Cleaning of the APU Air Intake (131-9(A))

TASK 49-16-00-100-005-A
Cleaning of the APU Air Intake (131-9(A))

WARNING: BEFORE YOU START WORK, YOU MUST PUT ON A SAFETY HARNESS AND ATTACH IT TO THE ACCESS PLATFORM. WITHOUT A SAFETY HARNESS, YOU CAN FALL. THIS CAN KILL YOU OR CAUSE YOU INJURY.

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

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 315
ZONE: 316

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE
No specific	1	CLEANING EQUIPMENT - STEAM
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.08ABD1)	Aqueous Cleaner-Aircraft Exterior Gel Type -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315	TAIL CONE APU AND ACCESSORY COMPARTMENT
316	TAIL CONE APU AND ACCESSORY COMPARTMENT
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 49-00-00-860-008-A	APU Start by External Power
TASK 49-00-00-860-008-A-01	APU Start by Batteries
TASK 49-00-00-860-009-A	APU Shutdown by External Power (131-9(A))
TASK 49-00-00-860-009-A-01	APU Shutdown by Batteries (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

3. Job Set-up
Subtask 49-16-00-860-076-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, press the APU MASTER SW pushbutton switch then make sure that the APU air intake flap has moved to the fully open position.
(3) Put a WARNING NOTICE(S) 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 49-16-00-865-092-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 49-16-00-010-071-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an 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 switch 11LJ to the ON position.

4. Procedure
Subtask 49-16-00-110-055-A ** ON A/C NOT FOR ALL

A. Clean the APU air-intake system:
(1) Clean the APU air-intake flap, the air intake duct internally and externally and the APU access doors.
(a) Spray the Aqueous Cleaner-Aircraft Exterior Gel Type - (Material No.08ABD1) at a pressure to between 2 bar (29.01 psi) and 3 bar (43.51 psi) on:

The inner walls of the installed air intake duct from the two end sides
The inner walls of the air intake housing from the two sides with the air intake flap
The inner side of APU access doors 316AR and 315AL.

(2) Let the cleaning agent stay on the surfaces for 20 minutes to complete the cleaning procedure.
(3) Flush the cleaning agent from the surfaces with the CLEANING EQUIPMENT - STEAM at a maximum temperature of 130 deg.C (266.00 deg.F) and a maximum pressure of 5 bar (72.5189 psi).
(a) Make sure that:

The water steam pressure is not more than 5 bar (72.5189 psi).
The steam temperature is not more than 130 deg.C (266.00 deg.F).

(4) Inspect the surfaces after the cleaning procedure. If there is contamination, do the cleaning procedure again.
(5) Let the walls dry (for 15 minutes).
(a) If the temperature is less than 4 deg.C (39.20 deg.F), it is recommended that:

You do not let the inlet plenum dry for more than 15 minutes after you flushed it with hot steam water to remove the cleaning agent.
You use a Textile-Lint free Cotton - (Material No.14SBA1) to dry the surface immediately, and then you operate the APU.

(6) Start and operate the APU in the RTL or the GEN LOAD mode for 15 minutes (Ref. AMM TASK 49-00-00-860-008).
(7) Stop the APU (Ref. AMM TASK 49-00-00-860-009).

5. Close-up
Subtask 49-16-00-410-073-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 switch 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 access platform(s).

Subtask 49-16-00-865-093-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 49-16-00-860-077-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) On the panel 25VU, push the APU MASTER SW pushbutton switch and make sure that the APU air intake flap moves to the fully closed position.
(2) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).
(3) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(4) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 01:27:44 UTC