DOC AIRBUS | AMM A320FBorescope Inspection of High-Pressure Turbine Nozzle Assembly [CFMB]
TASK 72-51-00-290-004-A
Borescope Inspection of High-Pressure Turbine Nozzle Assembly
1. Reason for the Job
This TASK is applicable for NON/P, NON/3, and NON /3PIP engines.
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 72-51-00-941-051-A ** ON A/C NOT FOR ALL
Subtask 72-51-00-010-056-A ** ON A/C NOT FOR ALL
Subtask 72-51-00-410-052-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:42:50 UTC
Borescope Inspection of High-Pressure Turbine Nozzle Assembly
1. Reason for the Job
This TASK is applicable for NON/P, NON/3, and NON /3PIP engines.
NOTE: Inspection of the high pressure turbine (HPT) nozzle assembly is limited to the areas that can be seen with a rigid borescope at the 1, 3, 6, and 10 o'clock borescope ports, and at the 2 spark igniter ports. The borescope ports at the 1, 3, 6, and 10 o'clock position are located immediately in front of the fuel manifold. Special inspection of the HPT nozzle convex side can be accomplished, if required using with a flexible borescope.
2. Job Set-up InformationA. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 1M(3 FT) |
| No specific | AR | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )  | |
| No specific | Torque wrench: range to between 135 and 120 lbf.in (1.53 and 1.36 m.daN ) | |
| 856A1310 | 1 | KIT, BORESCOPE GUIDE - HP TURBINE |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1321 | 1 | FIBERSCOPE SET |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 856A1323 | 1 | MONITOR, RESOLUTION BORESCOPE |
| 856A1351 | 1 | GUIDE TUBE,BORESCOPE-HPT SHROUD |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1064) | milk of magnesia |
| (Material No.CP2101) | graphite grease |
| (Material No.CP2619) | Never Seez-Pure Nickel, Special |
| (Material No.CP8001) | lockwire 0.032 in. (0.8 mm) dia. |
| (Material No.CP8002) | lockwire 0.032 in. (0.8 mm) dia |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR, 451AL, 452AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR, 461AL, 462AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-040-B | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-040-B | Closing of the Fan Cowl Doors |
| TASK 72-00-00-200-025-A | Over-Serviceable-Limit Extensions |
| TASK 72-00-00-200-025-A-01 | Over-Serviceable-Limit Extensions |
| TASK 73-11-40-790-002-A | Leak Check of the Fuel Nozzles for SAC Engines |
| TASK 73-11-40-790-002-A-01 | Leak Check of the Fuel Nozzles for DAC Engines |
| TASK 74-21-30-000-002-A | Removal of the Spark Igniter |
| TASK 74-21-30-400-002-A | Installation of the Spark Igniter |
| TASK 78-30-00-081-041-B | Make the Thrust Reverser Serviceable after Maintenance |
| TASK 78-30-00-481-041-B | Make the Thrust Reverser Unserviceable for Maintenance |
| TASK 78-36-00-010-040-B | Opening of the Thrust Reverser Doors |
| TASK 78-36-00-410-040-B | Closing of the Thrust Reverser Doors |
Inspection of the High-Pressure Turbine-Nozzle AssemblySubtask 72-51-00-941-051-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
Subtask 72-51-00-010-053-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).
B. Get Access
(1) Open the fan cowls doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.
Subtask 72-51-00-040-051-A ** ON A/C NOT FOR ALL Subtask 72-51-00-010-054-A ** ON A/C NOT FOR ALL (1) Open the fan cowls doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(2) Put the ACCESS PLATFORM 1M(3 FT) in position.
D. Open the thrust reverser cowl doors (Ref. AMM TASK 78-36-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR.
4. Procedure(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR.
Subtask 72-51-00-010-056-A ** ON A/C NOT FOR ALL
A. Remove parts before borescope inspection.
(1) Remove the borescope plugs from the approximate 3 and 10 o'clock positions on the combustion case.
Subtask 72-51-00-290-052-A ** ON A/C NOT FOR ALL (1) Remove the borescope plugs from the approximate 3 and 10 o'clock positions on the combustion case.
B. Do a Borescope Inspection
(1) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320 P04 or P05), and to the porton 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322 P02 or P03 or P04 or P07 or P08).
(3) Rotate and adjust the borescope to view the HPT nozzle area.
(4) If inspection of the nozzle convex side is necessary, use a 856A1321 FIBERSCOPE SET (856A1321 P01 or P03) and 856A1310 KIT, BORESCOPE GUIDE - HP TURBINE (856A1310G01), or 856A1351 GUIDE TUBE,BORESCOPE-HPT SHROUD (856A1351P01).
(6) When the inspection is complete, turn off the light source and remove the borescope and the guide tube.
(7) If any defects are found then remove additional borescope plugs and the spark igniters to inspect all of the HPT nozzle assembly.
Subtask 72-51-00-010-055-A ** ON A/C NOT FOR ALL (1) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320 P04 or P05), and to the porton 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322 P02 or P03 or P04 or P07 or P08).
NOTE: Use the 856A1323 MONITOR, RESOLUTION BORESCOPE (856A1323G01) to make sure the borescope or the fiberscope and the light source are serviceable. See the Non-Destructive Test Manual for this procedure (Ref. NDTM 720000).
(2) Put the rigid borescope, of the 856A1320 BORESCOPE-KIT (856A1320/P04 or P05), into the ports and turn on the light source 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322/PO3 or PO4). (3) Rotate and adjust the borescope to view the HPT nozzle area.
(4) If inspection of the nozzle convex side is necessary, use a 856A1321 FIBERSCOPE SET (856A1321 P01 or P03) and 856A1310 KIT, BORESCOPE GUIDE - HP TURBINE (856A1310G01), or 856A1351 GUIDE TUBE,BORESCOPE-HPT SHROUD (856A1351P01).
NOTE: If 856A1310 KIT, BORESCOPE GUIDE - HP TURBINE (856A1310G01) is used to view the convex side, an 8 ft. (2.43 m) fiberscope must be used.
(5) Inspect the following: | INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Leading edge of vane airfoil for: | | |
| A.Cracks that interconnect nose holes. | Any number, 0.3 in. (7.62 mm) long; no missing material. | If crack is not more than 1 inch (25.4 mm), then do an inspection again in 400 cycles. See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| B.Burns or spalling. | Any amount, burns through airfoil limited to 0.3 in. (7.62 mm) X 0.5 in. (12.7 mm) per vane, maximum of 4 vanes per 90-degree arc. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Baffle. NOTE: The airfoil's baffle is visible inside the airfoil when missing material occurs. It is sheet metal with cooling holes. | | |
| (1)Cracks. | Any number. | |
| (2)Missing material. | Any area equivalent to a rectangle defined by 4 adjacent holes. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| 2.Concave surface of vane airfoil for: | | |
| A.Radial cracks extending out of gill holes. | Any number; no missing material. | If missing material caused by cracks is not more than 0.04 square in. (25.81 square mm), and no more than 4 airfoils for each engine have missing material caused by cracks, do the inspection again in 400 cycles. See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| B.Other cracks (not in gill hole rows). | Any number; no missing material. | If missing material caused by cracks is not more than 0.04 square in. (25.81 square mm), and no more than 4 airfoils for each engine have missing material caused by cracks, do the inspection again in 400 cycles. See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| C.Burns. | Any number; no missing material or burn through. | If missing material caused by burns is not more than 0.04 square in. (25.81 square mm), and no more than 4 airfoils for each engine have missing material caused by burns, do the inspection again in 400 cycles. See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| 3.Convex surface of vane airfoil for: | | |
| A.Radial cracks. | Any number. | |
| B.Axial cracks. | Any number. | |
| C.Burns and bulges. | Any number. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| D.Missing panel | Not serviceable. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| E.Missing Thermal Barrier Coating (TBC) | Any amount. | |
| 4.Trailing edge of vane airfoil for: | | |
| A.Axial cracks starting from slots adjacent to trailing edge | Any number. | |
| B.Burns and cracks. | Any number. | |
| C.Buckling or bowing | Any amount. | |
| D.Missing material (loss of metal). | Total area removed from trailing edge not to be more than 0.5 in. (12.7 mm) in axial direction. | See limit extension (Ref. AMM TASK 72-00-00-200-025). |
| 5.All areas of airfoil for: | | |
| A.Craze cracking. | Any amount. NOTE: Craze cracking looks like many surface cracks that have no visual width or depth. | |
| B.Nicks, scores, scratches and dents. | Any number. | |
| C.Metal splatter. | Any amount. | |
| D.Missing codep coating. | Any amount. | |
| 6.Inner and outer platform for: | | |
| A.Cracks in parent metal. | Any number. | |
| B.Missing metal or burning of parent metal. | No through holes, but any amount of missing material from cracking or burning is permitted. | If through hole is in or less than 1 in. (25.4 mm) of the leading edge of inner or outer platform, the through hole is not more than 0.06 square in. (38.71 square mm), and no more than 4 segments for each engine have through holes on the inner or outer platform, do the inspection again in 400 cycles. See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Nicks, scores, scratches and dents or platform surface. | Any amount. | |
| D.Bulging and bowing. | Any amount. | |
| E.Cracks in platform braze joint. | Any amount, no separation of braze joint allowed unless caused by burning. | |
(7) If any defects are found then remove additional borescope plugs and the spark igniters to inspect all of the HPT nozzle assembly.
C. Remove parts before borescope inspection.
(1) Remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug.
(3) Remove both spark igniters (Ref. AMM TASK 74-21-30-000-002)
Subtask 72-51-00-290-053-A ** ON A/C NOT FOR ALL (1) Remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug.
NOTE: If you remove the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, you will be required to perform a leak check after this inspection. Use the 6 o'clock borescope port only if necessary.
(2) Remove the borescope plugs from the approximate 1 and 6 o'clock positions. (3) Remove both spark igniters (Ref. AMM TASK 74-21-30-000-002)
D. Do a borescope inspection.
(1) Repeat paragraph 4.B.(1) thru (6) for each borescope and spark igniter location.
Subtask 72-51-00-410-054-A ** ON A/C NOT FOR ALL (1) Repeat paragraph 4.B.(1) thru (6) for each borescope and spark igniter location.
E. Install parts removed for borescope inspection.
CP2619 Never Seez-Pure Nickel, Special
(2) Install the borescope plugs and TORQUE to between 63 and 57 lbf.in (0.71 and 0.64 m.daN ).
(3) Wirelock the plugs withCP8001 lockwire 0.032 in. (0.8 mm) dia. CP8002 lockwire 0.032 in. (0.8 mm) dia
(4) If necessary, install the fuel drain tube to the fuel nozzle adjacent to the 6 o'clock borescope plug. TORQUE the coupling nuts on the fuel drain tube to between 135 and 120 lbf.in (1.53 and 1.36 m.daN ) and safety with CP8001 lockwire 0.032 in. (0.8 mm) dia. CP8002 lockwire 0.032 in. (0.8 mm) dia
(5) Install the spark igniters (Ref. AMM TASK 74-21-30-400-002).
Subtask 72-51-00-790-050-A ** ON A/C NOT FOR ALL CAUTION:
BE SURE TO INSTALL THE CORRECT BORESCOPE PLUGS. THE COMBUSTOR BORESCOPE PLUGS DO NOT HAVE A STEM FEATURE. INADVERTENT INSTALLATION OF BORESCOPE PLUGS WITH STEMS FROM OTHER LOCATIONS WILL RESULT IN THE STEM FEATURE BEING BURNED AWAY BY COMBUSTION GASES.
(1) Apply a small amount of graphite grease (Material No.CP2101) , (2) Install the borescope plugs and TORQUE to between 63 and 57 lbf.in (0.71 and 0.64 m.daN )
. (3) Wirelock the plugs with
(4) If necessary, install the fuel drain tube to the fuel nozzle adjacent to the 6 o'clock borescope plug. TORQUE the coupling nuts on the fuel drain tube to between 135 and 120 lbf.in (1.53 and 1.36 m.daN )
and safety with (5) Install the spark igniters (Ref. AMM TASK 74-21-30-400-002).
F. Do a fuel nozzle leak check.
(1) If you removed the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, do a fuel nozzle leak check (Ref. AMM TASK 73-11-40-790-002)
5. Close-up(1) If you removed the drain tube from the fuel nozzle adjacent to the 6 o'clock borescope plug, do a fuel nozzle leak check (Ref. AMM TASK 73-11-40-790-002)
Subtask 72-51-00-410-052-A ** ON A/C NOT FOR ALL
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors: (Ref. AMM TASK 78-36-00-410-040).
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
(3) Remove the access platform(s).
Subtask 72-51-00-440-051-A ** ON A/C NOT FOR ALL Subtask 72-51-00-410-053-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors: (Ref. AMM TASK 78-36-00-410-040).
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
(3) Remove the access platform(s).