Inspection of the NLG Proximity Sensor and Target Clearances

TASK 32-31-73-200-002-A
Inspection of the NLG Proximity Sensor and Target Clearances

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.

ZONE: 711

1. Reason for the Job
This procedure is for proximity sensors 18GA, 19GA, 24GA, 25GA, 36GA, 37GA, 38GA and 39GA only.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)
98D32203502000	1	SAFETY PIN - NLG DOOR

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
711	NOSE GEAR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 07-11-00-581-003-A	Lifting of the Aircraft at the Forward Jacking Point, MLG Wheels on the Ground
TASK 07-11-00-586-001-A	Lowering of the Aircraft at Forward Jacking Point, MLG Wheels on the Ground
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 31-36-00-740-008-A	Access to the Parameter Call-Up Menus
TASK 32-00-00-481-001-A	Installation of the Safety Devices on the Landing Gears
TASK 32-00-00-481-002-A	Installation of the Safety Devices on the Landing Gear Doors
TASK 32-00-00-860-001-A	Flight Configuration Precautions with Electrical Power
TASK 32-00-00-860-001-A-01	Flight Configuration Precautions without Electrical Power
TASK 32-00-00-860-002-A	Ground Configuration after Flight Configuration with Electrical Power
TASK 32-00-00-860-002-A-01	Ground Configuration after Flight Configuration without Electrical Power
TASK 32-22-00-010-001-A	Nose Gear Doors - Ground Doors Opening
TASK 32-22-00-410-001-A	Nose Gear Doors - Ground Doors Closing
TASK 32-31-73-820-004-A	Adjustment of the NLG Door Open Proximity Sensors
TASK 32-31-73-820-005-A	Adjustment of the NLG Downlock Proximity Sensors
TASK 32-31-73-820-006-A	Adjustment of the NLG Extension/Steering Proximity Sensors
TASK 32-31-73-820-006-A-01	Check/Adjustment of the NLG Extension/Steering Proximity Sensors with the Aircraft Weight on Wheels
CMM 322774
CMM 322743	(for corrective action)
Dimensional Check of the NLG Proximity Sensors 18GA, 19GA, 36GA, 37GA, 38GA, 39GA
Dimensional Check of the NLG Extension/Steering Proximity Sensor 24GA, 25GA ** ON A/C NOT FOR ALL
Dimensional Check of the NLG Extension/Steering Proximity Sensor 24GA, 25GA ** ON A/C NOT FOR ALL
Dimensional Check of the NLG Extension/Steering Proximity Sensors 24GA, 25GA ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 32-31-73-941-055-A

A. Safety Precautions
(1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Make sure that the ground safety locks are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(3) On the panel 400VU:

make sure that the landing-gear control-lever 6GA is in the DOWN position
put a WARNING NOTICE(S) in position to tell persons not to operate the landing gear and the NLG doors.

Subtask 32-31-73-582-054-A

B. Aircraft Maintenance Configuration
(1) If you are to do a check of the proximity sensors 24GA and 25GA, lift the aircraft on jacks (Ref. AMM TASK 07-11-00-581-003).

Subtask 32-31-73-010-054-A

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position below the applicable zone 123.
(2) Open the NLG doors (Ref. AMM TASK 32-22-00-010-001).
(3) Make sure that a 98D32203502000 SAFETY PIN - NLG DOOR is installed in each NLG door (Ref. AMM TASK 32-00-00-481-002).

Subtask 32-31-73-869-058-A

D. Flight Configuration Precautions
(1) If the electrical power is not necessary for other maintenance tasks, de-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002). Then, it is not necessary to operate the LGCIU circuit breakers.
(2) If the electrical power is necessary, do the precautions for flight configuration (Ref. AMM TASK 32-00-00-860-001) before you open the LGCIU circuit breakers.

Subtask 32-31-73-865-067-A

E. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	L/G/LGCIU/SYS1/NORM	1GA	C09
** ON A/C NOT FOR ALL
121VU	LGCIU/BAT SPLY/SYS2	59GA	R33
121VU	LGCIU/BAT SPLY/SYS1	58GA	R32
** ON A/C ALL
121VU	HYDRAULIC/LGCIU/SYS2	2GA	Q35
121VU	HYDRAULIC/LGCIU/SYS1/GRND SPLY	52GA	Q34
** ON A/C NOT FOR ALL
121VU	LGCIU/BAT SPLY/SYS2	59GA	R32
121VU	LGCIU/BAT SPLY/SYS1	58GA	R31

4. Procedure
Subtask 32-31-73-210-084-B ** ON A/C NOT FOR ALL

A. Do a Visual inspection
(1) Examine the target lever and attached link of the NLG extension/steering proximity sensors 24GA(25GA) for:

corrosion
deterioration of protective treatment
distortion and/or cracks
wear or fretting
scores, dents or burrs
damaged screw threads.

(a) If you find damage, repair or replace the components CMM 322743.

Subtask 32-31-73-210-084-C ** ON A/C NOT FOR ALL

A. Visual Inspection
(1) Examine the target lever and attached link of the NLG extension/steering proximity sensors 24GA(25GA) for:

Corrosion
Deterioration of protective treatment
Distortion and/or cracks
Wear or fretting
Scores, dents or burrs
Damaged screw threads.

(a) If you find damage, repair or replace the components CMM 322774.

Subtask 32-31-73-220-078-A

B. Inspection of the NLG Proximity Sensor and Target Clearances

Dimensional Check of the NLG Proximity Sensors 18GA, 19GA, 36GA, 37GA, 38GA, 39GA

Dimensional Check of the NLG Extension/Steering Proximity Sensor 24GA, 25GA ** ON A/C NOT FOR ALL

NOTE: This subtask is only applicable for the NLG leg assembly installed with the support part numbers D65451 or D59978 or D60661.

(1) Measure and record dimensions X and Z for the NLG downlock proximity sensors 18GA (19GA):

Make sure that dimension X is 6.5 mm (0.2559 in.) +/- 0.10 mm (0.0039 in.)
Make sure that dimension Z is 1.5 mm (0.0591 in.) +/- 0.10 mm (0.0039 in.).

(a) If the dimensions are incorrect, do the adjustment of the NLG downlock proximity sensors 18GA (19GA) (Ref. AMM TASK 32-31-73-820-005).
(2) The steps that follow are applicable for the NLG leg assembly installed with only one lubrication fitting on the flight/ground sensing mechanism:
(a) Measure and record dimensions X and Z for the NLG extension/steering proximity sensors 24GA (25GA):

Make sure that dimension X is 1.35 mm (0.0531 in.) +/- 0.75 mm (0.0295 in.)
Make sure that dimension Z is 2.0 mm (0.0787 in.) +/- 0.20 mm (0.0079 in.).

1 If the dimensions are incorrect, do the adjustment of the NLG extension/steering proximity sensors 24GA (25GA) (Ref. AMM TASK 32-31-73-820-006).
(3) Measure and record dimensions X, Y and Z for the NLG door open proximity-sensors 36GA (37GA) and 38GA (39GA):
(a) Make sure that dimension X (the vertical distance between the center of the proximity sensor and the center of its target) is a maximum of 3.0 mm (0.1181 in.).

NOTE: The target center location can be on each side of the sensor center location.

(b) Make sure that dimension Y (the horizontal distance between the center of the proximity sensor and the center of its target) is a maximum of 2.5 mm (0.0984 in.).

NOTE: The target center location can be on each side of the sensor center location.

(c) Make sure that dimension Z (the distance between the proximity sensor and its target) is 2.0 mm (0.0787 in.) +/- 0.50 mm (0.0197 in.).
(d) If the dimensions are incorrect, do the adjustment of the NLG door open proximity-sensors 36GA (37GA), 38GA (39GA) (Ref. AMM TASK 32-31-73-820-004).

Subtask 32-31-73-220-094-A ** ON A/C NOT FOR ALL

C. Inspection of the NLG Proximity Sensor and Target Clearances

Dimensional Check of the NLG Proximity Sensors 18GA, 19GA, 36GA, 37GA, 38GA, 39GA ** ON A/C NOT FOR ALL

Dimensional Check of the NLG Extension/Steering Proximity Sensors 24GA, 25GA ** ON A/C NOT FOR ALL

NOTE: This subtask is only applicable for the NLG leg assembly installed with the support part numbers 30-3753122-00 or 30-3753124-00.

(1) Measure and record dimensions X and Z for the NLG downlock proximity sensors 18GA (19GA):

Make sure that dimension X is 6.5 mm (0.2559 in.) +/- 0.10 mm (0.0039 in.)
Make sure that dimension Z is 1.5 mm (0.0591 in.) +/- 0.10 mm (0.0039 in.).

(a) If the dimensions are incorrect, do the adjustment of the NLG downlock proximity sensors 18GA (19GA) (Ref. AMM TASK 32-31-73-820-005).
(2) The steps that follow are applicable for the NLG leg assembly installed with two lubrication fittings on the flight/ground sensing mechanism:
(a) Measure and record dimensions X and Z for the NLG extension/steering proximity sensors 24GA (25GA):

Make sure that dimension X is 3.5 mm (0.1378 in.) +/- 0.10 mm (0.0039 in.)
Make sure that dimension Z is 2.0 mm (0.0787 in.) +/- 0.10 mm (0.0039 in.).

NOTE: The target center location can be on each side of the sensor center location.

(b) Make sure that dimension Y (the horizontal distance between the center of the proximity sensor and the center of its target) is a maximum of 2.5 mm (0.0984 in.).

NOTE: The target center location can be on each side of the sensor center location.

Subtask 32-31-73-865-068-A

D. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	L/G/LGCIU/SYS1/NORM	1GA	C09
** ON A/C NOT FOR ALL
121VU	LGCIU/BAT SPLY/SYS2	59GA	R33
121VU	LGCIU/BAT SPLY/SYS1	58GA	R32
** ON A/C ALL
121VU	HYDRAULIC/LGCIU/SYS2	2GA	Q35
121VU	HYDRAULIC/LGCIU/SYS1/GRND SPLY	52GA	Q34
** ON A/C NOT FOR ALL
121VU	LGCIU/BAT SPLY/SYS2	59GA	R32
121VU	LGCIU/BAT SPLY/SYS1	58GA	R31

Subtask 32-31-73-869-059-A

E. Flight Configuration Precautions
(1) If you did the flight configuration precautions, put the aircraft back to the ground configuration (Ref. AMM TASK 32-00-00-860-002).

Subtask 32-31-73-710-052-A

F. Test of the Landing-Gear Proximity Sensors
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Do a test of the landing-gear proximity sensors with the NLG extended:
(a) Do a check of LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).

ACTION	RESULT
1.With the MCDU keyboard, on the AIDS PAR LAB CALL-UP page, enter the parameter labels with the alphanumeric keys: NOTE: The format is EQ/SYS/LAB/SDI. You can enter the equipment number (EQ) with two digits (6D) or three digits (06D). The format changes with the FDIMU or DMU configuration. NOTE: You can enter the two parameter labels, left for LGCIU1 and right for LGCIU2, on the same page.
For the LGCIU1, enter 06D/1/021/01 or 6D/1/021/01.	If 24GA senses the weight-off-wheels condition, bit 12 in the DATABITS column shows 0.
For the LGCIU2, enter 06D/2/021/10 or 6D/2/021/10.	If 25GA senses the weight-off-wheels condition, bit 12 in the DATABITS column shows 0.

(3) Do a test of the landing-gear proximity sensors with the NLG compressed
(a) Lower the aircraft at the forward jacking point (Ref. AMM TASK 07-11-00-586-001).
(b) Do a check of the LGCIU1 and LGCIU2 label 021 as follows:
1 Get access to the parameter call-up menus (Ref. AMM TASK 31-36-00-740-008).

ACTION	RESULT
1.With the MCDU keyboard, on the AIDS PAR LAB CALL-UP page, enter the parameter labels with the alphanumeric keys: NOTE: The format is EQ/SYS/LAB/SDI. You can enter the equipment number (EQ) with two digits (6D) or three digits (06D). The format changes with the FDIMU or DMU configuration. NOTE: You can enter the two parameter labels, left for LGCIU1 and right for LGCIU2, on the same page.
For the LGCIU1, enter 06D/1/021/01 or 6D/1/021/01.	If 24GA senses the weight-on-wheels condition, bit 12 in the DATABITS column shows 1.
For the LGCIU2, enter 06D/2/021/10 or 6D/2/021/10.	If 25GA senses the weight-on-wheels condition, bit 12 in the DATABITS column shows 1.

(4) De-energize the aircraft circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 32-31-73-410-055-A

G. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the 98D32203502000 SAFETY PIN - NLG DOOR from each of the NLG doors.
(3) Close the NLG doors (Ref. AMM TASK 32-22-00-410-001).

5. Close-up
Subtask 32-31-73-942-056-A

A. Removal of Equipment
(1) Remove the SAFETY BARRIER(S).
(2) Remove the WARNING NOTICE(S).
(3) Remove the access platform(s).
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.01 00:46:09 UTC