NLG Shock Absorber Does Not Extend (L/G will not retract)

TASK 32-31-00-810-868-A
NLG Shock Absorber Does Not Extend (L/G will not retract)

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.

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.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

1. Possible Causes

PROX SNSR-NLG EXT, SYS 1 [24GA]
PROX SNSR-NLG EXT, SYS 2 [25GA]
NLG upper-support anti-rotation lugs
NLG upper-support anti-rotation lugs.

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 31-32-00-860-009	Procedure to Get Access to the SYSTEM REPORT/TEST/L/G Page
AMM 32-21-00-200-002	General Visual Inspection of the Nose Landing Gear
AMM 32-21-00-200-008	Borescope Inspection of the Nose Landing Gear Upper-Support Anti-Rotation lugs and Cylinder lugs
AMM 32-21-00-210-802	General Visual Inspection of the Flight/Ground Sensing-Mechanism
AMM 32-31-00-720-003	Functional Test of the Normal Extension and Retraction of the Nose Landing Gear

3. Fault Confirmation
Subtask 32-31-00-860-100-A ** ON A/C NOT FOR ALL

A. Procedure
(1) If this fault has occurred on the ground, make sure that the aircraft nose does not have too much height. This could be caused by the aircraft center of gravity in the aft position.
(a) Make sure the aircraft center of gravity is correct before you do the Fault Isolation.
(2) No maintenance steps are necessary if this fault has occurred:

During flight phase 8
During taxi on a runway that has snow.

NOTE: In these conditions the radio altimeter can show non-computed data and cause the removal of the inhibition of the ECAM warning. Refer to TFU 344200013.

(3) Do a check of the PFR. Do the Fault Isolation procedure if one or more of the messages that follow are shown:

NLG SHOCK ABSORBER 2526GM
NLG EXT PROX SNSR 24GA TGT POS
NLG EXT PROX SNSR 25GA TGT POS.

(4) No maintenance steps are necessary, if:

The fault has occurred during landing with slow de-rotation (de-rotation more than 10 seconds) in flight phase 7 or 8. The TSD for this will show the first word as 08Ex (fault code is 08E where x = the occurrence count), the fourth word is 7xxx or 8xxx (flight phase 7 or 8) and the sixth word is 1D70.
AND
No ECAM warning 'L/G Shock Absorber Fault' is shown.

Subtask 32-31-00-860-100-B ** ON A/C NOT FOR ALL

A. Procedure
(1) If this fault has occurred on the ground, make sure that the aircraft nose does not have too much height. This could be caused by the aircraft center of gravity in the aft position:
(a) Make sure the aircraft center of gravity is correct before you do the Fault Isolation.
(2) No maintenance steps are necessary if this fault has occurred:

During taxi on a runway that has snow.

NOTE: In these conditions, the radio altimeter can show non-computed data and cause the removal of the inhibition of the ECAM warning. Refer to TFU 344200013.

(3) Do a check of the PFR. If one or more of the messages that follow are shown:

NLG SHOCK ABSORBER(2526GM)
NLG EXT PROX SNSR(24GA)TGT POS
NLG EXT PROX SNSR(25GA)TGT POS:

(a) Get access to the SYSTEM REPORT/TEST/L/G page AMM 31-32-00-860-009:
1 Select the LGCIU 1 main menu:
a If you cannot select the LGCIU 1 menu:

Make sure that the aircraft electrical circuits are energized with an external power supply AMM 24-41-00-861-002. If external power is not available, go to Para. 4. A. (2) (Do the general visual inspection of the NLG).

2 Select the trouble shooting data (TSD).
3 Decode the LGCIU 1 TSD Ref. 32-31-00 PB 301.
4 Record the fault code and the flight phase during which the fault occurred.
(b) Get access to the SYSTEM REPORT/TEST/L/G page AMM 31-32-00-860-009:
1 Select the LGCIU 2 main menu.
2 Select the trouble shooting data (TSD).
3 Decode the LGCIU 2 TSD Ref. 32-31-00 PB 301.
4 Record the fault code and the flight phase during which the fault that occurred.
(4) No maintenance steps are necessary, if

The fault has occuurred during landing with slow de-rotation (de-rotation more than 10 seconds) in flight phase 7 or 8. The TSD for this will show the first word as 08Ex (fault code is 08E where x = the occurrence count), the fourth word is 7xxx or 8xxx (flight phase 7 or 8) and the sixth word is 1D70.
AND
No ECAM warning 'L/G Shock Absorber Fault' is shown.

(5) If the fault is not in the specified limit, do the Fault Isolation.
(6) If a message or messages that follow are shown during ground maintenance with no ECAM warning shown:

NLG EXT PROX SNSR(24GA)TGT POS and N LG EXT PROX SNSR(25GA)TGT POS.

(a) Get access to the SYSTEM REPORT/TEST L/G page AMM 31-32-00-860-009.
(b) Select the applicable LGCIU.
(c) Select TSD.
(d) The TSD shows 1X00 on word 4.

1 shows the aircraft on ground
X is not applicable
00 shows the BITE recording command from the CFDS was null.
This shows that the fault has occurred on the ground it can be ignored.

(e) Refer to table 1.

Table 1

!Word 1 ! Word 2! Word 3! Word 4!

! XXXX ! XXXX ! XXXX ! 1X00 !

! XXXX ! XXXX ! XXXX ! XXXX !

NOTE: This fault can occur with one L/G lifted off the ground and the aircraft electrical power on.

4. Fault Isolation
Subtask 32-31-00-810-126-A ** ON A/C NOT FOR ALL

A. Procedure
(1) At each step, if defects are found:
(a) Do the applicable adjustment or replacement.
(b) Do the functional test of the NLG AMM 32-31-00-720-003.
(2) Do the general visual inspection of the NLG AMM 32-21-00-200-002.
(3) Do a visual check of the PROX SNSR-NLG EXT, SYS 1 [24GA] , the PROX SNSR-NLG EXT, SYS 2 [25GA] and the related NLG flight and ground sensing mechanism AMM 32-21-00-210-802.
(4) If the installed NLG is controlled with a BSCU STD L4.1, L4.5 or L4.8:
(a) Do the borescope inspection of the NLG upper-support anti-rotation lugs AMM 32-21-00-200-008.
(5) Make sure that you cannot turn the NLG shock absorber around its vertical axis by hand.

Subtask 32-31-00-810-126-B ** ON A/C NOT FOR ALL

A. Procedure
(1) At each step, if defects are found:
(a) Do the applicable adjustment or replacement.
(b) Do the functional test of the NLG AMM 32-31-00-720-003.
(2) Do the general visual inspection of the NLG AMM 32-21-00-200-002.
(3) Do a visual check of the PROX SNSR-NLG EXT, SYS 1 [24GA] , the PROX SNSR-NLG EXT, SYS 2 [25GA] and the related NLG flight and ground sensing mechanism AMM 32-21-00-210-802.
(4) Before you do this procedure you must refer to (Ref. SB 32-1310) inspection of the NLG upper-support. This is necessary to make sure that the inspection is applicable.

NOTE: A Borescope inspection is not necessary if:
A L4.8 or later STD or non EMM STD BSCU was installed at manufacture.
or
A L4.8 or later STD or non EMM STD BSCU is installed. Also a new NLG or a NLG
with new upper-support anti-rotation lugs and new cylinder lugs was
installed since the L4.8 or later STD or non EMM Std BSCU was installed.
or
A NLG is installed that is not controlled with a EMM L4.1 or L4.5 STD BSCU.

A Borescope inspection is necessary if:
A NLG was installed that was controlled with a EMM L4.1 or L4.5 STD BSCU. This applies if a L4.8 or later STD or non EMM STD BSCU is installed.

(a) If applicable, do the borescope inspection of the NLG upper-support anti-rotation lugs. AMM 32-21-00-200-008
(5) Make sure that you cannot turn the NLG shock absorber around its vertical axis by hand.

[Rev.8 from Aug 2018] 2026.04.04 04:40:14 UTC