L/G or L/G Door Uplock TGT POS Fault (sensors 8GA thru 13GA and 26GA thru 31GA)
TASK 32-31-00-810-837-A
L/G or L/G Door Uplock TGT POS Fault (sensors 8GA thru 13GA and 26GA thru 31GA)
A. Referenced Information
3. Fault Confirmation
Subtask 32-31-00-740-077-A
Subtask 32-31-00-810-088-A
Subtask 32-31-00-942-064-A
[Rev.8 from Aug 2018]
2026.04.04 04:40:15 UTC
L/G or L/G Door Uplock TGT POS Fault (sensors 8GA thru 13GA and 26GA thru 31GA)
WARNING:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
WARNING:
MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. MOVEMENT OF THE LANDING GEAR CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.
1. Possible CausesL/G or L/G door slow to operate - UPLOCK ASSY-MLG, L [2509GM]
- UPLOCK ASSY-MLG, R [2510GM]
- UPLOCK ASSY-NLG [2530GM]
- UPLOCK ASSY-MLG DOOR, L [2521GM]
- UPLOCK ASSY-MLG DOOR, R [2520GM]
- UPLOCK ASSY-NLG DOOR [2534GM]
- LGCIU-1 [5GA1]
- LGCIU-2 [5GA2]
- Aircraft wiring
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 32-31-00-810-859-A | NLG Doors Do Not Close Fully or Slow to Operate |
| TSM TASK 32-31-00-810-860-A | MLG Door (LH) Does Not Close Fully or Slow to Operate |
| TSM TASK 32-31-00-810-861-A | MLG Door (RH) Does Not Close Fully or Slow to Operate |
| TSM TASK 32-31-00-810-865-A | NLG Does Not Uplock |
| TSM TASK 32-31-00-810-866-A | MLG (LH) Does Not Uplock |
| TSM TASK 32-31-00-810-867-A | MLG (RH) Does Not Uplock |
| AMM 32-31-00-710-002 | Operational Test of the Landing Gear Doors (With False Targets) |
| AMM 32-31-00-720-002 | Functional Test of the Normal Extension and Retraction of the Landing Gear |
| ASM 323103 | |
| AMM 32-31-14-000-001 | Removal of the NLG Door Uplock Assy |
| AMM 32-31-14-400-001 | Installation of the NLG Door Uplock Assy |
| AMM 32-31-21-000-001 | Removal of the NLG Uplock Assy |
| AMM 32-31-21-400-001 | Installation of the NLG Uplock Assy |
| AMM 32-31-33-000-001 | Removal of the MLG Door Uplock 2520GM |
| AMM 32-31-33-400-002 | Installation of the MLG Door Uplock 2520GM |
| AMM 32-31-44-000-001 | Removal of the MLG Uplock Assembly |
| AMM 32-31-44-400-001 | Installation of the MLG Uplock Assembly |
| AMM 32-31-71-000-001 | Removal of the LGCIU |
| AMM 32-31-71-400-001 | Installation of the LGCIU |
| AMM 32-31-73-000-001 | Removal of the MLG Proximity-Sensors |
| AMM 32-31-73-000-005 | Removal of the NLG Proximity-Sensors |
| AMM 32-31-73-400-001 | Installation of the MLG Proximity-Sensors |
| AMM 32-31-73-400-005 | Installation of the NLG Proximity-Sensors |
| AMM 32-31-73-820-008 | Inductance Check of the Proximity Sensors/Switches |
| AMM 32-31-73-820-009 | Resistance Check of the Proximity Sensors |
| ASM 324304 |
Subtask 32-31-00-740-077-A
A. Message Analysis
or a
L/G DOOR CLOSED PROX SNSR TGT POS
message is shown on the Post Flight Report (PFR), on a set of sensors at the same time (+/- 1 minute), then the fault isL/G or L/G door slow to operate . In this condition, do the trouble shooting as follows:
4. Fault IsolationNOTE: Target position faults can only be confirmed by continuous monitoring (BITE) during the L/G operation.
(1) If an UPLK PROX SNSR or a
L/G DOOR CLOSED PROX SNSR TGT POS
message is shown on the Post Flight Report (PFR), on a set of sensors at the same time (+/- 1 minute), then the fault is
- For NLG Uplock Sensors (12GA and 13GA) do (Ref. TSM TASK 32-31-00-810-865)
- for LH MLG Uplock Sensors (9GA and 11GA) do (Ref. TSM TASK 32-31-00-810-866)
- for RH MLG Uplock Sensors (8GA and 10GA) do (Ref. TSM TASK 32-31-00-810-867)
- for NLG Door Closed Sensors (30GA and 31GA) do (Ref. TSM TASK 32-31-00-810-859)
- for LH MLG Door Closed Sensors (27GA and 29GA) do (Ref. TSM TASK 32-31-00-810-860)
- for RH MLG Door Closed Sensors (26GA and 28GA) do (Ref. TSM TASK 32-31-00-810-861).
- Record which LGCIU reported the fault and do the fault isolation procedure in Para. 4.A.
Subtask 32-31-00-810-088-A
A. Procedure
(6) Do the applicable functional or operational test that follows:
(7) Replace the applicable LGCIU-1 [5GA1] or LGCIU-2 [5GA2] which identified the fault, AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(8) Do a check of and repair as necessary the Aircraft wiring between the:
5. Close-upNOTE: Uplock proximity sensors are a part of the uplock assembly and can not be adjusted.
(1) Do a check of the resistance of the applicable proximity sensor AMM 32-31-73-820-009: - if the resistance values are correct, do the next step
- if one or more of the resistance values is not correct do step (3).
- if the inductance is correct, do step (6)
- if the inductance is not correct, do next step.
- for the proximity sensors 8GA, 9GA, 10GA, 11GA, 26GA, 27GA, 28GA or 29GA AMM 32-31-73-000-001 and AMM 32-31-73-400-001
- for the proximity sensors 12GA, 13GA, 30GA or 31GA AMM 32-31-73-000-005 and AMM 32-31-73-400-005.
- if the inductance is correct, no more maintenance work is necessary
- if the inductance is not correct, do next step.
NOTE: If the inductance of the proximity sensor continues to be incorrect after replacement. The fault is with the sensor/target gap which cannot be adjusted. Thus the complete uplock must be replaced.
(5) Replace the applicable uplock assembly as follows: - for the proximity sensors 9GA, 11GA or (8GA, 10GA) replace UPLOCK ASSY-MLG, L [2509GM] or ( UPLOCK ASSY-MLG, R [2510GM] ), AMM 32-31-44-000-001 and AMM 32-31-44-400-001
- for the proximity sensors 12GA, 13GA replace UPLOCK ASSY-NLG [2530GM] , AMM 32-31-21-000-001 and AMM 32-31-21-400-001
- for the proximity sensors 27GA, 29GA or (26GA, 28GA) replace UPLOCK ASSY-MLG DOOR, L [2521GM] or ( UPLOCK ASSY-MLG DOOR, R [2520GM] ), AMM 32-31-33-000-001 and AMM 32-31-33-400-002
- for the proximity sensors 30GA, 31GA replace UPLOCK ASSY-NLG DOOR [2534GM] , AMM 32-31-14-000-001 and AMM 32-31-14-400-001.
(6) Do the applicable functional or operational test that follows:
- for the proximity sensors 8GA, 9GA, 10GA, 11GA, 12GA or 13GA, do the Functional Test of the Normal Extension and Retraction of the Landing Gear AMM 32-31-00-720-002
- for the proximity sensors 26GA, 27GA , 28GA, 29GA, 30GA or 31GA, do the Operational Test of the Landing Gear Doors AMM 32-31-00-710-002.
(7) Replace the applicable LGCIU-1 [5GA1] or LGCIU-2 [5GA2] which identified the fault, AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(8) Do a check of and repair as necessary the Aircraft wiring between the:
- electrical connectors on the applicable proximity sensor and related LGCIU ARINC tray
ASM 323103 or ASM 324304.
Subtask 32-31-00-942-064-A
A. Put the aircraft back to its initial configuration.