Inspection of the Combustion Case Assembly [CFML]

TASK 72-41-00-200-802-A
Inspection of the Combustion Case Assembly

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 400

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 70-28-00-300-801-A	Replacement of Key-Locked Inserts
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 73-11-30-300-801-A	Repair of the Fuel Nozzles Pad Inserts
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Combustion Case Assembly

3. Job Set-up
Subtask 72-41-00-941-055-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch and
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 72-41-00-010-060-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.

Subtask 72-41-00-040-055-A

C. Deactivation of the Thrust Reverser System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 72-41-00-010-061-A

D. Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR.
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR.
(3) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 72-41-00-210-052-A

A. Visual Inspection
(1) Do a visual inspection that follows:

Combustion Case Assembly

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS

1. Examine the combustion case assembly forward and aft flanges for:
(a) Cracks	Not serviceable
2. Examine the combustion case casing body (does not include pads, ports, flanges) for:
(a) Cracks	Not serviceable
(b) Dents	Any amount, 0.010 in. (0.25 mm) in depth
(c) Buckling and distortion	Not serviceable
(d) Discoloration	Any amount
3. Examine areas of the combustor thermal insulation blankets (insulation) that you can see for:
(a) Discoloration	Any amount
(b) Varnish film (soot or oil build-up) (external)	Any amount
(c) Burning (charring)	Not serviceable
(d) Missing and loose capstan	Not serviceable
(e) Cuts, tears and holes in the outer skin	Not serviceable
(f) Looseness	Any amount, if the insulation can be correctly installed.
(g) Dents in the outer skin	Any amount, if dents are less than 50 percent of the thermal blanket thickness, and the total amount of dents in the blanket are less than 10 percent of the blanket area.
(h) Distortions caused by trapped air	Not serviceable
(i) Imperfections on the folded edge	Any amount, if they are less than 0.20 in. (5.1 mm) in length each and that insulation is not exposed.
NOTE Examine the combustor case pads, bores and ports when the line replaceable units are removed for other maintenance.
4. Examine igniter ports, Environmental Control System (ECS) ports and Transient Bleed Valve (TBV) port for:
(a) Cracks	Not serviceable
(b) Nicks, scores and scratches (does not include insert holes)	Any amount, not more than 0.005 in. (0.13 mm) in depth, if damage does not go across more than 25 percent of the sealing surface.
(c) Broken bolts	Not serviceable
(d) Galling or pickup on the threads on the threaded insert	Four threads (cumulative or continuous) must remain of the first six entry threads.
(e) Loose or missing threaded inserts:
PRE SB 72-0219 (Combustor Cases with Ring Lock Inserts)
- Loose	Turning until the locking ring engages is permitted.
- Missing	Not serviceable
- Repair method	Replace only the damaged inserts (Ref. AMM TASK 73-11-30-300-801).
END OF PRE SB 72-0219
POST SB 72-0219 (Combustor Cases with Key Lock Inserts)
- Loose	Turning the insert and pushing the protruding locking keys is permitted only when the insert and all keys are not damaged.
- Missing	Not serviceable
- Repair method	Replace only the damaged inserts (Ref. AMM TASK 70-28-00-300-801).
END OF POST SB 72-0219
(f) Galling or pickup on the threads at the ECS ports and TBV ports (0.164-32 UNJC-3B threads)	Four threads (cumulative or continuous) must remain of the first six entry threads.
5. Examine aft ECS pads for:
(a) Cracks	Not serviceable
(b) Nicks, scores and scratches	Any amount of small surface defects, 0.005 in. (0.13 mm) in depth, that do not extend across more than 25 percent of the seal surface.
(c) Broken bolts	Not serviceable
(d) Galling or pickup on the threads on the threaded insert	Five threads (cumulative or continuous) must remain of the first six entry threads.
(e) Loose or missing threaded inserts:
PRE SB 72-0219 (Combustor Cases with Ring Lock Inserts)
- Loose	Turning until the locking ring engages is permitted.
- Missing	Not serviceable
- Repair method	Replace only the damaged inserts (Ref. AMM TASK 73-11-30-300-801).
END OF PRE SB 72-0219
POST SB 72-0219 (Combustor Cases with Key Lock Inserts)
- Loose	Turning the insert and pushing the protruding locking keys is permitted only when the insert and all keys are not damaged.
- Missing	Not serviceable
- Repair method	Replace only the damaged inserts (Ref. AMM TASK 70-28-00-300-801).
END OF POST SB 72-0219
6. Examine borescope ports for:
(a) Cracks	Not serviceable
(b) Galling or pickup on the threads	Permitted on the first three entry threads
(c) Nicks, scores and scratches	Not serviceable
7. Examine PS3/T3 sensor ports for:
(a) Cracks	Not serviceable
(b) Galling or pickup on the threads	Permitted on the first three entry threads
(c) Nicks, scores and scratches	Any amount, 0.005 in. (0.13 mm) in depth, if damage does not go across more than 25 percent of the sealing surface.
8. Examine the fuel nozzle pads for:
(a) Cracks	Not serviceable
(b) Nicks, scores and scratches	Any amount of small surface defects, 0.005 in. (0.13 mm) in depth, that do not extend across more than 25 percent of the sealing surface.
(c) Broken bolts	Not serviceable
(d) Galling or pickup on the threads on the threaded insert	Five threads (cumulative or continuous) must remain of the first six entry threads.
(e) Loose or missing threaded inserts:
PRE SB 72-0082 (Combustor Cases with Ring Lock Inserts)
- Loose	Turning until the locking ring engages is permitted.
- Missing	Not serviceable
END OF PRE SB 72-0082
POST SB 72-0082 (Combustor Cases with Key Lock Inserts)
- Loose	Turning the insert and pushing the protruding locking keys is permitted only when the insert and all keys are not damaged.
- Missing	Not serviceable
END OF POST SB 72-0082

5. Close-up
Subtask 72-41-00-410-059-A

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 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR.

Subtask 72-41-00-440-055-A

B. Reactivation of the Thrust Reverser After Maintenance
(1) Do the reactivation of the thrust reverser after maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 72-41-00-410-060-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:53:43 UTC