Removal of the Yaw Damper Position Transducer Unit

TASK 27-26-17-000-001-A
Removal of the Yaw Damper Position Transducer Unit

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: 325
FIN: 2CC

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
98D27207548000	1	PIN-RIGGING
98D27207549000	1	PIN-RIGGING

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
325	VERTICAL STABILIZER TRAILING EDGE
325BL, 325BR

C. Referenced Information

REFERENCE	DESIGNATION
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 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-10-00-863-003-A	Pressurize the Blue Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-003-A-01	Pressurize the Blue Hydraulic System with the Blue Electric Pump
TASK 29-10-00-864-003-A	Depressurize the Blue Hydraulic System
TASK 55-33-13-010-002-A	Opening/Removal of the Trailing Edge Access-Panels of the Vertical Stabilizer
Position Transducer Unit

3. Job Set-up
Subtask 27-26-17-860-051-A

A. Aircraft Maintenance Configuration

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Pressurize the Blue hydraulic system with the electric pump. (Ref. AMM TASK 29-10-00-863-003)
(2) Put the rudder pedals in the neutral position.
(3) Make sure that the RUD TRIM indicator on the panel 110VU of the center pedestal shows zero.
(4) Release the FLT CTL/FAC 1 pushbutton switch on the overhead panel 23VU and the OFF legend comes on.
(5) Release the FLT CTL/FAC 2 pushbutton switch on the overhead panel 24VU and the OFF legend comes on.
(6) Put the WARNING NOTICE(S) in the cockpit to tell persons not to operate the flight controls.
(7) Depressurize the Blue hydraulic system (Ref. AMM TASK 29-10-00-864-003).

Subtask 27-26-17-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AUTO FLT/FAC1/28VDC	5CC1	B04
49VU	AUTO FLT/FAC1/26VAC	14CC1	B03
** ON A/C NOT FOR ALL
49VU	AUTO FLT/FAC1/28VDC	5CC1	H10
49VU	AUTO FLT/FAC1/26VAC	14CC1	H09
** ON A/C ALL
121VU	AUTO FLT/FAC2/28VDC	5CC2	M19
121VU	AUTO FLT/FAC2/26VAC	14CC2	M18

Subtask 27-26-17-860-050-A

C. Aircraft Maintenance Configuration
(1) Make sure that the hydraulic systems are depressurized and put them in the maintenance configuration
(Ref. AMM TASK 29-00-00-864-001)
(2) De-energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-862-002)
(3) Put the WARNING NOTICE(S) in position to tell persons not to operate the hydraulic systems.

Subtask 27-26-17-010-050-B

D. Get Access
(1) Put the ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE in position.
(2) Open the access panels 325BL 325BR at the trailing edge of the vertical stabilizer (1) (Ref. AMM TASK 55-33-13-010-002).

Subtask 27-26-17-480-050-A

E. Installation of the Rigging Pins
(1) Put the rigging pin (5) 98D27207549000 PIN-RIGGING in the bellcrank of the yaw damper.
(2) Put the rigging pin (4) 98D27207548000 PIN-RIGGING in the mixer of the artifical feel unit.

4. Procedure
Subtask 27-26-17-020-050-A

A. Removal of the Yaw Damper Position Transducer Unit 2CC
(1) Disconnect the electrical connectors (18) from the plugs (19) on the transducer unit 2CC (3).

NOTE: Do not disconnect the bonding jumpers (17) from the electrical connectors (18) unless a repair or a new installation is necessary.

(2) Put the CAP - BLANKING on the electrical connectors (18) and the plugs (19).
(3) Disconnect the push-rod (13) from the transducer unit 2CC (3) as follows:
(a) Remove and discard the cotter pin (9).
(b) Remove the nut (10), the washer (11) and the bolt (22) from the connection of the transducer lever (12) and the push-rod (13).
(c) Move the push-rod (13) clear of the transducer lever (12).
(d) Remove the bush (21) from the transducer lever (12).
(4) Remove the transducer unit (3) from the support bracket (8) as follows:
(a) Remove and discard the cotter pins (14).
(b) Support the transducer unit (3) and remove the nuts (15), the washers (16) and the bolts (6) and (7).

NOTE: Identify the bolt (6) to make sure that it is installed in the same position in the support bracket (8).

[Rev.10 from 2021] 2026.03.31 23:49:44 UTC