Removal of the Rudder Servo Control

TASK 27-24-51-000-001-A
Removal of the Rudder Servo Control

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

CAUTION: DO THIS PROCEDURE IN A HANGAR IF THERE ARE WIND GUSTS. WIND GUSTS CAN CAUSE DAMAGE TO THE LINKAGE WHEN THE RIGGING PINS ARE IN POSITION ON THE RUDDER CONTROL.

CAUTION: MAKE SURE THAT ONE SERVO CONTROL IS INSTALLED AT ALL TIMES. IF YOU MUST REMOVE ALL THREE SERVO CONTROLS, FIRST DO THE INSTALLATION, ADJUSTMENT AND TEST PROCEDURES FOR ONLY ONE OF THE SERVO CONTROLS. IF YOU REMOVE ALL THREE SERVO CONTROLS AT THE SAME TIME, DAMAGE TO THE AIRCRAFT CAN OCCUR.

NOTE: This procedure includes the removal of the rudder servo control with the eye-end with integrated roller bearing and grease nipple (post modification 154553 and post SB 27-1224).

ZONE: 325
FIN: 1025GM
FIN: 2025GM
FIN: 3025GM

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	1	CONTAINER 5 L (1.32 USGAL)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
98D27207546000	1	PIN-RIGGING

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
325	VERTICAL STABILIZER TRAILING EDGE
325BL, 325CL, 325CR, 325DL

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 29-14-00-614-001-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
Rudder Access Panels and Rigging Pin Location
Rudder Servo Controls
Servo Control Connection at the Vertical Stabilizer
Servo Control Connection at the Rudder

3. Job Set-up
Subtask 27-24-51-860-051-B

A. Aircraft Maintenance Configuration
(1) Put the rudder pedals in the neutral position.
(2) 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.

(3) Put the WARNING NOTICE(S) in the flight compartment to tell persons not to operate the flight controls.

Subtask 27-24-51-865-050-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 27-24-51-860-050-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) Put the WARNING NOTICE(S) in position to tell persons not to pressurize the hydraulic systems.
(3) Depressurize the reservoirs of the Green, Yellow and Blue hydraulic systems.
(Ref. AMM TASK 29-14-00-614-001).

Subtask 27-24-51-010-050-B

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

Subtask 27-24-51-480-050-A

E. Installation of the Rigging Pin

Rudder Access Panels and Rigging Pin Location

(1) Install the 98D27207546000 PIN-RIGGING (3) in the bellcrank assy (6) at the lower servo control 1025GM (5).

4. Procedure

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.

Subtask 27-24-51-020-052-E

A. Removal of the Rudder Servo Control 1025GM/2025GM/3025GM

NOTE: The removal of the upper servo control 2025GM is given. The removal of the center servo control 3025GM and the lower servo control 1025GM is the same but with different hydraulic systems.

NOTE: If a servo control with the integrated roller bearing and grease nipple (on the rudder side) is installed:
The removal of this servo control with the roller bearing is different.
Refer to step (10) to see the difference.

(1) Remove the cable assembly (11) and the clamp (10) (only at upper servo control 2025GM) as follows:

Rudder Servo Controls

(a) Remove and discard the cotter pin (13).
(b) Remove the nut (12) and the washer (8).
(c) Remove the screw (9) from the clamp (10) and the eye-end of the cable assembly (11).

NOTE: Do not disconnect the cable assembly (11) from the structure unless a new installation is necessary.

(2) Disconnect the hydraulic system and the bonding jumper (33) as follows:

Servo Control Connection at the Vertical Stabilizer

(a) Put the CONTAINER 5 L (1.32 USGAL) below the hydraulic connections (30), (37) to collect the unwanted fluid.
(b) Disconnect the union nut (38) of the pipe (37) from the union (39) at the pressure port of the servo control (5).
(c) Disconnect the union nut (29) of the pipe (30) from the union (28) at the return port of the servo control (5).
(d) Drain the remaining hydraulic fluid into the container.
(e) Put the CAP - BLANKING on the pipes (30), (37).
(f) Put the CAP - BLANKING on the unions (28), (39) of the servo control (5).
(g) Remove the screw (31) and the washer (32) and disconnect the bonding jumper (33) from the servo control (5).

NOTE: Do not disconnect the bonding jumper (33) from the structure unless a repair or a new installation is necessary.

(3) Disconnect the spring rod (21) from the input lever (17) of the servo control (5) as follows:

Servo Control Connection at the Vertical Stabilizer

(a) Remove and discard the cotter pin (27).
(b) Remove the nut (26), the washer (25) and the screw (18).
(c) Move the end of the spring rod (21) away from the input lever (17).
(d) Temporarily safety the flanged bushes (19), (24) and the sliding bush (20) in the input lever (17).
(4) Disconnect the servo control (5) from the bracket (65) of the rudder (2) as follows:

Servo Control Connection at the Rudder

(a) Remove and discard the cotter pin (98).
(b) Remove the locking cap (97), the nut (96), the washers (90) and the washer (95).

NOTE: Do not remove the bolt (62) at this time.

(5) Disconnect the servo control (5) from the bracket (52) of the vertical stabilizer (1) as follows:

Servo Control Connection at the Vertical Stabilizer

(a) Remove and discard the cotter pin (88).
(b) Remove the locking cap (87), the nut (86), the washers (89) and the washer (85).

NOTE: The servo control weighs approx. 5.5 kg (12.1254 lb).

(6) Remove the bolt (62) from the bracket (65) of the rudder (2).
(7) Remove the bolt (55) from the bracket (52) of the vertical stabilizer (1).
(8) Remove the servo control (5) together with the clamp (10) from the brackets (65),(52).
(9) Remove the quad rings (35) from the bearing of the servo control (5) and attach them to the servo control (5) for shop maintenance.
(10) Remove the quad rings (74) from the eye-end of the servo control (5) and attach them to the servo control (5) for shop maintenance.

NOTE: If you remove a servo control with the integrated roller bearing and grease nipple (100) there are no quad rings (74) installed.

(11) Remove the locking plate (64), the washer (77) and the bushes (73), (75) from the bracket (65) of the rudder (2).
(12) Remove the locking plate (53), the washer (58) and the bushes (34), (36) from the bracket (52) of the vertical stabilizer (1).
(13) Remove the clamp (10) from the servo control (5).

[Rev.10 from 2021] 2026.04.01 04:05:13 UTC