DOC AIRBUS | TSM A320FFailure of the Thrust Reverser HCU on Engine 1
1. Possible Causes
· HCU-THRUST REV (4101KS)
· wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
· wiring from the EEC (4000KS) to the RELAY-THRUST REV INHIBITION, ENG1 (14KS1)
· wiring from the RELAY-THRUST REV INHIBITION, ENG1 (14KS1) to the HCU-THRUST REV (4101KS)
· wiring from the EEC (4000KS) to the LOCK IND/PROX SENSOR-THRUST REV LOWER L ACTUATOR
(4007KS)
· wiring from the EEC (4000KS) to the LOCK IND/PROX SENSOR-THRUST REV LOWER R ACTUATOR
(4006KS)
· wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 73-22-00-710-040 Operational Test of the FADEC SYSTEM on the Ground
Ref. AMM 73-22-34-000-010 Removal of the Electronic Engine Control (EEC)
Ref. AMM 73-22-34-400-010 Installation of the Electronic Engine Control (EEC)
Ref. ASM 73-25-16
Ref. AMM 78-31-00-710-041 Operational Test of the Thrust Reverser System with the CFDS
Ref. AMM 78-31-51-000-010 Removal of the Thrust Reverser Hydraulic Control Unit
Ref. AMM 78-31-51-400-010 Installation of the Thrust Reverser Hydraulic Control Unit
Thrust Reverser HCU (Engine 1, Channel A) SHEET 1
Thrust Reverser HCU (Engine 1, Channel B) SHEET 1
Figure 78(IAE)-30-00-991-00700-A / SHEET 1/1 - Thrust Reverser HCU (Engine 1, Channel A) not
printed, as per printing preferences
Figure 78(IAE)-30-00-991-00800-B / SHEET 1/1 - Thrust Reverser HCU (Engine 1, Channel B) not
printed, as per printing preferences
3. Fault Confirmation
Subtask 78-30-00-710-266-A
A. FADEC Ground Test
(1) Do the CFDS Message Decoding and read the Scheduled Maintenance Report (Ref. 70-00-00 Page
Block 301 Task Supporting Data).
(2) If the readout gives one of the following fault codes in FADEC 1A or FADEC 1B (Fault Acronym:
ARMWAF, REVILF):
· do the FADEC Ground Test Ref. AMM 73-22-00-710-040 for fault confirmation.
· continue with Fault Isolation Para 4.
(3) If the fault code readout in (1) does not give one of the above listed fault codes:
· continue with fault confirmation by Engine Ground Run Section 4.B below.
Subtask 78-30-00-710-074-A
B. Test
(1) Do the operational test of the thrust reverser system with the CFDS (through FADEC 1A and 1B
menus) Ref. AMM 78-31-00-710-041 .
4. Fault Isolation
(Ref. Fig. Thrust Reverser HCU (Engine 1, Channel A) SHEET 1) (Ref. Fig. Thrust Reverser HCU (Engine 1,
Channel B) SHEET 1)
Subtask 78-30-00-810-062-A
A. If the test gives the maintenance message HYD CONT UNIT/HC/EEC1:
· replace the HCU-THRUST REV (4101KS) Ref. AMM 78-31-51-000-010 and Ref.
AMM 78-31-51-400-010 .
(1) If the fault continues:
· read the fault code shown on the FLIGHT DATA and GROUND DATA of the FADEC (1A and 1B)
menu on the MCDU (Ref. 70-00-00 Page Block 301 Task Supporting Data).
· make a record of the fault code.
(a) If the FADEC 1A menu gives the fault code ARMOFW:
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J1/C, k to pins A/7, 6
· do a check and repair the wiring from the EEC (4000KS) to the RELAY-THRUST REV
INHIBITION, ENG1 (14KS1) pin J3/A to pin A
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pin J3/B to pin A/5
· do a check and repair wiring from the RELAY-THRUST REV INHIBITION, ENG1 (14KS1) to
the HCU-THRUST REV (4101KS) pin 2 to pin A/4 Ref. ASM 73-25-16.
(b) If the FADEC 1A menu gives the fault code REVILF:
· do a check and repair the wiring from the EEC (4000KS) to the LOCK IND/PROX SENSORTHRUST
REV LOWER L ACTUATOR (4007KS) pins J1/S, k to pins A/B, C
· do a check and repair the wiring from the EEC (4000KS) to the RELAY-THRUST REV
INHIBITION, ENG1 (14KS1) pin J3/A to pin A
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pin J3/B to pin A/5
· do a check and repair the wiring from the RELAY-THRUST REV INHIBITION, ENG1 (14KS1)
to the HCU-THRUST REV (4101KS) pin 2 to pin A/4 Ref. ASM 73-25-16.
(c) If the FADEC 1B menu gives the fault code ARMOFW:
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J7/C, k to pins B/7, 6
· do a check and repair the wiring from the EEC (4000KS) to the RELAY-THRUST REV
INHIBITION, ENG1 (14KS1) pin J9/A to pin 4
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pin J9/B to pin B/5
· do a check and repair wiring from the RELAY-THRUST REV INHIBITION, ENG1 (14KS1) to
the HCU-THRUST REV (4101KS) pin B to pin B/4 Ref. ASM 73-25-16.
(d) If the FADEC 1B menu gives the fault code REVILF:
· do a check and repair the wiring from the EEC (4000KS) to the LOCK IND/PROX SENSORTHRUST
REV LOWER R ACTUATOR (4006KS) pins J7/s, k to pins A/B, C
· do a check and repair the wiring from the EEC (4000KS) to the RELAY-THRUST REV
INHIBITION, ENG1 (14KS1) pin J9/A to pin 4
· do a check and repair wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS) pin
J9/B to pin B/5
· do a check and repair the wiring from the RELAY-THRUST REV INHIBITION, ENG1 (14KS1)
to the HCU-THRUST REV (4101KS) pin B to pin B/4 Ref. ASM 73-25-16.
(e) If the FADEC 1A and FADEC 1B menus give the fault code ARMXCF:
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J1/C, k to pins A/7, 6
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J7/C, k to pins B/7, 6
(f) If the FADEC 1A and FADEC 1B menus give the fault code ARMXCW:
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J1/C, k to pins A/7, 6
· do a check and repair the wiring from the EEC (4000KS) to the HCU-THRUST REV (4101KS)
pins J7/C, k to pins B/7, 6
(2) If the fault continues:
· replace the EEC ( 4000KS ) Ref. AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
Subtask 78-30-00-710-267-A
B. Repeat the fault confirmation as given in Para. 3 using the same method (FADEC Ground Test or Engine
Ground Run) as before and confirm fault elimination.
5. Close-up
Subtask 78-30-00-860-062-A
A. Close the fan cowls 437AL and 438AR Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:38:06 UTC