DOC AIRBUS | TSM A320FSlow Operation or non Deployment of the Thrust Reverser
TASK 78-31-00-810-869-A
Slow Operation or non Deployment of the Thrust Reverser
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 78-31-00-710-182-A ** ON A/C NOT FOR ALL
Subtask 78-31-00-810-128-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:38:05 UTC
Slow Operation or non Deployment of the Thrust Reverser
1. Possible Causes
HCU-THRUST REV (4101KS) - CTL UNIT-THROTTLE, ENG 1 [8KS1]
- CTL UNIT-THROTTLE, ENG 2 [8KS2]
- RELAY-THRUST REV INHIBITION, ENG 1 [14KS1]
- RELAY-THRUST REV INHIBITION, ENG 2 [14KS2]
- CHECK VALVE-ENG 1 THR REV, G [3010KM1]
- CHECK VALVE-ENG 2 THR REV, Y [3010KM2]
- LATCH-BLOCKER DOOR, LOWER R [3002KM2]
- LATCH-BLOCKER DOOR, UPPER R [3002KM1]
- LATCH-BLOCKER DOOR, UPPER L [3002KM4]
- LATCH-BLOCKER DOOR, LOWER L [3002KM3]
- ACTUATOR-BLOCKER DOOR, UPPER R [3001KM1]
- ACTUATOR-BLOCKER DOOR, LOWER R [3001KM2]
- ACTUATOR-BLOCKER DOOR, LOWER L [3001KM3]
- ACTUATOR-BLOCKER DOOR, UPPER L [3001KM4]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 29-11-35-000-001 | Removal of the Engine 1 Thrust Reverser Check Valve |
| AMM 29-11-35-400-001 | Installation of the Engine 1 Thrust Reverser Check Valve |
| AMM 29-13-35-000-001 | Removal of the Engine 2 Thrust Reverser Check Valve |
| AMM 29-13-35-400-001 | Installation of the Engine 2 Thrust Reverser Check Valve |
| ASM 732516 | |
| AMM 76-11-19-000-040 | Removal of the Throttle Control Unit |
| AMM 76-11-19-000-042 | Removal of the Throttle Control Unit |
| AMM 76-11-19-400-040 | Installation of the Throttle Control Unit |
| AMM 76-11-19-400-042 | Installation of the Throttle Control Unit |
| AMM 78-31-00-710-040 | Operational Test of the Thrust Reverser System |
| AMM 78-31-00-710-042 | Operational Test of the Thrust Reverser System |
| AMM 78-31-19-000-001 | Removal of the Blocker Door Latches |
| AMM 78-31-19-000-040 | Removal of the Blocker Door Latches |
| AMM 78-31-19-400-001 | Installation of the Blocker Door Latches |
| AMM 78-31-19-400-040 | Installation of the Blocker Door Latches |
| AMM 78-31-41-000-001 | Removal of the Blocker Door Hydraulic Actuator |
| AMM 78-31-41-000-040 | Removal of the Blocker Door Hydraulic Actuators |
| AMM 78-31-41-400-001 | Installation of the Blocker Door Hydraulic Actuator |
| AMM 78-31-41-400-040 | Installation of the Blocker Door Hydraulic Actuators |
| AMM 78-31-51-000-040 | Removal of the Hydraulic Control Unit |
| AMM 78-31-51-000-042 | Removal of the Hydraulic Control Unit |
| AMM 78-31-51-210-041 | Check Hydraulic Control Unit Pop-Out Indicator Position |
| AMM 78-31-51-400-040 | Installation of the Hydraulic Control Unit |
| AMM 78-31-51-400-042 | Installation of the Hydraulic Control Unit |
| AMM 78-31-51-920-001 | Replacement of the Hydraulic Control Unit Filter |
| AMM 78-31-51-920-040 | Replacement of the Hydraulic Control Unit Filter |
Subtask 78-31-00-710-182-A ** ON A/C NOT FOR ALL
A. Make sure that the thrust reverser is not inhibited.
(1) Do an operational test of the thrust reverser system (1A and 1B) AMM 78-31-00-710-040.
Subtask 78-31-00-710-182-B ** ON A/C NOT FOR ALL (1) Do an operational test of the thrust reverser system (1A and 1B) AMM 78-31-00-710-040.
NOTE: If the thrust reverser does not deploy or is slow to deploy, do a check of the thrust reverser test result and the Post Flight Report (PFR). If any thrust reverser related fault message is present, do the relevant trouble shooting procedure.
A. Make sure that the thrust reverser is not inhibited.
(1) Do an operational test of the thrust reverser system (1A and 1B) AMM 78-31-00-710-042.
4. Fault Isolation(1) Do an operational test of the thrust reverser system (1A and 1B) AMM 78-31-00-710-042.
NOTE: If the thrust reverser does not deploy or is slow to deploy, do a check of the thrust reverser test result and the Post Flight Report (PFR). If any thrust reverser related fault message is present, do the relevant trouble shooting procedure.
Subtask 78-31-00-810-128-A ** ON A/C NOT FOR ALL
A. If no message is present:
Subtask 78-31-00-810-128-B ** ON A/C NOT FOR ALL - replace the
HCU-THRUST REV (4101KS) AMM 78-31-51-000-040 and AMM 78-31-51-400-040.
- replace the CTL UNIT-THROTTLE, ENG 1 [8KS1] ( CTL UNIT-THROTTLE, ENG 2 [8KS2] ) AMM 76-11-19-000-040 and AMM 76-11-19-400-040.
- replace the RELAY-THRUST REV INHIBITION, ENG 1 [14KS1] ( RELAY-THRUST REV INHIBITION, ENG 2 [14KS2] ) ASM 732516.
- remove the CHECK VALVE-ENG 1 THR REV, G [3010KM1] AMM 29-11-35-000-001 ( CHECK VALVE-ENG 2 THR REV, Y [3010KM2] AMM 29-13-35-000-001),
- do a check of the valve for signs of damage or contamination,
- clean or replace as required AMM 29-11-35-400-001 ( AMM 29-13-35-400-001).
- do a check of the HCU filter for contamination AMM 78-31-51-210-041.
- replace the HCU filter and flush the hydraulic circuit AMM 78-31-51-920-040.
NOTE: The thrust reverser latches and actuators opening sequence is set as follows:
first LATCH-BLOCKER DOOR, LOWER R [3002KM2] ,
second LATCH-BLOCKER DOOR, UPPER R [3002KM1] ,
third LATCH-BLOCKER DOOR, UPPER L [3002KM4] ,
fourth LATCH-BLOCKER DOOR, LOWER L [3002KM3] ,
the door will deploy only if all latches are opened.
first LATCH-BLOCKER DOOR, LOWER R [3002KM2] ,
second LATCH-BLOCKER DOOR, UPPER R [3002KM1] ,
third LATCH-BLOCKER DOOR, UPPER L [3002KM4] ,
fourth LATCH-BLOCKER DOOR, LOWER L [3002KM3] ,
the door will deploy only if all latches are opened.
- replace successively the four blocker doors latches AMM 78-31-19-000-040 and AMM 78-31-19-400-040 according to the opening sequence of the latches.
- replace successively the ACTUATOR-BLOCKER DOOR, UPPER R [3001KM1] ( ACTUATOR-BLOCKER DOOR, LOWER R [3001KM2] ) ( ACTUATOR-BLOCKER DOOR, LOWER L [3001KM3] ) ( ACTUATOR-BLOCKER DOOR, UPPER L [3001KM4] ) of the doors that do not deploy AMM 78-31-41-000-040 and AMM 78-31-41-400-040.
A. If no message is present:
Subtask 78-31-00-710-183-A ** ON A/C NOT FOR ALL - replace the
HCU-THRUST REV (4101KS) AMM 78-31-51-000-042 and AMM 78-31-51-400-042.
- replace the CTL UNIT-THROTTLE, ENG 1 [8KS1] ( CTL UNIT-THROTTLE, ENG 2 [8KS2] ) AMM 76-11-19-000-042 and AMM 76-11-19-400-042.
- replace the RELAY-THRUST REV INHIBITION, ENG 1 [14KS1] ( RELAY-THRUST REV INHIBITION, ENG 2 [14KS2] ) ASM 732516.
- remove the CHECK VALVE-ENG 1 THR REV, G [3010KM1] AMM 29-11-35-000-001 ( CHECK VALVE-ENG 2 THR REV, Y [3010KM2] AMM 29-13-35-000-001),
- do a check of the valve for signs of damage or contamination,
- clean or replace as required AMM 29-11-35-400-001 ( AMM 29-13-35-400-001).
- do a check of the HCU filter for contamination AMM 78-31-51-210-041.
- replace the HCU filter and flush the hydraulic circuit AMM 78-31-51-920-001.
NOTE: The thrust reverser latches and actuators opening sequence is set as follows:
first LATCH-BLOCKER DOOR, LOWER R [3002KM2] ,
second LATCH-BLOCKER DOOR, UPPER R [3002KM1] ,
third LATCH-BLOCKER DOOR, UPPER L [3002KM4] ,
fourth LATCH-BLOCKER DOOR, LOWER L [3002KM3] ,
the door will deploy only if all latches are opened.
first LATCH-BLOCKER DOOR, LOWER R [3002KM2] ,
second LATCH-BLOCKER DOOR, UPPER R [3002KM1] ,
third LATCH-BLOCKER DOOR, UPPER L [3002KM4] ,
fourth LATCH-BLOCKER DOOR, LOWER L [3002KM3] ,
the door will deploy only if all latches are opened.
- replace successively the four blocker doors latches AMM 78-31-19-000-001 and AMM 78-31-19-400-001 according to the opening sequence of the latches.
- replace successively the ACTUATOR-BLOCKER DOOR, UPPER R [3001KM1] ( ACTUATOR-BLOCKER DOOR, LOWER R [3001KM2] ) ( ACTUATOR-BLOCKER DOOR, LOWER L [3001KM3] ) ( ACTUATOR-BLOCKER DOOR, UPPER L [3001KM4] ) of the doors that do not deploy AMM 78-31-41-000-001 and AMM 78-31-41-400-001.
B. Do the test given in Para. 3.A.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.