Adjustment of the Lock Indicator Proximity Sensor [IAE]

TASK 78-31-15-820-010-A
Adjustment of the Lock Indicator Proximity Sensor

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
This TASK supplies the data to adjust and test the lock indicator proximity sensor.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-31-00-710-041-A	Operational Test of the Thrust Reverser System with the CFDS
TASK 78-31-00-710-041-A-02	Operational test of the Thrust Reverser without the CFDS and Engine Running
TASK 78-31-15-000-010-A	Removal of the Lock Indicator Proximity Sensor
TASK 78-31-15-400-010-A	Installation of the Lock Indicator Proximity Sensor
Proximity Sensor

3. Job Set-up
Subtask 78-31-15-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 78-31-15-010-050-A ** ON A/C NOT FOR ALL

B. Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR.
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR.

Subtask 78-31-15-040-052-A ** ON A/C NOT FOR ALL

C. Deactivate the Thrust Reverser:

WARNING: MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Deactivate the thrust reverser Hydraulic Control Unit (HCU) (Ref. AMM TASK 78-30-00-040-012).

4. Procedure
Subtask 78-31-15-820-050-A ** ON A/C NOT FOR ALL

A. Find the correct spacer dimension

Proximity Sensor ** ON A/C NOT FOR ALL

(1) Measure the distance between the face of the proximity switch and the target plate with feeler gauges. If distance is not between 0.06 in. (1.5 mm) and 0.08 in. (2 mm) continue with the adjustment procedure.
(2) Calculate the dimension of the spacer (3) that is necessary.

Subtask 78-31-15-020-051-A ** ON A/C NOT FOR ALL

B. Remove the proximity sensor (Ref. AMM TASK 78-31-15-000-010).

Subtask 78-31-15-420-051-A ** ON A/C NOT FOR ALL

C. Adjust the thickness of the spacer as follows:

Proximity Sensor ** ON A/C NOT FOR ALL

(1) If the distance between the face of the proximity switch and the target plate is larger than 0.08 in. (2.0 mm), replace the spacer with a new one and grind material from the spacer to get the correct distance.

NOTE: The spacer is made of one piece and ground to the correct thickness when the switch is assembled in the factory.

(2) If the distance between the face of the proximity switch and the target plate is smaller than 0.06 in. (1.5 mm), replace the spacer with a new one and grind material from the spacer to get the correct distance.
(3) Install the proximity sensor (Ref. AMM TASK 78-31-15-400-010).

Subtask 78-31-15-820-051-A ** ON A/C NOT FOR ALL

D. Measure the distance between the face of the proximity switch and the target plate on the actuator lock lever. If the distance is not between 0.06 in. (1.5 mm) and 0.08 in. (2 mm), repeat step C.

5. Close-up
Subtask 78-31-15-440-051-A ** ON A/C NOT FOR ALL

A. Activate the thrust reverser HCU (Ref. AMM TASK 78-30-00-440-012).

Subtask 78-31-15-410-050-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR.
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(3) Remove the WARNING NOTICE(S).

Subtask 78-31-15-710-051-A ** ON A/C NOT FOR ALL

C. Operational Test
(1) Do an operational test of the thrust reverser system (Ref. AMM TASK 78-31-00-710-041).

NOTE: As an alternative procedure, you can do the operational test without the CFDS (Ref. AMM TASK 78-31-00-710-041).

[Rev.10 from 2021] 2026.04.01 03:27:33 UTC