Replacement of the Helical Coil Inserts on the Diffuser Case [PW11]

TASK 72-41-01-920-801-A
Replacement of the Helical Coil Inserts on the Diffuser Case

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AND THE ADJACENT COMPONENTS AFTER ENGINE SHUTDOWN. THE ENGINE, THE ENGINE OIL AND THE ADJACENT COMPONENTS CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

CAUTION: THIS AIRCRAFT MAINTENANCE MANUAL REPAIR LETS YOU REPLACE ONLY THE ORIGINAL EQUIPMENT MANUFACTURER'S HELICAL COIL INSERT(S). IF THERE IS DAMAGE TO THE HOLE(S) AND AN OVERSIZED INSERT IS NECESSARY, THEN YOU MUST NOT DO THE REPAIR ON-WING. YOU MUST REMOVE AND REPAIR THE PART AS PER THE APPLICABLE CLEANING, INSPECTION & REPAIR MANUAL.

CAUTION: MAKE SURE THAT NO HELICAL COIL INSERT(S) OR DEBRIS GOES (GO) INTO THE ENGINE DURING THIS REPAIR PROCEDURE. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE ENGINE PARTS CAN OCCUR.

ZONE: 400

1. Reason for the Job
Use this procedure to repair loose or damaged helical coil insert(s) on the diffuser case.
For more information about the diffuser case, refer to 72-41-00-00 CONF 21 - DIFFUSER CASE - DESCRIPTION AND OPERATION.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE

B. Work Zones and Access Panels

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

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
1	INSERT OPTION	EIPC 72-41-00-01-020

D. Referenced Information

REFERENCE	DESIGNATION
TASK 70-24-00-910-803-A	SPOP 415 - Installation of Helical Coil Threaded Inserts
TASK 71-00-00-860-833-A	Procedure to Prevent Engine Motoring
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-802-A	Closing of the Fan Cowl Doors
TASK 73-11-49-000-803-A	Removal of the Fuel Nozzle Supply Tubes
TASK 73-11-49-400-803-A	Installation of the Fuel Nozzle Supply Tubes
TASK 75-32-02-000-801-A	Removal of the HPC Bleed Valve
TASK 75-32-02-400-801-A	Installation of the HPC Bleed Valve
TASK 75-32-04-000-801-A	Removal of the High Pressure Compressor (HPC) Active Bleed Valve
TASK 75-32-04-400-801-A	Installation of the High Pressure Compressor (HPC) Active Bleed Valve
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-805-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
TASK 78-36-00-410-802-A	Closing of the Thrust Reverser Cowl-Doors
Helical Coil Inserts on the Diffuser Case

3. Job Set-up
Subtask 72-41-01-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).

Subtask 72-41-01-010-050-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR.
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.

Subtask 72-41-01-040-050-A ** ON A/C NOT FOR ALL

C. Deactivation of the Thrust Reverser for Ground 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 ground maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 72-41-01-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL, 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL, 462AR.

4. Procedure

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

Subtask 72-41-01-920-050-A ** ON A/C NOT FOR ALL

A. Replacement of the Helical Coil Inserts on the Diffuser Case
(1) Remove and install all the external attachments that are necessary to help with the removal and installation of the helical coil insert(s) as follows if necessary:
(a) Remove and install the High Pressure Compressor (HPC) bleed valve (Ref. AMM TASK 75-32-02-000-801) and (Ref. AMM TASK 75-32-02-400-801).
(b) Remove and install the HPC active bleed valve (Ref. AMM TASK 75-32-04-000-801) and (Ref. AMM TASK 75-32-04-400-801).
(c) Remove and install the fuel nozzle supply tubes (Ref. AMM TASK 73-11-49-000-803) and (Ref. AMM TASK 73-11-49-400-803).
(2) Remove the loose or damaged helical coil insert(s) from the diffuser case by SPOP 415 (Ref. AMM TASK 70-24-00-910-803).

Helical Coil Inserts on the Diffuser Case ** ON A/C NOT FOR ALL

(3) Do a visual inspection of the helical coil threaded insert holes(s) for thread damage. No damage is permitted.
(4) Install the new EIPC 72-41-00-01-020 INSERT OPTION (1) by SPOP 415 (Ref. AMM TASK 70-24-00-910-803):

Helical Coil Inserts on the Diffuser Case ** ON A/C NOT FOR ALL

(a) The use of oversize inserts or twinserts is not permitted.
(b) Make sure that the top face of the first insert coil is 1 to 1.5 pitch below the insert hole top surface.
(5) Do a visual inspection of the repaired area(s) to make sure that they are installed as specified in SPOP 415 (Ref. AMM TASK 70-24-00-910-803).
(6) Install all the external attachments that you removed during this repair procedure.
(7) Examine the assembly for foreign objects, damage and correct assembly.

5. Close-up
Subtask 72-41-01-410-050-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 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL, 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL, 462AR.

Subtask 72-41-01-440-050-A ** ON A/C NOT FOR ALL

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-805).

Subtask 72-41-01-410-051-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Remove the access platform(s).
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR.
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:49:30 UTC