesGE Aircraft Engines

Customer Technical Education Center123 Merchant Street

Mail Drop Y2Cincinnati, Ohio 45246

USA

CFM56-2A/2B/2C TRAINING MANUAL

Page 1Aug 2000INTRO

EFFECTIVITYB737-600, -700, -800, -900, -BBJ, COMBI, C40A/ALL

CFMI PROPRIETARY INFORMATION

THIS PAGE INTENTIONALLY LEFT BLANK


Page 2Aug 2000INTRO



This CFMI publication is for Training Purposes Only . The information is accurate at the time of compilation; however, no update service will be furnished to maintain accuracy. For authorized maintenance practices and specifications, consult pertinent maintenance publications.

The information (including technical data) contained in this document is the property of CFM International (GE and SNECMA). It is disclosed in confidence, and the technical data therein is exported under a U.S. Government license. Therefore, None of the information may be disclosed to other than the recipient.

In addition, the technical data therein and the direct product of those data, may not be diverted, transferred, re-exported or disclosed in any manner not provided for by the license without prior written approval of both the U.S. Government and CFM International.

COPYRIGHT 2000 CFM INTERNATIONAL


Page 3Aug 2000INTRO





Page 4Aug 2000INTRO



Table of Contents

Section Topic Revision Page Numbers

Intro Table of Contents Aug. 2000 5

Intro Acronyms and Abbreviations Aug. 2000 7-12

1. Engine Inspection Areas And Components Aug. 2000 1Borescope Inspection Areas Aug. 2000 2-3Fan and Booster Aug. 2000 4-5High Pressure Compressor (HPC) Aug. 2000 6-7HPC Inspection Areas Aug. 2000 8-9Combustion Chamber Aug. 2000 10-11Combustion Chamber (SAC) Inspection Areas Aug. 2000 12-17High Pressure Turbine Nozzle Guide Vane Inspection Areas Aug. 2000 18-19High Pressure Turbine (HPT) Rotor Blades And Shrouds Aug. 2000 20-21Low Pressure Turbine (LPT) Rotor Blades And Nozzles Aug. 2000 22-23LPT Rotor Blades And Nozzle Inspection Areas Aug. 2000 24-26

2. Borescope Ports Aug. 2000 1Borescope Ports Aug. 2000 2-5Low Pressure Compressor Borescope Port Aug. 2000 6-7High Pressure Compressor Borescope Ports Aug. 2000 8-9HPC Special BSI Tools Aug. 2000 10-11 Combustion Chamber Borescope Ports Aug. 2000 12-13HPT Section / LPT Stage 1 Nozzle Borescope Ports Aug. 2000 14-15Low Pressure Turbine Borescope Ports Aug. 2000 16-17Borescope Access Limitations Aug. 2000 18-22


Page 5Aug 2000INTRO



Table of Contents

Section Topic Revision Page Numbers

3. Borescope Equipment Aug. 2000 1Rigid Borescope Set Aug. 2000 2-3Flexible Borescope Set Aug. 2000 4-5Core Engine Pneumatic Rotation Tool Aug. 2000 6-7Core Engine Electronic Rotation Tool Aug. 2000 8-10

4. Borescope Inspection Aug. 2000 1Scheduled/Unscheduled Inspection Aug. 2000 2-5N1 Rotor Indexing Aug. 2000 6-7N2 Rotor Indexing Aug. 2000 8-9Fan And Booster Inspection Aug. 2000 10-19High Pressure Compressor Inspection Aug. 2000 20-27Combustion Chamber (SAC) Inspection Aug. 2000 28-31HPT Nozzle Inspection Aug. 2000 32-37HPT Rotor Blades And HPT Shroud Inspection Aug. 2000 38-45Low Pressure Turbine Inspection Aug. 2000 46-58


Page 6Aug 2000INTRO



ABBREVIATIONS & ACRONYMS


Page 7Aug 2000INTRO



AA/C AircraftADEPT Airline Data Engine Performance TrendADIRU Air Data and Inertial Reference UnitAGB Accessory GearboxALF Aft Looking ForwardALTN AlternateAOG Aircraft On GroundA/P AirplaneAPU Auxiliary Power UnitATA Air Transport AssociationA/T Auto throttleAVM Airborne Vibration Monitoring

BBITE Built In Test EquipmentBSI Borescope InspectionBSV Burner Staging Valve (SAC)BSV Burner Selection Valve (DAC)

CC Celsius/Centigrade (° degrees)CCW Counter ClockwiseCDP Compressor Discharge Pressure (Ps3) CDS Common Display SystemCDU Control Display UnitCFMI CFM InternationalCIP Compressor Inlet PressureCIT Compressor Inlet Temperature

cm.g Centimeter GramsCSI Cycles Since InstallationCW ClockwiseDDAC Double Annular CombustorDEU Display Electronics UnitDOD Domestic Object Damage

EEBU Engine Buildup Unit ECS Environmental Control SystemECU Electronic Control Unit (or EEC)EE Electronic EquipmentEEC Electronic Engine Control (or ECU)EGT Exhaust Gas Temperature (T49.5)ESN Engine Serial Number

FF Fahrenheit (° Degrees)F/I Flight IdleFAA Federal Aviation AdministrationFADEC Full Authority Digital Electronic ControlFAR Federal Aviation RegulationFF Fuel FlowFFCCV Fan Frame Compressor Case VerticalFDAU Flight Data Acquisition UnitFIM Fault Isolation ManualFIT Fan Inlet TemperatureFLA Forward Looking Aft


Page 8Aug 2000INTRO



IFSD In-flight ShutdownIGB Inlet Gearbox IGN IgnitionIGV Inlet Guide Vane in. inchesIPB Illustrated Parts BreakdownIPC Illustrated Parts Catalogips Inches Per Second

K°K Kelvin (Degrees)

LL LeftL/E Leading Edgelbs. Pounds, WeightL/H Left HandLP Low PressureLPC Low Pressure CompressorLPT Low Pressure Turbine LPTACC Low Pressure Turbine Active Clearance Control LPTN Low Pressure Turbine NozzleLPTR Low Pressure Turbine RotorLRU Line Replaceable UnitLVDT Linear Variable Differential Transformer

Mma Milliamperes (Current)MCD Magnetic Chip DetectorMCL Maximum Climb

FMC Flight Management ComputerFOD Foreign Object DamageFQIS Fuel Quantity Indicating System

Gg.in gram inchesG/I Ground IdleGEAE General Electric Aircraft EnginesGEM Ground-based Engine MonitoringGRD GroundGSE Ground Support Equipment

HHMU Hydromechanical Unit HP High PressureHPC High Pressure Compressor HPCR High Pressure Compressor RotorHPT High Pressure Turbine HPTACC High Pressure Turbine Active Clearance

ControlHPTACCV High Pressure Turbine Active Clearance

Control ValveHPTN High Pressure Turbine NozzleHPTR High Pressure Turbine RotorHPSOV High Pressure Shutoff Valve

II/O Input/OutputIAS Indicated Air SpeedID Inside DiameterIDG Integrated Drive Generator


Page 9Aug 2000INTRO



MCR Maximum CruiseMCT Maximum Continuousmils D.A. Mils Double Amplitudemm MillimetersMo Mach NumberMPA Maximum Power AssurancemV MillivoltsmVDC Millivolts Direct Current

NN1 Actual Fan SpeedN1* Desired Fan SpeedN1K Corrected Fan SpeedN2 Actual Core SpeedN2* Desired Core SpeedN2K Corrected Core SpeedN/C Normally ClosedN/O Normally Open

OOAT Outside Air TemperatureOD Outside DiameterOVBD Overboard

PPN Part NumberPo Pressure AmbientPPH Pounds Per HourPRSOV Pressure Regulating Shutoff Valve

Ps Pump Supply PressurePs13 Fan Outlet Static Air PressurePs3 Compressor Discharge Pressurepsi Pounds Per Square Inchpsia Pounds Per Square Inch Absolutepsid Pounds Per Square Inch DifferentialPT Pressure TotalPT25 High Pressure Compressor Total Inlet Air

Pressure

QQAD Quick Attach DetachQEC Quick Engine ChangeQty. Quantity

RR/H Right HandRPM Revolutions Per MinuteRVDT Rotary Variable Differential Transducer

SSAC Single Annular combustorSAV Starter Air Valvesfc Specific Fuel ConsumptionSLS Sea Level StandardSLSD Sea Level Standard DaySN Serial NumberSNECMA Societe d’Etude et de Construction de

Moteurs d’Aviation


Page 10Aug 2000INTRO



TTAI Thermal Anti IceTBV Transient Bleed ValveT/E Trailing EdgeT/O TakeoffT/R Thrust ReverserT12 Fan Inlet Total Air TemperatureT25 HPC Air Inlet TemperatureT49.5 Exhaust Gas TemperatureTAI Thermal Anti-IceTAT Total Air TemperatureTBC Thermal Barrier CoatingTBO Time Between OverhaulTCCV Turbine Clearance Control ValveTGB Transfer GearboxTLA Thrust Lever AngleTM Torque MotorTR Thrust ReverserTR Transformer Rectifier TRA Thrust Resolver AngleTRF Turbine Rear FrameTSI Time Since Installation

VV ac Volts Alternating CurrentVBV Variable Bleed ValveV dc Volts Direct CurrentVIB VibrationVSV Variable Stator Vane

WWf Weight of Fuel or Fuel FlowWOW Weight on Wheels





Given an objective exercise, the student will identify;...the borescope inspection areas of a CFM56-7B engine (4.A.a) ...selected components of the CFM56-7B Fan and Booster (4.A.a)...selected components of the CFM56-7B High Pressure Compressor (4.A.a)...definitions of selected areas within the High Pressure Compressor of the CFM56-7B engine (4.A.a)...selected components of the CFM56-7B Combustor (4.A.a)...definitions of selected areas within the Combustor of the CFM56-7B engine (4.A.a)...definitions of selected areas within the HPT Nozzle Guide Vanes of the CFM56-7B engine (4.A.a)...selected components of the CFM56-7 B HPT Rotor Blades And Shrouds (4.A.a)...selected components of the CFM56-7 B LPT Rotor Blades And Nozzles (4.A.a)...definitions of selected areas within the LPT Rotor Blades And Nozzles of the CFM56-7B engine (4.A.a)

Given an objective exercise, the student will select the purpose of;...the borescope inspection areas of a CFM56-7B engine (4.B.a) ...selected inspection areas of the CFM56-7B Fan and Booster (4.B.a)...selected inspection areas of the CFM56-7B High Pressure Compressor (4.B.a)...selected inspection areas of the CFM56-7B Combustor (4.B.a)...selected inspection areas of the CFM56-7 B HPT Rotor Blades And Shrouds (4.B.a)...selected inspection areas of the CFM56-7 B LPT Rotor Blades And Nozzles (4.B.a)


Page 1Jan 98

72-00-00ENGINE INSPECTION

AREAS AND COMPONENTS



ENGINE INSPECTION AREAS AND COMPONENTS

BORESCOPE INSPECTION AREAS

Identification (4.A.a)The following are the inspection areas borescoped by the technician on the CFM56-7 engine:-Fan and booster - the fan blades, outlet guide vanes, booster blades and the booster vanes.

-High pressure compressor - high pressure compressor (HPC) rotor blades and stator vanes.

-Combustora. Single annular combustor (SAC)b. Dual annular combustor (DAC) optional

-Fuel nozzles (20)-High pressure turbine (HPT) - rotor and HPT nozzle guide vanes.

-Low pressure turbine (LPT) - rotors and nozzle guidevanes.

Purpose (4.B.a)The purpose of the CFM56-7B borescope inspection of selected areas is to evaluate the condition of the individual components and, if necessary, monitor them under a cycle limitation, repair them or remove the engine before a failure of the component occurs.

The high bypass, dual rotor, axial flow turbofan engine uses a low pressure and a high pressure rotor, which turn independently.


Page 2 Jan 98






Page 3Jan 98





BORESCOPE INSPECTION AREAS

FUEL NOZZLES

FAN AND BOOSTER

LOW PRESSURETURBINE

HIGHPRESSURETURBINE

COMBUSTOR

HIGH PRESSURE

COMPRESSOR

ACCESSORYGEARBOX

OGVS

FAN AND BOOSTER

Identification (4.A.a)The following are the components of the fan and booster which are inspected by a BSI technical expert.

Number of blades per stage

- Stage 1 fan blades 24 blades- Stage 1 booster vanes (limited visibility)

- Stage 2 booster blades 74 blades- Stage 2 booster vanes (limited visibility)



- Outlet guide vanes (OGV’S)- Blade platforms- Locking lugs

The fan and booster components compress the air that is given to the high pressure compressor, pressurize the sumps and provide internal cooling.

Purpose (4.B.a)The purpose of the CFM56-7B borescope inspection areas is to evaluate the condition of the fan and booster components and if necessary place the components under a cycle limitation or remove the engine before a failure of the component occurs.

The fan has 24 wide-chord blades with independent platforms installed between each fan blade and a spacer underneath each of the blades. The booster stage 1 consists of the fan blades and the stage 1 booster stator located just aft of the fan blades. The booster blades are installed in circumferential slots. Two blade locking lugs per stage maintain the blades in position. The blade locking lugs are staggered in position from one stage to another and are inspected by the technician. The blue abradable material on the fan case prevents direct contact of the fan blade tips and the case. The abradable material on the booster vane assembly which faces the booster blade tips is grey color. These abradable materials are also inspected by a borescope.

The outlet guide vanes are in the secondary airflow path.


Page 4Jan 98






Page 5Jan 98





FAN AND BOOSTER

FWD

BLADELOCKING

LUGS

PLATFORMS

FANBLADES

ABRADABLEMATERIAL

ROTORSTG 3

ROTORSTG 2

STATORVANESSTG 1

ROTORSTG 4

STATORVANESSTG 2

STATORVANESSTG 3

STATORVANESSTG 4

ABRADABLEMATERIAL

HIGH PRESSURE COMPRESSOR (HPC)

Identification (4.A.a)The following are components of the high pressure compressor that are inspected.

Number of blades per stage-Inlet guide vanes- Stage 1 rotor blades: 38 blades- Stage 1 variable stator vanes (limited visibility)- Stage 2 rotor blades: 53 blades- Stage 2 variable stator vanes (limited visibility)- Stage 3 rotor blades: 60 blades- Stage 3 variable stator vanes (limited visibility)- Stage 4 rotor blades: 68 blades- Stage 4 stator vanes (limited visibility)- Stage 5 rotor blades: 75 blades- Stage 5 stator vanes (limited visibility)- Stage 6 rotor blades: 82 blades- Stage 6 stator vanes (limited visibility)- Stage 7 rotor blades: 82 blades- Stage 7 stator vanes (limited visibility)- Stage 8 rotor blades: 80 blades- Stage 8 stator vanes (limited visibility)- Stage 9 rotor blades: 76 blades- Locking lugs 2 locking lugs per stage

Purpose (4.B.a)The purpose of the HPC IGV’s, VSV’s and rotor blade inspection of the CFM56-7B, is to evaluate the condition of each of the HPC components and if necessary place the components under a cycle limitation, repair them if possible, or remove the engine before a failure of the component occurs.

The Inlet Guide Vanes (IGV) are at the inlet of the HPC.

The IGV and stages 1, 2, and 3 vanes are variable and are called Variable Stator Vanes (VSV).

The HPC rotor blades stages 1, 2, and 3 are maintained in axial slots by retaining rings. The HPC rotor blades are installed in circumferential slots and maintained by blade locking lugs in stages 4 to 9 and the stator vanes are stationary type.


Page 6Jan 98






Page 7Jan 98





HIGH PRESSURE COMPRESSOR (HPC)

INLETGUIDEVANES

(VARIABLE)VSV

STG 1(VARIABLE)

VSVSTG 2

(VARIABLE)

VSVSTG 3

(VARIABLE)

HPCSTATOR

STG 4

HPCSTATOR

STG 5

HPCSTATOR

STG 6

HPCSTATOR

STG 7

HPCSTATOR

STG 8

HPCROTORSTG 1

HPCROTORSTG 2

HPCROTORSTG 3

HPCROTORSTG 4

HPCROTORSTG 5

HPCROTORSTG 6

HPCROTORSTG 7

HPCROTORSTG 8

HPCROTORSTG 9

AXIAL SLOTS CIRCUMFERENTIAL SLOTS

HPC INSPECTION AREAS

Identification (4.A.a)The following selected areas of the HPC are inspected by a BSI technician.

-The outer third of the rotor blade tip area and the anti-abrasion hard coating on the concave side.

-Squealer tips.-HPC stage 1 blades feature a blade stiffener near the tip of the blade.

-The HPC rotor stages 4 to 9 feature two blade locks per stage to maintain the blades in the circumferential slots.

-A plasma sprayed abradable coating that faces the blade tips on the HPC stator case to protect against direct contact.


Page 8Jan 98






Page 9Jan 98





HPC INSPECTION AREAS

BLADESTIFFENER HARD COATING

(CONCAVE SIDEALL BLADESALL STAGES)

ABRADABLECOATING(ALL STAGES)

FWD

BLADELOCKING

LUGS

COMBUSTION CHAMBER

Identification (4.A.a)The following are the components in the combustion chamber area that are borescoped.

- Combustion chamber either:a. Single annular combustor (SAC) or theb. Double annular combustor (DAC) optional.

- High pressure turbine nozzles- Fuel nozzles

The CFM56-7B has a single annular combustor with 20 fuel nozzles and 2 igniter plugs which allow access for additional inspections.

Purpose (4.B.a)The purpose of the combustor borescope inspection areas is to evaluate the condition of the combustor for defects and if necessary put the combustor under a cycle limitation or remove the engine before a failure of the combustor occurs.


Page 10Jan 98






Page 11Jan 98





COMBUSTION CHAMBER

COMBUSTIONCHAMBER

FUELNOZZLES

HPTSHROUD

HPT NOZZLE

SINGLE ANNULAR COMBUSTOR (SAC)HPT

NOZZLEDACCOMBUSTION

CHAMBER

DOUBLE ANNULAR COMBUSTOR (DAC)

COMBUSTION CHAMBER (SAC) INSPECTION AREAS

Identification (1A.a)The following are the inspection areas of the SAC combustion chamber.

-The inner and outer liners - are designed with paneloverhangs which contain closely spaced holes for film cooling.

-The dilution holes in the liners - that provide additional air for combustion. Four of them are used as borescope ports.

-Thermal barrier coating (TBC) - on both outer and inner liners.

- Inner and outer cowls

The outer liner accommodates 2 ferrules for the igniters which are used as borescope ports.


Page 12Jan 98






Page 13Jan 98






COOLINGHOLES

OUTERLINER

PANELOVERHANG

INNERCOWL INNER

LINER

DILUTIONHOLES

IGNITERFERRULE

PANELS

OUTERCOWL


IdentificationThe following are the combustion chamber inspection areas:

- Fuel nozzle tips- Fuel nozzle stems outside the combustor dome- Sleeves with 2 concentric swirlers.- Deflectors.- Inner cowl.- Outer cowl.- Spectacle plate or the dome plate.- Dome area includes all of the above components.

A thermal barrier coating (TBC) is applied on the deflectors, the spectacle plate and the other areas of the hot section of the engine. The TBC is inspected and is a light brown orwhite color.


Page 14Jan 98






Page 15Jan 98






DETAIL B

TBC SPECTACLEOR DOME

PLATE

FUEL NOZZLETIP

SLEEVE

VIEW ADEFLECTOR

SECONDARYSWIRL NOZZLE

SECONDARYSWIRL NOZZLE IGNITER

FERRULE

SPECTACLEPLATE

SLEEVE

DEFLECTOR

TBCOUTERCOWL

PRIMARY SWIRLNOZZLE

INNERCOWL DETAIL B

VIEW A


IdentificationThe following are the inspection areas for the combustion chamber liners.

The outer liner has 5 panels:- Panel 1 features 2 igniter holes (with ferrule), and 38

medium and large dilution holes. Four of the large holes are used as borescope ports.

- Panel 3 features 60 medium dilution holes.- Dome band.

The inner liner has 4 panels:- Panel 1 features 40 medium and large dilution holes.- Panel 3 features 60 medium dilution holes.- Dome band.

Numerous film cooling holes are under the overhang between each panel with thermal barrier coating (TBC) on all liner panels.


Page 16Jan 98






Page 17Jan 98






OUTER LINER

INNER LINER

PANEL 1

PANEL 2

PANEL 3PANEL 4 PANEL 5

PANEL 1

PANEL 2

PANEL 3

PANEL 4

DOMEBAND

DOMEBAND

DOMEBAND

PANEL 1PANEL 2

PANEL 3

PANEL 4

PANEL 5

OUTER LINER

60 HOLES

2 IGNITERSAND 18 HOLES

20 HOLES

TBC ON ALL SURFACES

20 HOLES

DOMEBAND

PANEL 1

PANEL 2

PANEL 3

PANEL 4

60 HOLES

20 HOLESINNER LINER

HPT NOZZLE GUIDE VANE INSPECTION AREAS

Identification (4.A.a)The following are the inspection areas for the HPT Nozzle Guide Vanes.

- Leading edge- Trailing edge- TBC- Nose holes- Gill holes- Trailing edge slots - Concave surfaces of vanes- Convex surfaces of vanes or the aft side of the vane.

The HPT nozzle assembly consists of 21 nozzle segments of 2 vanes each.

Each vane has numerous cooling holes, gill holes, leading edge holes and trailing edge slots for cooling. A thermal barrier coating (TBC) protects the HPT nozzle and is inspected.


Page 18Jan 98






Page 19Jan 98





HPT NOZZLE GUIDE VANE INSPECTION AREAS

TBC(ALL SURFACES IN THE AIRFLOW)

COOLING SLOTS

VANE TRAILINGEDGE

GILLHOLES

INNERPLATFORM

NOSEHOLES

VANE LEADINGEDGE

OUTERPLATFORM

CONCAVESIDE

HIGH PRESSURE TURBINE ROTOR BLADES ANDSHROUDS

Identification (4.A.a)The main rotating component of the CFM56-7B is the high pressure turbine rotor blades.

- HPT rotor 80 blades

The following are inspection areas of the HPT rotor blades:- Leading edge- Trailing edge- TBC- Nose holes- Gill holes- Trailing edge slots - Concave surfaces- Convex surface- Wear notches- Platforms- HPT shroud

The HPT shrouds segments face the blade tips and are air cooled using CDP air. These shroud segments are inspected during the leading edge of the HPT rotor and nozzle guide vane trailing edge inspection.

Purpose (4.B.a)The purpose of the HPT rotor blades and shroud borescope inspection areas is to evaluate their condition for defects and if necessary, put the them under a cycle limitation or remove the engine before a failure of the rotor or shroud occurs.

The HPT rotor extracts energy from the combustion chamber to turn the high pressure compressor and the exiting gases to turn the LPT rotors.

The HPT blade features 8 rows of holes and trailing edge slots for cooling.

To help you to estimate the HPT blade wear, four of the blades have 3 tip wear notches .010, .020, .030 of an inch. The 4 blades are located at 90° from each other aro und the rotor.


Page 20Jan 98






Page 21Jan 98





HPT ROTOR BLADES AND SHROUDS

VIEW A

TBC

WEAR NOTCHES

.030.020

.010

HPT SHROUD SEGMENTCONVEX SIDE

LEADINGEDGE AREA

VIEW A

CONCAVE SIDE

TRAILINGEDGE AREA

ROW 8

ROW 1

ROW 2

ROW 3

ROW 4

ROW 5ROW 6

ROW 7

NOTES:1. ROW 1, 6-8 (GILL COOLING HOLES)2. ROW 2-5 (NOSE COOLING HOLES)

LPT ROTOR BLADES AND NOZZLES

Identification (4.A.a)The following are components of the low pressure turbine that are to be inspected by the borescope.

Number of blades per stage - Stage 1 LPT rotor blades 162 blades- Stage 1 LPT nozzle (limited visibility)- Stage 2 LPT rotor blades 150 blades- Stage 2 LPT nozzle (limited visibility)- Stage 3 LPT rotor blades 150 blades- Stage 3 LPT nozzle (limited visibility)- Stage 4 LPT rotor blades 134 blades- Stage 4 LPT nozzle (limited visibility)- Honeycomb material which faces the blade tips and acts as an abradable material.

The LPT extracts energy from the exiting gases to turn the fan module that produces 80% of the thrust.

The LPT nozzle stage 1 is housed within the combustion case and belongs to the core engine. It consists of sectors of 4 vanes each. It has trailing edge slots for cooling purposes. There is an anti corrosion anodization coating on the LPT rotor stage 1 and stage 2. The color is different from the color of the other stages. Each blade tip shroud has 2 seal teeth for air sealing. A hard coating is applied on the shrouded tip contact faces to prevent wear and is an important inspection area.

Purpose (4.B.a)The purpose of the LPT rotor blade and nozzle borescope inspection areas is to evaluate their condition for defects and if necessary, put the them under a cycle limitation or remove the engine before a failure of the LPT component occurs.


Page 22Jan 98






Page 23Jan 98





LPT ROTOR BLADES AND NOZZLES

LPTROTORSTG 1

LPTROTORSTG 2

LPTROTORSTG 3

LPTROTORSTG 4

LPTNOZZLESTG 1

LPTNOZZLESTG 2

LPTNOZZLESTG 3

LPTNOZZLESTG 4

TURBINEREAR FRAME

HONEYCOMBABRADABLEMATERIAL(4 STAGES)

LPT ROTOR BLADES AND NOZZLES INSPECTION AREAS

Identification (4.A.a)The following are inspection areas of the LPT rotor blades and nozzles:

- Rotor blade leading edge- Rotor blade trailing edge- Concave surfaces of rotor blade- Convex surfaces of rotor blade- Hard face surface of the rotor blade tip shroud- Trailing edge of nozzle slots stage 1 - Leading edge of some of the LPT nozzles- Trailing edge of some of the LPT nozzles- Concave surfaces of some of the LPT nozzles- Convex surfaces of some of the LPT nozzles.


Page 24Jan 98






Page 25Jan 98





LPT ROTOR BLADES AND NOZZLES INSPECTION AREAS

LPT NOZZLE STAGE 1

TRAILING EDGE

LEADINGEDGE

COATING(ANODIZATION)

LPT

LPTBLADE(TYPICAL)

HARD FACEDCONTACTSURFACE

HARDFACING

SEALTOOTH

BLADETIPSHROUD

LPT ROTOR BLADE



Page 26Jan 98





Given an objective exercise, the student will identify;...the borescope ports of a CFM56-7B engine (1.A.a)...the Low Pressure Compressor borescope port (4.A.a)...the High Pressure Compressor borescope ports (4.A.a)...the HPC Special BSI tools. ( 4.A.a )...the Combustion Chamber borescope ports (4.A.a)...the HPT Section/LPT Stage 1 Nozzle borescope ports (4.A.a)...the Low Pressure Turbine borescope ports (4.A.a)...the factors of Borescope Access Limitations (4.A.a)

Given an objective exercise, the student will select the purpose of;...the borescope ports of a CFM56-7B engine (1.B.a)...the Low Pressure Compressor borescope port (4.B.a)...the High Pressure Compressor borescope ports (4.B.a)...the Combustion Chamber borescope ports (4.B.a)...the HPT Section/LPT Stage 1 Nozzle borescope ports (4.B.a)...the Low Pressure Turbine borescope ports (4.B.a)...the Borescope Access Limitations (4.B.a)

Given an objective exercise, the student will select the functional description of;...the Borescope Access Limitations (4.D.a)


Page 1Jan 98

72-00-00BORESCOPE PORTS



BORESCOPE PORTS

BORESCOPE PORTS (LH SIDE)

Identification (1.A.a)There are 21 borescope inspection ports located around and along the engine. Other areas may be used for special inspections. Fuel nozzles may be removed to see the outer and inner cowls of the combustor.

These are the borescope inspection ports on the left side of the engine.

- S11- S15- S17

Purpose (1.B.a)The purpose of these BSI ports is to inspect the following:

- 1 port to inspect the booster or LPC- 9 ports for the HPC- 4 ports for the combustor- 2 igniter ports- 2 ports for the HPT- 3 ports for the LPT

They allow inspection of the rotating parts without engine disassembly.


Page 2Jan 98





Page 3Jan 98



BORESCOPE PORTS (LH SIDE)

10 O’CLOCKBORESCOPEPORT (S15)

LEFTIGNITER PLUGPORT (S11)

S17


BORESCOPE PORTS (RH SIDE)

IdentificationThese are the borescope inspection ports on the right side of the engine.

- S0 (no plug installed here)- S1- S2- S3- S4- S5- S6- S7- S8- S9- S10- S12- S13- S14- S16- S18- S19- S20


Page 4Jan 98





Page 5Jan 98



BORESCOPE PORTS (RH SIDE)


6 O’CLOCKBORESCOPE PORT (S14)


S16 S1 THROUGH S9

RIGHT SPARKIGNITER PORT(S10)

S0 BORESCOPE PORT(AT 3:30 O’CLOCK, INNER WALLOF FAN BYPASS CUT, BETWEEN 2OGV’S.)

S18 THROUGH S20


LOW PRESSURE COMPRESSOR BORESCOPE PORT

Identification (4.A.a.)S0 is located aft of the fan blades in the secondary air area atapproximately the 4 o’clock position, in between the platforms of an OGV (Outlet Guide Vane). S0 is an open port.

Purpose (4.B.a)The BSI port S0 is used for a specific purpose. The inspection of the Low Pressure Compressor section of the engine.


Page 6Jan 98





Page 7Jan 98



LOW PRESSURE COMPRESSOR BORESCOPE PORT

S0

TOP VERTICAL

AFT LOOKING FORWARD

S0


HIGH PRESSURE COMPRESSOR BORESCOPE PORTS

Identification (4.A.a.)These are the 9 ports for inspection of the High Pressure Compressor section of the engine. They are numbered from S1 to S9 on the HPC.

The HPC borescope ports are located at approximately the 5 O’clock position, on the compressor case.

CAUTION: DO NOT MIX PLUGS BETWEEN PORTS. DAMAGE TO THE ENGINE MAY OCCUR.

Borescope ports S1 to S6 accommodate a simple plug with a hexagonal head.

Borescope ports S7 to S9 feature a cap and a plug linked by a spring-loaded shaft.

Refer to the Aircraft Maintenance Manual section 72-00-00 for more information on the removal/install procedure of the borescope plugs S7 to S9.

Purpose (4.B.a)The HPC ports S1 thru S9 are used to view stages 1 thru 9 of the HPC rotor blades.

- S1 Stage 1 rotor blade leading edges- S2 Stage 1 rotor blade trailing edges

Stage 2 rotor blade leading edges- S3 Stage 2 rotor blade trailing edges

Stage 3 rotor blade leading edges- S4 Stage 3 rotor blades trailing edges

Stage 4 rotor blades leading edges- S5 Stage 4 rotor blades trailing edges





Stage 9 rotor blades leading edges


Page 8Jan 98





Page 9Jan 98



HIGH PRESSURE COMPRESSOR BORESCOPE PORTS

TOP VERTICAL

AFT LOOKING FORWARD

S1 TO S9

S1 TO S6BORESCOPE PLUGS

BORESCOPECAP

RETAININGRING

SHAFT

BORESCOPEPLUG

S7, S8, S9 BORESCOPEPLUG ASSEMBLY

FWD

FWD

FWD

S1

S2S3

S4S5S6

S1S5S7S9 S8

S6 S2S4 S3


HPC SPECIAL BSI TOOLS

Identification (4.A.a.)

Deep-well socketIn case of shaft breakage of borescope plugs S7, S8 or S9, use a deep-well socket to remove the inner plug, using the six-flats at the very end of the shaft.

Alignment rodThe HPC stator vanes may move slightly, causing a shift of the borescope port and the corresponding hole in the stator. If it is impossible to introduce the probe into the port, use an alignment rod to realign the stator vane segment.

Refer to the AMM 72-00-00 for more information on this locally manufactured tool.


Page 10Jan 98





Page 11Jan 98



HPC SPECIAL BSI TOOLS

ALIGNMENT ROD

ALUMINUM

MODIFIED DEEP-WELL SOCKET

WELD

WELD

3/8 INCHDRIVESOCKET

REMOVE INSIDEMATERIALTO PERMIT 7/16 INCH12 POINT BOLT HEAD TOPASS

7/16 INCH 12 POINTSOCKET UNDER CUT TOFIT STEEL TUBE


COMBUSTION CHAMBER BORESCOPE PORTS

Identification (4.A.a.)The combustor borescope ports are located around the combustor case. Ports S10 and S11 are the igniter ports while the borescope ports S12 to S15 accommodate a simple plug with an hexagonal head.

Purpose (4.B.a.)The purpose of the 6 borescope ports is for the inspection of the combustor section of the engine. They are numbered on the diagram from S10 to S15.

CAUTION: DO NOT MIX THESE PLUGS WITH THE S16 AND S17 PLUGS. IF YOU INSTALL THEM IN THE WRONG PLACE ENGINE DAMAGE MAY OCCUR.


Page 12Jan 98





Page 13Jan 98



COMBUSTION CHAMBER BORESCOPE PARTS

S12, S13, S14, S15BORESCOPE PLUG

S12,S13, S14, S15

IGNITER (S10, S11)

AFT LOOKING FORWARD

S12

S13

S10

S14

BORESCOPE PORTLOCATIONS

S11 IGNITER

S15

FWD

S12

S15

S11IGNITER

S13

S10

S14

FWD

.. .

..

.


HPT SECTION / LPT STAGE 1 NOZZLE BORESCOPE PORTS

Identification (4.A.a.)The HPT Section / LPT Stage 1 Nozzle borescope ports are located around the combustor case. Ports S10 and S11 are the igniter ports while the borescope ports S16 and S17 accommodate a spring loaded type plug with a hexagonal head.

Either Port S10 and S11 are the igniter plug BSI ports. Refer to the AMM to remove the igniter plugs.

Borescope ports S16 and S17 have a cap with a hexagonal head, and a spring loaded plug.

CAUTION: DO NOT MIX THESE PLUGS WITH THE S12 TO S15 PLUGS. THEY ARE SIMILAR, BUT IF YOU TRY TO INSTALL THEM, ENGINE DAMAGE MAY OCCUR.

Purpose (4.B.a)The purpose of this inspection, through the ports S10 and S11, and S16 and S17, is to allow viewing of the HPT section of the engine.

There is no port Use a flexible borescope with a guide tube going through the combustion chamber and the HPT nozzles to inspect the HPT blade leading edges.


Page 14Jan 98





Page 15Jan 98



HPT SECTION / LPT STAGE 1 NOZZLE BORESCOPE PORTS

S16, S17BORESCOPEPLUGS

FWD

S16, S17

FWD

FWD

AFT LOOKING FORWARD


S10IGNITER

S11IGNITER

S17

S17

S11

S16S16

S10 .. ..


LOW PRESSURE TURBINE BORESCOPE PORTS

Identification (4.A.a.)The LPT Stage 1 Nozzle borescope ports are located around the combustor case. The borescope ports S16 and S17 accommodate a spring loaded type plug with a hexagonal head. The borescope ports S18, S19, and S20 accommodate a short spring loaded type plug with a hexagonal head.

Borescope S16 and S17 have a cap with a hexagonal head, and a long spring loaded plug. Borescope ports S18, S19 and S20 have a cap with a hexagonal head and a short spring loaded plug.

CAUTION: DO NOT MIX SHORT AND LONG PLUGS BETWEEN PORTS. DAMAGE TO THE ENGINE MAY OCCUR.

The LPT borescope ports are located at approximately the 5 O’clock and the 8 O’clock positions, on the combustion case and on the LPT case.

Purpose (4.B.a.)The purpose of the 5 borescope ports, S16 to S20, is for the inspection of the Low Pressure Turbine section of the engine are.


Page 16Jan 98





Page 17Jan 98



LOW PRESSURE TURBINE BORESCOPE PORTS

S16, S17BORESCOPEPLUGS

S18, S19, S20BORESCOPEPLUGS

AFT LOOKING FORWARD


S17S16, S18, S19, S20

S18S19S20 S16

S20

S18

S19

S16S17

FWD

..


BORESCOPE ACCESS LIMITATIONS

Identification (4.A.a.)There are two limitations factors that have to be considered when preparing for borescope inspection on the CFM56-7B engine. These considerations are;

-the size of the borescope probe to be inserted into the engine, and

-the temperatures of the engine parts at each BSI inspection port.

Purpose (4.B.a.)The purpose of having probe size and temperature limitations is to prevent damage to the borescope equipment. Without borescope size limitations a borescope probe could be lodged, or seized in a borescope port during installation or removal. The use of temperature limitations prevents melting or heat distortion of a borescope probe, should a probe be inserted into a hot engine. Without these limitations there can be a subsequent deformation of borescope probes, excessive replacement/repair costs of borescope equipment, and even Foreign Object Damage (FOD) to the engine itself.


Page 18Jan 98





Page 19Jan 98



HOT AND NORMAL ENGINE BORESCOPE INSPECTION AND PORT S

4.5 hrs 3.0 hrs{-HPT BLADE L/E{ L/E AND T/E1 1/4 HEX10 MMS11

4.5 hrs 3.0 hrs{-HPT NOZZLE3.5 hrs 2.0 hrs{-COMBUSTOR1 1/4 HEX10 MMS10CASE

COMBUSTION2.5 hrs 1.5 hrsSTAGE 9 L/E

STAGE 8 T/E1 1/16 HEX8 MMS92.5 hrs 1.5 hrsSTAGE 8 L/E

4.5 hrs 3.0 hrs{-HPT SHROUD

STAGE 7 T/E1 1/16 HEX8 MMS82.0 hrs 1.5 hrsSTAGE 7 L/E

STAGE 6 T/E1 1/16 HEX8 MMS71.5 hrs 1 hrSTAGE 6 L/E

STAGE 5 T/E1/2 HEX10MMS660 mn 30 mnSTAGE 5 L/E

STAGE 4 T/E1/2 HEX10 MMS560 mn 30 mnSTAGE 4 L/E

STAGE 3 T/E1/2 HEX8 MMS430 mn 20 mnSTAGE 3 L/E

STAGE 2 T/E1/2 HEX10 MMS330 mn --STAGE 2 L/E

STAGE 1 T/E1/2 HEX8 MMS230 mn --STAGE 1 L/E1/2 HEX10 MMS1HPC CASE

-- --STAGE 4 L/E-- --STAGE 3 T/EN/AN/AS0BOOSTER

WITHOUT MONITORING TIME TO REACH

100%F (38C) 200%F (93C)

INSPECTEDCOMPONENTS

WRENCHSIZE

BORESCOPEPORT SIZE (MM)

BORESCOPE PORT No

ENGINE SECTION

(Continued on page 21)


BORESCOPE ACCESS LIMITATIONS

Functional Description (4.D.a)The hot and normal engine inspection limits using the engine borescope ports are:

Probe 1 diameter limitationConsult the table for port diameters where probe 1 can be used.

Borescope equipment temperature limitationsIt is not recommended that borescope inspection be accomplished at temperatures above 130°F (54°C) .High temperatures may cause damage to the fiber optic type of borescope equipment. The table on the next page provides information about time limitations, prior to an inspection on a hot engine.

To speedup the engine cool down time after shutdown, you may use the engine starter to motor the engine, (Refer to the AMM). This reduces the hot section area temperature sufficiently to allow inspection. But as the temperature will rise due to engine temperature soak-back, it is further recommended that engine hot section inspection be accomplished within 20 minutes, or before the internal engine temperature reaches 130°F (54°C ).


Page 20Jan 98



CAUTION: REFER TO AIRPLANE OPERATION MANUAL FOR STARTER DUTY CYCLE LIMITATION PRIOR TO MOTORING THE ENGINE.



Page 21Jan 98



HOT AND NORMAL ENGINE BORESCOPE INSPECTION AND PORT S

STAGE 4 L/E4.5 hrs 2.0 hrsSTAGE 3 T/E9/16 HEX10 MMS204.5 hrs 2.0 hrsSTAGE 3 L/E

STAGE 2 T/E9/16 HEX10 MMS194.5 hrs 3.0 hrsSTAGE 2 L/E4.5 hrs 3.0 hrsSTAGE 1 T/E9/16 HEX10 MMS18LPT CASE

{ BLADES L/E7/8 HEX8 MMS174.5 hrs 3.0 hrs{-STAGE 1 LPT4.5 hrs 3.0 hrs{-HPT BLADES T/E7/8 HEX8 MMS16

{-COMBUS TOR7/8 HEX10 MMS15{ L/E7/8 HEX10 MMS14

4.5 hrs 3.0 hrs{ -HPT NOZZLE7/8 HEX10 MMS13(CONT)3.5 hrs 2.0 hrs{ -COMBUSTOR7/8 HEX10 MMS12COMB CASE

WITHOUT MONITORING TIME TO REACH

100%F (38C) 200%F (93C)

INSPECTEDCOMPONENTS

WRENCHSIZE

BORESCOPEPORT SIZE (MM)

BORESCOPE PORT No

ENGINE SECTION




Page 22Jan 98




Given an objective exercise, the student will identify:.. the Rigid Borescope Set used on the CFM56-7B engine (4.A.a).. the Flexible Borescope Set used on the CFM56-7B engine (4.A.a).. the Core Engine Pneumatic Rotational Tool used on the CFM56-7B engine (4.A.a).. the Core Engine Electronic Rotational Tool used on the CFM56-7B engine (4.A.a)

Given an objective exercise, the student will select the purpose of:.. the Rigid Borescope Set used on the CFM56-7B engine (4.B.a).. the Flexible Borescope Set used on the CFM56-7B engine (4.B.a).. the Core Engine Pneumatic Rotational Tool used on the CFM56-7B engine (4.B.a).. the Core Engine Electronic Rotational Tool used on the CFM56-7B engine (4.B.a)


Page 1Jan 98

72-00-00BORESCOPE EQUIPMENT



BORESCOPE EQUIPMENT

RIGID BORESCOPE SET

Identification (4.A.a.)This is the CFM56-7 engine standard rigid borescope equipment tool set used for borescope inspection:

- the rigid borescope set with a light source

The CFMI tool 856A1320P04 rigid borescope set and the light source 856A1322P02 are designed to meet the CFMI specification M50TF1855. Optional equipment is available for cameras, computers, VCR’S, and special tools that attach to the borescope equipment.

Other borescope systems may be acceptable if they meet the CFMI specification mentioned above.

Refer to the Non Destructive Test Manual and to the CFMI specifications M50TF1855 for more information on the required characteristics.

Note: The table on the page below describes the general features of the 4 rigid borescope probes.

Purpose (4.B.a)Each probe is used for a specific purpose, to look inside the engine to inspect engine hardware areas.

- Probe 1 ( black ): Magnification, close inspection, detailed evaluation and confirmation of defects (cannot be used in every hole due to its diameter).

- Probe 2 ( yellow ): General inspection.- Probe 3 ( green ): Fore-oblique angle probe,

platform inspection.- Probe 4 ( blue ): Retro angle probe, blade tip

inspection.


Page 2Jan 98





Page 3Jan 98



RIGID BORESCOPE SET


FLEXIBLE BORESCOPE SET

Identification (4.A.a.)This is the CFM56-7 engine standard flexible borescope equipment tool used for borescope inspection:

-flexible borescope kit with a light source and guide tubes.

The CFMI tool 856A1321 flexible borescope set and the borescope guide tube 856A1310 are designed to be used on the CFM56 engines and are designed to meet the CFMI specification M50TF1855. Equivalent borescope equipment can be used for borescope inspection. Optional equipment is available for cameras, computers, VCR’S, and special tools that attach to the borescope equipment. Other borescope systems may be acceptable if they meet the CFMI specification mentioned above.

Refer to the Non Destructive Test Manual and to the CFMI specifications M50TF1855 for more information on the required characteristics.

Purpose (4.B.a)The flexible probe is used for a specific purpose, the inspection of the engine hot section or special inspections.

Refer to the Non Destructive Test Manual for more information.


Page 4Jan 98





Page 5Jan 98



FLEXIBLE BORESCOPE SET

GUIDE TUBE

STRAIGHTENING ROD

FLEXIBLE LIGHT SOURCE CABLE DISTAL LIGHTAND VIEWING LENS

CONNECTOR

CAMERA ADAPTOR

TELEVISION ADAPTOR

CONTROL

FLEXIBLE LIGHT ANDOPTICAL VIEWING CABLE


CORE ENGINE PNEUMATIC ROTATION TOOL

Identification (4.A.a.)This is the CFM56-7B engine core pneumatic rotational tool used for borescope inspection.

Purpose (4.B.a)Several methods are used to rotate the core and the purpose is to inspect all the rotor blades:

- Manual methodInsert a ¾ inch drive ratchet in the hand cranking

pad. If you turn the drive CW, the rotor turns CW ALF. To turn the N2 rotor, you can turn it through the hand cranking pad. Refer to the AMM (72-63-01) to remove the hand cranking pad cover.

- Air driven motor:Install the pneumatic motor assembly on the pad. The

direction of rotation and speed of the core engine rotor can be selected through the hand or foot control device. Refer to the NDT manual for more information on the pneumatic motor assembly.

TIP:The air supply source must be free of unwanted water or other particles. So it is highly recommended to install a filter upstream the pneumatic air drive. A device to add lubricant in the air supply is also recommended.


Page 6Jan 98





Page 7Jan 98



CORE ENGINE PNEUMATIC ROTATION TOOL

HAND CONTROL(FOOT CONTROLALTERNATE)

SHOP AIRSUPPLYCONNECTION

DRIVE MOTOR

PROTRACTOR

HANDCRANKINGCOVER


CORE ENGINE ELECTRONIC ROTATIONAL TOOL

Identification (4.A.a.)This is the CFM56-7B engine core electronic rotational tool used for borescope inspection.

Purpose (4.B.a)Several methods are used to rotate the core and the purpose is to inspect all the rotor blades:

- Manual method- Electronic Turning Tool

Install the ETT motor assembly on the pad. The direction of rotation and speed of the core engine rotor can be selected on the control box.

The ETT can control rotation and help to avoid overshoot during inspection of the rotor blades. It also has an automatic feature to count blades and you can flag damage if found for a quick future reference. The information can also be stored for the next inspection.

- Electronic Turnover Tool (ETT)Sweeney P/N18946.

Install the electronic rotational tool by inserting the 3/4 inch square drive of the ETT adapter into the core drive pad.


Page 8Jan 98





Page 9Jan 98



CORE ENGINE ELECTRONIC ROTATIONAL TOOL

ETT ADAPTOR ETT DRIVEMOTOR

ETT POWERUNITPROTRACTOR

3/4 INCH SQUARE DRIVE

ETT CONTROLLER




Page 10Jan 98




Given an objective exercise the student will Identify;... the two basic types of borescope inspections used on the CFM56-7B engine (4.A.a)

Given an objective exercise the student will select the purpose of;... the two basic types of borescope inspections used on the CFM56-7B engine (4.B.a)

Given an objective exercise the student will select the functional description of; ... the two basic types of borescope inspections used on the CFM56-7B engine (4.D.a)... selected elements of Fan and Booster Inspection (4.D.a)... selected elements of High Pressure Compressor Inspection (4.D.a)... selected elements of Combustion Chamber (SAC) Inspection (4.D.a)... selected elements of HPT Nozzle Inspection (4.D.a)... selected elements of HPT Rotor and HPT Shroud Inspection (4.D.a)... selected elements of Low Pressure Turbine Inspection (4.D.a)

Given an objective exercise the student will select elements of the maintenance practices associated with; ... N1 Rotor indexing used on the CFM56-7B engine (4.E.a)... N2 Rotor indexing used on the CFM56-7B engine (4.E.a)


Page 1Jan 98

72-00-00BORESCOPE INSPECTION



BORESCOPE INSPECTION

SCHEDULED / UNSCHEDULED INSPECTION

The Borescope Inspection (BSI) is a part of the On Condition Maintenance Program.

Identification (4.A.a)These are the 2 basic types of borescope inspections.

- Scheduled inspectionInspect the fan blades, OGV’s, and the BSI ports S1,S4, S9, S13, S14, S15, S16.

- Unscheduled inspectionInspect the fan blades, OGV’s, and all the BSI ports, So through S20.

Purpose (4.B.a)ScheduledThe purpose of the scheduled inspection is inspect for defects inside the engine at regular time intervals.

- 5000 hours or- 5000 cycles which ever comes first.- combustor and HPT at 1600 cycles.

UnscheduledThe purpose of the unscheduled inspection is to find defects inside the engine which is done at abnormal time intervals or engine event.

Functional Description (4.D.a)ScheduledA scheduled inspection is performed on specific areas of the engine to assess its condition. Inspect these areas through the borescope ports. During this inspection, look for defects which may be found in these areas.

If no defects are found, the engine is serviceable.If defects are found refer to the AMM to find out if the engine is serviceable, with or without cycle limitations.

As a supplement you can refer to the Non Destructive Test Manual (NDTM), in the On Condition paragraph of each engine section, to get a list of the possible defects.


Page 2Jan 98





Page 3Jan 98



SCHEDULED AND UNSCHEDULED INSPECTIONS

ON CONDITION MAINTENANCE PROGRAM

ENGINE CONDITIONREVIEW

DISPATCH

- HPC 5000 HRS/CYCLES (WHICHEVER COMES FIRST)- COMBUSTOR AND HPT 1600 CYCLES

(ABNORMAL OPERATIONS)

ENGINE REMOVAL

NO LIMITATIONSCYCLE LIMITED

NO

YES

SCHEDULED UNSCHEDULED


SCHEDULED / UNSCHEDULED INSPECTIONS

UnscheduledIf an engine experiences a problem, it may have to be inspected to reveal internal defects.

As a supplement refer to the Non Destructive Test Manual (NDTM). The special inspection of the AMM, engine section, will list the engine events and which inspection ports must be used by the inspector.

During an unscheduled inspection, all areas of the engine may be inspected.

Functional DescriptionDuring a Scheduled inspection, the inspection of the engine through these following borescope inspection ports is done.

- Fan blades (visual inspection),- S1 (first stage HPC),- S4 (Stg 3/4 HPC),- S9 (Stg 8/9 HPC),- S13, S14, S15 (Combustion Chamber),- S16 (HPT).

During an unscheduled inspection, most the parts of the engine maybe inspected, depending on the problem and the defects discovered.

Follow the AMM for the special inspection procedures.


Page 4Jan 98





Page 5Jan 98



SCHEDULED / UNSCHEDULED INSPECTIONS

FAN BLADES

SCHEDULED

UNSCHEDULED

FAN BLADES(VISUAL INSPECTION)

OGVS

OGV’SS0

VISUALINSPECTIONSTAGE 4 LPTROTOR``

S10S11S12S13S14S15

S16S17 S18 S19

S16S1

S20

S4 S9

S13S14S15

S1 S2 S3 S4 S5 S6 S7 S8 S9


N1 ROTOR INDEXING

GeneralSetting a reference angular position to the rotor provides an easy method to come back quickly and accurately to a defect found earlier.

The following procedure enables the reference point for the N1 rotor to be obtained. Refer to the AMM, 72.00.00, for more information.

Maintenance Practice (4.E.a)Align N°1 fan blade leading edge with the T12 temperature sensor installed on the fan inlet cowl at the 2 O’clock position.

The N°1 fan blade is easily identified; it faces a spherical indent mark on the rear spinner cone.

Numbering fan blades is performed by turning the rotor in the clockwise direction.

CAUTION: THE N1 ROTOR IS TURNED BY HAND. USE CAUTION AND WEAR GLOVES TO AVOID INJURY.


Page 6Jan 98





Page 7Jan 98



N1 ROTOR INDEXING


N2 ROTOR INDEXING

GeneralSetting a reference angular position to the rotor provides an easy method to come back quickly and accurately to a defect found earlier.

The following procedure enables the reference point for the N2 rotor to be obtained. Refer to the AMM, 72.00.00, for more information.

Maintenance Practice (4.E.a)1. Open the VSV system. (Refer to the AMM section

75-31-00.) 2. Insert borescope probe N°3 (green) into

borescope port S4, and look toward the back of the engine to the stage 4 compressor rotor blade platform.

3. Rotate the core (manually or with a tool) until the first blade locking lug appears in the field of view. Compressor rotor blade rotation must be in the CW direction viewed through the probe.

4. Continue core rotation until the second locking lug appears. This lock is located 2 blades past the first locking lug.

5. The next blade is blade N°1. Position the blade N°1 leading edge in line with the leading edge of the stage 4 stator vane looking aft throughthe borescope port.

6. Position the pointer on the protractor to the 0alignment mark, or position the wrench to the topvertical position.

The N2 rotor is now in the zero reference position.


Page 8Jan 98





Page 9Jan 98



N2 ROTOR INDEXING


FAN AND BOOSTER INSPECTION

Functional Description (4.D.a)

Scheduled inspectionVisual inspection of the fan blades, platforms and OGV’s are performed on a regular basis. There is no borescope inspection of the booster rotor during a scheduled inspection.

Check the condition of the fan blades and inner platforms. These are typical defects that may found on fan blades:

- Missing material, tip curl- Nicks, dents, pits, and scratches usually due to

ingestion of small foreign objects such as sand, stones, dust, tarmac, etc.

- Distortion, tip curl, cracks and deformation are usually due to heavier foreign object damages such as birds, ice, hail, tires, etc.

Note: If defects are found on the fan blades, or if the engine experienced an abnormal operating problem, then perform an unscheduled inspection.

Perform a visual inspection on the Outlet Guide Vanes (OGVs) installed in the fan frame.


Page 10Jan 98





Page 11Jan 98




FAN BLADE

PLATFORM



Functional Description

Unscheduled inspectionIf defects are found on the fan blades, or if the engine experienced an abnormal operating problem, then perform an unscheduled inspection.

First, perform the zero index position procedure for the N1 rotor.

Then, use probe N°2 (yellow), installed on the long right angle adapter, to reach the S0 port. The port is located between 2 OGV’s, approximately at the 4 O’clock position. Insert the borescope into port So andgo through the 2 cases before reaching the rotor blade area.

TIP:Depending on the configuration of the long right angle extension, there is the possibility of turning the probe to change the direction of view and to adjust the focus directly from the extension.

From the S0 port, the following components are visible:- Rotor stage 3 trailing edge (T/E)- Rotor stage 4 leading edge (L/E)- 2 adjacent vanes of the stator stage 3

Map the defects on the special reporting form located in the NDT manual, or the BSI maintenance area of the individual airlines.


Page 12Jan 98





Page 13Jan 98







Unscheduled inspectionUse rigid probe N°2 (yellow), installed on the long right angle adapter, to reach the front of the splitter fairing area.

From this position the following are visible.- Vanes of the stator stage 1- Rotor stage 2 leading edge (L/E) through the

stator stage 1

The fan blades, platforms and OGV’s can be inspected visually from the front of the engine, or inspected even with the fan blades removed.

TIP:Borescope equipment is not needed to inspect stator stage 1 and stage 2 rotor blades if the fan blades are removed (when fan blades have to be relubricated, for example).


Page 14Jan 98





Page 15Jan 98







Typical defectsSometimes during the life of an engine, an assessment of the condition of the fan and booster rotor blades may be required as part of the On condition Engine Maintenance program. Whenever the fan and booster blades are inspected, the following defects should be assessed against the Aircraft Maintenance Manual serviceability limits.

- Cracks or tears,- Nicks and scratches,- Dents,- Erosion,- Tip curl,- Pits,- Distortion of leading and/or trailing edges,- Missing material,

Fan and booster rotor damage may occur after the engine experienced an abnormal problem The following list provides the conditions where a complete borescope inspection should be performed:

- Fan or Low Pressure Compressor stall (this may occur during engine deceleration).

- Foreign Object Damage (FOD) and suspected bird ingestion.

- High level of vibration of the N1 rotor.- N1 rotor overspeed.- Heavy landing (acceleration is above the

threshold limit).


Page 16Jan 98





Page 17Jan 98



BOOSTER BLADE TYPICAL DEFECTS

LEADINGEDGE

TRAILINGEDGE

TRAILINGEDGE

LEADINGEDGE

DENT

NICK,SCRATCH

TIPCURL

CRACK

EROSION

WEAR

MISSINGMATERIAL

DISTORTION




Inspection AreasOn the booster blades, there are 3 areas which are dimensionally defined by using letters.

-Section E: This section of the blade starts from the top of the platform and extends toward the blade tip for approximately 10 millimeters or 0.4 inch.

-Section G: This section of the blade starts from the tip of the blade and extends toward the blade platform for approximately 20 millimeters or 0.79 inch.

-Other Airfoil areas: This is the remaining area of the blade that does not include areas E and G.


Page 18Jan 98





Page 19Jan 98



BOOSTER BLADE INSPECTION AREAS

OTHERAIRFOILAREAS

TIP

LEADINGEDGE

TRAILINGEDGE

PLATFORM

0.79IN.(20mm)

0.4IN. (10MM)


HIGH PRESSURE COMPRESSOR INSPECTION


Scheduled InspectionTo inspect the HPC rotor blades, you may open the Variable Stator Vanes to obtain a better view.

During a scheduled inspection, inspect the High Pressure Compressor through ports S4, S1 and S9.

First, go through HPC port S4.Use rigid probe N°3 (green) and inspect the:

- stage 4 rotor L/E platform area,- stage 3 rotor T/E platform area.

Then use probe N°4 (blue) and inspect the:- stage 4 rotor L/E blade tip area,- stage 3 rotor T/E blade tip area.

Secondly, go through HPC port S1.Use probe N°3 (green) to perform inspection.

- stage 1 rotor L/E platform area

After switching back to probe N°4 (blue), inspect t he:- stage 1 rotor L/E blade tip area.

Thirdly go to port S9.Use probe N°3 (green) to perform inspection of the:

- stage 9 rotor L/E platform area,- stage 8 rotor T/E platform area.

Use probe N°4 (blue), to inspect the:- stage 9 rotor L/E blade tip area,- stage 8 rotor T/E blade tip area.

Map the defects on the special reporting form (Refer to the NDT Manual).

Note: If defects are found during this inspection, a complete HPC borescope inspection of all rotor stages has to be performed.

Tip:To get a better evaluation of the defects, use probe N° 1 (black) where possible.


Page 20Jan 98





Page 21Jan 98




OPEN VSV’STO VIEW

S1

S4

S9

SCHEDULED INSPECTIONPROBE 2 (YELLOW): GENERAL VIEWPROBE 3 (GREEN): PLATFORM AREAPROBE 4 (BLUE): BLADE TIP




Unscheduled InspectionIf defects are found during a scheduled inspection, or if the engine experienced an abnormal operating problem, then perform an unscheduled inspection. During an unscheduled inspection, inspect the High Pressure Compressor through all ports.

First, go through the HPC port S4.Use rigid probe N°3 (green) to index the N2 rotor.

Once the core rotor is indexed, perform inspection of the stage 1 rotor, port S1. Use probe N° 2 (yellow) for general inspection of the rotor blades.

Defect assessment may require the use of probes N° 3 (green) and N° 4 (blue).

Use probe N°3 to perform inspection of the L/E plat form area and probe N°4 to inspect the L/E blade tip are a.

Repeat the same method for ports S2 to S9.

Map the defects on the special reporting form (Refer to NDT manual for the reporting maps).


Page 22Jan 98





Page 23Jan 98




UNSCHEDULED INSPECTIONPROBE 2 (YELLOW): GENERAL VIEWPROBE 3 (GREEN): PLATFORM AREAPROBE 4 (BLUE): BLADE TIP

OPEN VSVTO VIEW




Typical DefectsWhen the High pressure Compressor blades are inspected, the following defects should be evaluated with the aircraft maintenance manual serviceability limits:

- Cracks or tears,- Nicks and scratches,- dents,- Erosion,- Tip curl,- Pits,- Distortion of leading and/or trailing edges,- Missing material,- Dirt buildup- Shingling and/or distortion of blade platform.- Cracks in blade locking lugs.- Locking lugs missing or loose.

High Pressure Compressor (HPC) rotor blade damage may occur after the engine experienced an abnormal operating problem.The following list provides the conditions where a complete HPC borescope inspection should be performed:

- HPC stall (this may occur during engine acceleration).

- Foreign Object Damage (FOD).- High level of vibration of the N2 rotor.- N2 rotor overspeed.- Heavy landing.- Oil fumes detected in cabin air.


Page 24Jan 98





Page 25Jan 98



HIGH PRESSURE COMPRESSOR INSPECTION – TYPICAL DEFECTS

STAGES 4 TO 9

STAGES 2 TO 9

STAGE 1

FORWARD

LOOSELOCKINGLUGS

SHINGLING

WEAR

LEADINGEDGE

DENT

NICK

CRACK

DISTORTION

EROSION

LEADINGEDGE

FOD

SCRATCHES

TIP CURL

MISSINGCORNER

LEADINGEDGE

TEAR

CRACK

CHIPPED, WORNANTI – EROSIONCOATING (CONCAVESIDE)




Inspection AreasOn the High Pressure Compressor rotor blades there are specific inspection areas for each stage.

They are divided into 2 major groups:- Rotor blades Stages 1 to 4- Rotor blades Stages 5 to 9

Critical inspection areas are not dimensionally identical for each stage. On the blades, there are 3 particular areas which are dimensionally defined:

The lower area of the airfoilThis is the blade root radius area, plus the area which extends toward the blade tip and wraps around the L/E and the T/E for approximately 25% of the height of the airfoil (L) and up to 0.10 (2.54) width.

The top area of the airfoilThis is the portion of the blade which starts from the tip of the blade and which extends toward the blade platform and wraps around L/E and T/L for approximately 0.3 in (7.62 mm)

This area is divided in 2 different parts:- the tiparea A

Other SectionsThis area is the rest of the airfoil.- For stages 1 to 4 this is the remaining section of the blade.- For stages 5 to 9 this is the section which wraps - around L/E and T/E (area B).


Page 26Jan 98





Page 27Jan 98



HIGH PRESSURE COMPRESSOR BLADE INSPECTION AREAS

0.30(7.62)

0.10(2.54)

SEE CTIP

AIRFOILCENTERPANEL

SEE B

0.30(7.62)

B(STAGES 5-9)

B(STAGES 5-9)

0.10(2.54)

25% OF L

25% OF L

SEE A

EXAMPLE DOVETAIL

PLATFORM

AIRFOIL ROOTRADIUS AREA

A

AIRFOIL

AIRFOIL ROOTRADIUS

PLATFORM

0.10(2.54)

0.20(5.08)AREA A

TIPANY QUANTITYOF DAMAGEIS PERMITTED

SEE THE LIMITSFOR MISSING TIPCONERS AND TIP CURLTHAT EXTEND IN THIS AREA 0.06

(1.52)

0.10 (2.54) DEFINESCENTER PANEL

B

C

CHORDPERCENT

TIPCURL

MISSINGTIP CORNER

NICK

NICKDEPTH

DENTDEPTH

DENT

DENT DEFLECTIONFROM ORIGINALCONTOUR

NORMAL LEADINGEDGE CONTOUR

0.30(7.62)(STAGES 5-9)


COMBUSTION CHAMBER (SAC) INSPECTION


Scheduled InspectionDuring a scheduled inspection of the (SAC) combustor, inspect the combustion chamber through ports S13 and S15.

Borescope inspection of the CFM56 combustion chamber assembly may be accomplished using probes 1, 2, 3 and 4.

Probe 2 (yellow) is recommended for general viewing of the combustion chamber, especially the dome area.

Probe 3 (green) is recommended for viewing circumferentially around the combustion chamber and the inner liner near the borescope ports.

Probe 4 (blue) is recommended for viewing the outer liner around the borescope port.

Probe 1 (blue, hi-mag) is recommended for viewing the aft end of the combustion chamber inner and outer liners and for evaluating defects found when using probes 2, 3, or 4.

Note: if defects are found during this inspection, a complete inspection of the combustion chamber is performed.

Unscheduled InspectionIf defects are found during a scheduled inspection, or if the engine experienced a particular operating problem, then an unscheduled inspection must be performed.

During an unscheduled inspection, inspect the combustion chamber through ports S12, S13, S14 S15, plus igniter ports S10 and S11 and map the defects on the special reporting form.


Page 28Jan 98





Page 29Jan 98




FORWARD

S10, S11,S12, S13,S14,S15

COMBUSTION CHAMBER

RIGIDBORESCOPE

PROBE 2 (YELLOW) : GENERAL VIEW COMBUSTION CHAMBER, DOME AREA.PROBE 3 (GREEN) : INNNER LINER.PROBE 4 (BLUE) : OUTER LINER.PROBE 1 (BLACK) : AFT END OF COMBUSTION CHAMBER.




Typical DefectsWhenever the combustion chamber is inspected, the following defects should be assessed with the aircraft maintenance manual serviceability limits:

- Cracks or tears,- Erosion,- Distortion of internal parts,- Missing material,- Dirt buildup,- Burn through holes,- Flaking of Thermal Barrier Coating (TBC).

Combustion chamber damage may occur after the engine experienced a particular operating problem. The following list provides conditions where a complete borescope inspection should be performed:

- Foreign Object Damage (FOD) and suspectedbird ingestion.

- An engine over temperature occurred.- Flame out, and/or visible engine fire (flame)

during engine start.

Inspect for defects in the 3 following areas:- dome assembly- outer liner- inner liner

Training Tip:Carbon deposits are often misinterpreted as defects (holes or burn through, cracks, etc.). Use the high magnification probe, and higher light intensity to confirm the type of defect.

The aft panel of the inner liner is susceptible to distortion and cracking. The first evidence of this is a discoloration in a round spot approximately the size of the large dilution hole, which is followed by distortion and cracking. This usually occurs uniformly around the liner.


Page 30Jan 98





Page 31Jan 98




DOME ASSEMBLY

TYPICALCIRCUMFERENTIALCRACKS

TYPICALRADIALCRACKS

SPECTACLEPLATE TYPICAL

CONNECTEDCRACKS

TYPICALRADIALCRACKS

SLEEVETYPICALRADIALCRACKS

TYPICALCIRCUMFERENTIALCRACKS

SPECTACLEPLATE SLEEVE

TYPICALMISSINGMATERIAL

MISSING MATERIALBETWEEN THE CRACKS

DEFLECTOR BURNTHROUGHH0LE




Typical Defects(Continued)


Page 32Jan 98





Page 33Jan 98




LINERS

LINERS

IGNITERHOLE

EXAMPLE OFA CRACK AT THEIGNITER HOLE

EXAMPLE OF3 CRACKS ACROSSONE PANEL

EXAMPLE OFA BURNTHROUGHHOLE

EXAMPLE OFCRACKSACROSS4 PANELS

EXAMPLEOF MISSINGOVERHANG

DOMEBAND

PANEL1

PANEL2

PANEL3

PANEL4

PANEL5

EXAMPLE OF BURNTHROUGH HOLE

DILUTIONHOLES

EXAMPLE OF AN AXIALCRACK CONNECTED TOA CIRCUMFERENTIALCRACK

EXAMPLE OFCRACKS ACROSS3 PANELS

EXAMPLE OFCRACKS ACROSSMORE THAN 3PANELS

DOMEBAND

PANEL1

PANEL2

PANEL3

PANEL4


HPT Nozzle INSPECTION


Scheduled Inspection - Rigid ProbeDuring a scheduled inspection, inspect HPT nozzles through ports S13 and S15. This inspection is normally carried out in conjunction with the combustion chamber inspection.

Use probe N° 1 (black, high magnification) to inspe ct the HPT nozzle segments. The high intensity light source is used to accurately inspect the HPT nozzles.Insert the probe into the borescope ports and inspect the leading edges of the nozzle segments.

Note: If defects are found, a complete inspection of the combustion chamber and the nozzles has to be performed.

Unscheduled Inspection - Rigid ProbeIf defects are found during a scheduled inspection, or if the engine experienced an abnormal operating problem, then perform an unscheduled inspection.

For the HPT nozzles, use ports S12, S13, S14 and S15 plus igniters ports S10 and S11.

Use probe N°1 (black, high magnification) to inspec t the HPT nozzle segments concave sides and leading edges.


Page 34Jan 98





Page 35Jan 98



HPT NOZZLE INSPECTION – RIGID PROBE

GILLH0LES

VANETRAILINGEDGE

NOSEHOLES

COOLING SLOTS

VANE LEADING EDGE

OUTER PLATFORM

INNER PLATFORM

CONCAVE SIDEA

NOTE:NUMBER OF VANES: 42.(21 SEGMENTS OF 2 VANES EACH.)

RIGIDBORESCOPEPROBE 1

BORESCOPE PORTS:- S13, S15 (SCHEDULED)- S10, S11, S12, S14

FUELNOZZLE

OUTER PLATFORM

AVANE AIRFOIL

INNER PLATFORM


HPT Nozzle INSPECTION


Unscheduled Inspection - Flexible probeUse the flexible probe with a guide tube to inspect the HPT nozzle segments on the convex sides, the trailing edges and the platforms.

CAUTION: BE CAREFUL NOT TO INSERT THE BORESCOPE BETWEEN BLADES WHILE ROTATING THE ROTOR. THIS ACTION WILL RESULT IN BREAKAGE OF THE BORESCOPE PROBE AND MAY REQUIRE DISASSEMBLY OF THE ENGINE TO REMOVE THE BROKEN PIECE.

Insert the guide tube 856A1310 (blue) or 856A1351 (red), and position it between two nozzle vanes.

Carefully insert the flexible probe into the guide tube and monitor the probe insertion in between the nozzle vanes.Inspect the convex side and trailing edge.

Then inspect the inner and outer platforms by turning the flexible probe inside the guide tube.

Carefully push the flexible probe into the guide tube to inspect the next HPT nozzle segment.

Insert the guide tube in another borescope port and repeat the previous steps. Map the defects on the special reporting form.

Tip:It is more convenient to use the left borescope port (S12) to inspect the bottom left hand side of the engine, and port (S14), to inspect the nozzle right hand side.


Page 36Jan 98





Page 37Jan 98



HPT NOZZLE INSPECTION – FLEXIBLE PROBE

HPT SHROUD

GUIDE TUBEFOR FLEXIBLEBORESCOPE

COMBUSTOR CASE

IGNITER PLUG PORT

HPTN UPPERPLATFORM INSPECTION

HPTN TRAILINGEDGE INSPECTION

HPTN INNERPLATFORM INSPECTION

ROLL FEED FLEXPROBE IN THISDIRECTIONONLY


HPT NOZZLE INSPECTION


Typical DefectsWhenever the High Pressure Turbine nozzle is inspected, the following defects should be assessed with the AMM serviceability limits:

- Discoloration (anywhere)- Leading edge damage for

crackburns and/or bulgesblocked cooling air passages

- Concave and convex surfacescracks

- Trailing edge damagebulking and/or bowingcracks

- Other airfoil areascracksnicks, scores, scratches, or dents

- Inner and outer platformsburnscracks

- Missing thermal barrier coating,- Erosion,- Bulked or bowed trailing edges,- Spalled areas,- Craze cracks, and metal splatter,- Missing material,- Dirty airfoils.

Abnormal Engine EventsHPT nozzle damage may occur after the engine experienced an abnormal operating problem. The following list provides the conditions where a complete borescope inspection should be performed:

- Over temperature,- Engine stalls,- EGT trend step increase.


Page 38Jan 98





Page 39Jan 98



HPT NOZZLE INSPECTION – TYPICAL DEFECTS

TRAILING EDGECORNER PIECE MISSING

AIRFOILTRAILINGEDGE

TRAILING EDGE CRACKWITH BURNT / MISSINGMATERIAL

TRAILING EDGEAXIAL CRACK

AIRFOILLEADINGEDGE

INNERPLATFORM

LEADING EDGEBURN / MISSINGMATERIAL

OUTERPLATFORM


HPT ROTOR BLADES AND HPT SHROUD INSPECTION


Scheduled Inspection - Rigid ProbeDuring a scheduled inspection, inspect the HPT rotor blade T/E through ports S16 and S17and the rear portion of the HPT shroud.

First, go through the HPC port S4 and use probe N°3 (green) to perform the N2 rotor zero index position procedure.

Once the core rotor is indexed, inspect the HPT blade T/E, tips, concave and convex sides through the S16 and S17 ports.

Use probes 2, 3 and 4. Probe N°2 (yellow) is used f or general inspection. Probes N°3 (green) and N°4 (blu e) are used to carry out a detailed inspection of the platform and tip areas.

If defects are found, an inspection of the L/E has to be performed.


Page 40Jan 98





Page 41Jan 98



HPT ROTOR BLADES AND HPT SHROUD INSPECTION – RIGID P ROBE

S16, S17

RIGIDBORESCOPE

HPTSHROUD

HPTBLADES

SCHEDULED INSPECTION:PROBE 2 : GENERAL INSPECTIONPROBE 3 : PLATFORM INSPECTIONPROBE 4 : TIP INSPECTIONPROBE 1 : DEFECT ASSESSMENT


HPT ROTOR BLADES AND HPT SHROUDINSPECTION


Unscheduled Inspection - Flexible ProbeIf defects are found during a scheduled inspection, or if the engine experienced an abnormal operating problem, then perform an unscheduled inspection.

First, go through the HPC port S4 and use the rigid probe N°3 (green) to perform the N2 rotor zero index posi tion procedure.

If not already done, look through the S16 and S17 ports.Use probes 2, 3 and 4 and inspect platform and tip areas.

During an unscheduled inspection, inspect the HPT blade L/E and the forward part of the HPT shroud.You use the flexible probe with the guide tube.Insert the guide tube 856A1310 or 856A1351 through the S10 or S11 ports, and position it between two nozzle vanes.

Carefully insert the flexible probe into the guide tube and monitor the probe insertion in between the nozzle vanes.Guide the tip of the flexible probe between the nozzle vanes by using the tip deflection control and position it to see the L/E of the HPT blades.

Perform the inspection of the blades (rotate the core), then the inspection of the HPT shroud segments

CAUTION: BE CAREFUL NOT TO INSERT THE BORESCOPE BETWEEN BLADES WHILE ROTATING THE ROTOR. THIS ACTION WILL RESULT IN BREAKAGE OF THE BORESCOPE PROBE AND MAY REQUIRE DISASSEMBLY OF THE ENGINE TO REMOVE THE BROKEN PIECE.

Map the defects on the special reporting form.


Page 42Jan 98





Page 43Jan 98



HPT ROTOR BLADES AND HPT SHROUD INSPECTION – FLEXIBL E PROBE

COMBUSTION CASE S16, S17

RIGIDBORESCOPE

HPT BLADESHPT SHROUD

DO NOT ROTATE N2!

IGNITERPLUG PORT

GUIDE TUBEFOR FLEXIBLEBORESCOPE

T/E SCHEDULED INSPECTION:PROBE 2 : GENERAL INSPECTIONPROBE 3 : PLATFORM INSPECTIONPROBE 4 : TIP INSPECTIONPROBE 1 : DEFECT ASSESSMENT

HPTR TIP MAGNIFIED VIEWMAGNIFIED VIEWCONCAVE AIRFOIL

WIDE ANGLE OF VIEWSINGLE PASS

HPTR L/E MAGNIFIED VIEWMULTI-PASS INSPECTION




Typical DefectsWhenever borescope inspections of the HPT section are required, the following defects may be observed and should be assessed with the serviceability limits in the AMM.

These are typical defects to look for:-Trailing edgecracks.

- Tip areacracks,bent, curled, or missing pieces,tip trailing edge wear.

- Blade platformnicks and dents,cracks.

- Concave and convex airfoil surfacescracks,distortion,burning.

- Cooling holescracks,plugging.

Abnormal Engine EventsHPT blade damage may occur after the engine experienced an abnormal operating problem. The following list provides the conditions where a complete borescope inspection should be performed:

- Core stall (N2)- Over temperature- Metal in the tailpipe- N2 overspeed, abnormal core vibrations, hard

landing.


Page 44Jan 98





Page 45Jan 98



HPT ROTOR BLADE INSPECTION – TYPICAL DEFECTS

REMAINING SLOT

BLADE TIPWEAR

PLUGGED HOLES WORN TIP

RADIALCRACK

NICKS

MISSINGMATERIAL

T/ECRACK

CRACK BETWEENHOLES

L/E CRACK

MISSINGMATERIAL

BURNTHROUGHHOLE

DISCOLORATION,OVERHEATING




HPT Rotor Blade Inspection AreasOn the High Pressure Turbine rotor blade, specific areas of inspection are defined.These are:

-Area C: All around the blade, extending from thefirst T/E slot just above the root fillet, toward the tip of the blade, up to the sixth T/E slot.

-Area B: All around the blade, extending from the seventh T/E slot, toward the tip of the blade, up tothe twelfth T/E slot.

-Area A: All around the blade, extending from the thirteenth T/E slot, up to the tip film holes.


Page 46Jan 98





Page 47Jan 98



HPT ROTOR BLADE - INSPECTION AREAS

NOTES:1. ROW 1, 6-8 (GILL COOLING HOLES)

2. ROW 2-5 (NOSE COOLING HOLES)

CONCAVE SIDE

CONVEX SIDE

T/EAIRSLOTS

T/E SLOTS 7THROUGH 12

1st 6 T/ESLOTS

ROOTFILLET

TIPAREA AREA A

(ALLAROUND)

AREA B(ALLAROUND)

AREA C(ALLAROUND)

TRAILINGEDGE AREA

ROW 8

ROW 7

ROW 6

ROW 1

ROW 2

ROW 3

ROW 4

ROW 5

CAVITY 2

LEADINGEDGE AREA

0.50


LOW PRESSURE TURBINE INSPECTION


Typical DefectsWhenever the blades are inspected, the following defects should be assessed against the Aircraft Maintenance Manual serviceability limits:

- Cracks in the airfoil surface, platform, or tip shroud.- Convex and/or concave surfaces nicks and dents.- Leading edge distortion due to over temperature.- Large dent, or pieces of metal missing.- Metallization of the leading edges and/or concave

surface. (Gold coloration).- Gaps in the tip shroud interlocks.- Shingled or unlatched tip shroud.- Circumferential wear.- Seal teeth wear.- Flaking on the hardened seal teeth.

Abnormal Engine EventsLPT rotor blade damage may occur after the engine experienced an abnormal operating condition. The following list provides the conditions where a complete LPT borescope inspection should be performed:

- Engine stall (This may occur during engine acceleration HPC or deceleration LPC).

- Foreign Object Damage (FOD) and suspected birdingestion.

- High level of vibration on the N1 rotor.- N1 rotor overspeed.- Engine over temperature.- When flames are seen out of nozzle during start

procedure.


Page 48Jan 98





Page 49Jan 98



LPT BLADE INSPECTION – TYPICAL DEFECTS

WEAR

LEADINGEDGE

NICK

GOLDCOLORATION

CRACK

CRACK INSHROUD

TRAILINGEDGE

DISTORTION

OVERTEMPERATURE

DENT

LEADINGEDGE

TRAILINGEDGE

MISSINGMATERIAL

MELTEDAREA

CRACK INPLATFORM



Functional DescriptionThe LPT rotor blades (all stages) are long span blades. To inspect the total length, and airfoil surface, it is necessary to use the following method:

- Perform the N1 rotor zero index procedure.- To inspect the leading edge and concave side of the

LPT blades, turn the rotor in the normal direction of rotation ( CW aft looking forward ).

-To inspect the trailing edge and the convex side of the LPT blades, turn the rotor in the opposite direction of rotation ( CCW aft looking forward ).

-The LPT rotor blades are inspected starting at the blade platform, turning the rotor one revolution, then, pulling the probe back to the next inspection area.

Repeat this operation until the entire blade is inspected.


Page 50Jan 98





Page 51Jan 98




MOVING THE PROBE IN AND OUT ALLOWSFULL VIEWING OF THE COMPONENTS




Scheduled InspectionAn evaluation of the condition of the LPT blades may be required as part of the On condition Engine Maintenance program.

Inspection of the leading edges and the concave sides of the stage 1 LPT blades may be performed during the inspection of the HPT blade trailing edges.

Borescope plugs S16, S17, are removed and an initial overall inspection, using the yellow probe may be performed to evaluate the blade condition. Use probes 2 , 3 and 4 (yellow, green and blue) to inspect the blade roots and tips of the blades.


Page 52Jan 98





Page 53Jan 98



LOW PRESSURE TURBINE SCHEDULED INSPECTION

STAGE 1LPT NOZZLE

S16, S17

SCHEDULED INSPECTIONPROBE 2 (YELLOW) : GENERAL INSPECTIONPROBE 3 (GREEN) : PLATFORM INSPECTIONPROBE 4 (BLUE) : TIP INSPECTIONPROBE 1 (BLACK) : DEFECT ASSESSMENT




Unscheduled InspectionsWhen inspection of the Low Pressure Turbine section is required, check the condition of all the LPT stages.

Remove the borescope plug S18 and inspect the trailing edge of the first stage rotor blades. Use probes N°2,3 and 4. To get a better evaluation of the defects, you may use probe N° 1 (black) where possible. This port is als o used to carry out the inspection of stage 2 LPT blade leading edges.

Repeat the same operation for borescope ports S19 and S20.


Page 54Jan 98





Page 55Jan 98



LOW PRESSURE TURBINE UNSCHEDULED INSPECTION

S16, S17

S18

S19S20

UNSCHEDULED INSPECTIONPROBE 2 (YELLOW) : GENERAL INSPECTIONPROBE 3 (GREEN) : PLATFORM INSPECTIONPROBE 4 (BLUE) : TIP INSPECTIONPROBE 1 (BLACK) : DEFECT ASSESSMENT




Typical DefectsFor inspection of stage 4 turbine blades, in addition to the regular defects described, the following defects can also be found:

- No more axial preload on the tip shroud assembly.- Tip shroud interlock wear.- Wear on the lateral faces of the tip shroud.- Tip shroud not flush.- Peeling airfoil surfaces and leading and trailing

edges.


Page 56Jan 98





Page 57Jan 98



LPT BLADE STAGE 4 TYPICAL DEFECTS

SEEA

A - A

INTERLOCK WEAR AT A 45 DEG. ANGLE

CLEARANCE

OFFSET

LATERAL FACES WEAR

TIP SHROUDINTERLOCK WEAR

TIP SHROUD INTERLOCK GAPS

NOT ALIGNED

CLEARANCE

NO CLEARANCE

CLEARANCE AT MATEFACE

A

A

A A BB

A - A B - B

SHINGLING OUT OFFLUSH

A

D

C

B B CSEE

SEE

SEE

OUT OF FLUSHTIP SHROUDSSHINGLED

TIP SHROUDSOR SHINGLEDINTERLOCKS

UNLATCHEDTIP SHROUDS ORUNLATCHEDINTERLOCKS




Inspection AreasOn the LPT blades, there are 2 specific areas which are dimensionally defined through section letters:

- Area E (tip of the blade):- Portion of the blade airfoil starting from the bottom of

the tip shroud extending toward the blade platform for approximately, 10 millimeters or 0.4 inch for stage 1, and 5 millimeters or 0.2 inch for stage 3.

- Area E (bottom of the blade):Portion of the blade airfoil starting from the top of the blade platform and extending toward the blade tip for approximately, 10 millimeters or 0.4 inch for stage 1, and 12 millimeters or 0.47 inch for stages 2, 3 and 4.

- Other Sections:This is the remaining section of the blade which is all L/E and T/E not including sections E.


Page 58Jan 98





Page 59Jan 98



LPT BLADE INSPECTION AREASSTAGE 1 STAGE 2 STAGE 3 STAGE 4

AREA EAREA EAREA E

AREA E

AREA E

AREA E

AREA E

LEADINGEDGE

LEADINGEDGELEADING

EDGELEADINGEDGE

TRAILINGEDGE

SEAL TEETH

SEAL TEETH

SEAL TEETH

SEAL TEETH




Page 60Jan 98




cfm56 7 b borescope inspection manual vol 1

Education

borescope inspection

booster inspection

b borescope inspection

borescope equipment

engine inspection areas

nozzle inspection areas

hpt nozzle inspection

hpc inspection areas