Adjustment of the N/WS Zero Position with Adjusting Tool F26630200 for A/C with N/WS Feedback Sensor-Box P/N C24763000, NLG Centering Cams as Reference

TASK 32-51-00-820-002-A
Adjustment of the N/WS Zero Position with Adjusting Tool F26630200 for A/C with N/WS Feedback Sensor-Box P/N C24763000, NLG Centering Cams as Reference

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.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

1. Reason for the Job
Do this procedure when you adjust a gear box P/N C24764000 with the adjusting tool F26630200 and when you use the NLG centering cams as reference.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	VOLTMETER - AC, 0-20 V MIN, 0,001 V, 50 TO 2000 HTZ
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 0.15 and 0.1 m.daN (13.27 and 8.85 lbf.in )
F26630200	1	ADJUSTING TOOL-NWS GEARBOX
F26792000	1	SENSOR-VOLTAGE TEST
F26792000-1	1	SENSOR-VOLTAGE TEST

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.03LDA1)	Grease-Hydraulic Systems - -

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 29-10-00-864-001-A	Depressurize the Green Hydraulic System
TASK 32-46-00-740-001-A	BITE Test of the BSCU
TASK 32-51-19-000-001-B	Removal of the Nose Wheel Steering Feedback Sensor Box P/N E21336000
TASK 32-51-19-400-001-B	Installation of the Nose Wheel Steering Feedback Sensor Box P/N E21336000
Adjustment of the Gear Box P/N C24764000 with Adjusting Tool F26630200, NLG Cams as Reference
Calculated Chart - Gear Box P/N C24764000 with Adjusting Tool F26630200, NLG Cams as Reference

3. Job Set-up
Subtask 32-51-00-941-053-A

A. General
(1) Put a WARNING NOTICE(S) in the cockpit to tell persons not to operate the landing gear or the N/WS.
(2) On the panel 400VU, make sure that the L/G normal control lever is in the DOWN position.
(3) On the nose gear leg, on the nose wheel steering deactivation electrical box, make sure that the towing lever is in the normal position (engaged position).
(4) Make sure that the N/WS handwheels and the rudder pedals are in the neutral position.

Subtask 32-51-00-860-067-A

B. Aircraft Maintenance Configuration
(1) Jack up the front of the aircraft (Ref. AMM TASK 07-11-00-581-003).

NOTE: In the fully extended position of the shock absorber, the NLG is automatically centered (the nose wheel steering is in the zero position).

(2) Make sure that the Green hydraulic system is de-pressurized (Ref. AMM TASK 29-10-00-864-001).
(3) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 32-51-00-865-077-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	HYDRAULIC/BRAKING AND STEERING/SYS2/SPLY	4GG	M36
121VU	HYDRAULIC/BRAKING AND STEERING/SYS2/CTL	3GG	M35

Subtask 32-51-00-865-078-A

D. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	HYDRAULIC/BRAKING AND STEERING/SYS1/CTL	1GG	M34
121VU	HYDRAULIC/BRAKING AND STEERING/SYS1/IND AND/SPLY	2GG	M33

4. Procedure

NOTE: The voltages U1 and U2 are in volts (3V approximately).

Subtask 32-51-00-220-054-A

A. Check of the Play on the NLG Centering Cams
(1) On landing gear control and indicating panel 402VU, put the A/SKID & N/W STRG switch in the OFF position.
(2) Disconnect the connector (19) from the nose-wheel-steering feedback-sensor 3GC (16) (control channel) of the Rotary Variable Differential Transducer (RVDT).
(3) Connect the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) between the connector (19) and the RVDT 3GC (16).
(4) On landing gear control and indicating panel 402VU, put the A/SKID & N/W STRG switch in the ON position.
(5) Connect a VOLTMETER - AC, 0-20 V MIN, 0,001 V, 50 TO 2000 HTZ to the SECONDARY VOLTAGE connections on the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST.
(6) Do a check of the play on the NLG cams:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST set the selector switch to U1.
(b) Manually move the wheels in steering mode to the right stop. Record voltage U1.
(c) Manually move the wheels in steering mode to the left stop. Record voltage U1'.
(d) Use voltages U1 and U1' to calculate the average voltage U1".
(e) Manually move the wheels in steering mode to get voltage U1".

NOTE: The angular travel of the nose wheels includes the NLG centering cam play and the NLG torque-link play.

(7) Do the same procedure for the RVDT 4GC (monitoring channel).

Subtask 32-51-00-820-057-A

B. Set the NWS Zero Position

NOTE: The adjustment process is very sensitive.

NOTE: Do not move the wheels manually in the steering mode when you do the adjustment procedure.

(1) Stage 1:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U1.
(b) Record the voltage (U1).
(c) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U2.
(d) Record the voltage (U2).
(e) From the voltages U1 and U2, calculate the voltage U:

-----------------------

! U = U1 - U2 !

-----------------------

(2) If the voltage U is not equal to 0 +/- 20mV, adjust the gear box:
(a) Remove the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-000-001).
(b) On the F26630200 ADJUSTING TOOL-NWS GEARBOX (13), loosen the two knurled adjusters (14) so that the inner part of the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) can turn freely.
(c) Install the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) on the N/WS gearbox (10)

put the stud (22) of the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) in the drive slot (23) of the gearbox plate (12),
attach the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) on the gearbox (10) with the screws (15).

(d) Install the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-400-001)

engage the spigot (20) in the hole (21) on the F26630200 ADJUSTING TOOL-NWS GEARBOX (13),
make sure that it is flush with the N/WS gearbox (10).

NOTE: Lightly lubricate the packing of the sensor (16) with Grease-Hydraulic Systems - - (Material No.03LDA1) .

(3) Stage 2:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U1.
(b) Record the voltage (U1*).
(c) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U2.
(d) Record the voltage (U2*).
(e) From the voltages U1* and U2*, calculate the voltage U*:

-----------------------

! U* = U1* - U2* !

-----------------------

(4) Stage 3:
(a) Calculate the algebraic value T that has been introduced with the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) installed between the RVDT 3GC (16) and the N/WS gearbox (10):

-----------------------

! T = U - U* !

-----------------------

(5) Remove the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-000-001).
(6) Carefully loosen the screws (11) through elongated holes of the F26630200 ADJUSTING TOOL-NWS GEARBOX (13). Leave the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) installed.
(7) Install the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-400-001).
(8) Stage 4:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18), set the selector switch to U1 and then U2.
(b) On the F26630200 ADJUSTING TOOL-NWS GEARBOX, adjust the two knurled adjusters (14). (this will move the drive plate (12) of the gearbox (10)) until you get:

-----------------------------------------------

! U1 = U2 (plus or minus 10mV) !

!---------------------------------------------!

! This figure is the value U (reference) !

-----------------------------------------------

NOTE: When you turn the knurled adjusters, the gear box plate (12) moves and changes the secondary voltages U1 and U2.
When you turn the knurled adjuster:

in one direction, U1 increases and U2 decreases,
in the other direction, U2 increases and U1 dcreases.

(9) Stage 5:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18), set the selector switch to U1.
(b) Adjust the two knurled adjusters (14) again (this will compensate the value T put in with the installation of the F26630200 ADJUSTING TOOL-NWS GEARBOX (13) until you get:

--------------------------------------------------------------

! U1 = U (reference) minus (T/2) (plus or minus 10mV) !

!------------------------------------------------------------!

! This figure is the value U (final) !

--------------------------------------------------------------

(10) Tighten the two knurled adjusters (14). Make sure that the position of the drive plate does not move.
(11) Make sure that:

-------------------------------------

! U1 = U(Final)(plus or minus 10mV) !

-------------------------------------

If the value is not in the limits, do the procedure from stage 4 again.
(12) Remove the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-000-001).
(13) Tighten the screws (11) through elongated holes of the F26630200 ADJUSTING TOOL-NWS GEARBOX (13).
(14) TORQUE the screws (11) to between 0.15 and 0.1 m.daN (13.27 and 8.85 lbf.in )

(15) Loosen the knurled adjusters (14).
(16) Remove the F26630200 ADJUSTING TOOL-NWS GEARBOX (13).
(17) Install the RVDT 3GC (16) (Ref. AMM TASK 32-51-19-400-001).
(18) Do a check for the integrity of the adjustment:
(a) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U1.
(b) Record the voltage.
(c) On the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18) set the selector switch to U2.
(d) Record the voltage.
(e) Make sure that:

-------------------------------------

! U1 = U2 plus or minus 20mV. !

-------------------------------------

If the value is not in the limits, do the procedure from step (2) again.
(19) On landing gear control and indicating panel 402VU, put the A/SKID & N/W STRG switch in OFF position.
(20) Remove the F26792000 SENSOR-VOLTAGE TEST or F26792000-1 SENSOR-VOLTAGE TEST (18).
(21) Connect the electrical connector (19) to the RVDT 3GC (16).
(22) Do the procedure again for the RVDT 4GC (monitor channel).
(23) On landing gear control and indicating panel 402VU, put the A/SKID & N/W STRG switch in ON position.

Subtask 32-51-00-865-079-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
121VU	HYDRAULIC/BRAKING AND STEERING/SYS2/SPLY	4GG	M36
121VU	HYDRAULIC/BRAKING AND STEERING/SYS2/CTL	3GG	M35

5. Close-up
Subtask 32-51-00-581-054-A

A. Lower the aircraft to the ground (Ref. AMM TASK 07-11-00-586-001).

Subtask 32-51-00-740-053-A

B. Bite Test
(1) Do the Bite test of the BSCU (Ref. AMM TASK 32-46-00-740-001).

Subtask 32-51-00-942-060-A

C. Remove the Equipment
(1) Make sure that the work area is clean and clear of tools and other items.
(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 00:51:03 UTC