DOC AIRBUS | AMM A320FLeak Test of the APU Fuel Line
TASK 28-22-00-790-002-A
Leak Test of the APU Fuel Line
1. Reason for the Job
Leak test of the APU fuel line with left tank pump running after disconnection of the APU fuel pump system.
2. Job Set-up Information
A. Referenced Information
3. Job Set-up
Subtask 28-22-00-860-060-A
Subtask 28-22-00-790-051-A
Subtask 28-22-00-860-061-A
[Rev.10 from 2021]
2026.04.02 06:17:31 UTC
Leak Test of the APU Fuel Line
1. Reason for the Job
Leak test of the APU fuel line with left tank pump running after disconnection of the APU fuel pump system.
2. Job Set-up Information
A. Referenced Information
| 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 31-60-00-860-001-A | EIS Start Procedure |
Subtask 28-22-00-860-060-A
A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) On the APU section of the overhead panel 25VU, make sure that the APU MASTER SW is in the off position (the ON legend is off).
(4) On the FUEL overhead panel 40VU, make sure that all L TK PUMPS and R TK PUMPS pushbutton switches are released (the OFF legends are on).
Subtask 28-22-00-865-055-A (1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(3) On the APU section of the overhead panel 25VU, make sure that the APU MASTER SW is in the off position (the ON legend is off).
(4) On the FUEL overhead panel 40VU, make sure that all L TK PUMPS and R TK PUMPS pushbutton switches are released (the OFF legends are on).
B. Make sure that this(these) circuit breaker(s) is(are) closed:
4. Procedure| PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | FUEL/X FEED/VALVE/MOT1 | 2QE | A12 |
| 49VU | APU/FUEL/BLOW OFF/PUMP | 2QC | B14 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/FUEL/BLOW OFF/CTL | 1QC | K39 |
| ** ON A/C ALL | |||
| 121VU | APU/APU/CTL | 2KD | L42 |
| 121VU | APU/ECB/SPLY | 1KD | L41 |
| 121VU | APU/FUEL/LP VALVE/CTL | 1QF | M40 |
| 121VU | APU/FUEL/LP VALVE/SPLY | 2QF | M39 |
| 121VU | APU/FUEL/PUMP/CTL | 3QC | M38 |
| 121VU | FUEL/X FEED/VALVE/MOT2 | 1QE | M24 |
| 121VU | FUEL/L WING TK/PUMP2 SPLY | 7QA | N26 |
| 121VU | FUEL/L WING TK/PUMP1 SPLY | 1QA | N23 |
| 121VU | FUEL/R WING TK/PUMP2 SPLY | 8QA | Q26 |
| 121VU | FUEL/R WING TK/PUMP1 SPLY | 2QA | Q23 |
| ** ON A/C NOT FOR ALL | |||
| 121VU | APU/FUEL/BLOW OFF/CTL | 1QC | P38 |
Subtask 28-22-00-790-051-A
A. Leak Test of the APU Fuel Line
(1) On the FUEL overhead panel 40VU, push the L TK PUMPS 1 pushbutton switch (the OFF legend goes off).
(2) On the APU section of the overhead panel 25VU, push the APU MASTER SW to the on position (the ON legend comes on).
(3) On the ECAM control panel, push the FUEL pushbutton switch and make sure that on the lower ECAM display unit the APU fuel valve symbol is in the vertical position (valve open).
(4) Make sure that no fuel comes out of the drain mast at the FR47 and/or the APU compartment drain mast.
(6) On the FUEL overhead panel 40VU, release the L TK PUMPS 1 pushbutton switch (the OFF legend comes on).
5. Close-up(1) On the FUEL overhead panel 40VU, push the L TK PUMPS 1 pushbutton switch (the OFF legend goes off).
(2) On the APU section of the overhead panel 25VU, push the APU MASTER SW to the on position (the ON legend comes on).
(3) On the ECAM control panel, push the FUEL pushbutton switch and make sure that on the lower ECAM display unit the APU fuel valve symbol is in the vertical position (valve open).
(4) Make sure that no fuel comes out of the drain mast at the FR47 and/or the APU compartment drain mast.
NOTE: If the APU fuel line was disconnected, make sure that there are no fuel leaks on the connections before you connect the APU fuel line shroud.
(5) After 5 minutes, release the APU MASTER SW to the off position (the ON legend goes off). (6) On the FUEL overhead panel 40VU, release the L TK PUMPS 1 pushbutton switch (the OFF legend comes on).
Subtask 28-22-00-860-061-A
A. Put the aircraft back to its initial configuration.
(1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Put the system back to the serviceable condition.
(1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Put the system back to the serviceable condition.