DOC AIRBUS | TSM A320FDeploy Sequence Time Cycle Failure
TASK 78-31-00-810-989-A
Deploy Sequence Time Cycle Failure
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 78-31-00-710-306-A ** ON A/C NOT FOR ALL
Subtask 78-31-00-860-098-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:38:19 UTC
Deploy Sequence Time Cycle Failure
1. Possible Causes
tubes/hoses - filter element
- HCU-T/R, ENG1 [4310EG1]
- HCU-T/R, ENG2 [4310EG2]
- flexible drive shaft
- R UPPER ACTUATOR [3042KM1]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-843-A | Nacelle Component and Harness Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults |
| AMM 71-13-00-010-802 | Opening of the Fan Cowl Doors |
| AMM 71-13-00-410-802 | Closing of the Fan Cowl Doors |
| AMM 78-31-00-200-801 | General Visual Inspection (GVI) of the Thrust Reverser Actuation System (TRAS) |
| AMM 78-31-00-710-805 | Operational Test of Thrust Reverser with MCDU |
| AMM 78-31-01-000-801 | Removal of the TRAS Hydraulic Control Unit (HCU) |
| AMM 78-31-01-400-801 | Installation of the TRAS Hydraulic Control Unit (HCU) |
| AMM 78-31-02-610-801 | Servicing of the TRAS Filter Module 4314KM1, 4314KM2 |
| AMM 78-31-04-000-801 | Removal of the TRAS Locking-Feedback Actuator |
| AMM 78-31-04-400-801 | Installation of the TRAS Locking-Feedback Actuator |
| AMM 78-31-07-000-801 | Removal of the Flex Shaft |
| AMM 78-31-07-400-801 | Installation of the Flex Shaft |
| AMM 78-31-50-000-801 | Removal of the TRAS Hydraulic Tubes and Hoses |
| AMM 78-31-50-400-801 | Installation of the TRAS Hydraulic Tubes and Hoses |
| AMM 78-32-00-210-810 | Detailed Inspection of Thrust Reverser, Primary Sliders and Tracks |
| AMM 78-32-00-210-811 | Detailed Inspection of Thrust Reverser, Forward Frame to Beam Connections |
| AMM 78-32-00-210-813 | General Visual Inspection of the Thrust Reverser, Actuator Fittings and Attachment to Forward Frame |
| AMM 78-32-00-860-802 | Manual Extension of the Thrust-Reverser Translating Sleeves |
Subtask 78-31-00-710-306-A ** ON A/C NOT FOR ALL
A. Do the operational test of the thrust reverser with the MCDU to confirm this fault AMM 78-31-00-710-805.
(1) If the maintenance message does not come back, troubleshoot as described in the nacelle component and harness troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-843).
(a) Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
(3) During cycling, determine which side of thrust reverser system is slow to deploy or does not deploy.
4. Fault Isolation(1) If the maintenance message does not come back, troubleshoot as described in the nacelle component and harness troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-843).
(a) Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
(3) During cycling, determine which side of thrust reverser system is slow to deploy or does not deploy.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
Subtask 78-31-00-810-333-A ** ON A/C NOT FOR ALL A. If there is confirmation of the fault:
(1) If one side does not deploy, check for other fault messages regarding the thrust reverser system.
(a) Troubleshoot these messages first.
(b) Do the test given in Para. 3.
(c) If the fault continues:
1 Continues the troubleshooting.
(2) If both sides are slow:
(a) Check for hydraulic leakage between pylon and T piece.
1 Open the fan cowl doors AMM 71-13-00-010-802.
2 Inspect hydraulic tubes and hoses.
a Replacetubes/hoses as necessary AMM 78-31-50-000-801 and AMM 78-31-50-400-801.
3 If hydraulic leakage is corrected:
a Do the test given in Para. 3.
(b) If no leakagei is found or if the fault continues, check for hydraulic leakage in pylon.
(c) Get access to HCU:
1 Remove the access panel on the pylon to get access to the HCU:
a FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
b FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
2 Inspect hydraulic tubes and hoses.
a Replacetubes/hoses as necessary AMM 78-31-50-000-801 and AMM 78-31-50-400-801.
3 If hydraulic leakage is corrected:
a Do the test given in Para. 3.
(d) If no leakage is found or if the fault continues, check for clogged hydraulic filter (4314KM).
1 Check on filter module if red button is out.
2 If red button is out, replace filter element AMM 78-31-02-610-801.
3 Do the test given in Para. 3.
(e) If filter is not clogged or the fault continues, on HCU, check that flow limit valve works correctly.
1 Push the flow limiting valve pushbutton then release it and check it comes back in position.
2 If pushbutton does not come back:
a Replace HCU-T/R, ENG1 [4310EG1] or HCU-T/R, ENG2 [4310EG2] AMM 78-31-01-000-801 and AMM 78-31-01-400-801.
b Do the test given in Para. 3.
(3) If only one side is slow:
(a) Do a manual extension of low side AMM 78-32-00-860-802.
1 Check that both actuators move synchronized.
2 If not, replace flexible drive shaft AMM 78-31-07-000-801 and AMM 78-31-07-400-801.
3 Do the test given in Para. 3.
(b) If actuators are synchronized or if fault continues, inspect all components that could slow down the deploy sequence:
1 Inspect the primary sliders and tracks AMM 78-32-00-210-810.
2 Inspect locking feedback and locking actuators AMM 78-31-00-200-801.
3 Inspect fittings and attachment of locking feedback and locking actuators AMM 78-32-00-210-813.
4 Inspect the forward frame to beam connections AMM 78-32-00-210-811.
5 Correct all damages found.
6 If any damage corrected:
a Do the test given in Para. 3.
(c) If no damage found or if fault continues:
1 Replace R UPPER ACTUATOR [3042KM1] AMM 78-31-04-000-801 and AMM 78-31-04-400-801 if not already done.
2 Do the test given in Para. 3.
5. Close-up(1) If one side does not deploy, check for other fault messages regarding the thrust reverser system.
(a) Troubleshoot these messages first.
(b) Do the test given in Para. 3.
(c) If the fault continues:
1 Continues the troubleshooting.
(2) If both sides are slow:
(a) Check for hydraulic leakage between pylon and T piece.
1 Open the fan cowl doors AMM 71-13-00-010-802.
2 Inspect hydraulic tubes and hoses.
a Replace
3 If hydraulic leakage is corrected:
a Do the test given in Para. 3.
(b) If no leakagei is found or if the fault continues, check for hydraulic leakage in pylon.
(c) Get access to HCU:
1 Remove the access panel on the pylon to get access to the HCU:
a FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
b FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
2 Inspect hydraulic tubes and hoses.
a Replace
3 If hydraulic leakage is corrected:
a Do the test given in Para. 3.
(d) If no leakage is found or if the fault continues, check for clogged hydraulic filter (4314KM).
1 Check on filter module if red button is out.
2 If red button is out, replace filter element AMM 78-31-02-610-801.
3 Do the test given in Para. 3.
(e) If filter is not clogged or the fault continues, on HCU, check that flow limit valve works correctly.
1 Push the flow limiting valve pushbutton then release it and check it comes back in position.
2 If pushbutton does not come back:
a Replace HCU-T/R, ENG1 [4310EG1] or HCU-T/R, ENG2 [4310EG2] AMM 78-31-01-000-801 and AMM 78-31-01-400-801.
b Do the test given in Para. 3.
(3) If only one side is slow:
(a) Do a manual extension of low side AMM 78-32-00-860-802.
1 Check that both actuators move synchronized.
2 If not, replace flexible drive shaft AMM 78-31-07-000-801 and AMM 78-31-07-400-801.
3 Do the test given in Para. 3.
(b) If actuators are synchronized or if fault continues, inspect all components that could slow down the deploy sequence:
1 Inspect the primary sliders and tracks AMM 78-32-00-210-810.
2 Inspect locking feedback and locking actuators AMM 78-31-00-200-801.
3 Inspect fittings and attachment of locking feedback and locking actuators AMM 78-32-00-210-813.
4 Inspect the forward frame to beam connections AMM 78-32-00-210-811.
5 Correct all damages found.
6 If any damage corrected:
a Do the test given in Para. 3.
(c) If no damage found or if fault continues:
1 Replace R UPPER ACTUATOR [3042KM1] AMM 78-31-04-000-801 and AMM 78-31-04-400-801 if not already done.
2 Do the test given in Para. 3.
Subtask 78-31-00-860-098-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the fan cowl doors AMM 71-13-00-410-802.
(b) Close the pylon access panel:
1 FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
2 FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the fan cowl doors AMM 71-13-00-410-802.
(b) Close the pylon access panel:
1 FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
2 FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)