Installation of the APU Surge Duct (131-9(A))

TASK 49-51-52-400-004-A
Installation of the APU Surge Duct (131-9(A))

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

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 102.3 and 83.7 lbf.in (1.16 and 0.95 m.daN )
No specific	Torque wrench: range to between 0.627 and 0.513 m.daN (55.49 and 45.40 lbf.in )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
1	SEAL	AIPC 49-51-09-01-060
1	SEAL	AIPC 49-51-84-30-060

D. 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 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
APU Surge Duct (131-9(A))

3. Job Set-up
Subtask 49-51-52-860-059-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Make sure that the ground service network is energized
(Ref. AMM TASK 24-42-00-861-001).
(2) On the panel 25VU, make sure that the APU MASTER SW p/bsw is OFF.
(3) On the panel 25VU, make sure that the WARNING NOTICE(S) is in position 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).
(5) Make sure that the ACCESS PLATFORM 4M (13 FT) is in position below the APU compartment.
(6) Make sure that the APU access doors 315AL and 316AR are open (Ref. AMM TASK 52-41-00-010-001).
(7) Make sure that the LIGHT control SW 11LJ is set to the ON position.

Subtask 49-51-52-865-063-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

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

4. Procedure
Subtask 49-51-52-420-054-A ** ON A/C NOT FOR ALL

A. Installation of the APU Surge Duct
(1) Install a new AIPC 49-51-09-01-060 SEAL (1) or AIPC 49-51-84-30-060 SEAL (1) in the seal carrier of the engine assembly and on the surge control valve (6).
(2) Loosely attach the ends of the surge duct (7) to the engine assembly and to the surge control valve (6) with the clamps (5).
(3) Install the washers (3), bolt (2) and nut (4).
(4) TORQUE the nut (4) to between 0.627 and 0.513 m.daN (55.49 and 45.40 lbf.in )

.
(5) TORQUE the clamp (5) to between 102.3 and 83.7 lbf.in (1.16 and 0.95 m.daN )

5. Close-up
Subtask 49-51-52-410-054-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 SW 11LJ to the OFF position.
(3) Close the APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(5) Remove the access platform(s).

Subtask 49-51-52-865-064-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 49-51-52-860-060-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 12:43:12 UTC