W DOC AIRBUS | AMM A320F

Check APU Compartment and Air Intake Duct for Oil Contamination (APS 3200)

TASK 49-00-00-790-007-A
Check APU Compartment and Air Intake Duct for Oil Contamination (APS 3200)

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).
WARNING: DO NOT START THE APU WHEN THE AIRCRAFT IS IN THE HANGAR. WHEN THE APU OPERATES, THERE ARE RISKS OF INJURY FROM HIGH TEMPERATURES AND DANGEROUS FUMES (THAT CAN FILL THE HANGAR). MAKE SURE THAT PERSONS STAY AWAY FROM THE EXHAUST DUCT. THE EXHAUST DUCT IS DANGEROUS.
WARNING: LOCK THE MECHANISM OF THE ACCESS DOOR 316AR WITH THE PIP PIN WHEN YOU OPEN THE ACCESS DOOR. THIS WILL PREVENT INJURY.
CAUTION: DO NOT START THE APU WITH ACCESS DOORS 315AL AND 316AR OPEN/REMOVED. THE APU FIRE EXTINGUISHER SYSTEM IS NOT SUFFICIENT TO EXTINGUISH A FIRE IF THE ACCESS DOORS 315AL AND 316AR ARE OPEN/REMOVED.
CAUTION: DO NOT START OR TRY TO START THE APU MORE THAN THREE TIMES, ONE AFTER THE OTHER. AFTER THE THIRD TIME, THERE MUST BE A MINIMUM OF ONE HOUR BEFORE YOU START OR TRY TO START THE APU AGAIN. THIS MAKES SURE THAT THE TEMPERATURE OF THE STARTER MOTOR DECREASES SUFFICIENTLY.
ZONE: 315
ZONE: 316
1. Reason for the Job
Refer to the MPD TASK: 499000-A2
CHECK APU COMPARTMENT AND AIR INTAKE DUCT FOR OIL CONTAMINATION
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
1
CLEANING EQUIPMENT - STEAM
No specific
1
DEGREASING EQUIPMENT
No specific
AR
LIGHT SOURCE - HIGHPOWER
No specific
AR
LIGHT SOURCE - ULTRA-VIOLET, PORTABLE
No specific
AR
SAFETY CLIP - CIRCUIT BREAKER
No specific
1
WARNING NOTICE(S)
98L12003001000
AR
HARNESS,SAFETY
 B. 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
 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 49-00-00-860-005-A
APU Start by External Power
TASK 49-00-00-860-005-A-01
APU Start by Batteries
TASK 49-00-00-860-006-A
APU Shutdown by External Power
TASK 49-00-00-860-006-A-01
APU Shutdown by Batteries
TASK 49-11-11-000-003-A
Removal of the Power Plant (APU) (APS 3200)
TASK 49-11-11-400-003-A
Installation of the Power Plant (APU) (APS 3200)
TASK 49-17-00-200-001-A
Inspect the APU Drain System (APS 3200)
TASK 49-21-00-200-801-A
Visual Inspection of the Load-Compressor Buffer-Pressure Tube-Assembly (APS 3200)
TASK 49-21-00-200-802-A
Visual Inspection of the Inserts of the Load-Compressor Buffer-Pressure Tube-Assembly (APS 3200)
TASK 49-81-41-000-803-A
Partial Removal of the Exhaust Muffler for Inspection (APS 3200)
TASK 49-81-41-400-803-A
Installation of the Exhaust Muffler after Partial Removal for Inspection (APS 3200)
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 21-00-00-615-802-A
Level A Decontamination of the Environmental Control System (ECS) (for corrective action)
TASK 21-00-00-615-803-A
Level B Decontamination of the Environmental Control System (ECS) (for corrective action)
TASK 21-00-00-615-804-A
Level C Decontamination of the Environmental Control System (ECS) (for corrective action)
TASK 49-11-11-000-003-A
Removal of the Power Plant (APU) (APS 3200) (for corrective action)
TASK 49-11-11-400-003-A
Installation of the Power Plant (APU) (APS 3200) (for corrective action)
TASK 49-16-00-100-006-A
Cleaning of the APU Air Intake (APS 3200) (for corrective action)
TASK 49-16-00-210-002-A
Detailed Inspection of APU Air Intake, Diffuser Elbow, Seals and Felt Metal (APS 3200) (for corrective action)
TASK 49-16-45-000-002-A
Removal of the Air Intake Diffuser and Elbow (APS 3200) (for corrective action)
TASK 49-16-45-400-002-A
Installation of the Air Intake Diffuser and Elbow (APS 3200) (for corrective action)
TASK 49-17-41-400-002-A
Installation of the Drain Tank (APS 3200) (for corrective action)
TASK 49-52-53-000-001-A
Removal of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200) (for corrective action)
TASK 49-52-53-400-001-A
Installation of the Permanent Magnet Generator (PMG) and Cooling Fan Assembly (APS 3200) (for corrective action)
TASK 49-90-00-600-004-A
Check Oil Level and Replenish (APS 3200) (for corrective action)
F Load Compressor Seal Drain
F Load Compressor Gearbox Interface
F Firewall Seal at Frame 80
3. Job Set-up
Subtask 49-00-00-860-107-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 overhead panel 25VU, make sure that the APU MASTER SW pushbutton switch is released (ON legend is off).
   (3) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
4. Procedure
Subtask 49-00-00-790-056-A ** ON A/C NOT FOR ALL
A. Test the APU for Oil/Fuel Leaks
   (1) Start and operate the APU in the ECS mode (Ref. AMM TASK 49-00-00-860-005).
   (2) During APU operation:
  • Do a check for oil smell in the passenger compartment.
  • Do a check for smoke from the APU exhaust.
NOTE: Oil smell in the passenger compartment is an indication of internal and/or external oil leakage.
Smoke from the APU exhaust is an indication of oil leakage.
   (3) Stop the APU (Ref. AMM TASK 49-00-00-860-006).
   (4) On the APU section of overhead panel 25VU, put a WARNING NOTICE(S) to tell persons not to start the APU.
Subtask 49-00-00-865-119-A ** ON A/C NOT FOR ALL
B. Open, safety and tag this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
121VUAPU/APU/CTL2KDL42
121VUAPU/ECB/SPLY1KDL41
Subtask 49-00-00-010-073-A ** ON A/C NOT FOR ALL
C. Get Access
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.
   (1) Put on and attach the HARNESS, SAFETY before you start work in the work area.
   (2) Put an ACCESS PLATFORM 4M (13 FT)-ADJUSTABLE in position below APU access doors 315AL and 316AR.
   (3) Open APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-010-001).
   (4) Set the light switch 11LJ to the ON position.
Subtask 49-00-00-210-067-A ** ON A/C NOT FOR ALL
D. Internal APU Oil Leak
   (1) Examine if the APU oil level is correct (Ref. AMM TASK 49-90-00-600-004).
NOTE: If there is too much oil in the oil system, it can cause an internal APU oil leak and thus oil smell and/or fumes in the passenger compartment.
   (2) Do a check for oil at the forward bearing seal-drain.
     (a) If you find one drop of oil or more, do an inspection of:
       1 If you find a blockage, clean or replace the load-compressor buffer-pressure tube-assembly (Ref. AMM TASK 49-21-00-200-801).
       2 If you do not find a blockage, replace the APU (Ref. AMM TASK 49-11-11-000-003) and (Ref. AMM TASK 49-11-11-400-003).
     (b) If you find a thin layer of oil (not sufficient for a drop), surfaces wet with oil or discoloration because of oil:
       1 Clean the forward bearing witness-drain-line.
       2 Do a check of the drain mast for blockage (Ref. AMM TASK 49-17-00-200-001).
         a If you do not find a blockage, do this inspection again after 750 flight hours or at every A-check.
         b If you find a blockage:
   (3) Examine the load compressor-to-gearbox interface area for oil leakage. If there is oil leakage:
     (a) Clean and degrease the area.
     (b) Start and operate the APU for a minimum of five minutes (Ref. AMM TASK 49-00-00-860-005).
     (c) Stop the APU (Ref. AMM TASK 49-00-00-860-006).
     (d) Examine the area carefully again.
   (4) If you find an internal oil leak of the APU or oil ingestion from an external oil leak:
  • Remove the APU bleed ducts and do an internal inspection for oil contamination, before you put the aircraft back into service with a repaired or replaced APU.
     (a) If you find duct contamination, clean and degrease the ducts and the load control valve.
     (b) Clean the Environmental Control System (ECS) (Ref. AMM TASK 21-00-00-615-802) or (Ref. AMM TASK 21-00-00-615-803) or (Ref. AMM TASK 21-00-00-615-804).
Subtask 49-00-00-210-068-A ** ON A/C NOT FOR ALL
E. Fluid Migration in Intake Duct and APU Compartment
   (1) Do the steps that follow to detect and/or prevent APU internal/external fluid leakage:
NOTE: APU internal/external fluid leakage can cause an oil smell/fumes in the cabin.
     (a) Examine the APU air intake and intake duct internally and externally for fluid (engine oil/hydraulic oil/fuel/de-icing fluid) contamination by migration. If contamination is found:
  • clean the air-intake duct and diffuser elbow (Ref. AMM TASK 49-16-00-100-006).
  • clean the air-intake flap internally and externally.
  • clean the APU access doors internally and externally.
  • clean the APU compartment walls and fire bulkheads.
     (b) Examine the APU inlet plenum for oil/fluid contamination. If contamination is found:
  • clean the APU inlet plenum with a DEGREASING EQUIPMENT and/or CLEANING EQUIPMENT - STEAM.
Subtask 49-00-00-210-069-A ** ON A/C NOT FOR ALL
F. Inspection of the APU External Components/Interfaces for Oil Leakage
   (1) Examine the cooling fan inlet-duct for oil contamination:
     (a) Remove the cooling fan inlet-duct (Ref. AMM TASK 49-52-53-000-001).
     (b) Examine the inner side of the cooling fan inlet-duct for oil contamination. If there is contamination in the cooling fan inlet-duct and if the inner side of the APU inlet plenum is clean, do the inspection of the cooling fan.
     (c) Install the cooling fan inlet-duct (Ref. AMM TASK 49-52-53-400-001).
   (2) Examine the rear housing of the APU for oil leakage:
     (a) Remove the APU exhaust muffler (Ref. AMM TASK 49-81-41-000-803).
     (b) Examine the rear housing of the APU for oil leakage.
     (c) If you find oil leakage, replace the APU (Ref. AMM TASK 49-11-11-000-003) and (Ref. AMM TASK 49-11-11-400-003).
     (d) Install the APU exhaust muffler (Ref. AMM TASK 49-81-41-400-803).
Subtask 49-00-00-210-071-A ** ON A/C NOT FOR ALL
G. Inspection of the APU Compartment Fire, Duct and Drain Seals.
   (1) Examine the fire-wall seal at frame 80. If the seal is damaged or deformed, replace the seal (Ref. AMM TASK 49-16-00-210-002).
   (2) Examine the APU inlet seal (diffuser to plenum interface). If the seal is damaged or deformed, replace the seal (Ref. AMM TASK 49-16-45-000-002) and (Ref. AMM TASK 49-16-45-400-002).
   (3) Make sure that the air-intake diffuser is correctly aligned.
NOTE: If the diffuser is not correctly aligned, unwanted fluids can be ingested.
   (4) Make sure that the APU drain tubes are correctly aligned with the bellows collector-assembly on the RH APU access door. If they are not correctly aligned:
5. Close-up
Subtask 49-00-00-410-077-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 APU access doors 316AR and 315AL (Ref. AMM TASK 52-41-00-410-001).
   (4) Remove the access platform(s).
   (5) Remove the safety harness.
Subtask 49-00-00-865-120-A ** ON A/C NOT FOR ALL
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
121VUAPU/APU/CTL2KDL42
121VUAPU/ECB/SPLY1KDL41
Subtask 49-00-00-860-108-A ** ON A/C NOT FOR ALL
C. Put the aircraft back to its initial configuration.
   (1) Remove the WARNING NOTICE(S).
   (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).
[Rev.10 from 2021] 2026.04.01 01:25:54 UTC
"Aviabrain" 2025