DOC AIRBUS | AMM A320FEngine Borescope Examination Preparation [CFML]
TASK 72-00-00-290-812-A
Engine Borescope Examination Preparation
This task is the preparation for the borescope inspection of the engine.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 72-00-00-941-218-A
Subtask 72-00-00-290-131-A
Subtask 72-00-00-410-254-A
[Rev.10 from 2021]
2026.04.01 02:50:44 UTC
Engine Borescope Examination Preparation
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobThis task is the preparation for the borescope inspection of the engine.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | ACCESS PLATFORM 1M(3 FT) |
| No specific | 1 | THERMOMETER - METAL PROBE TYPE, 0 TO 400 DEG.F |
| No specific | AR | WARNING NOTICE(S) |
| No specific | 1 | WRENCH - STANDARD |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP2101) | graphite grease |
| (Material No.CP2442) | engine oil |
| (Material No.CP2544) | molykote P37 |
| (Material No.CP2619) | nickel never-seez |
| (Material No.CP2691) | aero kroil penetrant |
| (Material No.CP2961) | tiodize T8H-E grease |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 210 | CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD |
| 400 | POWER PLANT, NACELLES AND PYLONS |
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-00-00-700-805-A | Dry-Motoring Check |
| TASK 71-13-00-010-803-A | Opening of the Fan Cowl Doors |
| TASK 72-00-00-290-814-A | Borescope Inspection of the Stage 1 High Pressure Turbine (HPT) Nozzle Guide Vanes |
| TASK 72-00-00-290-815-A | Borescope Inspection of the Stage 2 High Pressure Turbine (HPT) Nozzle Guide Vanes (NGVs) |
| TASK 72-00-00-290-819-A | Borescope Inspection of Stage 2-7 Low Pressure Turbine (LPT) Nozzle Segments |
| TASK 72-00-00-290-820-A | Borescope Inspection of the Stage 1 High Pressure Turbine (HPT) Shrouds |
| TASK 72-00-00-290-821-A | Borescope Inspection of the Stage 2 High Pressure Turbine (HPT) Shrouds |
| TASK 72-00-00-290-822-A | Borescope Inspection of the Low Pressure Turbine (LPT) Blades |
| TASK 72-00-00-290-823-A | Borescope Inspection of the Low Pressure Turbine (LPT) Shroud Segments |
| TASK 72-21-00-290-802-A | Borescope Inspection of the Booster Blades and Vanes (PRE SB 72-00-0080) |
| TASK 72-21-00-290-802-A-01 | Borescope Inspection of the Booster Blades and Vanes (POST SB 72-00-0080) |
| TASK 72-30-00-290-801-A | Borescope Inspection of the High Pressure Compressor Section |
| TASK 72-52-00-290-803-A | Borescope Inspection of High Pressure Turbine |
| TASK 78-30-00-040-809-A | Deactivation of the Thrust Reverser System for Ground Maintenance |
| TASK 78-36-00-010-806-A | Opening of the Thrust Reverser Cowl Doors |
Identification of Engine Borescope PlugsSubtask 72-00-00-941-218-A
A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
Subtask 72-00-00-010-298-A (1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:
- The ENG/MODE selector switch, and
- The ENG/MASTER 1(2) control switch.
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).
B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
Subtask 72-00-00-040-147-A (1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.
C. Deactivation of the Thrust Reverser System for Maintenance
Subtask 72-00-00-010-299-A WARNING:
YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.
(1) Do the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-809). D. Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
4. Procedure(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
Subtask 72-00-00-290-131-A
A. Engine Borescope Examination Preparation
(c) If the engine has been recently run, measure the temperature of the engine with a THERMOMETER - METAL PROBE TYPE, 0 TO 400 DEG.F.
(a) Cut and discard the secondary retention.
(b) Remove the borescope plug.
(4) All double-wall borescope plugs I, J, L and M must be removed as follows:
(a) Apply a spray of aero kroil penetrant (Material No.CP2691) on the outer thread.
(b) Let it soak.
(c) Loosen the borescope cap and pull the cap straight out to engage the splines.
(d) Apply a spray of aero kroil penetrant (Material No.CP2691) to the inner thread.
(e) Let it soak.
(f) Loosen the borescope plug.
(g) Remove the borescope plug assembly.
(5) All borescope plugs with ratcheting mechanism N, Q, R, S, T, U, V, W, X, Y, Z must be removed as follows:
(a) Apply a spray of aero kroil penetrant (Material No.CP2691) to the ratcheting mechanism.
(b) Let it soak.
(c) Apply break torque with WRENCH - STANDARD to remove the plug from the case.
(d) Apply a spray of penetrating oil again to lubricate the plug thread if necessary.
(e) Continue to remove the plug.
(6) When the borescope plugs are removed, do an inspection of the borescope plugs and the borescope ports: refer to Table 1.
5. Close-upCAUTION:
MAKE SURE THE TEMPERATURE OF THE ENGINE AND OF THE AREAS ADJACENT TO THE BORESCOPE INSPECTION PORTS IS LESS THAN 150 °F (65.6 °C). DO NOT DO A BORESCOPE INSPECTION IF THE ADJACENT AREAS ARE TOO HOT TO TOUCH. DO THE BORESCOPE INSPECTION WHEN THE ENGINE TEMPERATURE IS LESS THAN 150 F(65.6 C). THIS WILL PREVENT DAMAGE TO THE BORESCOPE EQUIPMENT.
(1) Assemble the borescope plugs. NOTE: Use the assembly instructions given by the borescope tool manufacturer.
NOTE: It is permitted to substitute for the tools specified in the borescope inspection tasks, provided the tools that you use meet the specifications shown in the General Electric Standard Practices Manual SP-2.
NOTE: The specific configuration of the borescope tool that is necessary to do each inspection is found in the tables in this task.
(a) Lubricate the borescope plugs as follows: - Use engine oil (Material No.CP2442) for the plug threads C and D.
- Use nickel never-seez (Material No.CP2619) or tiodize T8H-E grease (Material No.CP2961) for the plugs E, F, G, H, I, J, K, L and M.
- Use nickel never-seez (Material No.CP2619) for the plugs N, Q, R, S, T, U, V, W, X, Y and Z on the threads and the ratcheting mechanism.
- Use graphite grease (Material No.CP2101) for the plug threads T and Z.
- Use molykote P37 (Material No.CP2544) for the plug threads U, V, W, X and Y.
- Use graphite grease (Material No.CP2101) or nickel never-seez (Material No.CP2619) to coat the rest.
(c) If the engine has been recently run, measure the temperature of the engine with a THERMOMETER - METAL PROBE TYPE, 0 TO 400 DEG.F.
NOTE: It is recommended to wait three to five hours after the engine shutdown to do the borescope inspection. This will permit the engine to become sufficiently cool.
NOTE: You can dry-motor the engine to decrease the engine core temperature (Ref. AMM TASK 71-00-00-700-805).
(2) (3) Borescope plug H must be removed as follows:(a) Cut and discard the secondary retention.
(b) Remove the borescope plug.
(4) All double-wall borescope plugs I, J, L and M must be removed as follows:
(a) Apply a spray of aero kroil penetrant (Material No.CP2691) on the outer thread.
(b) Let it soak.
(c) Loosen the borescope cap and pull the cap straight out to engage the splines.
(d) Apply a spray of aero kroil penetrant (Material No.CP2691) to the inner thread.
(e) Let it soak.
(f) Loosen the borescope plug.
(g) Remove the borescope plug assembly.
(5) All borescope plugs with ratcheting mechanism N, Q, R, S, T, U, V, W, X, Y, Z must be removed as follows:
(a) Apply a spray of aero kroil penetrant (Material No.CP2691) to the ratcheting mechanism.
(b) Let it soak.
(c) Apply break torque with WRENCH - STANDARD to remove the plug from the case.
(d) Apply a spray of penetrating oil again to lubricate the plug thread if necessary.
(e) Continue to remove the plug.
(6) When the borescope plugs are removed, do an inspection of the borescope plugs and the borescope ports: refer to Table 1.
| INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Borescope port for: | | |
| Minor damage permitted if repaired | Minor damage to the threads, including burrs or galling can be repaired. For thread information, refer to: If you repair the threads, make sure that you do not permit any debris to enter the engine. |
| 2.Borescope plugs for: | | |
| Not permitted | Replace the borescope plug. |
| Not permitted | Replace the borescope plug. |
| Not permitted | Replace the borescope plug. |
| No limit to the number permitted if the wear is not more than 0.004 in. (0.10 mm) in depth | |
| Not permitted | Replace the borescope plug. |
| Lead-in thread permitted to be incomplete | |
| | Other thread damage not permitted | Replace the borescope plug. |
| Any number less than 50 percent of the thread height in depth and less than one full thread | |
| A locking ring that can rotate in both directions with resistance is serviceable. | Prevent movement of the locking ring in one hand. Use a WRENCH - STANDARD or your other hand to rotate the plug. NOTE: It is permitted to use penetrating oil sprayed into the ratcheting mechanism to free the locking mechanism. This must be done before you replace the plug and before you repeat the rotation test. |
| | A locking ring that cannot rotate in both directions or rotate freely is not serviceable. | Replace the borescope plug. |
| Any amount up to 0.05 in. (1.27 mm) in depth | Replace the borescope plug. |
| - Defects are permitted provided that self-locking quality is serviceable. To verify self-locking capability make sure that run-on torque is not less than 12 lbf.in (0.14 m.daN) minimum. Run-on torque must be measured when vespel ring engages threads. - Missing or damaged vespel ring is not serviceable. | Replace the borescope plug. |
Table - Visual Inspection of the Borescope Ports and Plugs
Subtask 72-00-00-410-254-A
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Perform one or several borescope inspection task(s) below:
(a) Booster blades and vanes borescope inspection (Ref. AMM TASK 72-21-00-290-802).
(b) HPC section borescope inspection (Ref. AMM TASK 72-30-00-290-801).
(c) High Pressure Turbine (HPT) rotor borescope inspection (Ref. AMM TASK 72-52-00-290-803).
(d) HPT stage 1 nozzles guide vane borescope inspection (Ref. AMM TASK 72-00-00-290-814) and shrouds borescope inspection (Ref. AMM TASK 72-00-00-290-820).
(e) HPT stage 2 nozzles guide vane borescope inspection (Ref. AMM TASK 72-00-00-290-815) and shrouds borescope inspection (Ref. AMM TASK 72-00-00-290-821).
(f) Low Pressure Turbine (LPT) stages 2 to 7 nozzles segments borescope inspection (Ref. AMM TASK 72-00-00-290-819), LPT blades borescope inspection (Ref. AMM TASK 72-00-00-290-822) and LPT shrouds segments borescope inspection (Ref. AMM TASK 72-00-00-290-823).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Perform one or several borescope inspection task(s) below:
(a) Booster blades and vanes borescope inspection (Ref. AMM TASK 72-21-00-290-802).
(b) HPC section borescope inspection (Ref. AMM TASK 72-30-00-290-801).
(c) High Pressure Turbine (HPT) rotor borescope inspection (Ref. AMM TASK 72-52-00-290-803).
(d) HPT stage 1 nozzles guide vane borescope inspection (Ref. AMM TASK 72-00-00-290-814) and shrouds borescope inspection (Ref. AMM TASK 72-00-00-290-820).
(e) HPT stage 2 nozzles guide vane borescope inspection (Ref. AMM TASK 72-00-00-290-815) and shrouds borescope inspection (Ref. AMM TASK 72-00-00-290-821).
(f) Low Pressure Turbine (LPT) stages 2 to 7 nozzles segments borescope inspection (Ref. AMM TASK 72-00-00-290-819), LPT blades borescope inspection (Ref. AMM TASK 72-00-00-290-822) and LPT shrouds segments borescope inspection (Ref. AMM TASK 72-00-00-290-823).