DOC AIRBUS | AMM A320FInspection of the Stage 4 Blades [CFMI]
TASK 72-54-00-290-002-A
Inspection of the Stage 4 Blades
1. Reason for the Job
Self explanatory
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 72-54-00-941-051-A ** ON A/C NOT FOR ALL
Subtask 72-54-00-010-056-A ** ON A/C NOT FOR ALL
Subtask 72-54-00-410-053-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.02 07:32:25 UTC
Inspection of the Stage 4 Blades
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )  | |
| No specific | Torque wrench: range to between 110 and 95 lbf.in (1.24 and 1.07 m.daN ) | |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| REFERENCE | DESIGNATION |
|---|---|
| (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-A | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-040-A | Closing of the Fan Cowl Doors |
| TASK 72-00-00-200-005-A | Over-Serviceable-Limit Extensions |
| TASK 72-54-00-210-001-A | Optional Visual Inspection of the Stage 4 Blades from the Rear of the Engine |
| TASK 78-30-00-081-041-A | Make the Thrust Reverser Serviceable after Maintenance |
| TASK 78-30-00-481-041-A | Make the Thrust Reverser Unserviceable for Maintenance |
| TASK 78-36-00-010-040-A | Opening of the Thrust Reverser Doors |
| TASK 78-36-00-410-040-A | Closing of the Thrust Reverser Doors |
Location of the Borescope Ports and Possible Borescope Access Via One Instrumentation BossSubtask 72-54-00-941-051-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 72-54-00-010-051-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. Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR
Subtask 72-54-00-040-051-A ** ON A/C NOT FOR ALL Subtask 72-54-00-010-061-A ** ON A/C NOT FOR ALL (1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR
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 72-54-00-010-056-A ** ON A/C NOT FOR ALL
A. Remove the plugs which follow:
(1) Let the temperature of parts decrease to ambient temperature.
(2) Cut and remove the lockwire from the borescope plug S22. Remove the plug.
(a) Remove the 2 bolts and nuts which attach a blanking plug to this turbine frame boss.
(b) Remove the blanking plug and its gasket.
Subtask 72-54-00-480-051-A ** ON A/C NOT FOR ALL (1) Let the temperature of parts decrease to ambient temperature.
(2) Cut and remove the lockwire from the borescope plug S22. Remove the plug.
NOTE: The plug S22 is the aft-most borescope plug located at 5:00 o'clock on the LPT case (ALF).
(3) Locate the instrumentation boss located at the 8:30 o'clock position (ALF) on the turbine frame. (a) Remove the 2 bolts and nuts which attach a blanking plug to this turbine frame boss.
(b) Remove the blanking plug and its gasket.
NOTE: This gives you a borescope access to look at the trailing edge and tip shroud of the stage 4 LPT blades.
B. Install the 856A1320 BORESCOPE-KIT (856A1320 P04/P05) as follows:
(1) Connect the power supply.
(2) Connect light source cable to rigid borescope and to port on 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08).
(3) Turn light source on; insert borescope and position it as necessary for inspection.
Subtask 72-54-00-290-051-A ** ON A/C NOT FOR ALL (1) Connect the power supply.
CAUTION:
BEFORE YOU CONNECT THE POWER SUPPLY TO THE POWER SOURCE BE SURE THE ON-OFF SWITCH IS IN THE OFF POSITION AND LIGHT INTENSITY CONTROL IS SET TO MINIMUM. MAKE SURE THAT PROJECTOR AND POWER SUPPLY ARE CORRECTLY GROUNDED.
(a) Connect the power supply to a grounded 110 VAC 60 Hz power source. (2) Connect light source cable to rigid borescope and to port on 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08).
(3) Turn light source on; insert borescope and position it as necessary for inspection.
C. The stage 4 LPT rotor blades are long span blades. To fully examine their airfoil surface, it is recommended to do these steps.
(1) Turn the fan rotor slowly and smoothly to examine the blades.
(2) Change the probe engagement depth to see the airfoils as the blades move in front of the probe.
(3) While you change the probe engagement depth, turn the probe (azimuth). This will let you have a maximum view for given turn speed of the rotor.
(5) When you look at the trailing edges turn the rotor in the opposite direction so that the convex side (suction face) comes toward the borescope.
(6) Do the inspection of the stage 4 blades for damage as follows:
Subtask 72-54-00-080-051-A ** ON A/C NOT FOR ALL (1) Turn the fan rotor slowly and smoothly to examine the blades.
(2) Change the probe engagement depth to see the airfoils as the blades move in front of the probe.
(3) While you change the probe engagement depth, turn the probe (azimuth). This will let you have a maximum view for given turn speed of the rotor.
NOTE: The stage 4 blades have the longest span of the blade stage. So, as the full engagement of the probe is necessary, you may have to make 2, 3 or more turns of the LPT rotor to see all the blade areas.
(4) When you look at the leading edges of the blades, turn the rotor so that the concave side (or pressure face) of the blades comes toward the borescope. (5) When you look at the trailing edges turn the rotor in the opposite direction so that the convex side (suction face) comes toward the borescope.
(6) Do the inspection of the stage 4 blades for damage as follows:
| INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Cracks | Not serviceable | See limit extensions (Ref. AMM TASK 72-00-00-200-005) |
| 2.Nicks on concave or convex sides. Does not include area E. | Not more than 0.02 in. (0.5 mm) deep | See limit extensions (Ref. AMM TASK 72-00-00-200-005) |
| 3.Dents on concave or convex sides. Does not include area E. | Not more than 0.01 in. (0.25 mm) deep | See limit extensions (Ref. AMM TASK 72-00-00-200-005) |
| 4.Nicks and/or dents on leading or trailing edges. Does not include area E. | Not more than 0.02 in. (0.5 mm) deep | See limit extensions (Ref. AMM TASK 72-00-00-200-005) |
| 5.Nicks and/or dents in area E. | Not more than 0.01 in. (0.25 mm) deep | See limit extensions (Ref. AMM TASK 72-00-00-200-005) |
| 6.Bending or bowing of airfoil. | Tip shroud out of flush not to exceed 0.015 in. (0.38 mm) | See limit extensions (Ref. AMM TASK 72-00-00-200-005). |
| 7.Shingled or unlatched tip shrouds. | Not serviceable | If you find the blade tip shrouds shingled or unlatched on different borescope inspections, it may be the sign of a wear of the hard-facing on the blade tip interlock surfaces. See limit extension (Ref. AMM TASK 72-00-00-200-005). See NOTE below. |
| 8.Hard-facing wear. | Any quantity that does not cause a mismatch of the blade tip shroud aft face of more than 0.12 in. (3.05 mm). | See limit extensions (Ref. AMM TASK 72-00-00-200-005). See NOTE below. |
| 9.Blade airfoil pretwist that causes gaps such as interlocks do not touch each other. | Not serviceable | See limit extensions (Ref. AMM TASK 72-00-00-200-005) See NOTE below. NOTE: If the aircraft maintenance schedule permits, it is recommended to do a visual inspection when you find these defects (Ref. AMM TASK 72-54-00-210-001) |
| 10.Distortion of leading edge caused by overtemperature. | Not serviceable | |
| 11.Deposit material peeling off airfoil. | Any amount, provided there is no evidence of bowing and/or melting | |
| 12.Rubbing on leading edge platform, leading edge root radius in area E. | Not more than 0.012 in. (0.30 mm) deep | |
D. Removal of the Borescope
(1) When inspection is complete, turn lamp switch off, leave main light source blower on for a while to cool lamp and housing.
(2) Remove the borescope.
Subtask 72-54-00-410-052-A ** ON A/C NOT FOR ALL (1) When inspection is complete, turn lamp switch off, leave main light source blower on for a while to cool lamp and housing.
(2) Remove the borescope.
E. Install the Borescope Plug S22 on the LPT Case
(1) Apply graphite grease (Material No.CP2101) orCP2619 Never Seez-Pure Nickel, Special
(2) Install the plug on the LPT case. TORQUE to between 60 and 55 lbf.in (0.68 and 0.62 m.daN ).
(3) Safety the plug withCP8001 lockwire 0.032 in. (0.8 mm) dia. CP8002 lockwire 0.032 in. (0.8 mm) dia
Subtask 72-54-00-410-090-A ** ON A/C NOT FOR ALL (1) Apply graphite grease (Material No.CP2101) or
(2) Install the plug on the LPT case. TORQUE to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
. (3) Safety the plug with
F. Install the blanking plug on the turbine frame instrumentation boss at 8:30 o'clock (ALF) as follows:
(1) Lubricate the threads of the 2 plug attachment bolts with graphite grease (Material No.CP2101) .
(2) Install the gasket on the blanking plug and engage the plug in the turbine frame boss.
(3) Install the 2 bolts and the 2 nuts (self-locking) to attach the plug to the boss.
(4) TORQUE the 2 nuts to between 110 and 95 lbf.in (1.24 and 1.07 m.daN ).
5. Close-up(1) Lubricate the threads of the 2 plug attachment bolts with graphite grease (Material No.CP2101) .
(2) Install the gasket on the blanking plug and engage the plug in the turbine frame boss.
(3) Install the 2 bolts and the 2 nuts (self-locking) to attach the plug to the boss.
(4) TORQUE the 2 nuts to between 110 and 95 lbf.in (1.24 and 1.07 m.daN )
. Subtask 72-54-00-410-053-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 cowl doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR
Subtask 72-54-00-440-051-A ** ON A/C NOT FOR ALL Subtask 72-54-00-410-061-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 cowl doors (Ref. AMM TASK 78-36-00-410-040):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR