DOC AIRBUS | AMM A320FBorescope Inspection of the Stage 1 Low-Pressure Turbine Nozzle Assembly [CFMB]
TASK 72-53-00-290-003-A
Borescope Inspection of the Stage 1 Low-Pressure Turbine Nozzle Assembly
1. Reason for the Job
Inspection of the Low Pressure Turbine (LPT) nozzle is limited to the areas that can be seen with a rigid borescope. Insert the borescope through the borescope ports located on stage 1 LPT nozzle support. If no defects are found then the borescope inspection is complete. If defects are found then look at the High-Pressure Turbine (HPT) shrouds.
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 72-53-00-941-052-A ** ON A/C NOT FOR ALL
Subtask 72-53-00-020-051-A ** ON A/C NOT FOR ALL
Subtask 72-53-00-410-055-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:43:01 UTC
Borescope Inspection of the Stage 1 Low-Pressure Turbine Nozzle Assembly
1. Reason for the Job
Inspection of the Low Pressure Turbine (LPT) nozzle is limited to the areas that can be seen with a rigid borescope. Insert the borescope through the borescope ports located on stage 1 LPT nozzle support. If no defects are found then the borescope inspection is complete. If defects are found then look at the High-Pressure Turbine (HPT) shrouds.
2. Job Set-up Information
A. 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 65 and 59 lbf.in (0.73 and 0.67 m.daN )  | |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1321 | 1 | FIBERSCOPE SET |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 856A1323 | 1 | MONITOR, RESOLUTION BORESCOPE |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP2101) | graphite grease |
| (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 72-53-00-290-004-A | Borescope/Inspection of the High-Pressure Turbine Shroud |
| 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 |
Stage 1 LPT Nozzle and HPT Shroud InspectionSubtask 72-53-00-941-052-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 72-53-00-010-055-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 cowl 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 72-53-00-040-052-A ** ON A/C NOT FOR ALL Subtask 72-53-00-010-058-A ** ON A/C NOT FOR ALL (1) Open the fan cowl 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 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 72-53-00-020-051-A ** ON A/C NOT FOR ALL
A. Remove the borescope plugs found immediately in front of the aft flange of the combustion case.
Subtask 72-53-00-290-052-A ** ON A/C NOT FOR ALL B. Do a borescope inspection.
(1) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320P04/P05) and to the port on the 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08).
Subtask 72-53-00-080-052-A ** ON A/C NOT FOR ALL (1) Connect the fiber light cable to the 856A1320 BORESCOPE-KIT (856A1320P04/P05) and to the port on the 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08).
NOTE: Use the 856A1323 MONITOR, RESOLUTION BORESCOPE (856A1323G01) to make sure the borescope 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 (856A1320P04/P05) or 856A1321 FIBERSCOPE SET (856A1321P03/05/06), and to the port and turn on the light source of 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08). CAUTION:
DO A COMPLETE SET INSPECTION WITH FLEXIBLE BORESCOPE IF YOU FIND IMPORTANT CRACKS OR MISSING MATERIAL.
(3) Inspect the stage 1 LPT nozzle and use the limits that follow: NOTE: If you use rigid borescope, this inspection is limited to what you can see on two airfoils of the two nozzle segments.
| INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Stage 1 LPT nozzle for NON /P engines: | | |
| A.Cracks in leading edge. | Any number, that are not more than 0.6 in. (15.24 mm) long. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| B.Cracks in trailing edge. | Any number, that are not more than 0.8 in. (20.32 mm) long. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Cracks on concave/convex side of airfoil between inner and outer platforms. | Any number, that are not more than 1 in. (25.4 mm) long. If there is a separation of 0.25 in. (6.35 mm) between adjacent crack. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| D.Crack in radius in between airfoil L.E./T.E. and outer platforms. | One on each airfoil, not more than 1.2 in. (30 mm) long with a minimum of 0.4 in. (10 mm) from any adjacent crack. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| E.Burns, erosion and corrosion. | Any amount, if there is no missing material (no perforation of the airfoil cavity). | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| F.Nicks, scores, scratches, dents or deposits on concave/convex surface or trailing edge. | Any amount, not through, provided there are no cracks out of distressed area. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| G.Nicks, dents, tears in leading edge. | Any amount, if cracks criteria are in the limits. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| H.Cracks in outer platform forward lip. | Two on each nozzle segment, 0.59 in. (15 mm) apart minimum, if they run axially and do not grow longer circumferentially. | |
| J.Cracks in inner or outer platform. | Any number, no longer than 0.59 in. (15 mm). | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| K.Craze cracking | Any amount | |
| 2.Stage 1 LPT nozzle for /P, /3 and /3 PIP engines: | | |
| A.Alternative procedure available. Axial cracks in leading edge and trailing edge using a rigid borescope. | Any number on the two airfoils permitted, if crack length is less than 1/3 of the chord width 0.6 in. (15.24 mm). One crack on each airfoil permitted, if crack length is between 1/3 of the chord width 0.6 in. (15.24 mm) and 1/2 of the chord width 1.0 in. (25.40 mm). | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| B.Alternative procedure. Axial cracks in leading edge and trailing edge using a flexible borescope. | Any number permitted, if crack length is less than 1/3 of the chord width 0.6 in. (15.24 mm). Eight cracks per set of nozzles permitted, if crack length is between 1/3 of the chord width 0.6 in. (15.24 mm) and 3/4 of the chord width 1.35 in. (34.3 mm), provided there are no missing material, not more than two cracks per segment and one crack per airfoil. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| C.Radial cracks in the leading edge. | See limits extensions | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| D.Cracks on concave/convex side of airfoil between inner and outer platforms. | Any number, that are not more than 1 in. (25.4 mm) long. If there is a separation of 0.25 in. between adjacent crack. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| E.Crack in radius in between airfoil L.E./T.E. and outer platforms. | Any number, if crack length is less than 0.6 in. (15.24 mm) on all four airfoils of the nozzle segment. Do not agree more than one crack for each airfoil, for a maximum of two airfoils on the same nozzle segment, if crack length is between 0.6 in. (15.24 mm) (1/3 of the chord width) and 1.0 in. (25.4 mm) (1/2 of the chord width). Do a borescope inspection of the complete set of nozzle with a flexible borescope, if one airfoil has a full axial crack from leading edge to trailing edge or missing material more than 0.023 sq in. (15 sq mm). | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| F.Burns, erosion and corrosion. | Any amount, if there is no missing material (no perforation of the airfoil cavity) and no limit with discoloration. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| G.Nicks, scores, scratches, dents or deposits on concave/convex surface or trailing edge. | Any amount, not through, provided there are no cracks out of distressed area. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| H.Nicks, dents, tears in leading edge | Any amount, if cracks criteria are in the limits. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| J.Cracks in outer platform forward lip | Two on each nozzle segment 0.59 in. (15 mm) apart minimum, if they run axially and do not grow longer circumferentially. | |
| K.Cracks in inner or outer platform | Three cracks per segment not more than 0.59 in. (15mm) in length and Metal does not go into the gaspath. | See limit extensions (Ref. AMM TASK 72-00-00-200-025). |
| L.Craze cracking | Any amount | |
NOTE: Craze cracking is defined as numerous superficial surface cracks which have no visual width or depth.
(4) If defects are found, look at the HPT shrouds (Ref. AMM TASK 72-53-00-290-004). C. When the inspection is complete, turn off the light source 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/ P03/P04/P07/P08), and remove the rigid borescope, 856A1320 BORESCOPE-KIT (856A1320P04/P05).
Subtask 72-53-00-420-051-A ** ON A/C NOT FOR ALL D. Install parts removed for borescope inspection.
(1) Apply a small amount of graphite grease (Material No.CP2101) to the borescope plug threads and pressure faces.
(2) Install the borescope plugs and TORQUE to between 65 and 59 lbf.in (0.73 and 0.67 m.daN ).
(3) Wirelock the plugs withCP8001 lockwire 0.032 in. (0.8 mm) dia. CP8002 lockwire 0.032 in. (0.8 mm) dia
5. Close-up(1) Apply a small amount of graphite grease (Material No.CP2101) to the borescope plug threads and pressure faces.
(2) Install the borescope plugs and TORQUE to between 65 and 59 lbf.in (0.73 and 0.67 m.daN )
. (3) Wirelock the plugs with
Subtask 72-53-00-410-055-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
Subtask 72-53-00-440-052-A ** ON A/C NOT FOR ALL Subtask 72-53-00-410-058-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