Installation of the Rudder Servo Control

TASK 27-24-51-400-001-A
Installation 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.

WARNING: PRESSURIZE ONLY THE HYDRAULIC SYSTEM(S) THAT IS (ARE) NECESSARY FOR THE TASK. ISOLATE THE OTHER HYDRAULIC SYSTEM(S) BEFORE YOU SUPPLY HYDRAULIC POWER TO THE AIRCRAFT.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

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 installation 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	1	CALIPER
No specific	2	CAP - BLANKING
No specific	1	CONTAINER 5 L (1.32 USGAL)
No specific	2	GAGE - FEELER
No specific	1	GUN - GREASE
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft )
No specific	Torque wrench: range to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft )
No specific	Torque wrench: range to between 8.0 and 7.0 m.daN (59.00 and 51.62 lbf.ft )
98D27207546000	1	PIN-RIGGING

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.02ABA1)	Phosphate Ester Hydraulic Fluid-General Power - -
(Material No.03FDB1)	Mineral Oil base Grease-Anti-Fretting Paste -
(Material No.03GBC1)	Synthetic Oil base Grease-General Purpose Lithium Thickened Low Temp. -
(Material No.03GBD1)	Synthetic Oil base Grease-General Purpose Lithium Thickened -
(Material No.03HBD9)	Synthetic Ester base Grease-General Purpose Low Temp -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.12AGC2)	Corrosion Preventive Compound-- Soft Film System
(Material No.14QFB1)	Wire-Locking Dia: 0.8 mm CRES Nickel Alloy -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

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

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
27	COTTER PIN	AIPC 27-21-04-08-050
27	COTTER PIN	AIPC 27-21-84-11-010
88	COTTER PIN	AIPC 27-24-04-20-050
98	COTTER PIN	AIPC 27-24-04-20-050
13	COTTER PIN	AIPC 27-24-04-20-220
74	QUAD RINGS	AIPC 27-24-51-01-070
35	QUAD RINGS	AIPC 27-24-51-01-075
88	COTTER PIN	AIPC 27-24-84-20-050

E. Referenced Information

REFERENCE	DESIGNATION
TASK 20-23-22-910-001-A	Marking of the Unions after Application of Standard or Specific Tightening Torque
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 27-24-00-710-001-A	Operational Test of the Rudder Hydraulic Actuation
TASK 27-24-00-710-002-A	Operational Test of the Rudder Servocontrols with Individual Hydraulic System
TASK 27-24-00-820-001-A	Adjustment of the Rudder Neutral Position
TASK 27-24-00-820-001-A-01	Adjustment of the Rudder Neutral Position
TASK 27-24-00-820-001-B	Adjustment of the Rudder Neutral Position
TASK 29-00-00-864-001-A	Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action
TASK 29-10-00-863-001-A	Pressurize the Green Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-002-A	Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart
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 29-10-00-864-001-A	Depressurize the Green Hydraulic System
TASK 29-10-00-864-002-A	Depressurize the Yellow Hydraulic System
TASK 29-10-00-864-003-A	Depressurize the Blue Hydraulic System
TASK 29-14-00-614-001-A	Depressurization of the Hydraulic Reservoirs
TASK 29-14-00-614-002-A	Pressurization of the Hydraulic Reservoirs through the Ground Connector
TASK 29-14-00-614-002-A-01	Pressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU)
TASK 51-75-13-916-002-A	Repair to a layer of Corrosion Preventive Compound
TASK 55-33-13-010-002-A	Opening/Removal of the Trailing Edge Access-Panels of the Vertical Stabilizer
TASK 55-33-13-410-002-A	Closing/Installation of the Trailing Edge Access-Panels of the Vertical Stabilizer
Rudder Servo Controls
Servo Control Connection at the Vertical Stabilizer
Servo Control Connection at the Rudder
Measurement of the Dimension between the Nut and the Locking Cap
Rudder Access Panels and Rigging Pin Location

3. Job Set-up
Subtask 27-24-51-865-051-A

A. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

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 27-24-51-860-053-B

B. Aircraft Maintenance Configuration
(1) Make sure that the ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE is in position at zone 325.
(2) Make sure that the access panels 325CL 325CR, 325BL 325DL at the trailing edge of the vertical stabilizer are opened (Ref. AMM TASK 55-33-13-010-002).
(3) Make sure that the rudder pedals are in the neutral position.
(4) Make sure that the rudder trim control is set at the zero position.
(5) Make sure that the WARNING NOTICE(S) are in the flight compartment to tell persons not to operate the flight controls.
(6) Make sure that the hydraulic systems are depressurized and put them in the maintenance configuration
(Ref. AMM TASK 29-00-00-864-001).
(7) Make sure that the reservoirs of the Green, Blue and Yellow hydraulic systems are depressurized.
(Ref. AMM TASK 29-14-00-614-001).
(8) Make sure that the 98D27207546000 PIN-RIGGING (3) is installed in the bellcrank assy (6) at the lower servo control 1025GM (5).

4. Procedure

CAUTION: YOU MUST INSTALL HYDRAULIC TUBES WITH HYDRAULIC FLUID AS LUBRICANT.

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 27-24-51-910-051-A

A. Preparation for the Installation
(1) Do a visual check of the identification placard on the servo control:

1025GM.
for the lower servo control connected to the Green hydraulic system,
3025GM
for the center servo control connected to the Yellow hydraulic system,
2025GM
for the upper servo control connected to the Blue hydraulic system.

(2) Make sure that the structure, the paintwork, the rudder control surface and the bonding jumpers are clean and in the correct condition.
(3) Clean the attachment brackets, the bushes and the locking plates with the Non Aqueous Cleaner-General - - (Material No.08BAA9) and let them dry.
(4) Make sure that the bolts, the screws, the nuts, the bushes and the locking plates show no corrosion and are not damaged.
(5) If you install the upper rudder servo control 2025GM (5):

Rudder Servo Controls

(a) Install the clamp (10) to the new rudder servo control (5).

Subtask 27-24-51-560-051-A ** ON A/C NOT FOR ALL

B. Preparation for the Installation of the Rudder Servo Control with the Eye-End WITHOUT Integrated Roller Bearing and Grease Nipple
(1) If you install this type of rudder servo control:
(a) This preparation is not applicable.

Subtask 27-24-51-560-051-B ** ON A/C NOT FOR ALL

B. Preparation for the Installation of the Rudder Servo Control with the Eye-End WITH Integrated Roller Bearing and Grease Nipple
(1) If you install this type of rudder servo control:
(a) Make sure that the rudder servo control is in the correct condition:

Examine the eye-end with the grease nipple and
make sure that the grease nipple is on the same side as the servocontrol lever.

Subtask 27-24-51-420-051-E

C. Installation of the Rudder Servo Control 1025GM/2025GM/3025GM

Servo Control Connection at the Vertical Stabilizer

Servo Control Connection at the Rudder

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

NOTE: You can also install the servo control with the integrated roller bearing and grease nipple on the rudder side.
The installation of this servo control with the roller bearing is different.
Refer to step (10) to see the difference.

(1) Apply the Mineral Oil base Grease-Anti-Fretting Paste - (Material No.03FDB1) to all the bolts and the bushes but not to bolt (62).
(2) Install the bushes (34) and (36) in the bracket (52) of the vertical stabilizer (1).
(3) Install the washer (58), the locking plate (53) in the bracket (52) of the vertical stabilizer (1).
(4) Install the bushes (73) and (75) in the bracket (65) of the rudder (2).
(5) Install the washer (77) and the locking plate (64) in the bracket (65) of the rudder (2).
(6) Put the clamp (10) on the servo control (5).
(7) Put the servo control (5) in position at the bracket (52), (65).
(8) Make sure that the items that follow are correctly installed in the brackets (52) and (65):

The locking plates (53) and (64)
The washers (58) and (77)
The bushes (34), (36), (73) and (75).

(9) Connect the servo control (5) to the bracket (52) of the vertical stabilizer (1) as follows:

Servo Control Connection at the Vertical Stabilizer

NOTE: In this procedure it is necessary for two persons to install the items that follow in the bracket (52):

The servo control (5)
The quad rings (35).

(a) Apply a thin layer of the Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or the Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the new AIPC 27-24-51-01-075 QUAD RINGS (35).
(b) Attach the new quad rings (35) in position at the eye-end bearing of the servo control (5).
(c) Use the two GAGE - FEELER 0.25 mm (0.0098 in.) thick to carefully move the servo control (5) into the bracket (52).
(d) Align the eye-end bearing of the servo control (5) and the new quad rings (35). Do this with the bolt hole in the bracket (52).
(e) Install the bolt (55) through the connection of the bracket (52) and the servo control.
(f) Install the washer (85), the washers (89) and the nut (86) on the bolt (55).
(g) TORQUE the nut (86) to between 8.0 and 7.0 m.daN (59.00 and 51.62 lbf.ft )

.
(h) Install the locking cap (87) and the new AIPC 27-24-04-20-050 COTTER PIN (88) or AIPC 27-24-84-20-050 COTTER PIN (88).
(i) Measure the dimension between the nut and the locking cap with a CALIPER:

Measurement of the Dimension between the Nut and the Locking Cap

Make sure that the dimension is between 0.3 mm (0.01 in.) and 1.7 mm (0.07 in.).

(10) Connection of the servo control (5) to the bracket (65) of the rudder (2):

Servo Control Connection at the Rudder

(a) If you install the servo control with integrated roller bearing and grease nipple (item 100 on the related figure):

It is not necessary to install quad rings.
Because of this fact, the steps (d) thru (g) are NOT applicable.

(b) If you install the servo control WITHOUT integrated roller bearing and grease nipple (item 5 on the related figure):

Two persons are necessary to install the servo control (5) AND the quad rings (74) into the bracket (65).

(c) Apply the corrosion preventive Corrosion Preventive Compound-- Soft Film System (Material No.12AGC2) to the bolt (62).
(d) Apply a thin layer of the Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or the Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the new AIPC 27-24-51-01-070 QUAD RINGS (74).
(e) Attach the new quad rings (74) in position at the eye-end bearing of the servo control (5).
(f) Use the two GAGE - FEELER 0.25 mm (0.0098 in.) thick to carefully move the servo control (5) into the bracket (65).
(g) Align the eye-end bearing of the servo control (5) and the new quad rings (74). Do this with the bolt hole in the bracket (65).
(h) For the servo control (100):
Put the servo control (100) in position in the bracket (65) and make sure that the grease nipple is on the same side as the servo control lever.
(i) Install the bolt (62) through the connection of the bracket (65) and the servo control (5).
(j) Install the washer (95), the washers (90) and the nut (96) on the bolt (62).
(k) TORQUE the nut (96) to between 8.0 and 7.0 m.daN (59.00 and 51.62 lbf.ft )

.
(l) Install the locking cap (97) and the new AIPC 27-24-04-20-050 COTTER PIN (98) or AIPC 27-24-84-20-050 COTTER PIN (88).
(m) Measure the dimension between the nut and the locking cap with a CALIPER:

Measurement of the Dimension between the Nut and the Locking Cap

Make sure that the dimension is between 0.3 mm (0.01 in.) and 1.7 mm (0.07 in.).

(11) Apply a thin layer of the Corrosion Preventive Compound-- Soft Film System (Material No.12AGC2) (Ref. AMM TASK 51-75-13-916-002) to all attachment parts made of steel which you can see. Do not apply the Corrosion Preventive Compound-- Soft Film System (Material No.12AGC2) to the bearings of the servo control (5).
(12) Connect the spring rod (21) to the input lever (17) of the servo control (5) as follows:

Servo Control Connection at the Vertical Stabilizer

(a) Make sure that the items that follow are clean and correctly installed in the input lever (17):

The flanged bushes (19) and (24)
The sliding bush (20).

(b) Put the spring rod (21) in position in the input lever (17).
(c) Apply the Corrosion Preventive Compound-- Soft Film System (Material No.12AGC2) to the screw (18).
(d) Put the screw (18) into the connection of the input lever (17), and the eye-end of the spring rod (21).
(e) Install the washer (25) and the nut (26) on the screw (18).
(f) Tighten the nut (26).
(g) Safety the nut (26) with a new AIPC 27-21-04-08-050 COTTER PIN (27) or AIPC 27-21-84-11-010 COTTER PIN (27).
(13) Connect the hydraulic system as follows:
(a) Remove the CAP - BLANKING from the unions (28) and (39) of the servo control (5).
(b) Remove the CAP - BLANKING from the pipes (30) and (37).
(c) Make sure that the hydraulic line end-fittings are serviceable.
(d) Apply the Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the threads of the line end-fittings.
(e) Connect the union nut (38) of the pipe (37) to the union (39). Do this at the pressure port of the servo control (5).
(f) TORQUE the union nut (38) to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft )

.
(g) Connect the union nut (29) of the pipe (30) to the union (28). Do this at the return port of the servo control (5).
(h) TORQUE the union nut (29) to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft )

.
(i) Make sure that the pipes (30) and (37) have no deformation when you tighten the union nuts (29) and (38). Make sure that the pipes (30) and (37) do not touch the rear spar of the vertical stabilizer (1).
(j) Identify the tightened union nuts with a red line
(Ref. AMM TASK 20-23-22-910-001).
(14) Put the bonding jumper (33) in position at the servo control (5). Attach it with the screw (31) and the washer (32) (Ref. AMM TASK 20-28-00-912-802).
(15) Install the cable assembly (11) to the clamp (10) as follows:

Rudder Servo Controls

(a) Put the eye-end of the cable assembly (11) in position.
(b) Put the screw (9) into the clamp (10) and the eye-end of the cable assembly (11).
(c) Install the washer (8) and the nut (12) on the screw (9).
(d) Tighten and safety the nut (12) with a new AIPC 27-24-04-20-220 COTTER PIN (13).

Subtask 27-24-51-640-050-A

D. Lubrication of the Servo Control with the Integrated Roller Bearing

NOTE: This lubrication is only necessary if you have installed the servo control with the integrated roller bearing.

(1) Clean the grease nipple of the rudder servo control rod eye-end bearing with a clean Textile-Lint free Cotton - (Material No.14SBA1) .
(2) Use a GUN - GREASE to apply the Synthetic Oil base Grease-General Purpose Lithium Thickened Low Temp. - (Material No.03GBC1) through the grease nipple until the new grease comes out.
(3) Remove the unwanted grease from the grease nipple with a clean Textile-Lint free Cotton - (Material No.14SBA1) .

Subtask 27-24-51-080-050-A

E. Removal of the Rigging Pin

Rudder Access Panels and Rigging Pin Location

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

Subtask 27-24-51-865-052-A

F. Remove the safety clip(s) and the tag(s) and close 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 27-24-51-870-050-A

G. Bleeding Procedure of the Rudder Servo Control

NOTE: The bleeding procedure of the upper servo control 2025GM (Blue hydraulic system) is given. If you want to bleed the lower servo control 1025GM (Green hydraulic system) or the center servo control 3025GM (Yellow hydraulic system) you must pressurize/depressurize the related hydraulic system.

(1) Put the switch, A/SKID & N/W STRG, on the center panel 402VU to the OFF position.
(2) Pressurize the reservoirs of the hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(3) Pressurize the Blue hydraulic system (see NOTE above) (Ref. AMM TASK 29-10-00-863-003).
(4) Make sure that the travel range of the servo controls and the rudder are clear of tools and other items.
(5) Operate the left and the right rudder pedals to move the rudder surface.

NOTE: Make sure that there is full and free movement of the rudder pedals.

(6) Operate the rudder pedals ten times and then put them in the neutral position.
(7) Make sure that there are no leaks at the hydraulic connections to the servo control.
(8) Depressurize the Blue hydraulic system (see NOTE above) (Ref. AMM TASK 29-10-00-864-003).
(9) Remove the CONTAINER 5 L (1.32 USGAL).
(10) Remove all the signs of hydraulic fluid from the components in the work area.

Subtask 27-24-51-869-053-B

H. Check of the Rudder Position

NOTE: This procedure describes checks to make sure that the rudder is in the neutral position.
First you do the checks with the servo controls which you have NOT replaced (check 1 and 2). After this you do the check with the servo control which you have replaced (check 3).
In this procedure we describe the 3 checks of the replaced upper servo control 2025GM (Blue hydraulic system).
If you have replaced a different servo control refer to the steps (6) and (7) for details.

NOTE: The rudder is in the neutral position if the trailing edge of the rudder aligns with the red reference triangle on the tail cone.

(1) Install the 98D27207546000 PIN-RIGGING (3) in the bellcrank assy (6) at the lower servo control 1025GM.
(2) In the cockpit: Make sure that the RUD TRIM indicator on the center pedestal panel 110VU, shows zero.
(3) Do the check of the rudder position with a servo control which you have not replaced (check 1):
(a) Pressurize the Green hydraulic system (Ref. AMM TASK 29-10-00-863-001).
(b) Make sure that the trailing edge of the rudder aligns with the red reference triangle on the tail cone.
(c) If there is no red reference triangle on the tail cone, do the adjustment of the rudder neutral position (Ref. AMM TASK 27-24-00-820-001).
(d) If the trailing edge of the rudder and the red reference triangle do not align:

Do the adjustment procedure of the spring rod of the lower rudder servo control 1025GM (refer to the procedure below).

(e) Depressurize the Green hydraulic system (Ref. AMM TASK 29-10-00-864-001).

If you need to adjust the spring rod:
Do not depressurize the Green hydraulic system at this time.

(4) Do the check of the rudder position with a servo control which you have not replaced (check 2):
(a) Pressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-863-002).
(b) Make sure that the trailing edge of the rudder aligns with the red reference triangle on the tail cone.
(c) If there is no red reference triangle on the tail cone, do the adjustment of the rudder neutral position (Ref. AMM TASK 27-24-00-820-001).
(d) If the trailing edge of the rudder and the red reference triangle do not align:

Do the adjustment procedure of the spring rod of the center rudder servo control 3025GM (refer to the procedure below).

(e) Depressurize the Yellow hydraulic system (Ref. AMM TASK 29-10-00-864-002)

If you need to adjust the spring rod:
Do not depressurize the Yellow hydraulic system at this time.

(5) Do the check of the rudder position with the servo control which you have replaced (check 3):
(a) Pressurize the Blue hydraulic system (Ref. AMM TASK 29-10-00-863-003).
(b) Make sure that the trailing edge of the rudder aligns with the red reference triangle on the tail cone.
(c) If there is no red reference triangle on the tail cone, do the adjustment of the rudder neutral position (Ref. AMM TASK 27-24-00-820-001).
(d) If the trailing edge of the rudder and the red reference triangle do not align:

Do the adjustment procedure of the spring rod of the upper rudder servo control 2025GM (refer to the procedure below).

(e) Depressurize the Blue hydraulic system (Ref. AMM TASK 29-10-00-864-003).

If you need to adjust the spring rod:
Do not depressurize the Blue hydraulic system at this time.

(6) If you have replaced the center servo control 3025GM (Yellow hydraulic system):
(a) For check 1: Use the Green hydraulic system.
(b) For check 2: Use the Blue hydraulic system.
(c) For check 3: Use the Yellow hydraulic system.
(7) If you have replaced the lower servo control 1025GM (Green hydraulic system):
(a) For check 1: Use the Yellow hydraulic system.
(b) For check 2: Use the Blue hydraulic system.
(c) For check 3: Use the Green hydraulic system.

Subtask 27-24-51-820-050-B

I. Adjustment Procedure of the Spring Rod

Servo Control Connection at the Vertical Stabilizer

NOTE: This adjustment is only necessary if the rudder is not in the neutral position.

NOTE: The related hydraulic system must be pressurized for this adjustment (Refer to the subtask 'Check of the Rudder Position' above).

(1) Cut and remove the lockwire from the nuts (22) of the spring rod (21).
(2) Loosen the nuts (22) and the serrated locking device (23).
(3) Turn the body of the spring rod (21) until the rudder (2) is in the neutral position.

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

(4) Engage the serrated locking device (23).
(5) Tighten the nuts (22) against the serrated locking device (23).
(6) Make sure that the threads of the rod end, block the inspection holes in the body of the spring rod (21).
(7) Safety the nuts (22) with 14QFB1Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - to the serrated locking device (23).
(8) After the adjustment: Depressurize the related hydraulic system
(Ref. AMM TASK 29-10-00-864-001) or (Ref. AMM TASK 29-10-00-864-002) or (Ref. AMM TASK 29-10-00-864-003).

Subtask 27-24-51-860-054-A

J. Preparation for the Test
(1) Remove the 98D27207546000 PIN-RIGGING (3) from the bellcrank assy (6) at the lower servo control 1025GM.

Subtask 27-24-51-710-050-A

K. Test Procedure
(1) Do an operational test of the rudder system (Ref. AMM TASK 27-24-00-710-001).
(2) Do an operational test of the rudder servo controls (Ref. AMM TASK 27-24-00-710-002), if all three servo controls are replaced.

5. Close-up
Subtask 27-24-51-860-055-A

A. Put the aircraft back to the serviceable condition.
(1) Put the switch A/SKID & N/W STRG on the center panel 402VU to the ON position.
(2) Remove the WARNING NOTICE(S).

Subtask 27-24-51-410-050-B

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access panels 325BL 325CL 325CR 325DL at the trailing edge of the vertical stabilizer. (Ref. AMM TASK 55-33-13-410-002).
(3) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.01 04:05:14 UTC