Detailed Visual Inspection of the Sealing Ring Coupling (131-9(A))

TASK 49-81-00-200-010-A
Detailed Visual Inspection of the Sealing Ring Coupling (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	1	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	Torque wrench: range to between 0.34 and 0.31 m.daN (30.09 and 27.43 lbf.in )
No specific	Torque wrench: range to between 0.93 and 0.81 m.daN (82.30 and 71.68 lbf.in )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14QFB1)	Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

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 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 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
Hot Nozzle and Sealing Ring - Inspection

3. Job Set-up
Subtask 49-81-00-860-064-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 pushbutton switch 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 49-81-00-865-066-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 49-81-00-010-058-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 316AR (Ref. AMM TASK 52-41-00-010-001).
(3) Set the LIGHT control SW 11LJ to the ON position.

4. Procedure
Subtask 49-81-00-210-060-A ** ON A/C NOT FOR ALL

A. Disconnect the APU Exhaust Coupling for access.
(1) Remove of the lockwire:

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(a) Remove the lockwire from the upper and lower halves of the heat insulation (1) and (2), remove the heat insulation halves.
(2) Remove the clamp (3) from the exhaust hot nozzle assy. and APU exhaust duct.
(3) Push the hot nozzle and bellows assembly (7) as far rearwards as possible.

Subtask 49-81-00-210-061-A ** ON A/C NOT FOR ALL

B. Visual Inspection
(1) Examine the inner and outer flange areas of the hot nozzle assembly for distortion, wear-grooves and cracks. Replace if defective (Ref. AIPC 49-81-41-01-010).
(2) Use a hand mirror and examine the piston ring as far as possible for distortion, wear or damage. If the piston ring is found to be defective, replace the exhaust muffler (Ref. AMM TASK 49-81-41-000-003) and (Ref. AMM TASK 49-81-41-400-003).

Subtask 49-81-00-420-057-A ** ON A/C NOT FOR ALL

C. Connect the APU exhaust Coupling.
(1) Push the hot nozzle/bellows assembly forward until the hot nozzle flange touches the APU exhaust duct flange.
(2) Adjust the hot nozzle flange radially to the APU exhaust duct flange. The radial offset should be 0 +4 -4 mm (0.0 +0.16 -0.16 in.).
(3) Position the clamp (3) on the exhaust coupling flanges with the lockbolts in the 3 and 9 o'clock position.
(4) Secure the V-clamp (3). Torque the clamp lockbolts

of the V-clamp (P/N D49885041200) to between 0.93 and 0.81 m.daN (82.30 and 71.68 lbf.in ) ;
or
of the AEROQUIP V-clamp (P/N 6299342) to between 0.34 and 0.31 m.daN (30.09 and 27.43 lbf.in ) .

(5) Install the heat insulation upper (1) and lower (2) halves, connect the two halves with 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -.
(6) Connect the two halves with corrosion-resistant steel lockwire 0.8mm (0.032in.) to the hot nozzle assembly studs.

5. Close-up
Subtask 49-81-00-410-058-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 49-81-00-865-067-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 49-81-00-860-065-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 12:42:21 UTC