DOC AIRBUS | TSM A320FFLP APPU LH/RH Fault or Wiring Fault
TASK 27-51-00-810-809-A
FLP APPU LH/RH Fault or Wiring Fault
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 27-51-00-740-051-A
Subtask 27-51-00-810-060-A
Subtask 27-51-00-942-058-A
[Rev.8 from Aug 2018]
2026.04.04 04:27:37 UTC
FLP APPU LH/RH Fault or Wiring Fault
1. Possible Causes
- SLAT/FLAP CONTR.COMP. [21CV]
- SLAT/FLAP CONTR.COMP. [22CV]
- POSITION PICK OFF UNIT [29CV]
- POSITION PICK OFF UNIT [30CV]
- aircraft wiring
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 27-51-00-740-002 | BITE Test of the Slat and Flap Control Computers (Flap System) |
| ASM 275106 | |
| ASM 275107 | |
| AMM 27-51-18-000-001 | Removal of the Asymmetry-Position Pick-Off Unit |
| AMM 27-51-18-400-001 | Installation of the Asymmetry-Position Pick-Off Unit |
| AMM 27-51-34-000-001 | Removal of the SFCC |
| AMM 27-51-34-400-001 | Installation of the SFCC |
| AMM 27-54-00-710-001 | Operational Test of the Flap System |
Subtask 27-51-00-740-051-A
A. SFCC BITE Test
(1) Do a BITE test on the SFCC1(2) AMM 27-51-00-740-002.
(2) If the fault data "APPU disconnected or faulty and WTB set" is displayed, page block 301 Table 7 gives the SFCC test menu selection details.
(3) Do the fault isolation.
4. Fault Isolation(1) Do a BITE test on the SFCC1(2) AMM 27-51-00-740-002.
(2) If the fault data "APPU disconnected or faulty and WTB set" is displayed, page block 301 Table 7 gives the SFCC test menu selection details.
(3) Do the fault isolation.
Subtask 27-51-00-810-060-A
A. Procedure
(1) Swap SFCC1 with SFCC2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(2) If the fault moves to the other SFCC position:
(a) Swap back the serviceable SFCC.
(b) Replace the SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] that shows the fault.
(3) If the fault does not move to the other SFCC:
(a) Swap back the SFCCs.
(b) Open, safety and tag these circuit breakers:
Swap the electrical connectors 29CV-A and 29CV-B or 30CV-A and 30CV-B.
(d) Remove the safety clips and the tags and close the two circuit breakers.
(e) Wait 60 seconds for SFCC initialization.
(f) Set the MENU MODE and access the FLP ON GROUND FAULTS and do a check of the ground log.
(g) If the fault moves to the other SFCC:
1 Open, safety and tag the two circuit breakers.
2 Replace the applicable POSITION PICK OFF UNIT [29CV] or POSITION PICK OFF UNIT [30CV]
AMM 27-51-18-000-001 and AMM 27-51-18-400-001.
3 Make sure that the related electrical connectors are correctly installed.
(h) If the fault remains in the same circuit:
1 Swap back the related electrical connectors.
2 Do a check and repair the aircraft wiring between the left or right APPU and the applicable SFCC
ASM 275106 and ASM 275107.
3 Remove the safety clips and the tags and close the two circuit breakers.
4 Wait 60 seconds for SFCC initialization.
5 Set the MENU MODE and access the FLP ON GROUND FAULTS and do a check of the ground log.
(4) After the replacement or the repair of the wiring:
5. Close-up(1) Swap SFCC1 with SFCC2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(2) If the fault moves to the other SFCC position:
(a) Swap back the serviceable SFCC.
(b) Replace the SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] that shows the fault.
(3) If the fault does not move to the other SFCC:
(a) Swap back the SFCCs.
(b) Open, safety and tag these circuit breakers:
- 6CV and
- 8CV.
Swap the electrical connectors 29CV-A and 29CV-B or 30CV-A and 30CV-B.
(d) Remove the safety clips and the tags and close the two circuit breakers.
(e) Wait 60 seconds for SFCC initialization.
(f) Set the MENU MODE and access the FLP ON GROUND FAULTS and do a check of the ground log.
(g) If the fault moves to the other SFCC:
1 Open, safety and tag the two circuit breakers.
2 Replace the applicable POSITION PICK OFF UNIT [29CV] or POSITION PICK OFF UNIT [30CV]
AMM 27-51-18-000-001 and AMM 27-51-18-400-001.
3 Make sure that the related electrical connectors are correctly installed.
(h) If the fault remains in the same circuit:
1 Swap back the related electrical connectors.
2 Do a check and repair the aircraft wiring between the left or right APPU and the applicable SFCC
ASM 275106 and ASM 275107.
3 Remove the safety clips and the tags and close the two circuit breakers.
4 Wait 60 seconds for SFCC initialization.
5 Set the MENU MODE and access the FLP ON GROUND FAULTS and do a check of the ground log.
(4) After the replacement or the repair of the wiring:
- Do the operational test of the flap system AMM 27-54-00-710-001.
Subtask 27-51-00-942-058-A
A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.
Subtask 27-51-00-860-058-A B. Put the aircraft back to its initial configuration.