Removal of the Manual Drive Unit (MDU) [PW11]
TASK 78-31-05-000-801-A
Removal of the Manual Drive Unit (MDU)
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 78-31-05-941-050-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 03:31:13 UTC
Removal of the Manual Drive Unit (MDU)
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.
1. Reason for the JobSelf 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 | COVER - PROTECTION |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1) | |
| 437AL, 438AR | |
| FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2) | |
| 447AL, 448AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-00-00-860-832-A | Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC |
| TASK 71-13-00-010-802-A | Opening of the Fan Cowl Doors |
| TASK 78-30-00-040-805-A | Deactivation of the Thrust Reverser System for Ground Maintenance |
| TASK 78-31-61-000-811-A | Removal of the Left TRAS Monitoring Harness |
Subtask 78-31-05-941-050-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).
Subtask 78-31-05-010-050-A ** ON A/C NOT FOR ALL (1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).
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 an ACCESS PLATFORM 1M(3 FT) in position.
Subtask 78-31-05-040-050-A ** ON A/C NOT FOR ALL (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 an ACCESS PLATFORM 1M(3 FT) in position.
C. Deactivation of the Thrust Reverser for Maintenance
4. ProcedureWARNING:
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 78-30-00-040-805). CAUTION:
WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.
Subtask 78-31-05-020-050-A ** ON A/C NOT FOR ALL A. Removal of the Manual Drive Unit (MDU)
(1) Remove the MDU.
(a) Disconnect the left TRAS monitoring harness connector (4034KS-A) from the left locking actuator (Ref. AMM TASK 78-31-61-000-811).
(c) Remove the MDU (1) from the locking actuator.
(2) Installation of the protection covers
(1) Remove the MDU.
(a) Disconnect the left TRAS monitoring harness connector (4034KS-A) from the left locking actuator (Ref. AMM TASK 78-31-61-000-811).
NOTE: The step above is only necessary for the left MDU (1).
(b) Loosen the MDU (1) coupling nut that attaches the MDU (1) to the locking actuator. (c) Remove the MDU (1) from the locking actuator.
(2) Installation of the protection covers
CAUTION:
INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.
(a) Make sure that you install COVER - PROTECTION as necessary to prevent damage to the engine.
Manual Drive Unit (MDU)