Inspection of the MLG Proximity Sensor and Target Clearances

TASK 32-31-73-200-001-A
Inspection of the MLG 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: 734
ZONE: 744

1. Reason for the Job

NOTE: This procedure is for proximity sensors 14GA, 15GA, 16GA, 17GA, 20GA, 21GA, 22GA, 23GA, 32GA, 33GA, 34GA and 35GA 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)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
734	MAIN DOOR
744	MAIN DOOR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 07-11-00-581-001-A	Lifting for Aircraft Maintenance Operations
TASK 07-11-00-586-002-A	Lowering of the Aircraft for Maintenance Operations
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 32-00-00-481-001-A	Installation of the Safety Devices on the Landing Gears
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 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
TASK 32-31-73-820-001-A	Adjustment of the MLG Downlock Proximity Sensors
TASK 32-31-73-820-002-A	Adjustment of the MLG Extension Proximity Sensors
TASK 32-31-73-820-003-A	Adjustment of the MLG Door Open Proximity Sensors
TASK 32-69-00-740-001-A	BITE Check of Landing-Gear Control Interface-Unit (LGCIU) With Use of MCDU to Ensure that Continuous BITE is Operative
MLG Downlock Proximity Sensor (System 1)
MLG Downlock Proximity Sensor (System 2)
MLG Extension Proximity Sensor
MLG Door Open Proximity Sensor

3. Job Set-up
Subtask 32-31-73-941-054-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 MLG doors.

Subtask 32-31-73-582-053-A

B. Aircraft Maintenance Configuration
(1) If you are to do a check of the MLG proximity sensors 20GA, 21GA, 22GA and 23GA, lift the aircraft on jacks (Ref. AMM TASK 07-11-00-581-001).

Subtask 32-31-73-010-053-A

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position below the applicable zone 734(744).
(2) Open the applicable MLG door (Ref. AMM TASK 32-12-00-010-001).

Subtask 32-31-73-869-056-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 32-31-73-865-065-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 32-31-73-220-077-F ** ON A/C NOT FOR ALL

A. Inspection of the MLG Proximity Sensor and Target Clearances

NOTE: For the dimensions 'new' and 'in service', you must refer to the list that follows:

when the two interface components are new, you must refer to the new dimensions
when one interface component is new and the other component is in service, you must refer to the in service dimensions
when the two interface components are in service, you must refer to the in service dimensions.
'New' refers to a component not used since it was made.
'In service' refers to a component that has been overhauled or used since it was made.

(1) For the MLG downlock proximity sensors 14GA (15GA) (System 1):

MLG Downlock Proximity Sensor (System 1) ** ON A/C NOT FOR ALL

(a) For a new MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

2 Measure the dimension X:

make sure it is between 0.7 mm (0.0276 in.) and 0.9 mm (0.0354 in.).

(b) For an in service MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 0.6 mm (0.0236 in.) and 2.4 mm (0.0945 in.).

2 Measure the dimension X:

make sure it is between 0.35 mm (0.0138 in.) and 1.25 mm (0.0492 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG downlock proximity sensors 14GA (15GA) (Ref. AMM TASK 32-31-73-820-001).
(2) For the MLG downlock proximity sensors 16GA (17GA) (System 2):

MLG Downlock Proximity Sensor (System 2) ** ON A/C NOT FOR ALL

(a) For a new MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

2 Measure the dimension X:

make sure it is between 2.4 mm (0.0945 in.) and 2.6 mm (0.1024 in.).

(b) For an in service lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.05 mm (0.0413 in.) and 1.95 mm (0.0768 in.).

2 Measure the dimension X:

make sure it is between 2.2 mm (0.0866 in.) and 2.8 mm (0.1102 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG downlock proximity sensors 16GA (17GA) (Ref. AMM TASK 32-31-73-820-001).
(3) For the MLG extension proximity sensors 20GA (21GA) (System 1):

MLG Extension Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

(b) Measure the dimension X:

make sure it is between 3.9 mm (0.1535 in.) and 4.1 mm (0.1614 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG extension proximity sensors 20GA (21GA) (Ref. AMM TASK 32-31-73-820-002).
(4) For the MLG extension proximity sensors 23GA (22GA) (System 2):

MLG Extension Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

(b) Measure the dimension X:

make sure it is between 3.9 mm (0.1535 in.) and 4.1 mm (0.1614 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG extension proximity sensors 22GA (23GA) (Ref. AMM TASK 32-31-73-820-002).
(5) For the MLG door open proximity sensors 32GA (33GA), 34GA (35GA):

MLG Door Open Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension X:

make sure it is between -2.5 mm (-0.0984 in.) and 2.5 mm (0.0984 in.)

(b) Measure the dimension Z:

make sure it is between 1.5 mm (0.0591 in.) and 2.5 mm (0.0984 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG door open proximity sensors 32GA (33GA), 34GA (35GA) (Ref. AMM TASK 32-31-73-820-003).

Subtask 32-31-73-220-077-G ** ON A/C NOT FOR ALL

A. Inspection of the MLG Proximity Sensor and Target Clearances

NOTE: For the dimensions 'new' and 'in service', you must refer to the list that follows:

when the two interface components are new, you must refer to the new dimensions
when one interface component is new and the other component is in service, you must refer to the in service dimensions
when the two interface components are in service, you must refer to the in service dimensions.
'New' refers to a component not used since it was made.
'In service' refers to a component that has been overhauled or used since it was made.

(1) For the MLG downlock proximity sensors 14GA (15GA) (System 1):

MLG Downlock Proximity Sensor (System 1) ** ON A/C NOT FOR ALL

(a) For a new MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

2 Measure the dimension X:

make sure it is between 0.7 mm (0.0276 in.) and 0.9 mm (0.0354 in.).

(b) For an in service MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 0.6 mm (0.0236 in.) and 2.4 mm (0.0945 in.).

2 Measure the dimension X:

make sure it is between 0.35 mm (0.0138 in.) and 1.25 mm (0.0492 in.).

MLG Downlock Proximity Sensor (System 2) ** ON A/C NOT FOR ALL

(a) For a new MLG lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

2 Measure the dimension X:

make sure it is between 2.4 mm (0.0945 in.) and 2.6 mm (0.1024 in.).

(b) For an in service lockstay or sidestay:
1 Measure the dimension Z:

make sure it is between 1.05 mm (0.0413 in.) and 1.95 mm (0.0768 in.).

2 Measure the dimension X:

make sure it is between 2.2 mm (0.0866 in.) and 2.8 mm (0.1102 in.).

MLG Extension Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

(b) Measure the dimension X:

make sure it is between 3.9 mm (0.1535 in.) and 4.1 mm (0.1614 in.).

MLG Extension Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension Z:

make sure it is between 1.4 mm (0.0551 in.) and 1.6 mm (0.0630 in.).

(b) Measure the dimension X:

make sure it is between 3.9 mm (0.1535 in.) and 4.1 mm (0.1614 in.).

MLG Door Open Proximity Sensor ** ON A/C NOT FOR ALL

(a) Measure the dimension X:

make sure it is between -2.5 mm (-0.0984 in.) and 2.5 mm (0.0984 in.).

(b) Measure the dimension Z:

make sure it is between 1.5 mm (0.0591 in.) and 2.5 mm (0.0984 in.).

(c) If the dimensions are incorrect, do the adjustment of the MLG door open proximity sensors 32GA (33GA), 34GA (35GA) (Ref. AMM TASK 32-31-73-820-003).

Subtask 32-31-73-586-052-A

B. Aircraft Maintenance Configuration
(1) If you did a check of the proximity sensors 20GA, 21GA, 22GA and 23GA, lower the aircraft off jacks (Ref. AMM TASK 07-11-00-586-002).

Subtask 32-31-73-865-066-A

C. 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 32-31-73-869-057-A

D. 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 32-31-73-410-054-A

E. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the access platform(s).
(3) Close the applicable MLG door (Ref. AMM TASK 32-12-00-410-001).

Subtask 32-31-73-740-055-A

F. Test
(1) Do a BITE test of the landing gear (Ref. AMM TASK 32-69-00-740-001).

5. Close-up
Subtask 32-31-73-942-055-A

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

[Rev.10 from 2021] 2026.04.01 00:46:07 UTC