Removal of the AOC Heat Shield Blankets [PW11]

TASK 79-21-41-000-802-A
Removal of the AOC Heat Shield Blankets

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 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)

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
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 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
AOC Heat Shield Blankets

3. Job Set-up
Subtask 79-21-41-941-055-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 79-21-41-010-054-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 an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 79-21-41-040-050-A ** ON A/C NOT FOR ALL

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 78-30-00-040-805).

Subtask 79-21-41-010-055-A ** ON A/C NOT FOR ALL

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

4. Procedure

CAUTION: DO NOT LET THE THERMAL INSULATION BLANKETS BECOME WET. FLUIDS CAN GO INTO THE VENT HOLES OF THE BLANKETS AND MAKE THE INSULATION UNSATISFACTORY.

CAUTION: BE CAREFUL WHEN YOU MOVE THE THERMAL INSULATION BLANKETS. IF YOU DO NOT HOLD THE BLANKETS CORRECTLY, THEY CAN FOLD BECAUSE OF THEIR OWN WEIGHT. DO NOT STEP ON OR PUT OBJECTS ON THE BLANKETS. DO NOT PUT THE BLANKETS ON SURFACES THAT CAN CAUSE DAMAGE. HOLD THE BLANKETS ON THEIR THICKEST PARTS. IF YOU DO NOT OBEY THESE INSTRUCTIONS, DAMAGE TO THE BLANKETS CAN OCCUR.

Subtask 79-21-41-020-053-A ** ON A/C NOT FOR ALL

A. Removal of the AOC Heat Shield Blankets
(1) Remove the four retainers (1) and washers (2) that attach the main duct blanket (3), the upper duct blanket (4) and the lower duct blanket (5) to the AOC duct.
(2) Remove the main duct blanket (3) from the AOC duct.
(3) Remove the retainer (1) and the washer (2) that attach the lower duct blanket (5) to the AOC duct.
(4) Remove the lower duct blanket (5) from the AOC duct.
(5) Remove the three washers (2) from the heat shield retainer studs.
(6) Remove the retainer (1) and washer (2) that attach the upper duct blanket (3) to the AOC duct.
(7) Remove the upper duct blanket (3) from the AOC duct.
(8) Remove the three washers (2) from the heat shield retainer studs.
(9) Remove the nut (6) and washer (7) that attach the lower flange blanket (8) to the AOC duct.
(10) Remove the washer (9) from the heat shield retainer stud.
(11) Remove the nut (6) and washer (7) that attach the upper flange blanket (10) to the AOC duct.
(12) Remove the washer (9) from the heat shield retainer stud.
(13) Remove the two nuts (11), the two washers (12) and the two washers (14) that attach the stabilizer bracket (13) to the AOC duct.
(14) Remove the stabilizer bracket (13), the upper duct blanket (8) and the lower duct blanket (10) from the AOC duct.

[Rev.10 from 2021] 2026.04.01 03:41:55 UTC