Stow Sequence Time Cycle Failure

TASK 78-31-00-810-990-A
Stow Sequence Time Cycle Failure

1. Possible Causes

flexible drive shaft
R UPPER ACTUATOR [3042KM1]

2. Job Set-up Information
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 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 78-31-04-000-801	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 78-32-00-210-810	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
AMM 78-32-00-860-803	Manual Retraction of the Thrust-Reverser Translating Sleeves

3. Fault Confirmation
Subtask 78-31-00-710-307-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 stow.

4. Fault Isolation

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 78-31-00-810-334-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Do a manual extension of low side AMM 78-32-00-860-802.
(a) Check that both actuators move synchronized.
(b) If not, replace flexible drive shaft AMM 78-31-07-000-801 and AMM 78-31-07-400-801.
(c) Do the test given in Para. 3.
(2) If actuators are synchronized or if fault continues, inspect all components that could slow down the deploy sequence:
(a) Inspect the primary sliders and tracks AMM 78-32-00-210-810.
(b) Inspect locking feedback and locking actuators AMM 78-31-00-200-801.
(c) Inspect fittings and attachment of locking feedback and locking actuators AMM 78-32-00-210-813.
(d) Inspect the forward frame to beam connections AMM 78-32-00-210-811.
(e) Do a manual retraction of low side AMM 78-32-00-860-803.
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.
(f) Correct all damages found.
(g) If any damage is corrected:
1 Do the test given in Para. 3.
(h) If no damage is 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.

[Rev.8 from Aug 2018] 2026.04.04 04:38:19 UTC