Visual Inspection of the APU Compartment Overpressure Release Door

TASK 52-92-00-210-001-A
Visual Inspection of the APU Compartment Overpressure Release Door

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
To make sure that the force to open the overpressure release door is correct.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 5M (16 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	SPRING BALANCE 20 DAN (48 LBF)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315AL, 316AR

C. Referenced Information

REFERENCE	DESIGNATION
Overpressure Release Door

3. Job Set-up
Subtask 52-92-00-941-050-A

A. Aircraft Maintenance Configuration
(1) Put the ACCESS PLATFORM 5M (16 FT) in position below the APU compartment.
(2) Put the warning notice in the flight compartment to tell persons not to start the APU.

Subtask 52-92-00-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

Subtask 52-92-00-010-050-A

C. Open the APU access doors 315AL 316AR.

4. Procedure
Subtask 52-92-00-220-050-A

A. Measurement of the Force to Open the Door
(1) Attach the SPRING BALANCE 20 DAN (48 LBF) (3) to the hole of the overpressure release door (2).
(2) Make sure that the force which is necessary to open the overpressure release door (2) is 11.7 +0.5 daN or -0.5 daN (26.3026 +1.1240 lbf or -1.1240 lbf). Pull at a right angle to the door.
(3) Release the overpressure release door (2) and remove the spring scale (3).
(4) If necessary, adjust the tension of the springs with the nut (1) in the APU compartment.

Subtask 52-92-00-210-050-A

B. Inspection of the Overpressure Release Door
(1) Examine the overpressure release door (2) for damage. Replace the door if necessary.
(2) Examine the tension springs, the support, the connecting link and the spring connecting link for damage or wear. Replace the items if necessary.
(3) Examine the hinge for damage or wear. Replace the hinge if necessary.

5. Close-up
Subtask 52-92-00-410-050-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the APU access doors 316AR 315AL.

Subtask 52-92-00-942-050-A

B. Put the aircraft back to its initial configuration.
(1) Remove the access platform(s).
(2) Remove the WARNING NOTICE(S).

Subtask 52-92-00-865-051-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	APU/APU/CTL	2KD	L42
121VU	APU/ECB/SPLY	1KD	L41

[Rev.10 from 2021] 2026.04.02 06:28:39 UTC