Removal of the Yaw Damper Servo Actuator

TASK 27-26-51-000-001-A
Removal of the Yaw Damper Servo Actuator

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: 3CC1
FIN: 3CC2

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 6M (20 FT) - ADJUSTABLE
No specific	1	CAP - BLANKING
No specific	1	CONTAINER - HYDRAULIC FLUID RESISTANT
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
98D27207548000	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 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-00-00-910-002-A	Safety Procedures of the Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 55-33-13-010-002-A	Opening/Removal of the Trailing Edge Access-Panels of the Vertical Stabilizer
Position of the Rigging Pin (in the Mixer of the Artificial Feel Unit)
Yaw Damper - Servo Actuator

3. Job Set-up
Subtask 27-26-51-010-050-B

A. Get Access
(1) Put the ACCESS PLATFORM 6M (20 FT) - ADJUSTABLE in position.
(2) Open the access panel 325BL (for 3CC1) and/or 325BR (for 3CC2) at the trailing edge of the vertical stabilizer (Ref. AMM TASK 55-33-13-010-002).

Subtask 27-26-51-860-050-B

B. 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.

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES.

(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002).
(2) Put the rudder pedals in the neutral position.
(3) Make sure that the rudder trim control is set at the zero position.

NOTE: Make sure that the trailing edge of the rudder is in line with the red triangle on the tail cone.

(4) Put the WARNING NOTICE(S) in the flight compartment to tell persons not to operate the flight controls.
(5) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(6) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(7) Depressurize the reservoirs of the Green and Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-001).
(8) Put the WARNING NOTICE(S) in position to tell persons not to operate the Green, Yellow and Blue hydraulic systems:

in the cockpit on the hydraulic section 40VU of the overhead panel,
on the ground service panels of the Green, Yellow and Blue hydraulic systems.

(9) Install the 98D27207548000 PIN-RIGGING (100) in the mixer of the artificial feel unit (101).

Position of the Rigging Pin (in the Mixer of the Artificial Feel Unit)

Subtask 27-26-51-865-050-A

C. 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

4. Procedure
Subtask 27-26-51-020-050-A

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT HYDRAULIC LINES ON UNIONS. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL LOOSEN OR TIGHTEN THE UNION TOO MUCH.

A. Removal of the Yaw Damper Servo Actuator 3CC1 and 3CC2

NOTE: The procedure for the removal of the servo actuators 3CC1 (1) and 3CC2 (2) is the same.

(1) Disconnect the electrical connectors (12),(14) from the plugs on the actuator (1),(2).

NOTE: Do not disconnect the bonding straps (13) from the electrical connectors (12),(14) unless a repair or a new installation is necessary.

(2) Put the CAP - BLANKING on the electrical connectors (12).(14) and the plugs on the actuator (1),(2).
(3) Disconnect the hydraulic system from the actuator (1),(2).
(4) Put a CONTAINER - HYDRAULIC FLUID RESISTANT in position below the connections of the hydraulic pipes (16),(19) to the actuator (1),(2).
(5) Disconnect the union nut (18) of the pipe (19) from the union (20) at the pressure port of the actuator (1),(2).
(6) Disconnect the union nut (15) of the pipe (16) from the union (17) at the return port of the actuator (1),(2).
(7) Drain the remaining hydraulic fluid into the CONTAINER - HYDRAULIC FLUID RESISTANT.
(8) Put the CAP - BLANKING on the unions (17),(20) of the actuator (1),(2).
(9) Put the CAP - BLANKING on the ends of the pipes (16),(19).
(10) Disconnect the actuator (1),(2) from the lever (11).
(a) Remove and discard the cotter pin (10).
(b) Remove the nut (9), the washer (8) and the bolt (3).
(c) Move the connection of the actuator (1),(2) away from the lever (11).
(d) Remove the sliding bush (4) from the flanged bush (6) in the lever (11).
(11) Disconnect the actuator (1),(2) from the lever (5).
(a) Support the actuator (1),(2).
(b) Remove and discard the cotter pin (10).
(c) Remove the nut (9), the washer (8) and the bolt (3).
(d) Move the connection of the actuator (1),(2) away from the lever (5).
(e) Remove the actuator (1),(2).
(f) Remove the sliding bush (4) from the flanged bush (6) in the lever (5).

NOTE: Do not remove the flanged bushes (6),(7) from the levers (5),(11). The bushes (6),(7) are safetied in the levers (5),(11) with loctite.

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