ctc-229 borescope inspection

TRAINING MANUAL

CFM56-ALL

BORESCOPE INSPECTION

SEP 2003

CTC-229 Level 3

CFM56-ALL TRAINING MANUAL

GENERAL Page 1Issue 01

EFFECTIVITYALL CFM56 ENGINES

CFMI PROPRIETARY INFORMATION

CFMI Customer Training CenterSnecma Services

Site de Melun-Montereau,Arodrome de Villaroche

Chemin de Viercy, B.P. 1936,77019 - Melun Cedex

FRANCE

CFMI Customer Training ServicesGE Aircraft Engines

Customer Technical Education Center123 Merchant Street

Mail Drop Y2Cincinnati, Ohio 45246

USA

Published by CFMI

THIS PAGE INTENTIONALLY LEFT BLANK









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 1998 CFM INTERNATIONAL




LEXIS Page 5Issue 02

LEXIS





AA/C AIRCRAFTAC ALTERNATING CURRENTACARS AIRCRAFT COMMUNICATION ADRESSING and REPORTING SYSTEMACAU AIR CONDITIONING ACCESSORY UNITACMS AIRCRAFT CONDITION MONITORING SYSTEMACS AIRCRAFT CONTROL SYSTEMADC AIR DATA COMPUTERADEPT AIRLINE DATA ENGINE PERFORMANCE TRENDADIRS AIR DATA AND INERTIAL REFERENCE SYSTEMADIRU AIR DATA AND INERTIAL REFERENCE UNITAGB ACCESSORY GEARBOXAIDS AIRCRAFT INTEGRATED DATA SYSTEMALF AFT LOOKING FORWARDALT ALTITUDEALTN ALTERNATEAMB AMBIENTAMM AIRCRAFT MAINTENANCE MANUALAOG AIRCRAFT ON GROUNDA/P AIRPLANEAPU AUXILIARY POWER UNITARINC AERONAUTICAL RADIO, INC. (SPECIFICATION)ASM AUTOTHROTTLE SERVO MECHANISMA/T AUTOTHROTTLE

ATA AIR TRANSPORT ASSOCIATIONATC AUTOTHROTTLE COMPUTERATHR AUTO THRUSTATO ABORTED TAKE OFFAVM AIRCRAFT VIBRATION MONITORING

BBITE BUILT IN TEST EQUIPMENTBMC BLEED MANAGEMENT COMPUTERBPRV BLEED PRESSURE REGULATING VALVEBSI BORESCOPE INSPECTIONBSV BURNER STAGING VALVE (SAC)BSV BURNER SELECTION VALVE (DAC)BVCS BLEED VALVE CONTROL SOLENOID

CC CELSIUS or CENTIGRADECAS CALIBRATED AIR SPEEDCBP (HP) COMPRESSOR BLEED PRESSURECCDL CROSS CHANNEL DATA LINKCCFG COMPACT CONSTANT FREQUENCY GENERATORCCU COMPUTER CONTROL UNITCCW COUNTER CLOCKWISECDP (HP) COMPRESSOR DISCHARGE PRESSURE CDS COMMON DISPLAY SYSTEMCDU CONTROL DISPLAY UNITCFDIU CENTRALIZED FAULT DISPLAY INTERFACE UNITCFDS CENTRALIZED FAULT DISPLAY SYSTEM





CFMI JOINT GE/SNECMA COMPANY (CFM INTERNATIONAL)CG CENTER OF GRAVITYCh A channel ACh B channel BCHATV CHANNEL ACTIVECIP(HP) COMPRESSOR INLET PRESSURECIT(HP) COMPRESSOR INLET TEMPERATUREcm.g CENTIMETER X GRAMSCMC CENTRALIZED MAINTENANCE COMPUTERCMM COMPONENT MAINTENANCE MANUALCMS CENTRALIZED MAINTENANCE SYSTEMCMS CENTRAL MAINTENANCE SYSTEMCODEP HIGH TEMPERATURE COATINGCONT CONTINUOUSCPU CENTRAL PROCESSING UNITCRT CATHODE RAY TUBECSD CONSTANT SPEED DRIVECSI CYCLES SINCE INSTALLATIONCSN CYCLES SINCE NEWCTAI COWL THERMAL ANTI-ICINGCTEC CUSTOMER TECHNICAL EDUCATION CENTERCTL CONTROLCu.Ni.In COPPER.NICKEL.INDIUMCW CLOCKWISE

DDAC DOUBLE ANNULAR COMBUSTORDAMV DOUBLE ANNULAR MODULATED VALVE

DAR DIGITAL ACMS RECORDERDC DIRECT CURRENTDCU DATA CONVERSION UNITDCV DIRECTIONAL CONTROL VALVE BOEING DEU DISPLAY ELECTRONIC UNITDFCS DIGITAL FLIGHT CONTROL SYSTEMDFDAU DIGITAL FLIGHT DATA ACQUISITION UNITDFDRS DIGITAL FLIGHT DATA RECORDING SYSTEMDISC DISCRETEDIU DIGITAL INTERFACE UNITDMC DISPLAY MANAGEMENT COMPUTERDMD DEMANDDMS DEBRIS MONITORING SYSTEMDMU DATA MANAGEMENT UNITDOD DOMESTIC OBJECT DAMAGEDPU DIGITAL PROCESSING MODULEDRT DE-RATED TAKE-OFF

EEAU ENGINE ACCESSORY UNITEBU ENGINE BUILDUP UNITECA ELECTRICAL CHASSIS ASSEMBLYECAM ELECTRONIC CENTRALIZED AIRCRAFT MONITORINGECS ENVIRONMENTAL CONTROL SYSTEMECU ELECTRONIC CONTROL UNITEE ELECTRONIC EQUIPMENTEEC ELECTRONIC ENGINE CONTROL





EFH ENGINE FLIGHT HOURSEFIS ELECTRONIC FLIGHT INSTRUMENT SYSTEMEGT EXHAUST GAS TEMPERATUREEHSV ELECTRO-HYDRAULIC SERVO VALVEEICAS ENGINE INDICATING AND CREW ALERTING SYSTEMEIS ELECTRONIC INSTRUMENT SYSTEMEIU ENGINE INTERFACE UNITEIVMU ENGINE INTERFACE AND VIBRATION MONITORING UNITEMF ELECTROMOTIVE FORCEEMI ELECTRO MAGNETIC INTERFERENCEEMU ENGINE MAINTENANCE UNITEPROM ERASABLE PROGRAMMABLE READ ONLY MEMORY(E)EPROM (ELECTRICALLY) ERASABLE PROGRAMMABLE READ ONLY MEMORYESN ENGINE SERIAL NUMBERETOPS EXTENDED TWIN OPERATION SYSTEMSEWD/SD ENGINE WARNING DISPLAY / SYSTEM DISPLAY

FF FARENHEITFAA FEDERAL AVIATION AGENCYFADEC FULL AUTHORITY DIGITAL ENGINE CONTROLFAR FUEL/AIR RATIOFCC FLIGHT CONTROL COMPUTERFCU FLIGHT CONTROL UNIT

FDAMS FLIGHT DATA ACQUISITION & MANAGEMENT SYSTEMFDIU FLIGHT DATA INTERFACE UNITFDRS FLIGHT DATA RECORDING SYSTEMFDU FIRE DETECTION UNITFEIM FIELD ENGINEERING INVESTIGATION MEMOFF FUEL FLOW (see Wf) -7BFFCCV FAN FRAME/COMPRESSOR CASE VERTICAL (VIBRATION SENSOR)FI FLIGHT IDLE (F/I)FIM FAULT ISOLATION MANUALFIN FUNCTIONAL ITEM NUMBERFIT FAN INLET TEMPERATUREFLA FORWARD LOOKING AFTFLX TO FLEXIBLE TAKE-OFFFMC FLIGHT MANAGEMENT COMPUTERFMCS FLIGHT MANAGEMENT COMPUTER SYSTEMFMGC FLIGHT MANAGEMENT AND GUIDANCE COMPUTERFMGEC FLIGHT MANAGEMENT AND GUIDANCE ENVELOPE COMPUTERFMS FLIGHT MANAGEMENT SYSTEMFMV FUEL METERING VALVEFOD FOREIGN OBJECT DAMAGEFPA FRONT PANEL ASSEMBLYFPI FLUORESCENT PENETRANT INSPECTIONFQIS FUEL QUANTITY INDICATING SYSTEMFRV FUEL RETURN VALVEFWC FAULT WARNING COMPUTER





FWD FORWARD

Gg.in GRAM X INCHESGE GENERAL ELECTRICGEAE GENERAL ELECTRIC AIRCRAFT ENGINESGEM GROUND-BASED ENGINE MONITORINGGI GROUND IDLE (G/I) GMM GROUND MAINTENANCE MODEGMT GREENWICH MEAN TIMEGND GROUNDGPH GALLON PER HOURGPU GROUND POWER UNITGSE GROUND SUPPORT EQUIPMENT

HHCF HIGH CYCLE FATIGUEHCU HYDRAULIC CONTROL UNITHDS HORIZONTAL DRIVE SHAFTHMU HYDROMECHANICAL UNITHP HIGH PRESSUREHPC HIGH PRESSURE COMPRESSORHPCR HIGH PRESSURE COMPRESSOR ROTORHPRV HIGH PRESSURE REGULATING VALVEHPSOV HIGH PRESSURE SHUT-OFF VALVEHPT HIGH PRESSURE TURBINEHPT(A)CC HIGH PRESSURE TURBINE (ACTIVE) CLEARANCE CONTROL

HPTC HIGH PRESSURE TURBINE CLEARANCEHPTCCV HIGH PRESSURE TURBINE CLEARANCE CONTROL VALVEHPTN HIGH PRESSURE TURBINE NOZZLEHPTR HIGH PRESSURE TURBINE ROTORHz HERTZ (CYCLES PER SECOND)

II/O INPUT/OUTPUTIAS INDICATED AIR SPEEDID INSIDE DIAMETERID PLUG IDENTIFICATION PLUGIDG INTEGRATED DRIVE GENERATORIFSD IN FLIGHT SHUT DOWNIGB INLET GEARBOXIGN IGNITIONIGV INLET GUIDE VANEin. INCHIOM INPUT OUTPUT MODULEIPB ILLUSTRATED PARTS BREAKDOWNIPC ILLUSTRATED PARTS CATALOGIPCV INTERMEDIATE PRESSURE CHECK VALVEIPS INCHES PER SECONDIR INFRA RED

KK KELVINk X 1000KIAS INDICATED AIR SPEED IN KNOTSkV KILOVOLTS





Kph KILOGRAMS PER HOUR

LL LEFTL/H LEFT HANDlbs. POUNDS, WEIGHTLCD LIQUID CRYSTAL DISPLAYLCF LOW CYCLE FATIGUELE (L/E) LEADING EDGELGCIU LANDING GEAR CONTROL INTERFACE UNITLP LOW PRESSURELPC LOW PRESSURE COMPRESSORLPT LOW PRESSURE TURBINELPT(A)CC LOW PRESSURE TURBINE (ACTIVE) CLEARANCE CONTROLLPTC LOW PRESSURE TURBINE CLEARANCELPTN LOW PRESSURE TURBINE NOZZLELPTR LOW PRESSURE TURBINE ROTORLRU LINE REPLACEABLE UNITLVDT LINEAR VARIABLE DIFFERENTIAL TRANSFORMER

MmA MILLIAMPERES (CURRENT)MCD MAGNETIC CHIP DETECTORMCDU MULTIPURPOSE CONTROL AND DISPLAY UNITMCL MAXIMUM CLIMBMCR MAXIMUM CRUISE

MCT MAXIMUM CONTINUOUSMDDU MULTIPURPOSE DISK DRIVE UNITMEC MAIN ENGINE CONTROLmilsD.A. Mils DOUBLE AMPLITUDEmm. MILLIMETERSMMEL MAIN MINIMUM EQUIPMENT LISTMO AIRCRAFT SPEED MACH NUMBER MPA MAXIMUM POWER ASSURANCEMPH MILES PER HOURMTBF MEAN TIME BETWEEN FAILURESMTBR MEAN TIME BETWEEN REMOVALSmV MILLIVOLTSMvdc MILLIVOLTS DIRECT CURRENT

NN1 (NL) LOW PRESSURE ROTOR ROTATIONAL SPEEDN1* DESIRED N1N1ACT ACTUAL N1N1CMD COMMANDED N1N1DMD DEMANDED N1N1K CORRECTED FAN SPEEDN1TARGET TARGETED FAN SPEEDN2 (NH) HIGH PRESSURE ROTOR ROTATIONAL SPEEDN2* DESIRED N2N2ACT ACTUAL N2N2K CORRECTED CORE SPEEDN/C NORMALLY CLOSEDN/O NORMALLY OPEN





NAC NACELLENVM NON VOLATILE MEMORY

OOAT OUTSIDE AIR TEMPERATUREOD OUTLET DIAMETEROGV OUTLET GUIDE VANEOSG OVERSPEED GOVERNOROVBD OVERBOARDOVHT OVERHEAT PPb BYPASS PRESSUREPc REGULATED SERVO PRESSUREPcr CASE REGULATED PRESSUREPf HEATED SERVO PRESSUREP/T25 HP COMPRESSOR INLET TOTAL AIR PRESSURE/TEMPERATUREP/N PART NUMBERP0 AMBIENT STATIC PRESSUREP25 HP COMPRESSOR INLET TOTAL AIR TEMPERATUREPCU PRESSURE CONVERTER UNITPLA POWER LEVER ANGLEPMC POWER MANAGEMENT CONTROLPMUX PROPULSION MULTIPLEXERPPH POUNDS PER HOURPRSOV PRESSURE REGULATING SERVO VALVEPs PUMP SUPPLY PRESSUREPS12 FAN INLET STATIC AIR PRESSURE

PS13 FAN OUTLET STATIC AIR PRESSUREPS3HP COMPRESSOR DISCHARGE STATIC AIR PRESSURE (CDP)PSI POUNDS PER SQUARE INCHPSIA POUNDS PER SQUARE INCH ABSOLUTEPSID POUNDS PER SQUARE INCH DIFFERENTIALpsig POUNDS PER SQUARE INCH GAGEPSM POWER SUPPLY MODULEPSS (ECU) PRESSURE SUB-SYSTEMPSU POWER SUPPLY UNITPT TOTAL PRESSUREPT2 FAN INLET TOTAL AIR PRESSURE (PRIMARY FLOW)PT25 HPC TOTAL INLET PRESSURE

QQAD QUICK ATTACH DETACHQEC QUICK ENGINE CHANGEQTY QUANTITYQWR QUICK WINDMILL RELIGHT

RR/H RIGHT HANDRAC/SB ROTOR ACTIVE CLEARANCE/START BLEEDRACC ROTOR ACTIVE CLEARANCE CONTROLRAM RANDOM ACCESS MEMORYRCC REMOTE CHARGE CONVERTERRDS RADIAL DRIVE SHAFTRPM REVOLUTIONS PER MINUTE





RTD RESISTIVE THERMAL DEVICERTO REFUSED TAKE OFFRTV ROOM TEMPERATURE VULCANIZING (MATERIAL)RVDT ROTARY VARIABLE DIFFERENTIAL TRANSFORMER

SS/N SERIAL NUMBERS/R SERVICE REQUESTS/V SHOP VISITSAC SINGLE ANNULAR COMBUSTORSAR SMART ACMS RECORDERSAV STARTER AIR VALVESB SERVICE BULLETINSCU SIGNAL CONDITIONING UNITSDAC SYSTEM DATA ACQUISITION CONCENTRATORSDI SOURCE/DESTINATION IDENTIFIER (BITS) (CF ARINC SPEC)SDU SOLENOID DRIVER UNITSER SERVICE EVALUATION REQUESTSFC SPECIFIC FUEL CONSUMPTIONSFCC SLAT FLAP CONTROL COMPUTERSG SPECIFIC GRAVITYSLS SEA LEVEL STANDARD (CONDITIONS : 29.92 in.Hg / 59F)SLSD SEA LEVEL STANDARD DAY (CONDITIONS : 29.92 in.Hg / 59F)SMM STATUS MATRIX

SMP SOFTWARE MANAGEMENT PLANSN SERIAL NUMBERSNECMA SOCIETE NATIONALE DETUDE ET DE CONSTRUCTION DE MOTEURS DAVIATIONSOL SOLENOIDSOV SHUT-OFF VALVESTP STANDARD TEMPERATURE AND PRESSURESVR SHOP VISIT RATESW SWITCH BOEINGSYS SYSTEM

TT oil OIL TEMPERATURET/C THERMOCOUPLET/E TRAILING EDGET/O TAKE OFFT/R THRUST REVERSERT12 FAN INLET TOTAL AIR TEMPERATURET25 HP COMPRESSOR INLET AIR TEMPERATURET3 HP COMPRESSOR DISCHARGE AIR TEMPERATURET49.5 EXHAUST GAS TEMPERATURE T5 LOW PRESSURE TURBINE DISCHARGE TOTAL AIR TEMPERATURETAI THERMAL ANTI ICE TAT TOTAL AIR TEMPERATURETBC THERMAL BARRIER COATINGTBD TO BE DETERMINEDTBO TIME BETWEEN OVERHAULTBV TRANSIENT BLEED VALVE





TC(TCase) HP TURBINE CASE TEMPERATURETCC TURBINE CLEARANCE CONTROLTCCV TURBINE CLEARANCE CONTROL VALVETCJ TEMPERATURE COLD JUNCTIONT/E TRAILING EDGETECU ELECTRONIC CONTROL UNIT INTERNAL TEMPERATURETEO ENGINE OIL TEMPERATURETGB TRANSFER GEARBOXTi TITANIUMTLA THROTTLE LEVER ANGLE AIRBUSTLA THRUST LEVER ANGLE BOEINGTM TORQUE MOTORTMC TORQUE MOTOR CURRENTT/O TAKE OFFTO/GA TAKE OFF/GO AROUNDT/P TEMPERATURE/PRESSURE SENSORTPU TRANSIENT PROTECTION UNITTR TRANSFORMER RECTIFIERTRA THROTTLE RESOLVER ANGLE AIRBUSTRA THRUST RESOLVER ANGLE BOEINGTRDV THRUST REVERSER DIRECTIONAL VALVE TRF TURBINE REAR FRAMETRPV THRUST REVERSER PRESSURIZING VALVETSI TIME SINCE INSTALLATION (HOURS)TSN TIME SINCE NEW (HOURS)TTL TRANSISTOR TRANSISTOR LOGIC

UUER UNSCHEDULED ENGINE REMOVAL

UTC UNIVERSAL TIME CONSTANT

VVAC VOLTAGE, ALTERNATING CURRENTVBV VARIABLE BLEED VALVEVDC VOLTAGE, DIRECT CURRENTVDT VARIABLE DIFFERENTIAL TRANSFORMERVIB VIBRATIONVLV VALVEVRT VARIABLE RESISTANCE TRANSDUCERVSV VARIABLE STATOR VANE

WWDM WATCHDOG MONITORWf WEIGHT OF FUEL OR FUEL FLOW WFM WEIGHT OF FUEL METERED WOW WEIGHT ON WHEELSWTAI WING THERMAL ANTI-ICING





IMPERIAL / METRIC CONVERSIONS

1 mile = 1,609 km1 ft = 30,48 cm1 in. = 25,4 mm1 mil. = 25,4

1 sq.in. = 6,4516 cm

1 USG = 3,785 l (dm)1 cu.in. = 16.39 cm

1 lb. = 0.454 kg

1 psi. = 6.890 kPa

F = 1.8 x C + 32

METRIC / IMPERIAL CONVERSIONS

1 km = 0.621 mile1 m = 3.281 ft. or 39.37 in.1 cm = 0.3937 in.1 mm = 39.37 mils.

1 m = 10.76 sq. ft.1 cm = 0.155 sq.in.

1 m = 35.31 cu. ft.1 dm = 0.264 USA gallon1 cm = 0.061 cu.in.

1 kg = 2.205 lbs

1 Pa = 1.45 10-4 psi.1 kPa = 0.145 psi1 bar = 14.5 psi

C = ( F - 32 ) /1.8

TABLE OF CONTENTS




CONTENTSBORESCOPEINSPECTION

Page 15Sep 03




CONTENTSBORESCOPEINSPECTION

Page 16Sep 03

SECTION PAGE SECTION PAGE

LEXIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

BASIC ENGINE PARTICULARS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

INSPECTION OF FAN AND BOOSTER . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

INSPECTION OF HIGH PRESSURE COMPRESSOR. . . . . . . . . . . . . . . . 91

INSPECTION OF COMBUSTOR SECTION . . . . . . . . . . . . . . . . . . . . . . . 103

INSPECTION OF HIGH PRESSURE TURBINE. . . . . . . . . . . . . . . . . . . . 127

INSPECTION OF LOW PRESSURE TURBINE . . . . . . . . . . . . . . . . . . . . 147

APPENDIX : NUMBER OF BLADES PER ROTOR . . . . . . . . . . . . . . . . . 157

SERVICE BULLETINS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161




INTRODUCTIONBORESCOPE INSPECTION

Page 17Sep 03

INTRODUCTION





Page 18Sep 03

ON CONDITION MAINTENANCE

CFM56 engines use a maintenance concept called On Condition Maintenance. This means that engines have no periodic overhaul schedules and can remain installed under the wing until something important occurs, or when lifetime limits of parts are reached.

For this reason, to monitor and maintain the health of an engine, different tools are available.

Engine performance trend monitoring.To evaluate engine deterioration over a period of time, certain engine parameters, such as gas temperature, are recorded and compared to those initially observed at engine installation on the aircraft. Any abnormalities can be immediately identified and further investigation initiated.

For troubleshooting, record and report the following engine and aircraft data as soon as engine and records are available for initial inspection.

- Hours since engine last used.- Flight data prior to, during, and after the event.- Hours since last shop visit.- Service Bulletin compliance.- Pilots report of the event.- Condition of engine inlet.

- Any obvious incidents that may have contributed to, or immediately preceded, an event.

Lubrication particles analysis.Lubrication oil circulating in the engine is filtered, and large, visible-to-the-eye particles (larger than 10 microns) are collected in filters and magnetic chip detectors, for visual inspection. Analysis of these particles, that usually indicate worn or broken engine parts, may show that the internal parts of the engine have to be inspected in detail.

Engine vibration monitoring system.Sensors located in various positions in the engine, send vibration values to the on-board monitoring system. When vibration values are excessive, the data recorded can be used to take remedial balancing action.

Borescope inspection.To visually check the condition of engine internal parts that are not easily accessible, borescope probes can be inserted through various ports that are located on the engine outer casing.





Page 19Sep 03

CTC-229-001-00





Page 20Sep 03

SCHEDULED / UNSCHEDULED INSPECTION

These are the 2 basic types of borescope inspections. - Scheduled inspection - Unscheduled inspection

Scheduled

The purpose of the scheduled inspection is to inspect for defects inside the engine at regular time intervals, depending on :- the Maintenance Review Board (MRB)- the Maintenance Planning Document (MPD). A scheduled inspection is performed on specific areas of the engine to assess its condition.

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, refer to the Non Destructive Test Manual (NDTM). In the On Condition paragraph of each engine section, there is a list of possible defects.

Unscheduled

The purpose of the unscheduled inspection is to find defects inside the engine at abnormal time intervals, or after an engine event, such as FOD, hot start, overspeed, vibration, etc...

If an engine experiences such a problem, it may have to be inspected to ascertain internal defects.

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

As a supplement refer to the NDTM. The AMM, engine section, special inspection, will list the engine events and which inspection ports must be used by the inspector.





Page 21Sep 03

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Page 22Sep 03




BASIC ENGINEPARTICULARS


Page 23Sep 03

BASIC ENGINE PARTICULARS






Page 24Sep 03

CFM56 MAIN CHARACTERISTICS

CFM56 engines consist of two independent rotating systems:

- The low pressure system, with a rotational speed designated N1.

- The high pressure system, with a rotational speed designated N2.

Type of engine Turbo fan

Arrangement Two spool axial flow

Rotation Clockwise (ALF)

Fan & Booster Module

Fan Stage 1

(-2, -3, -5A, -7B) : Booster Stages 2 to 4(-5B, -5C) : Booster Stages 2 to 5

(ALL) :High Pressure Compressor (HPC) Module

Stages 1 to 9

Combustor Section

(-2, -3, -5A, -5C) : Annular SAC(-5B, -7B) : Annular SAC (option DAC)

(ALL) :High Pressure Turbine (HPT) Module

Stage 1

Low Pressure Turbine (LPT) Module

(-2, -3, -5A, -5B, -7B) : Stages 1 to 4 (-5C) : Stages 1 to 5

(ALL) :Accessory Drive Module Inlet Gearbox (IGB) Transfer Gearbox (TGB) Accessory Gearbox (AGB)






Page 25Sep 03

CTC-229-004-00






Page 26Sep 03

FAN AND BOOSTER

(ALL) :After entering the air inlet cowl, the total engine airflow passes through fan rotor blades, which form stage 1 of the low pressure compressor (LPC).

Most of the airflow (secondary), is ducted overboard through Outlet Guide Vanes (OGVs). The remaining airflow (primary), is directed through a booster, where it is pressurized.

(-5B, -5C) :The booster has 4 stages: stage 2 to stage 5. (-2, -3, -5A, -7B) :The booster has 3 stages: stage 2 to stage 4.

(ALL) :The OGV assembly consists of vanes and an inner shroud. A splitter fairing separates the primary and secondary airflows.

Booster stator.The stator assembly consists of vanes and inner & outer shrouds. All vane stages are bolted together.

The shrouds have abradable material, which faces rotating parts.

Booster spool rotating air seals rub against the inner shroud, and rotor blades rub against the outer shrouds.

Booster rotor.The booster rotor consists of a booster spool mounted on the rear of the fan disk. The blades are installed in circumferential dovetail slots.

(-5A, -5B, -5C, -7B) :Each stage has 2 blade locks to ensure the blades are retained and prevented from rotating in the slot. The position of the locks is shifted between stages.

Borescope ports.(-2, -3, -5A, -7B) :At approx. the 3:30 clock position, there is an unplugged hole S0, through the OGV inner shroud, at the stage 3 vane assembly.

(-5B, -5C) :At approx. the 3:30 clock position, there are 2 unplugged holes, S03 and S05, through the OGV inner shroud.

S03 is located at the stage 3 vane assembly, and S05 at the stage 5 vane assembly.






Page 27Sep 03

CTC-229-005-00 FAN AND BOOSTER






Page 28Sep 03

THE HIGH PRESSURE COMPRESSOR (HPC)

(ALL) :The HPC is a 9-stage compressor mounted between the fan frame and the combustor case. It consists of a rotor and front and rear stators.

Front stator.The front stator is constructed with upper and lower cases bolted together at their split-line flanges.

It consists of :- the inlet guide vanes (IGVs).- the variable stator vanes (VSVs), stages 1, 2 and 3.- the fixed stator vanes stages 4 and 5.

The IGVs and VSVs stages 1, 2 and 3 are installed individually through the case.

There are 2 circumferential slots machined inside the front stator case to hold fixed vane stages 4 and 5. The vanes are assembled into segments.

Rear stator.The rear stator case is made up of two halves bolted together at their split-line flanges. It is installed inside the front stator casing.

The case has internal machined circumferential slots that hold the fixed vanes of stages 6, 7 and 8. The vanes are assembled into segments. Fixed vane stage 9 is part of the combustion case.

Rotor.The stage 1-2 spool is mounted on the rotor shaft. It has individual axial blade slots and inter-stage labyrinth seals.

The stage 3 disk supports the stage 4-9 spool and also has individual axial blade slots.

The stage 4-9 spool is bolted onto the stage 3 disk. It has circumferential dovetail blade grooves and inter-stage labyrinth seals.

Each stage on the 4-9 spool has 2 blade locks to immobilize the blades. Their position is shifted between stages for balancing purposes.






Page 29Sep 03

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Page 30Sep 03

THE HIGH PRESSURE COMPRESSOR (HPC)

(ALL) :Borescope ports.

There are 9 plugged borescope ports on the lower stator case, at approximately the 5 oclock position, and they are numbered S1 thru S9, where S1 is the most forward.

Ports S1, S3, S5, and S6 have a 10mm diameter.

Ports S2, S4, S7, S8 and S9 have an 8mm diameter.

S7, S8 and S9 plugs have a particular design. They are double plugs.

CAUTION: MAKE SURE TO FOLLOW THE PROCEDURE IN THE AIRCRAFT MAINTENANCE MANUAL (AMM) WHEN YOU REMOVE PLUGS S7, S8 AND S9.

The inner thread engages the HPC rear stator case, while the outer thread is tightened on the HPC case.

A spring-loaded system enables the outer plug to drive the inner plug.

Both inner and outer plugs have specific torque values.

Special tools.

Deep-well socket.In case the shaft of borescope plugs S7, S8 or S9 breaks, remove the inner plug with a deep-well socket, using the six flats at the end of the shaft.

IMPORTANT : WHEN RE-INSTALLING PLUGS S7, S8 OR S9, BE SURE TO APPLY THE RECOMMENDED LUBRICANT TO THE THREADS AND CAREFULLY FOLLOW THE TORQUING PROCEDURES IN THE AMM .






Page 31Sep 03

CTC-229-007-00






Page 32Sep 03

COMBUSTOR SECTION

(ALL) :The combustor section, consisting of the combustion case and chamber, is located between the HPC and the LPT. It produces the necessary energy to drive the turbine rotors.

Fuel, supplied by 20 fuel nozzles around the combustion case, is mixed with air from the HPC and ignited by 2 igniter plugs, which are at the 4 and 8 oclock positions.

The front face of the combustor is attached to the rear of the HPC and its rear face is bolted onto the LPT module front flange.

The rear part of the combustor houses the HPT module and the stage 1 LPT nozzle.

Single Annular Combustor (SAC).

The combustion chamber is housed in the combustion case and is installed between the HPC stator stage 9 and the HPT nozzle.

The combustion chamber consists of :

- The dome, which supports the fuel nozzles, sleeves and deflectors.

- The outer and inner cowls, which are bolted to the outer and inner liners and the dome.

- The outer and inner liners, which are designed with panel overhangs containing closely spaced holes for film cooling.






Page 33Sep 03

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Page 34Sep 03

COMBUSTOR SECTION

(-5B, -7B) :Double Annular Combustor (DAC).

The combustion case has 20 double-tip fuel nozzles mounting pads and accommodates 3 fuel supply manifolds.

The combustion chamber is a short, conical structure with a double burner and is contained in the combustion case.

The Double Annular Combustor has an outer dome, known as pilot, and an inner dome, known as main.

The DAC consists of :- outer and inner liners.- cowl.- centerbody.- 20 pilot swirl cups.- 20 main swirl cups.

The outer and inner liners are designed with panel overhangs which have closely spaced holes providing air film cooling. Both inner and outer liners are thermal barrier coated.

The cowl forms the front end of the combustor and is scalloped to allow passage for HPC delivery air and for fuel nozzles installation.

The centerbody separates the pilot area from the main area. There are 40 centerbodies that are a cast part, which is cooled through film air cooling holes and internal heat transfer is increased by fins.

Each swirl cup consists of a primary and a secondary swirl nozzle. They force the air to rotate in opposite directions for efficient mixing of air with fuel.






Page 35Sep 03

CTC-229-009-00






Page 36Sep 03

COMBUSTOR SECTION


There are 4 borescope ports located around the combustor case to enable inspection of the combustion chamber.

The ports are numbered S12 to S15 and accommodate a simple plug with a hexagonal head.

Ports S12, S13, S14 and S15 have a 10mm diameter.

Two other ports are available using the spark igniter ports S10 and S11, which also have a 10mm diameter. Refer to the AMM for removal procedures.

(-5B, -7B) :The DAC combustion chamber has an extra port, S14.5, at approximately the 9 oclock position.






Page 37Sep 03

CTC-229-010-00






Page 38Sep 03

THE HIGH PRESSURE TURBINE (HPT) & STAGE 1LPT NOZZLE

(ALL) :The HPT converts the kinetic energy of gasses from the combustion chamber into torque to drive the HPC and it is housed in the combustion case.

It is a single-stage assembly that consists of :- the HPT nozzle.- the HPT rotor.- the HPT shroud and stage 1 LPT nozzle.

The HPT nozzle is made up of segments which consist of vanes brazed onto inner and outer platforms.

The forward inner and outer platforms are pushed by springs against the combustion case inner and outer liners. The vanes rear outer platforms are pushed against the shroud support by spring-loaded clips.

The HPT rotor is a single stage assembly housed in the combustion case and consists of individual replaceable blades with dovetail roots that slide into slots on the outer rim of a disk.

The HPT shroud and stage 1 LPT nozzle assembly forms the connection between the core section and the LPT module.

Stage 1 LPT nozzle is housed within the combustion case, and consists of an assembly of vane sectors. It features trailing edge slots for cooling purposes.






Page 39Sep 03

CTC-229-011-00 THE HPT & STAGE 1 LPT NOZZLE






Page 40Sep 03

THE HIGH PRESSURE TURBINE (HPT) & STAGE 1LPT NOZZLE


The HPT section / stage 1 LPT nozzle borescope ports are located around the combustor case.

(-2, -3, -5A) :They are numbered S17 and S18.(-5B, 5C, -7B) :They are numbered S16 and S17.

(ALL) : Having an 8 mm diameter, they accommodate long spring-loaded plugs with hexagonal heads, and can be used to inspect the blades trailing edges.Blades leading edges can be viewed through combustion chamber ports S12 thru S15.

(-2, -3, -5A) :CAUTION : DO NOT MIX PLUGS S17 & S18 WITH PLUGS S12 TO S15. INSTALLING THEM IN THE WRONG PLACE MAY CAUSE ENGINE DAMAGE.

(-5B, 5C, -7B) :CAUTION : DO NOT MIX PLUGS S16 & S17 WITH PLUGS S12 TO S15. INSTALLING THEM IN THE WRONG PLACE MAY CAUSE ENGINE DAMAGE.

(ALL) :Ports S10 and S11 correspond to the igniter plugs and can be used to look at the HPT front sections.

They have a 10mm diameter.

Refer to the AMM for igniter plugs removal procedure.

Because of their location, HPT blades cannot be inspected with a rigid probe. Use a flexible probe with a guide tube, and pass through the combustion chamber and HPT nozzles, to access the HPT blades.






Page 41Sep 03

CTC-229-012-00






Page 42Sep 03

THE LOW PRESSURE TURBINE (LPT)

The LPT drives the fan and booster through the LPT shaft. The LPT rotor/stator has:(-2, -3, -5A, -5B, -7B) : 4 stages (-5C) : 5 stages.

(ALL) : It is located between the HPT and the turbine frame. Its front flange is mounted on the rear flange of the combustion module.There is an aluminization coating on:(-2, -3, -5A) : rotor stg 1 (-5B, -5C, -7B) : rotor stg 1 & 2.

(ALL) :On all stages, each blade tip shroud has 2 seal teeth for air sealing, and 3 of the blades have hard-coated tips to rub against honeycomb material on the stator seal segments.

Borescope ports.The LPT borescope ports are located on the combustion case and around the LPT case at approximately:(-5A, -5B, -5C, -7B) 5 and 8 oclock (-2, -3) 3, 5 and 8 oclock.

(-2, -3, -5A) :5 ports are available to inspect the LPT.They are designated S17, S18 ( stage 1), S20 (stage 2), S21 (stage 3) and S22 (stage 4).

(-5B, -7B) :5 ports are available to inspect the LPT.They are designated S16, S17 ( stage 1), S18 (stage 2), S19 (stage 3) and S20 (stage 4).

(-5C) :6 ports are available to inspect the LPT.They are designated S16, S17 ( stage 1), S18 (stage 2), S19 (stage 3), S20 (stage 4) and S21 (stage 5).

(ALL) :Stg 1 ports have an 8 mm diameter, and long plugs with hexagonal heads.

(-2, -3, -5A, -5B, -7B) :Stages 2 to 4 ports have a 10mm diameter, and are fitted with (-2, -3, -5A) short plugs with hexagonal heads locked with wire (-5B, -7B) short self-locking plugs with socket cylindrical socket heads.

(-5C) :Stages 2 to 5 ports have a 10mm diameter, and are fitted with short plugs with hexagonal heads locked with wire.

(ALL) :CAUTION: DO NOT MIX SHORT AND LONG PLUGS BETWEEN PORTS. ENGINE DAMAGE MAY OCCUR.






Page 43Sep 03

CTC-229-013-00






Page 44Sep 03

ACCESSORY DRIVE SYSTEM

(ALL) :At engine start, the accessory drive system transmits external power from the engine air starter to drive the core engine.

When the engine is running, the accessory drive system extracts part of the core engine power and transmits it through a series of gearboxes and shafts in order to drive the engine and aircraft accessories.

(-2, -5A, -5B, -5C) :The accessory drive system is located at 6 oclock and consists of the following components:(-3, -7B) :The accessory drive system is located at 9 oclock and consists of the following components:(ALL) :

- The Inlet Gearbox (IGB), that takes power from the HPC front shaft.

- The Radial Drive Shaft (RDS), that transmits the power to the Transfer Gearbox.

- The Transfer Gearbox (TGB), which redirects the torque.

- The Horizontal Drive Shaft (HDS), that transmits power from the TGB to the Accessory Gearbox.

- The Accessory Gearbox (AGB), that supports and drives both engine and aircraft accessories.

(-2) :For maintenance tasks, the core can be turned manually through a handcranking pad on left side of the TGB.

(-3, -5A, -5B, -5C, -7B) :For maintenance tasks, the core can be turned manually through a handcranking pad on the front face of the AGB.






Page 45Sep 03

CTC-229-014-00







Page 46Sep 03




REQUIREMENTSBORESCOPE INSPECTION

Page 47Sep 03

REQUIREMENTS





Page 48Sep 03

BORESCOPE ACCESS LIMITATIONS

(ALL) :There are two limitation factors that have to be considered when preparing for borescope inspection on CFM56 engines.

These considerations are :

- the size of the borescope probe to be inserted into the engine.

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

The purpose of having probe size and temperature limitations is to prevent damage to the borescope equipment.

Without size limitations a 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, if it is inserted into a hot engine. Without these limitations there can be subsequent deformation of borescope probes, excessive replacement/repair costs of equipment, and even Foreign Object Damage (FOD) to the engine itself.





Page 49Sep 03

ENGINE LOCATION

PORT No. PORT SIZE (MM)

WRENCH SIZE AREAS VIEWED

WITHOUT MOTORING TIME TO REACH

-2/-3/-5A -5B/-5C -7B 100F(38C) 200F(93C)

BOOSTER S0 S03 S0 N/A N/A STAGE 3 T/E -- --

STAGE 4 L/E -- --

-- S05 -- N/A N/A STAGE 5 T/E -- --

HPC CASE S1 S1 S1 10 MM 1/2 HEX STAGE 1 L/E 30 mn --

S2 S2 S2 8 MM 1/2 HEX STAGE 1 T/E

STAGE 2 L/E 30 mn --


STAGE 3 L/E 30 mn 20 mn


STAGE 4 L/E 1 hr 30 mn


STAGE 5 L/E 1 hr 30 mn


STAGE 6 L/E 1.5 hrs 1 hr


STAGE 7 L/E 2.0 hrs 1.5 hrs


STAGE 8 L/E 2.5 hrs 1.5 hr

S9 S9 S9 8 M 11/16 HEX STAGE 8 T/E






Page 50Sep 03

BORESCOPE ACCESS LIMITATIONS

(ALL) :Probe 1 diameter limitation.

Consult the table for port diameters where probe 1 can be used.

Borescope equipment temperature limitations.

It is not recommended that borescope inspection be accomplished at temperatures above 130F (54C).

WARNING: HIGH TEMPERATURES MAY CAUSE SERIOUS BURNS TO PERSONNEL AND DAMAGE TO THE FIBER OPTIC EQUIPMENT.

Consult the table for information about time limitations, prior to inspecting a hot engine.

To speed up the engine cool down time after shutdown, the engine starter may be used to dry motor the engine, (Refer to the AMM).

This sufficiently reduces the hot section area temperature to allow inspection. But as the temperature will rise again 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 130F (54C).

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





Page 51Sep 03

ENGINE LOCATION

PORT No. PORT SIZE (MM)

WRENCH SIZE AREAS VIEWED

WITHOUT MOTORING TIME TO REACH

-2/-3/-5A -5B/-5C -7B 100F(38C) 200F(93C)

COMBUSTION CASE

S10 S10 S10 10 MM 1 1/4 HEX COMBUSTOR 3.5 hrs 2.0 hrs

HPT NOZZLE L/E & T/E 4.5 hrs 3.0 hrs

S11 S11 S11 10 MM 1 1/4 HEX HPT BLADE L/E 4.5 hrs 3.0 hrs

HPT SHROUD 4.5 hrs 3.0 hrs

S12 S12 S12 10 MM 7/8 HEX COMBUSTOR 3.5 hrs 2.0 hrs

S13 S13 S13 10 MM 7/8 HEX COMBUSTOR 3.5 hrs 2.0 hrs

S14 S14 S14 10 MM 7/8 HEX AND

S15 S15 S15 10 MM 7/8 HEX HPT NOZZLE L/E 4.5 hrs 3.0 hrs

S17 S16 S16 8 MM 7/8 HEX HPT BLADES T/E 4.5 hrs 3.0 hrs

S18 S17 S17 8 MM 7/8 HEX LPT STAGE 1 L/E 4.5 hrs 3.0 hrs

LPT CASE S20 S18 S18 10 MM 9/16 HEX STAGE 1 T/E 4.5 hrs 3.0 hrs






-5C ONLY

-- S21 -- 10 MM 9/16 HEX STAGE 4 T/E 4.5 hrs 2.0 hrs






Page 52Sep 03

DOCUMENTATION

(ALL) :AMM.

The Aircraft Maintenace Manual (AMM) provides comprehensive instructions on how to perform a borescope inspection and provides the limits for the various engine parts.

There are no definitive measurement devices for the borescope.

Evaluating inconsistencies is not an easy task because all measurements by borescope are comparative.

The inspector can make a comparison with some known area within the field of view which can then be referenced to a specific paragraph in the maximum serviceable limits specified in the AMM.

Note : The language used in the serviceability limits may take some study for proper interpretation.





Page 53Sep 03

CTC-229-015-00 AIRCRAFT MAINTENANCE MANUAL INSPECTION CRITERIA

---------------------------------------------------------------------------------------------------------------------------------------------- INSPECT/CHECK MAXIMUM REMARKS SERVICEABLE LIMITS---------------------------------------------------------------------------------------------------------------------------------------------- Stages 1-4 compressor blade airfoil leading and trailing edge, upper 75 percent:

A.Tears Not serviceable Replace the engine Ref. TASK 71-00-00-000- 042) or repair (Ref. TASK 72-31-00-300-004). B.Nicks, missing Any number 0.04 in. (1.0 See limit extensions material and mm) max depth Ref. TASK 72-00-00-200- erosion 025) or repair (Ref. TASK 72-31-00-300-004). C.Dents Any number 0.04 in. (1.0 See limit extensions mm) max depth or 0.060 (Ref. TASK 72-00-00-200- in. (1.52 mm) max 025) or repair (Ref. TASK deflection from original 72-31-00-300-004). contour





Page 54Sep 03

DOCUMENTATION

(ALL) :NDTM.

Words such as nicks, dents and scratches, for example, are often used in the AMM.

The NDTM (Non Destructive Test Manual) provides a comprehensive list and an explanation of these words in its Introduction section.

It also provides sample forms on which to record the defects encountered, which include record forms and maps for each rotor stage.

Recording of defects.

It is highly recommended that a record be maintained for each borescope inspection conducted.

The maps are provided so that any damage within serviceable limits can be recorded pictorially by blade number and position on the blade.

Propagation of the damage can then be pictorially illustrated during subsequent inspections. The rotor blade maps are oriented about the zero reference for inspection continuity.

The records and maps will remain in the engine folder until the damaged parts are repaired, or replaced.

Note : When defect/damage maps are used, accomplish the mapping at the inspection site. Do not rely on memory of the defect in order to carry out the mapping in an office after the inspection.

Photo recording.

Whenever photos are made of a defect, a record of the photo should be made immediately.

If the photo is not recorded relative to the engine serial number, stage, port, direction of view and date, correlation of the hardware damage and the photo will be extremely difficult.

Refer to the NDTM for more information.





Page 55Sep 03

CTC-229-016-00





Page 56Sep 03

MATERIALS AND EQUIPMENT

(ALL) :Rigid borescope probe set.

CFMI have designed their own light source 856A1322 and rigid borescope set 856A1320, including various probes, adapters and extensions.

Optional equipment is available for cameras, computers, VCRS, and special tools that attach to the equipment.

Other borescope systems may be acceptable if they meet CFMI specifications.

Refer to the NDTM specifications for more information on the required characteristics.





Page 57Sep 03

CTC-229-017-00





Page 58Sep 03


(ALL) :Rigid borescope probe set.

There are 4 rigid borescope probes for inspection of the internal areas of the engine and each probe is used for a specific purpose :

- 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 59Sep 03

CTC-229-018-00





Page 60Sep 03


(ALL) :Flexible probe set.

Flexible borescope set 856A1321 and guide tube 856A1310 (blue) or 856A1351 (red), are designed to be used on CFM56 engines and meet CFMI specifications.

(-5B, -7B) :Guide tube 856A1702 (red) is used for DAC engines.

(ALL) :Optional equipment is available for cameras, computers, VCRS, and special tools that attach to the borescope equipment.

Other borescope systems may be acceptable if they meet CFMI specifications.

Refer to the NDTM specifications for more information on the required characteristics.





Page 61Sep 03

CTC-229-019-00





Page 62Sep 03

EQUIPMENT CHECKS

(ALL) :The borescope resolution monitor.

Before starting any inspection inside the engine, the inspector should ensure that the viewing definition of the rigid and flexible borescope probes is as precise as possible.

Borescope resolution monitor 856A1323 allows both rigid and flexible probes to be checked against a calibrated display.

The male end of the light bundle is inserted into a light source and the female end is connected to the male connector on the resolution monitor.

The rigid or flexible probe is inserted and hand-tightened into a clamping device located on the arm on the resolution monitor. The probes lens faces a resolution target.

The light intensity is adjusted to obtain the best view and the borescope probe is aligned to ensure that the resolution target is centered in the field of view.

If only part of the target is illuminated, then the borescope probe is not serviceable for engine inspection.





Page 63Sep 03

BORESCOPE RESOLUTION MONITORCTC-229-020-00

RESOLUTIONTARGET

BORESCOPELENS

CLAMPINGDEVICE

LIGHT BUNDLE





Page 64Sep 03

EQUIPMENT CHECKS

(ALL) :The resolution target.

The resolution target is divided into group and element numbers, which gradually diminish in size towards the center of the display.

Group 0 is the largest display and group 7 is the smallest.

All 7 groups have 6 elements in each.

Group 0, element 1, is located at the lower right of the target and its 6 lines (horizontal and vertical) should be clearly visible to the eye.

Group 1 is located in the top right side of the target and is smaller than group 0.

In the center of the display, group 2 is located on the left side of the target and group 3 is located on the right side.

Each group continues to diminish in size down to group 7.

Rigid probes.

For rigid probes with a 1:1 magnification at 2in., the 6 individual lines (3 vertical and 3 horizontal) of group 3, element 4, should be distinguishable.

For rigid probes with a magnification of 1:1 at 7in., the 6 individual lines of group 5, element 2, should be distinguishable.

Flexible probes.

For flexible probes with 90 direction of view, the 6 individual lines of group 1, element 4, should be distinguishable.





Page 65Sep 03

CTC-229-021-00

e075915





Page 66Sep 03

CORE ENGINE ROTATION

(-5A, -5B, -5C) :Two pads on the accessory gearbox (AGB) are used to rotate the core engine:

- The handcranking pad- The starter pad for motor-driven rotation

The handcranking pad is located on the front face of the AGB .

The starter pad is located on the rear face of the AGB.

Refer to the AMM (72-63-00) or (80-11-10) for procedures to remove the handcranking pad cover or the starter.

(-3, -7B) :A pad is available on the front face of the AGB, to perform either manual or motor-driven core engine rotation.

(-2) :A pad is available on the left side of the transfer gearbox (TGB), to perform either manual or motor-driven core engine rotation.

(ALL) :Manual method:

- Insert a 34 inch square drive socket attached to a 2ft. long breaker bar into the handcranking drive pad.





Page 67Sep 03

CTC-229-022-00





Page 68Sep 03


(ALL) :The N2 rotor can also be turned with a pneumatic motor.

(-2) :Pneumatic motor 856A1142 is installed on the handcranking pad on the left side of the TGB.(-3) :Pneumatic motor 856A2002 is installed on the handcranking pad on the front side of the AGB.(-5A, -5B, -5C) :Pneumatic motor 856A1488 is installed on the starter pad on the rear side of the AGB.(-7B) :Pneumatic motor 856A1815 is installed on the handcranking pad on the front side of the AGB.

(-ALL) :Supplied by a shop, or line air supply, this device provides a smooth, even speed for turning the core rotor.

Reversible control, as well as speed control are provided and the need for an additional mechanic to turn the rotor is eliminated.

A 360 protractor is integral with the device.

Air drive method:

Install the pneumatic motor assembly on the pad.The direction of rotation and speed of the core engine rotor can be selected through a hand, or foot control device.

Refer to the AMM for instructions on installation and use.

Note : When using the pneumatic motor, the air supply must be free of unwanted water, or other particles. It is highly recommended to install a filter upstream and also a device to add lubricant to the air supply.





Page 69Sep 03

CTC-229-023-00





Page 70Sep 03


(ALL) :Another way of turning the core is through Electronic Turning Tool (ETT) Sweeney, P/N 18946, which adapts on the same pad as the pneumatic motor.

ETT method:

Install the plate adapter, drive shaft and ETT motor assembly on the adequate pad, with a QAD clamp.

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 avoid overshoot during inspection of the rotor blades. It also has an automatic feature to count blades and damage can be flagged for a quick future reference.

The information can also be stored for the next inspection.





Page 71Sep 03

CTC-229-024-00






Page 72Sep 03




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 73Sep 03

INSPECTION OF FAN AND BOOSTER




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 74Sep 03

FAN AND BOOSTER

(ALL) :N1 rotor indexing.

Setting a reference angular position for the rotor provides an easy method to return 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.

Align the leading edge of fan blade No 1 with the T12 temperature sensor, installed on the fan inlet cowl.

The No 1 fan blade is easily identified : it faces a spherical indent mark on the spinner rear cone.

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




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 75Sep 03

CTC-229-025-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 76Sep 03

FAN AND BOOSTER

(ALL) :Visual inspection of the fan blades is performed on a regular basis depending on the MRB, or MPD.

If defects are found, then an unscheduled inspection is required.

Possible defects:

- missing material, tip curl.- nicks, dents, pits or scratches, usually due to

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

- distortion, cracks and deformation, usually due to heavier foreign object damage (FOD), such as birds, ice, hail, tires, etc.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 77Sep 03

CTC-229-026-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 78Sep 03

FAN AND BOOSTER

(ALL) :Visual inspection of the outlet guide vanes (OGV) is performed on a regular basis depending on the MRB, or MPD.

If defects are found, then an unscheduled inspection is required.

Possible defects:

- missing material.- nicks, dents, pits or scratches, usually due to

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

- distortion, cracks and deformation, usually due to heavier foreign object damage (FOD), such as birds, ice, hail, tires, etc.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 79Sep 03

CTC-229-064-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 80Sep 03

FAN AND BOOSTER

(ALL) :Rigid probe No 2 (yellow), installed on a long right angle adapter, can be used to reach the front of the splitter fairing area in order to inspect the booster.

From this position the following are visible:- Stator vane stage 1- Rotor stage 2 leading edge through stator stage 1.

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).




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 81Sep 03

CTC-229-027-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 82Sep 03

FAN AND BOOSTER

(-2, -3, -5A, -7B) :To inspect the booster, unplugged borescope port S0 can be accessed with a probe installed on a long right angle adapter.

(-5B, -5C) :To inspect the booster, unplugged borescope port S03 can be accessed with a probe installed on a long right angle adapter.

(ALL) :The port is located between 2 OGVs, at approximately the 3 oclock position.

Insert the No 2 (yellow) borescope probe into the port and go through the 2 cases to reach the inspection area.

Depending on the configuration of the long right angle extension, it is possible to turn the probe to change the direction of view and adjust the focus directly from the extension.

The following components are visible: - Rotor stage 3 trailing edge.- Rotor stage 4 leading edge.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 83Sep 03

CTC-229-028-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 84Sep 03

FAN AND BOOSTER

(-5B, -5C) :After inspection through port S03, continue inspection of the booster through port S05, using probe No 2 (yellow), installed on a long right angle adapter.

Port S05 is located at approximately 4 oclock. Insert the borescope probe into the port and go through the 2 cases to reach the inspection area.

The rotor stage 5 trailing edge is visible through port S05.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 85Sep 03

CTC-229-029-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 86Sep 03

FAN AND BOOSTER

(ALL) :Booster rotor damage may occur after the engine experienced an abnormal problem. The following list provides examples of 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 N1 rotor vibration.- N1 rotor overspeed.- Heavy landing (acceleration above threshold limit).

Booster blade inspection areas.

There are 3 areas on the booster blades, which are dimensionally defined using letters.

Area E :- This area of the blade starts from the top of the

platform and extends toward the blade tip for approximately 10 mm.

Refer to the AMM for precise area.

Area G : - This area of the blade starts from the tip of the

blade and extends toward the blade platform for approximately 20 mm.

Refer to the AMM for precise area.

Other airfoil areas : - This is the remaining area of the blade that does not

include areas E and G.

Note : Defects should be classified in terms of criticality. Defects seen in one area can be more critical than the same defects seen in another.

(-5A, -5B, -5C, -7B) :Blade locks :Each booster rotor stage has blade locks. Experience has shown that they sometimes work loose and, therefore, should also be inspected.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 87Sep 03

CTC-229-030-00




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 88Sep 03

FAN AND BOOSTER

(ALL) :During an inspection of the booster, any defects should be assessed against the serviceability limits in the Aircraft Maintenance Manual.

Possible defects:

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

Map the defects on the special reporting form.




FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 89Sep 03

CTC-229-031-00





FAN ANDBOOSTER

BORESCOPEINSPECTION

Page 90Sep 03




Page 91Sep 03

HIGH PRESSURECOMPRESSOR

BORESCOPEINSPECTION

INSPECTION OF HIGH PRESSURE COMPRESSOR





BORESCOPEINSPECTION

Page 92Sep 03

HIGH PRESSURE COMPRESSOR (HPC)

(ALL) :HPC rotor blade damage may occur after the engine experienced an abnormal operating problem. The following list provides examples of 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 N2 rotor vibration.- N2 rotor overspeed.- Heavy landing.- Oil fumes detected in cabin air.

Alignment rod.

The HPC stator vanes may move slightly, causing misalignment 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 for more information.

General inspection method.

To inspect the blades, it is necessary to open the VSVs. Refer to the appropriate procedure in the AMM.

Inspection starts with stage 1 rotor, through port S1.

Probe No 2 (yellow) is used for a general inspection of the blades.

Probes No 3 (green) and No 4 (blue) may be necessary for defect assessment.

Probe No 3 is used to inspect the L/E platform area and probe No 4 to inspect the L/E blade tip area.

Repeat the same method for ports S2 to S9.

Map the defects on the special reporting form.





BORESCOPEINSPECTION

Page 93Sep 03

CTC-229-032-00





BORESCOPEINSPECTION

Page 94Sep 03

N2 ROTOR INDEXING

(ALL) :Stage 4 of the High Pressure Compressor is the first stage where the blades are retained in position with blade locks. These locks can be used to determine a reference point.

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

1. Open the VSV system. (AMM section 75-31-00).

2. Insert probe No 3 (green) into borescope port S4, and look rearward at the compressor stage 4 rotor blades.

3. Rotate the core (manually, or with a tool) in the CW direction so that blades convex side comes into view. Continue turning until the first blade lock appears in the field of view.

4. Continue rotating the core until the second blade lock appears. This lock is located 2 blades past the first blade lock.

5. The next blade is blade No 1. Position the leading edge of blade No 1 in line with the leading edge of the stage 4 stator vane.

6. If using a rotation tool, position the pointer on the protractor to the 0 alignment mark.

If turning the core manually through the handcranking pad, position the wrench to the top vertical position.

The N2 rotor is now in the zero reference position.





BORESCOPEINSPECTION

Page 95Sep 03

CTC-229-033-00

e075915





BORESCOPEINSPECTION

Page 96Sep 03


Inspection areas:

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

- The squealer tips.

- The stage 1 blade stiffener near the tip of the blade.

- The blade locks on stages 4 to 9, which maintain the blades in the circumferential slots.





BORESCOPEINSPECTION

Page 97Sep 03

CTC-229-034-00





BORESCOPEINSPECTION

Page 98Sep 03


(ALL) :Rotor blades specific inspection areas.

HPC rotor blade stages are all different.

From stage 1 to stage 9, they become smaller and are under greater load as the air pressure increases.

They are divided into 2 groups:- stages 1 to 4- stages 5 to 9

Critical inspection areas are not dimensionally identical for each stage, and the level of criticality is also different.

Refer to the AMM for the precise dimensions of the following critical areas:

The lower area of the airfoil.This is the airfoil root radius area, plus the area which extends toward the blade tip over approximately 25% of the height of the airfoil, and wraps around the leading and trailing edges.

The top area of the airfoil.- For stages 1 to 4, this is the blade tip.- For stages 5 to 9, this is the blade tip, plus Area A.

Remaining areas.They include:

- For stages 1 to 4, the area which wraps round the leading and trailing edges over the remaining 75% of the airfoil height.

- For stages 5 to 9, the area which wraps round the leading and trailing edges, over a height limited to Area B.





BORESCOPEINSPECTION

Page 99Sep 03

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BORESCOPEINSPECTION

Page 100Sep 03


(ALL) :Possible defects:

When the HPC blades are inspected, the following defects should be evaluated with the AMM serviceability limits :

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





BORESCOPEINSPECTION

Page 101Sep 03

CTC-229-036-00






BORESCOPEINSPECTION

Page 102Sep 03




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 103Sep 03

INSPECTION OF COMBUSTOR SECTION




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 104Sep 03

COMBUSTION SECTION

(ALL) :Single Annular Combustor (SAC).

The combustor is inspected through ports S12, S13, S14, S15 and igniter ports S10 and S11, using probes 1, 2, 3 or 4.

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

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 (black, hi-mag) is recommended for viewing the aft end of the inner and outer liners. It is also used for evaluating defects that were found when using probes 2, 3, or 4.

Note: If any defects are found during this inspection, do a complete inspection of the combustion chamber. Map the defects on the special reporting form.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 105Sep 03

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COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 106Sep 03

COMBUSTION SECTION

(ALL) :Borescope inspection of the combustion section may be required for a visual assessment as part of the on-condition maintenance plan.

It may also result from engine problems, FOD, emission of pollution, trend symptoms such as overtemperature, or troubleshooting / fault isolation.

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

Inspection of SAC outer liner.

The outer liner has a dome band and 5 panels.

Panel 1 features 2 igniter holes (with ferrules), and medium and large dilution holes. Four of the large holes are used as borescope ports.

Panel 3 features medium dilution holes.

Inspection of SAC inner liner.

The inner liner has a dome band and 4 panels.

Panel 1 features medium and large dilution holes.

Panel 3 features medium dilution holes.

There are many film cooling holes under the overhang between each panel of the inner and outer liners.

Both inner and outer liners have a thermal barrier coating (TBC) on their inner surface.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 107Sep 03

CTC-229-039-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 108Sep 03

COMBUSTION SECTION

(ALL) :Possible defects on SAC liners.

Carbon deposits are often misinterpreted as defects (holes, 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 prone to distortion and cracking. The first evidence of this is a discoloration in a round spot approximately the size of a large dilution hole, which is followed by distortion and cracking. This usually occurs uniformly around the liner.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 109Sep 03

CTC-229-040-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 110Sep 03

COMBUSTION SECTION

(ALL) :Inspection of the SAC dome area.

The following areas of the combustion chamber also need to be inspected:

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

components.

A thermal barrier coating is applied to the deflectors and the spectacle plate.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 111Sep 03

CTC-229-041-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 112Sep 03

COMBUSTION SECTION

(ALL) :Possible defects in the SAC dome area.

The following defects should be assessed with the AMM serviceability limits :

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




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 113Sep 03

CTC-229-042-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 114Sep 03

COMBUSTION SECTION

Inspection of SAC chamber after birdstrike/FOD.

Insert a rigid probe into the left igniter position and examine the position of the fuel nozzle tips in relation to the bore of the inner and outer ferrules to make sure they are in the bore of the ferrules.

Inspect the tip of the fuel nozzle that is counterclockwise from the igniter.

Turn the borescope probe until the tips of the second fuel nozzle, clockwise from the igniter are visible.

Inspect the other fuel nozzles visible from the igniter.

Insert the probe in the right igniter and then the other borescope ports and repeat the same steps.All the fuel nozzles must be examined in turn and assessed against the AMM serviceability limits.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 115Sep 03

CTC-229-065-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 116Sep 03

COMBUSTION SECTION

(-5B, -7B) :Double Annular Combustor (DAC).

The combustor is inspected through ports S12, S13, S14, S14.5, S15 and igniter ports S10 and S11.

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

Probe 2 (yellow) is recommended for general viewing of the combustion chamber.

Probe 3 (green) is recommended for viewing circumferentially around the combustion chamber and the inner liner that is adjacent to the borescope port.

Probe 4 (blue) is recommended for viewing the outer liner that is adjacent to the borescope port.

Probe 1 (black) is recommended for viewing the aft ends of the inner and outer liners. It is also used for evaluating defects that were found when using probes 2, 3, or 4.

If any defects are found during this inspection, a complete inspection of the combustion chamber is performed. Map the defects on the special reporting form.

Note: Take care when introducing the probe into the chamber, so as not to damage the thermal barrier coating on the centerbody.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 117Sep 03

CTC-229-043-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 118Sep 03

COMBUSTION SECTION

(-5B, -7B) :Inspection of DAC outer liner.

The outer liner has a dome band and 4 panels.

Panel 1 features 2 igniter holes (with ferrules), and small dilution holes.

Panel 2 features 5 borescope holes and 2 small dilution holes near the igniters.

Inspection of DAC inner liner.

The inner liner has a dome band and 4 panels.

Panel 2 features small dilution holes.

There are many film cooling holes under the overhang between each panel of the inner and outer liners.

Both inner and outer liners have a thermal barrier coating (TBC) on their inner surface.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 119Sep 03

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COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 120Sep 03

COMBUSTION SECTION

(-5B, -7B) :Inspection of DAC dome area.

The following areas of the combustion chamber also need to be inspected:

- Fuel nozzle tips.- Fuel nozzle stems outside the combustor dome.- Spectacle plate and inner and outer deflectors.- Inner and outer liners.- Centerbodies.- Dome area, which includes all of the above

components.

A thermal barrier coating is applied to the deflectors and spectacle plate.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 121Sep 03

CTC-229-045-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 122Sep 03

COMBUSTION SECTION

(-5B, -7B) :Possible defects in the DAC dome area.

Whenever the combustion chamber is inspected, the following defects should be assessed with the AMM serviceability limits :

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

Possible defects on the DAC outer and inner liners.

Carbon deposits are often misinterpreted as defects (holes, 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 a large dilution hole, which is followed by distortion and cracking. This usually occurs uniformly around the liner.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 123Sep 03

CTC-229-046-00




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 124Sep 03

COMBUSTION SECTION

(-5B, -7B) :Inspection of DAC chamber after birdstrike/FOD.

Insert a rigid probe into the left igniter position and examine the position of the fuel nozzle tips in relation to the bore of the inner and outer ferrules to make sure they are in the bore of the ferrules.

Inspect the tip of the fuel nozzle that is counterclockwise from the igniter.

Turn the borescope probe until the tips of the second fuel nozzle, clockwise from the igniter are visible.

Inspect the other fuel nozzles visible from the igniter.

Insert the probe in the right igniter and then the other borescope ports and repeat the same steps.All the fuel nozzles must be examined in turn and assessed against the AMM serviceability limits.




COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 125Sep 03

CTC-229-047-00





COMBUSTIONCHAMBER

BORESCOPEINSPECTION

Page 126Sep 03




HIGH PRESSURETURBINE

BORESCOPEINSPECTION

Page 127Sep 03

INSPECTION OF HIGH PRESSURE TURBINE





BORESCOPEINSPECTION

Page 128Sep 03

HIGH PRESSURE TURBINE (HPT)

(ALL) :Inspection with rigid probe.

Inspect the HPT nozzles through ports S13 and S15.

Use probe No 1 (black, high magnification) to inspect the nozzle segments. The high intensity light source is used to accurately inspect the nozzles.

Insert the probe into the ports and inspect the concave sides and 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.





BORESCOPEINSPECTION

Page 129Sep 03

CTC-229-048-00





BORESCOPEINSPECTION

Page 130Sep 03


(ALL) :Inspection with flexible probe.

Use the flexible probe with a guide tube to inspect the HPT nozzle segments on the convex sides, the trailing edges and the platforms.

CAUTION : DO NOT INSERT THE BORESCOPE BETWEEN BLADES WHILE ROTATING THE ROTOR. THIS WILL BREAK THE PROBE AND MAY REQUIRE ENGINE DISASSEMBLY TO REMOVE THE BROKEN PIECE.

Insert 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.

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.

Remove the flexible probe and guide tube, re-insert them in another borescope port and repeat the previous steps.

It is more convenient to use port S12 to inspect the bottom left hand side of the engine, and port S14, to inspect the right hand side.





BORESCOPEINSPECTION

Page 131Sep 03

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BORESCOPEINSPECTION

Page 132Sep 03


(ALL) :Inspection of the HPT nozzle is usually carried out in conjunction with the combustion chamber inspection.

HPT nozzle inspection areas.

ctc-229 borescope inspection

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