Installation of the AOC Heat Shield Blankets [PW11]

TASK 79-21-41-400-802-A
Installation 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)
No specific	Torque wrench: range to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

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 71-13-00-410-802-A	Closing of the Fan Cowl Doors
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
AOC Heat Shield Blankets

3. Job Set-up
Subtask 79-21-41-941-056-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Make sure that you did the procedure to prevent engine motoring
(Ref. AMM TASK 71-00-00-860-833).

Subtask 79-21-41-010-056-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Make sure that the fan cowl doors are open (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) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

Subtask 79-21-41-040-051-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) Make sure that you did the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-805).

Subtask 79-21-41-010-057-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Make sure that the left thrust-reverser cowl-door is open (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 79-21-41-420-052-A ** ON A/C NOT FOR ALL

A. Installation of the AOC Heat Shield Blankets
(1) Install the six washers (2), the two washers (9) and the two washers (14) on the AOC duct retainer studs.
(2) Install the upper duct blanket (8) and the lower duct blanket (10) on the AOC duct. Use the two nuts (6) and the two washers (7).
(3) Put the lower duct blanket (10) on top of the upper duct blanket (8).
(4) TORQUE the nuts (6) to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

.
(5) Install the stabilizer bracket (13) on the upper duct blanket (8), the lower duct blanket (10) and the AOC duct. Use the two nuts (11) and the two washers (12).
(6) TORQUE the nuts (11) to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

.
(7) Install the upper duct blanket (4) on the AOC duct with the retainer (1) and washer (2).
(8) TORQUE the retainer (1) to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

.
(9) Install the lower duct blanket (5) on the AOC duct with the retainer (1) and washer (2).
(10) TORQUE the retainer (1) to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

.
(11) Install the main duct blanket (3) on the upper duct blanket (4), the lower duct blanket (5) and the AOC duct with the four retainers (1) and the four washers (2).
(12) TORQUE the four retainers (1) to between 27 and 23 lbf.in (0.31 and 0.26 m.daN )

5. Close-up
Subtask 79-21-41-410-052-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 left thrust-reverser cowl-door (Ref. AMM TASK 78-36-00-410-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
461AL

Subtask 79-21-41-440-050-A ** ON A/C NOT FOR ALL

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

Subtask 79-21-41-410-053-A ** ON A/C NOT FOR ALL

C. Close Access
(1) 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
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:41:56 UTC