Inspection of the Stage 1-3 Blades [CFMB]
TASK 72-54-00-290-005-A
Inspection of the Stage 1-3 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 72-54-00-941-056-A ** ON A/C NOT FOR ALL
Subtask 72-54-00-010-067-A ** ON A/C NOT FOR ALL
Subtask 72-54-00-410-067-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 12:59:36 UTC
Inspection of the Stage 1-3 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 | 1 | WRENCH 1/4 IN - RATCHET |
| 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 65 and 59 lbf.in (0.73 and 0.67 m.daN ) ![]() | |
| 856A1320 | 1 | BORESCOPE-KIT |
| 856A1322 | 1 | BORESCOPE-LIGHT SOURCE SET |
| 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 |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| 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 |
Subtask 72-54-00-941-056-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 72-54-00-010-066-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):
(2) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL 448AR
Subtask 72-54-00-040-056-A ** ON A/C NOT FOR ALL Subtask 72-54-00-010-075-A ** ON A/C NOT FOR ALL (1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(2) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(3) FOR [1000EM2] (ENGINE-2)
447AL 448AR
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 72-54-00-010-067-A ** ON A/C NOT FOR ALL
A. Removal of Borescope Plugs
PRE SB CFMI 72-0376
(2) Cut and remove the lockwires. Then, remove the borescope plugs S16, S17, S18, S19 and S20.
END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(3) Cut and remove the lockwires. Then, remove the borescope plugs S16 and S17.
END OF SB CFMI 72-0376
Subtask 72-54-00-480-054-A ** ON A/C NOT FOR ALL CAUTION:
DO NOT REMOVE THE NUTS WHICH HOLD THE LPT BORESCOPE PLUG BOSS. TACK WELDS HOLD THE NUTS IN THEIR POSITIONS. THE REMOVAL OF THE NUTS CAN CAUSE DAMAGE TO THE STUDS.
(1) Let the temperature of parts decrease to ambient temperature. PRE SB CFMI 72-0376
(2) Cut and remove the lockwires. Then, remove the borescope plugs S16, S17, S18, S19 and S20.
NOTE: The borescope plugs S16 and S17 are in the same plane and located, respectively, at 5:30 and 8:30 (ALF) immediately in front of the combustion case aft flange. The borescope plugs S18, S19 and S20 are located approximately at 5:00 o'clock (ALF) on the LPT case and, from front to rear, relate to the 2nd, 3rd and 4th stages of the LPT, respectively.
END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(3) Cut and remove the lockwires. Then, remove the borescope plugs S16 and S17.
NOTE: The borescope plugs S16 and S17 are in the same plane and located, respectively, at 5:30 and 8:30 (ALF) immediately in front of the combustion case aft flange.
(4) Remove the self-locking borescope cap assemblies S18, S19 and S20. NOTE: The borescope cap assemblies S18, S19 and S20 are located approximately at 5:00 o'clock (ALF) on the LPT case and, from front to rear, relate to the 2nd, 3rd and 4th stages of the LPT, respectively.
NOTE: Specific procedure is not required to remove a self-locking borescope cap assembly. You can use a WRENCH 1/4 IN - RATCHET to loosen it.
END OF SB CFMI 72-0376
B. Install the 856A1320 BORESCOPE-KIT (856A1320P04/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 desired for inspection.
Subtask 72-54-00-290-054-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, 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 desired for inspection.
C. The stage 1-3 LPT rotor blades are long span blades. To fully examine the airfoil surface, it is recommended to do as follows:
(1) Turn the fan rotor slowly and smoothly to examine the blades.
(2) Change the probe engagement depth so as to see the blade airfoils as they move in front of the probe.
(3) While you adjust the probe engagement depth, turn the probe about its axis (azimuth) to get a maximum view, for a given turn speed of the rotor.
(5) To look at the trailing edges, turn the rotor in the opposite direction so that the convex side (suction face) of the blades comes toward the borescope.
(6) Do the inspection of the stage 1-3 blades for the damage as follows:
Subtask 72-54-00-080-054-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 so as to see the blade airfoils as they move in front of the probe.
(3) While you adjust the probe engagement depth, turn the probe about its axis (azimuth) to get a maximum view, for a given turn speed of the rotor.
NOTE: The blade span increases from the 2nd to the 3rd LPT stages. As the full engagement of the probe is necessary, you may have to make more than one turn of the LPT rotor to see all the blade airfoils.
(4) When you look at the leading edges of the blades, turn the rotor so that their concave side (pressure face) comes toward the borescope. (5) To look at the trailing edges, turn the rotor in the opposite direction so that the convex side (suction face) of the blades comes toward the borescope.
(6) Do the inspection of the stage 1-3 blades for the damage as follows:
| INSPECT/CHECK | MAXIMUM SERVICEABLE LIMITS | REMARKS |
|---|---|---|
| 1.Cracks. | Not serviceable. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 2.Nicks on concave or convex sides. Does not include areas E. | Not more than 0.01 in. (0.25 mm) deep for stage 1 and 0.02 in. (0.5 mm) deep for stages 2-3. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 3.Dents on concave or convex sides. Does not include areas E. | Not more than 0.01 in. (0.25 mm) deep. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 4.Nicks and/or dents on leading or trailing edges. Does not include areas E. | Not more than 0.02 in. (0.5 mm) deep. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 5.Nicks and/or dents in areas E. | Not more than 0.01 in. (0.25 mm) deep. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 6.Stage 3 blade airfoil trailing edge deflection from original contour. | Smooth, no sharp edges. Not more than 2 blades impacted and with L / D > 5. | |
| 7.Rubbing on leading edge platform, leading edge root radius in area E. | Not more than 0.01 in. (0.25 mm) deep. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 8.Distortion of leading edges caused by overtemperature. | Not serviceable. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 9.Pretwist clearances such that adjacent interlocks do not touch each other. | Permitted if the faces of the interlocks are not worn for stage 1. Not serviceable for stage 2-3. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| For CFM56-5B non/P engines | | |
| 10.Stage 1, 2 and 3 blades tip shroud out of flush. | Not more than 0.0150 in. (0.38 mm). | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| For CFM56-5B/P engines | | |
| 11.Stage 1 blades tip shroud out of flush. | Not more than 0.0472 in. (1.20 mm), and not more than 0.0413 in. (1.05 mm) on the hard faces. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) NOTE: If this out of flush condition is caused by over welding and if there is no evidence of unusual wear on the mating or hard faces all along the notch and the interlocks do fit one in another, this condition is serviceable. If different, refer to the criteria. |
| 12.Stage 2 blades tip shroud out of flush. | Not more than 0.0472 in. (1.20 mm), and not more than 0.0354 in. (0.90 mm) on the hard faces. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) NOTE: If this out of flush condition is caused by over welding and if there is no evidence of unusual wear on the mating or hard faces all along the notch and the interlocks do fit one in another, this condition is serviceable. If different, refer to the criteria. |
| 13.Stage 3 blades tip shroud out of flush. | Not more than 0.0472 in. (1.20 mm), and not more than 0.0433 in. (1.10 mm) on the hard faces. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) NOTE: If this out of flush condition is caused by over welding and if there is no evidence of unusual wear on the mating or hard faces all along the notch and the interlocks do fit one in another, this condition is serviceable. If different, refer to the criteria. |
| 14.Stage 1 blades root platform out of flush. | Not more than 0.0198 in. (0.50 mm). | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 15.Stage 2 and 3 blades root platform out of flush. | Not more than 0.0236 in. (0.60 mm). | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| For CFM56-5B/P DAC engines | | |
| 16.Stage 2 blades tip shroud mismatch. | Not serviceable. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| 17.Stage 2 blades tip shroud notch wear. | Not serviceable. | See limit extensions. (Ref. AMM TASK 72-00-00-200-025) |
| For ALL CFM56-5B engines | | |
| 18.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 extensions. (Ref. AMM TASK 72-00-00-200-025) |
| | | |
| 19.Deposit material, peeling off on airfoil. | Any amount provided there is no evidence of bowing and/or melting. | |
| 20.Rubbing/scratches on forward face of root platform. | Any amount. | |
| 21.Blades seal teeth wear. | 1/2 of tooth height worn if only one stage is affected. 1/3 of tooth height worn if 2 stages are affected. 1/4 of tooth height worn if 3 stages are affected. | |
| 22.Corrosion / Pitting | For CFM56-5B/P and CFM56-5B/3 engines: Any amount | |
D. Removal of 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 72-54-00-410-066-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 Plugs
PRE SB CFMI 72-0376
(1) Apply graphite grease (Material No.CP2101) to the threads of the borescope plugs S16, S17 and on the combustion case (S16, S17).
(2) Apply graphite grease (Material No.CP2101) to the threads of the borescope plugs S18, S19, S20 and install on the LPT case (S18, S19, S20).
END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(3) Apply graphite grease (Material No.CP2101) to the threads of the self-locking borescope cap assemblies S18, S19, S20 and install on the LPT case (S18, S19, S20).
END OF SB CFMI 72-0376
PRE SB CFMI 72-0376
(4) TORQUE plugs S16, S17 to between 65 and 59 lbf.in (0.73 and 0.67 m.daN )
and safety with CP8001 lockwire 0.032 in. (0.8 mm) dia. or CP8002 lockwire 0.032 in. (0.8 mm) dia .
(5) TORQUE plugs S18, S19 and S20 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
and safety with CP8001 lockwire 0.032 in. (0.8 mm) dia. or CP8002 lockwire 0.032 in. (0.8 mm) dia .
END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(6) TORQUE plugs S16, S17 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
and safety with CP8001 lockwire 0.032 in. (0.8 mm) dia. or CP8002 lockwire 0.032 in. (0.8 mm) dia .
(7) TORQUE self-locking borescope caps assemblies S18, S19, S20 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
.
END OF SB CFMI 72-0376
5. Close-upPRE SB CFMI 72-0376
(1) Apply graphite grease (Material No.CP2101) to the threads of the borescope plugs S16, S17 and on the combustion case (S16, S17).
(2) Apply graphite grease (Material No.CP2101) to the threads of the borescope plugs S18, S19, S20 and install on the LPT case (S18, S19, S20).
END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(3) Apply graphite grease (Material No.CP2101) to the threads of the self-locking borescope cap assemblies S18, S19, S20 and install on the LPT case (S18, S19, S20).
END OF SB CFMI 72-0376
PRE SB CFMI 72-0376
(4) TORQUE plugs S16, S17 to between 65 and 59 lbf.in (0.73 and 0.67 m.daN )
and safety with (5) TORQUE plugs S18, S19 and S20 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
and safety with END OF PRE SB CFMI 72-0376
POST SB CFMI 72-0376
(6) TORQUE plugs S16, S17 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
and safety with (7) TORQUE self-locking borescope caps assemblies S18, S19, S20 to between 60 and 55 lbf.in (0.68 and 0.62 m.daN )
. NOTE: To achieve the correct installation of the self-locking borescope cap assembly, the slot of its ring must be positioned on the borescope boss lug at the final tightening.
END OF SB CFMI 72-0376
Subtask 72-54-00-410-067-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 72-54-00-440-056-A ** ON A/C NOT FOR ALL Subtask 72-54-00-410-076-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.
Location of the Borescope Ports and Possible Borescope Access Via One Instrumentation Boss