DOC AIRBUS | AMM A320FDeactivation of the APU Leak-Detection Loop
TASK 36-12-00-040-811-A
Deactivation of the APU Leak-Detection Loop
MMEL 36-09-01E
AIR APU BLEED LEAK ALERT
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 36-12-00-861-054-A ** ON A/C NOT FOR ALL Subtask 36-12-00-941-081-A ** ON A/C NOT FOR ALL
Subtask 36-12-00-740-052-A ** ON A/C NOT FOR ALL
Subtask 36-12-00-860-150-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 01:14:53 UTC
Deactivation of the APU Leak-Detection Loop
WARNING:
MAKE SURE THAT THE PNEUMATIC SYSTEM IS DEPRESSURIZED BEFORE YOU START WORK. PRESSURIZED AIR CAN CAUSE INJURY TO PERSONNEL.
1. Reason for the JobMMEL 36-09-01E
AIR APU BLEED LEAK ALERT
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | CAP - BLANKING |
| No specific | AR | SAFETY CLIP - CIRCUIT BREAKER |
| No specific | AR | WARNING NOTICE(S) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 191 | AIR CONDITIONING COMPT AND FAIRINGS |
| 211 | COCKPIT |
| 191DB |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 24-41-00-861-002-A | Energize the Aircraft Electrical Circuits from the External Power |
| TASK 24-41-00-861-002-A-01 | Energize the Aircraft Electrical Circuits from the APU |
| TASK 24-41-00-861-002-A-02 | Energize the Aircraft Electrical Circuits from Engine 1(2) |
| TASK 24-41-00-862-002-A | De-energize the Aircraft Electrical Circuits Supplied from the External Power |
| TASK 24-41-00-862-002-A-01 | De-energize the Aircraft Electrical Circuits Supplied from the APU |
| TASK 24-41-00-862-002-A-02 | De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2) |
| TASK 36-11-00-740-001-A | BITE Test of the BMC 1(2) |
| TASK 36-12-51-200-001-A | Remove and Check the Auxiliary Power Unit (APU) Bleed Check-Valve for Condition |
| TASK 36-22-00-790-001-A | Leak Check on all the Bleed Air Ducts and the Packs Components |
| AWM 362201 |
Subtask 36-12-00-861-054-A ** ON A/C NOT FOR ALL Subtask 36-12-00-941-081-A ** ON A/C NOT FOR ALL
B. Safety Precautions
(1) In the cockpit, on AIR COND panel 25VU:
(a) Make sure that the ENG BLEED 1 and 2 pushbutton switches are released (the OFF legends are on).
(b) Make sure that the APU BLEED pushbutton switch is released (the ON legend is off).
(c) Make sure that the PACK 1 and 2 pushbutton switches are released (the OFF legends are on).
(d) Make sure that the X BLEED selector switch is set to the OFF position.
(e) Put a WARNING NOTICE(S) in position to tell persons not to operate the ENG BLEED 1 and 2 pushbutton switches.
(f) Put the WARNING NOTICE(S) in position to tell persons not to operate the APU BLEED system.
(2) Open access door 191DB on the HP ground connector:
(a) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the pneumatic system.
4. Procedure(1) In the cockpit, on AIR COND panel 25VU:
(a) Make sure that the ENG BLEED 1 and 2 pushbutton switches are released (the OFF legends are on).
(b) Make sure that the APU BLEED pushbutton switch is released (the ON legend is off).
(c) Make sure that the PACK 1 and 2 pushbutton switches are released (the OFF legends are on).
(d) Make sure that the X BLEED selector switch is set to the OFF position.
(e) Put a WARNING NOTICE(S) in position to tell persons not to operate the ENG BLEED 1 and 2 pushbutton switches.
(f) Put the WARNING NOTICE(S) in position to tell persons not to operate the APU BLEED system.
(2) Open access door 191DB on the HP ground connector:
(a) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the pneumatic system.
Subtask 36-12-00-740-052-A ** ON A/C NOT FOR ALL
A. BITE Test
(1) Do the BITE test of BMC 1(2) (Ref. AMM TASK 36-11-00-740-001):
(a) Make sure that the fault "36-22-17 - APU LOOP" comes into view.
Subtask 36-12-00-790-072-A ** ON A/C NOT FOR ALL (1) Do the BITE test of BMC 1(2) (Ref. AMM TASK 36-11-00-740-001):
(a) Make sure that the fault "36-22-17 - APU LOOP" comes into view.
B. Leak Test
(1) Do a leak check of the APU bleed-air ducts (Ref. AMM TASK 36-22-00-790-001):
(a) Make sure that there are no leaks.
Subtask 36-12-00-865-161-A ** ON A/C NOT FOR ALL (1) Do a leak check of the APU bleed-air ducts (Ref. AMM TASK 36-22-00-790-001):
(a) Make sure that there are no leaks.
NOTE: A leak on the APU bleed-air ducts is a NO GO condition.
C. Open, safety and tag this(these) circuit breaker(s):
Subtask 36-12-00-040-059-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | AIR BLEED/X FEED/VALVE/BAT | 2HV | D13 |
| 49VU | AIR BLEED/ENG 1/CTL | 3HA1 | D12 |
| 49VU | AIR BLEED/ENG 1/MONG | 2HA1 | D11 |
| 122VU | AIR BLEED/ENG 2/CTL | 3HA2 | Z23 |
| 122VU | AIR BLEED/ENG 2/MONG | 2HA2 | Z22 |
| 122VU | AIR BLEED/X FEED VALVE/NORM | 1HV | Z20 |
D. Deactivation of the APU Leak-Detection Loops
(1) On lower-right connector-plate 95VU, do the steps that follow:
(a) Remove connector 251VC-A from its location.
(b) Disconnect pins 25 and 26 from connector 251VC-A and put the CAP - BLANKING on the pins to prevent them from contamination AWM 362201.
(c) Identify the disconnected cables with a label.
(d) Install connector 251VC-A on the plate.
Subtask 36-12-00-220-062-A ** ON A/C NOT FOR ALL (1) On lower-right connector-plate 95VU, do the steps that follow:
(a) Remove connector 251VC-A from its location.
(b) Disconnect pins 25 and 26 from connector 251VC-A and put the CAP - BLANKING on the pins to prevent them from contamination AWM 362201.
(c) Identify the disconnected cables with a label.
(d) Install connector 251VC-A on the plate.
E. Inspection of the APU Bleed Check-Valve
(1) Make sure that the APU bleed check-valve is serviceable (Ref. AMM TASK 36-12-51-200-001).
Subtask 36-12-00-865-162-A ** ON A/C NOT FOR ALL (1) Make sure that the APU bleed check-valve is serviceable (Ref. AMM TASK 36-12-51-200-001).
NOTE: An unserviceable APU bleed check-valve is a NO GO condition.
F. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
5. Close-up| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | AIR BLEED/X FEED/VALVE/BAT | 2HV | D13 |
| 49VU | AIR BLEED/ENG 1/CTL | 3HA1 | D12 |
| 49VU | AIR BLEED/ENG 1/MONG | 2HA1 | D11 |
| 122VU | AIR BLEED/ENG 2/CTL | 3HA2 | Z23 |
| 122VU | AIR BLEED/ENG 2/MONG | 2HA2 | Z22 |
| 122VU | AIR BLEED/X FEED VALVE/NORM | 1HV | Z20 |
Subtask 36-12-00-860-150-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).
(3) Close access door 191DB.
(4) Make an entry in the logbook.
Subtask 36-12-00-862-053-A ** ON A/C NOT FOR ALL (1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).
(3) Close access door 191DB.
(4) Make an entry in the logbook.