Failure of the Thrust Reverser Actuators on Engine 1

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1. Possible Causes
· LOCK IND/PROX SENSOR-THRUST REV LOWER R ACTUATOR ( 4006KS )
· LOCK IND/PROX SENSOR-THRUST REV LOWER L ACTUATOR ( 4007KS )
· LVDT-THRUST REV UPPER R ACTUATOR ( 4003KS )
· LVDT-THRUST REV UPPER L ACTUATOR ( 4004KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. ASM 73-25-16
Ref. AMM 78-31-00-710-041 Operational Test of the Thrust Reverser System with the CFDS
Ref. AMM 78-32-43-000-010 Removal of the C-Duct Locking Actuator
Ref. AMM 78-32-43-400-010 Installation of the C-Duct Locking Actuator
Ref. AMM 78-32-48-000-010 Removal of the C-Duct Non-Locking Actuator
Ref. AMM 78-32-48-400-010 Installation of the C-Duct Non-Locking Actuator
3. Fault Confirmation
Subtask 78-30-00-710-182-A
A. 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
Subtask 78-30-00-810-134-A
A. NOTE: If REVERSE UNLOCKED E/W is reported flashing during A/C electrical power transfer, check and
ensure that only one proximity sensor post S/N 7883 is installed per T/R system.
NOTE: No maintenance action is necessary if the message HC/PROX SW/T/R UP ACT1 is detected
during the EEC ground scanning and if the ECAM warning ENG1 REVERSE UNLOCKED is not
triggered.
(1) If the test gives the ECAM warning ENG1 REVERSE UNLOCKED and the maintenance message
HC/PROX SW/T/R UP ACT1:
· do a check for 28VDC:
. at pin A of the proximity sensor (4006KS)
. at pin A of the proximity sensor (4007KS)
Ref. ASM 73-25-16.
(2) If there is no 28VDC at the proximity sensor (4006KS):
· repair the wiring from pin A of the proximity sensor (4006KS) to the circuit breaker 1EN1 Ref. ASM
73-25-16.
(3) If there is no 28VDC at the proximity sensor (4007KS):
· repair the wiring from pin A of the proximity sensor (4007KS) to the circuit breaker 2EN1 Ref. ASM
73-25-16.
(4) If there is 28VDC at the sensors:
· replace the LOCK IND/PROX SENSOR-THRUST REV LOWER R ACTUATOR ( 4006KS )
and the LOCK IND/PROX SENSOR-THRUST REV LOWER L ACTUATOR ( 4007KS ) Ref.
AMM 78-32-43-000-010 and Ref. AMM 78-32-43-400-010 .
(a) If the fault continues:
· replace the LVDT-THRUST REV UPPER R ACTUATOR ( 4003KS ) and LVDTTHRUST
REV UPPER L ACTUATOR ( 4004KS ) Ref. AMM 78-32-48-000-010 and Ref.
AMM 78-32-48-400-010 .
Subtask 78-30-00-710-183-A
B. Do the test given in Para. 3. [Rev.6 from Feb 2017] 2026.04.04 04:38:09 UTC