DOC AIRBUS | AMM A320FCheck of the APU Compartment and the Air Intake Duct for Oil Contamination or Oil Leakage after Oil Smell in the Cabin (APS 3200)
TASK 49-00-00-790-805-A
Check of the APU Compartment and the Air Intake Duct for Oil Contamination or Oil Leakage after Oil Smell in the Cabin (APS 3200)
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 49-00-00-861-067-A ** ON A/C NOT FOR ALL Subtask 49-00-00-860-198-A ** ON A/C NOT FOR ALL
Subtask 49-00-00-790-064-A ** ON A/C NOT FOR ALL
Subtask 49-00-00-410-096-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 12:41:43 UTC
Check of the APU Compartment and the Air Intake Duct for Oil Contamination or Oil Leakage after Oil Smell in the Cabin (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.
1. Reason for the JobSelf 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 | 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 |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 315 | TAIL CONE APU AND ACCESSORY COMPARTMENT |
| 316 | TAIL CONE APU AND ACCESSORY COMPARTMENT |
| 315AL, 316AR |
| 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 49-16-45-400-002-A | Installation of the Air Intake Diffuser and Elbow (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 49-81-41-000-803-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) |
Load-Compressor Seal DrainSubtask 49-00-00-861-067-A ** ON A/C NOT FOR ALL Subtask 49-00-00-860-198-A ** ON A/C NOT FOR ALL
B. Aircraft Maintenance Configuration
(1) On overhead panel 25VU, make sure that the APU MASTER SW pushbutton switch is released (the ON legend is off).
Subtask 49-00-00-864-050-A ** ON A/C NOT FOR ALL (1) On overhead panel 25VU, make sure that the APU MASTER SW pushbutton switch is released (the ON legend is off).
C. Depressurize the aircraft hydraulic systems
(1) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
4. Procedure(1) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-00-00-864-001).
Subtask 49-00-00-790-064-A ** ON A/C NOT FOR ALL
A. Test of 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 the operation of the APU:
(4) On the APU section of overhead panel 25VU, put the WARNING NOTICE(S) in position to tell persons not to start the APU.
Subtask 49-00-00-865-195-A ** ON A/C NOT FOR ALL (1) Start and operate the APU in the ECS mode (Ref. AMM TASK 49-00-00-860-005).
(2) During the operation of the APU:
- Do a check for oil smell in the passenger compartment. We recommend that you use an air-quality measuring device to get an accurate estimate.
- 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). Smoke from the APU exhaust is an indication of oil leakage.
(4) On the APU section of overhead panel 25VU, put the WARNING NOTICE(S) in position to tell persons not to start the APU.
B. Open, safety and tag this(these) circuit breaker(s):
Subtask 49-00-00-010-102-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
| 121VU | APU/ECB/SPLY | 1KD | L41 |
C. Get Access
(2) Put the 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 LIGHT control switch 11LJ to the ON position.
Subtask 49-00-00-210-098-A ** ON A/C NOT FOR ALL 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 the 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 LIGHT control switch 11LJ to the ON position.
D. Internal Leak of the APU Oil
(1) Examine if the APU oil level is correct (Ref. AMM TASK 49-90-00-600-004).
(a) If you find signs of oil at the forward bearing witness-drain-line:
1 Do an inspection of the load-compressor buffer-pressure tube-assembly for blockage (including the housing ports and the tee-fitting) (Ref. AMM TASK 49-21-00-200-801).
1 Do an inspection of the load-compressor buffer-pressure tube-assembly and of the forward bearing witness-drain-line (Ref. AMM TASK 49-21-00-200-801) and (Ref. AMM TASK 49-17-00-200-001).
(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.
(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 49-00-00-210-099-A ** ON A/C NOT FOR ALL (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 leak of the APU oil and thus oil smell and/or fumes in the passenger compartment.
(2) Do a check for oil at the forward bearing witness-drain-line. (a) If you find signs of oil at the forward bearing witness-drain-line:
1 Do an inspection of the load-compressor buffer-pressure tube-assembly for blockage (including the housing ports and the tee-fitting) (Ref. AMM TASK 49-21-00-200-801).
- If a blockage is found, clean and/or replace the load-compressor buffer-pressure tube-assembly (Ref. AMM TASK 49-21-00-200-801).
- If no blockage is found in the load-compressor buffer-pressure tube-assembly, replace the APU (Ref. AMM TASK 49-11-11-000-003) and (Ref. AMM TASK 49-11-11-400-003).
1 Do an inspection of the load-compressor buffer-pressure tube-assembly and of the forward bearing witness-drain-line (Ref. AMM TASK 49-21-00-200-801) and (Ref. AMM TASK 49-17-00-200-001).
- If a blockage is found, clean and/or replace the load-compressor buffer-pressure tube-assembly and the forward bearing witness-drain-line (Ref. AMM TASK 49-21-00-200-801) and (Ref. AMM TASK 49-17-00-200-001).
- If no blockage is found, continue this procedure.
(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.
- Use a LIGHT SOURCE - HIGHPOWER or a LIGHT SOURCE - ULTRA-VIOLET, PORTABLE and do a check for oil leaks. If there is an oil leak which exceeds permitted levels, replace the APU (Ref. AMM TASK 49-11-11-000-003) and (Ref. AMM TASK 49-11-11-400-003).
- 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.
(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).
E. Fluid that goes into the Intake Duct and the APU Compartment
(1) Do the steps that follow to find and/or prevent APU internal/external fluid leaks:
Subtask 49-00-00-210-100-A ** ON A/C NOT FOR ALL (1) Do the steps that follow to find and/or prevent APU internal/external fluid leaks:
NOTE: APU internal/external fluid leaks can cause oil smell/fumes in the cabin.
(a) Examine the APU air intake and air intake duct internally and externally for fluid (engine oil, hydraulic oil, fuel, de-icing fluid) contamination. 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.
- Clean the APU inlet plenum with a DEGREASING EQUIPMENT and/or CLEANING EQUIPMENT - STEAM.
F. Inspection of the APU External Components/Interfaces for Oil Contamination
(1) Examine the cooling fan discharge-duct for oil contamination.
(a) Remove the cooling fan discharge-duct (Ref. AMM TASK 49-52-53-000-001).
(b) Examine the inside of the duct for oil contamination. If the duct is dirty and the inside of the APU inlet plenum is clean, continue the inspection of the cooling fan.
(c) Install the cooling fan discharge-duct (Ref. AMM TASK 49-52-53-400-001).
(2) Examination of the APU rear housing for oil leakage.
(a) Remove the APU exhaust muffler (Ref. AMM TASK 49-81-41-000-803).
(b) Examine the APU rear housing 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 49-00-00-210-101-A ** ON A/C NOT FOR ALL (1) Examine the cooling fan discharge-duct for oil contamination.
(a) Remove the cooling fan discharge-duct (Ref. AMM TASK 49-52-53-000-001).
(b) Examine the inside of the duct for oil contamination. If the duct is dirty and the inside of the APU inlet plenum is clean, continue the inspection of the cooling fan.
(c) Install the cooling fan discharge-duct (Ref. AMM TASK 49-52-53-400-001).
(2) Examination of the APU rear housing for oil leakage.
(a) Remove the APU exhaust muffler (Ref. AMM TASK 49-81-41-000-803).
(b) Examine the APU rear housing 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).
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 has deformation, 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 has deformation, 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. If necessary, align the air intake diffuser (Ref. AMM TASK 49-16-45-400-002).
5. Close-up(1) Examine the fire-wall seal at Frame 80. If the seal is damaged or has deformation, 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 has deformation, 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. If necessary, align the air intake diffuser (Ref. AMM TASK 49-16-45-400-002).
NOTE: If the air intake diffuser is not correctly aligned, unwanted fluids can go into the air intake system.
(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: - Adjust the bellows assembly (Ref. AMM TASK 49-17-41-400-002).
Subtask 49-00-00-410-096-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 LIGHT control switch 11LJ to the OFF position.
(3) Close APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).
(5) Remove the safety harness.
Subtask 49-00-00-865-196-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Set LIGHT control switch 11LJ to the OFF position.
(3) Close APU access doors 315AL and 316AR (Ref. AMM TASK 52-41-00-410-001).
(4) Remove the access platform(s).
(5) Remove the safety harness.
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 49-00-00-860-199-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
| 121VU | APU/ECB/SPLY | 1KD | L41 |
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).
Subtask 49-00-00-862-063-A ** ON A/C NOT FOR ALL (1) Remove the WARNING NOTICE(S).
(2) Put the related hydraulic system in the pressurized configuration (Ref. AMM TASK 29-00-00-864-001).