General Visual Inspection of APU Compartment Exhaust Muffler Insulation Covers and Bellows (131-9(A))

TASK 49-81-00-200-017-A
General Visual Inspection of APU Compartment Exhaust Muffler Insulation Covers and Bellows (131-9(A))

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

ZONE: 310

1. Reason for the Job
Refer to the MPD TASK: 498000-B1
GENERAL VISUAL INSPECTION OF APU COMPARTMENT EXHAUST MUFFLER INSULATION COVERS AND BELLOWS
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
310	FUSLG TAIL SECTION AFT OF AFT PRESS BHD
315AL, 316AR, 317AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 49-81-41-000-003-A	Removal of the Exhaust Muffler (131-9(A))
TASK 49-81-41-400-003-A	Installation of the Exhaust Muffler (131-9(A))
TASK 49-81-42-000-003-A	Removal of the Hot Nozzle and the Bellows (131-9(A))
TASK 49-81-42-400-003-A	Installation of the Hot Nozzle and the Bellows (131-9(A))
TASK 52-41-00-010-001-A	Open the APU Doors for Access
TASK 52-41-00-410-001-A	Close the APU Doors after Access
TASK 52-41-18-000-001-A	Removal of the APU Exhaust Access-Fairing
TASK 52-41-18-400-001-A	Installation of the APU Exhaust Access-Fairing

3. Job Set-up
Subtask 49-81-00-860-070-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
(2) On the panel 25VU make sure that the APU MASTER SW p/b is OFF.
(3) Put a warning notice in the cockpit to tell persons not to start the APU.
(4) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).

Subtask 49-81-00-865-072-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-81-00-010-061-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below the APU access doors 315AL and 316AR.
(2) Open the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control SW 11LJ to the ON position.

4. Procedure
Subtask 49-81-00-210-064-A ** ON A/C NOT FOR ALL

A. General Visual Inspection of the APU-Compartment Exhaust-Muffler Insulation-Covers and Bellows (131-9(A))
(1) Examine the bellows for tears or cracks.
(a) If you find damage, remove the bellows (Ref. AMM TASK 49-81-42-000-003).
(b) Send the bellows to the workshop.
(c) If removed, install new/repaired bellows (Ref. AMM TASK 49-81-42-400-003).
(2) Examine the two bellows band clamps for signs of damage and make sure that they are attached correctly.
(a) If the band clamps are damaged, replace them.
(b) If the band clamps are not attached correctly and/or loose, attach them correctly and tighten them.
(3) Remove APU exhaust access-fairing 317AL (Ref. AMM TASK 52-41-18-000-001).
(4) Examine the thermal insulation of the exhaust muffler for tears, cracks or discoloration and make sure that they are not partially loose.
(a) If you find damage, remove the exhaust muffler (Ref. AMM TASK 49-81-41-000-003).
(b) Send the exhaust muffler to the workshop.
(c) If removed, install a new or repaired exhaust muffler (Ref. AMM TASK 49-81-41-400-003).
(5) Install APU exhaust access-fairing 317AL (Ref. AMM TASK 52-41-18-400-001).

5. Close-up
Subtask 49-81-00-410-061-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) Set the LIGHT control switch 11LJ to the off position.
(3) Close the APU access doors 315AL 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).

Subtask 49-81-00-865-073-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 49-81-00-860-071-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 01:32:36 UTC