DOC AIRBUS | AMM A320FBorescope Inspection of the Booster Rotor Blades, Stages 2, 3, 4 and 5 through the Booster Inlet and Borescope Ports SO3 and SO5 [CFMB]
TASK 72-21-00-290-003-A
Borescope Inspection of the Booster Rotor Blades, Stages 2, 3, 4 and 5 through the Booster Inlet and Borescope Ports SO3 and SO5
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 72-21-00-941-079-A ** ON A/C NOT FOR ALL
Subtask 72-21-00-290-053-A ** ON A/C NOT FOR ALL
(2) When the inspection is completed, turn the switch off. Leave the main light source blower on for a while to cool the lamp and the housing.
5. Close-up
Subtask 72-21-00-410-061-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:41:12 UTC
Borescope Inspection of the Booster Rotor Blades, Stages 2, 3, 4 and 5 through the Booster Inlet and Borescope Ports SO3 and SO5
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 | ACCESS PLATFORM 1M(3 FT) |
| No specific | AR | WARNING NOTICE(S) |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 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 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 |
Booster Borescope PortsSubtask 72-21-00-941-079-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 72-21-00-010-059-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 72-21-00-040-052-A ** ON A/C NOT FOR ALL Subtask 72-21-00-010-060-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 72-21-00-290-053-A ** ON A/C NOT FOR ALL
A. Borescope Inspection Methods
(1) Inspection of booster rotor blades through the borescope ports SO3 and SO5 and booster inlet.
(a) There are 2 borescope ports (SO3 and SO5) located (approximately) at the 3.30 o'clock position at the periphery of the booster section and almost radially in line with the stages 3 and 4 of the booster stator. Through these ports, you can see the leading and trailing edges of the booster stage 3, 4 and 5 rotor blades. Through the booster inlet, you can get a borescope view of the booster rotor blades, stage 2.
(b) To do the inspection of the booster stages 2, 3, 4 and 5 rotor blades:
1 Use 856A1320 BORESCOPE-KIT (856A1320P04/P05) (field of view 60 deg., angle of vision 90 deg.) with a long right angle extension.
2 Use 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08)
Subtask 72-21-00-480-060-A ** ON A/C NOT FOR ALL (1) Inspection of booster rotor blades through the borescope ports SO3 and SO5 and booster inlet.
(a) There are 2 borescope ports (SO3 and SO5) located (approximately) at the 3.30 o'clock position at the periphery of the booster section and almost radially in line with the stages 3 and 4 of the booster stator. Through these ports, you can see the leading and trailing edges of the booster stage 3, 4 and 5 rotor blades. Through the booster inlet, you can get a borescope view of the booster rotor blades, stage 2.
(b) To do the inspection of the booster stages 2, 3, 4 and 5 rotor blades:
1 Use 856A1320 BORESCOPE-KIT (856A1320P04/P05) (field of view 60 deg., angle of vision 90 deg.) with a long right angle extension.
2 Use 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08)
NOTE: It is necessary to index and turn the fan rotor. You can turn the fan and booster rotor assembly by hand from the engine inlet.
B. Installation of the borescope.
(a) 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).
(b) Turn the light source on. Engage the borescope and the long right-angle extension, and set it as necessary for inspection.
Subtask 72-21-00-290-054-A ** ON A/C NOT FOR ALL CAUTION:
MAKE SURE THAT THE INPUT VOLTAGE OF THE BORESCOPE LIGHT SOURCE SET CORRESPONDS TO THAT OF THE POWER SUPPLY.
CAUTION:
MAKE SURE THAT :
THE ON-OFF SWITCH IS IN THE OFF POSITION.
THE LIGHT INTENSITY CONTROL IS SET TO THE MINIMUM BEFORE YOU CONNECT THE BOROSCOPE LIGHT-SOURCE SET TO THE POWER SUPPLY. MAKE SURE THAT THE LIGHT SOURCE AND THE POWER SUPPLY ARE CORRECTLY GROUNDED.
(1) Connect the 856A1322 BORESCOPE-LIGHT SOURCE SET (856A1322P02/P03/P04/P07/P08) to a grounded power supply. (a) 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).
(b) Turn the light source on. Engage the borescope and the long right-angle extension, and set it as necessary for inspection.
WARNING:
BE CAREFUL WHEN YOU TURN THE FAN ROTOR MANUALLY. USE HEAVY PROTECTIVE GLOVES AND MAKE SURE THAT YOU CANNOT SLIP. IF YOU DO NOT OBEY THESE INSTRUCTIONS, INJURY CAN OCCUR.
C. Borescope Inspection of the booster blades. NOTE: Any amount of erosion/flaking of abradable lining material on the outer shroud is permitted on booster vane stages 3,4 & 5.
(1) Do an borescope inspection of the booster blades while you turn the fan rotor clockwise (aft looking forward) to complete the procedure. | INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Booster rotor blades (all stages) for: | | |
| A.Missing piece on tip corner | Axial or radial depth 0.25 in. (6.35 mm) max. | |
| B.Cracks | Not serviceable | |
| C.Wear or local deformation (blade tip corner on leading and/or trailing edges | Axial depth 0.5 in. (12.7 mm) and 0.8 in. (20.32 mm) radial max. | |
| D.Nicks, dents on concave and/or convex sides located in area E | No limited quantity if not deeper than 0.01 in. (0.25 mm) | |
| | | |
| E.Nicks, dents on concave and/or convex sides not located in area E | No limited quantity if not deeper than 0.04 in. (1.02 mm) | |
| F.Nicks, dents, on leading and/or mex trailing edges | Axial depth 0.02 in. (0.5 mm) max. NOTE: If any damage is found, do a borescope inspection of all booster downstream stages and compressor. | |
| G.Distorted leading and/or trailing edges not located in area E | Circumferential displacement 0.2 in. (5 mm) maximum NOTE: Whenever serviceable limits for the following are exceeded, refer to the over-serviceable limit extension if necessary (Ref. AMM TASK 72-00-00-200-025). | |
Subtask 72-21-00-410-061-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 72-21-00-440-052-A ** ON A/C NOT FOR ALL Subtask 72-21-00-410-062-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).