Installation of the Centering Spring Rod for the Actuator of the Yaw Damper Servo
TASK 27-26-41-400-001-A
Installation of the Centering Spring Rod for the Actuator of the Yaw Damper Servo
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Expendable Parts
E. Referenced Information
3. Job Set-up
Subtask 27-26-41-865-051-A
Subtask 27-26-41-910-050-A
Subtask 27-26-41-860-053-A
[Rev.10 from 2021]
2026.04.01 06:49:31 UTC
Installation of the Centering Spring Rod for the Actuator of the Yaw Damper Servo
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.
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.
ZONE: 325
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE |
| No specific | AR | WARNING NOTICE(S) |
| 98D27207549000 | 1 | PIN-RIGGING |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.03GBD1) | Synthetic Oil base Grease-General Purpose Lithium Thickened - |
| (Material No.03HBD9) | Synthetic Ester base Grease-General Purpose Low Temp - |
| (Material No.06LCG9) | Non Hardening Jointing Putty-Medium Temp. Area - - |
| (Material No.12ABE2) | Corrosion Preventive Compound-Water Displacing Oily Film System |
| (Material No.14QFB1) | Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 325 | VERTICAL STABILIZER TRAILING EDGE |
| 325BL |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 10 | COTTER PIN | AIPC 27-26-04-01-050 |
| 21 | COTTER PIN | AIPC 27-26-04-01-050 |
| 10 | COTTER PIN | AIPC 27-26-84-01-010 |
| 21 | COTTER PIN | AIPC 27-26-84-01-010 |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 27-24-00-710-001-A | Operational Test of the Rudder Hydraulic Actuation |
| TASK 29-00-00-864-001-A | Put the Related Hydraulic System in the Depressurized Configuration before Maintenance Action |
| 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 |
Subtask 27-26-41-865-051-A
A. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
Subtask 27-26-41-860-052-B | 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 |
B. 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) Make sure that the WARNING NOTICE(S) are in position.
(3) Make sure that the rudder pedals are in the neutral position.
(4) Make sure that the RUD TRIM indicator on the panel 110VU of the center pedestal shows zero.
(5) Make sure that the FLT CTL/FAC 1 pushbutton switch on the overhead panel 23VU is released and the OFF legend is on.
(6) Make sure that the FLT CTL/FAC 2 pushbutton switch on the overhead panel 24VU is released and the OFF legend is on.
(7) Make sure that the ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE is in position below the access panel 325BL
(8) Make sure that the access panel 325BL is open (Ref. AMM TASK 55-33-13-010-002).
(9) Make sure that the rigging pin 98D27207549000 PIN-RIGGING is installed in the bellcrank of the yaw damper.
4. Procedure(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) Make sure that the WARNING NOTICE(S) are in position.
(3) Make sure that the rudder pedals are in the neutral position.
(4) Make sure that the RUD TRIM indicator on the panel 110VU of the center pedestal shows zero.
(5) Make sure that the FLT CTL/FAC 1 pushbutton switch on the overhead panel 23VU is released and the OFF legend is on.
(6) Make sure that the FLT CTL/FAC 2 pushbutton switch on the overhead panel 24VU is released and the OFF legend is on.
(7) Make sure that the ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE is in position below the access panel 325BL
(8) Make sure that the access panel 325BL is open (Ref. AMM TASK 55-33-13-010-002).
(9) Make sure that the rigging pin 98D27207549000 PIN-RIGGING is installed in the bellcrank of the yaw damper.
Subtask 27-26-41-910-050-A
A. Preparation for Installation
(1) Make sure that the parts retained from the removed component are clean and in the correct condition.
(2) Clean the component interfaces and the adjacent area.
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Apply Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the threads of the bolts (4),(15).
(5) Apply Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the bushes (5),(16).
(6) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the shafts of the bolts (4) and (15).
Subtask 27-26-41-420-050-A (1) Make sure that the parts retained from the removed component are clean and in the correct condition.
(2) Clean the component interfaces and the adjacent area.
(3) Do an inspection of the component interfaces and the adjacent area.
(4) Apply Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the threads of the bolts (4),(15).
(5) Apply Synthetic Oil base Grease-General Purpose Lithium Thickened - (Material No.03GBD1) or Synthetic Ester base Grease-General Purpose Low Temp - (Material No.03HBD9) to the bushes (5),(16).
(6) Apply Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the shafts of the bolts (4) and (15).
B. Installation of the Centering Spring Rod
(a) Put the bush (5) in the flanged bush (6) of the lever arm (1).
(b) Put the spring rod (2) in position in the lever arm (1).
(c) Install the bolt (4), the washer (8) and the nut (9).
(d) Tighten the nut (9).
(2) Connect the spring rod (2) to the lever (3) as follows:
(a) Put the spring rod (2) in position in the lever (3).
(b) Put the bush (16) in the flanged bush (17) of the lever (3).
(c) Install the bolt (15).
1 If you cannot install the bolt (15) smoothly, adjust the length of the spring rod (2) as follows:
b Release the locknut (14).
c Turn the rod eye-end of the spring rod (2) until you can install the bolt (15) smoothly.
d Put a piece of lockwire through the inspection hole in the spring rod (2). This is to make sure that the thread of the rod eye-end engages sufficiently through the body of the spring rod (2).
e Remove and discard the piece of lockwire.
f Tighten the locknut (14).
14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - .
(d) Install the washer (19) and the nut (20).
(e) Tighten the nut (20).
14QFB1 Wire-Locking Dia: 0.8 mm CRES Nickel Alloy - .
Subtask 27-26-41-865-052-A CAUTION:
YOU MUST INSTALL THE CENTERING SPRING ROD WITH THE LARGER SECTION UP. THIS WILL PREVENT DAMAGE TO THE CENTERING SPRING ROD AND THE ARTIFICIAL FEEL SUPPORT.
(1) Connect the spring rod (2) to the lever arm (1) as follows: (a) Put the bush (5) in the flanged bush (6) of the lever arm (1).
(b) Put the spring rod (2) in position in the lever arm (1).
(c) Install the bolt (4), the washer (8) and the nut (9).
(d) Tighten the nut (9).
WARNING:
USE PROTECTIVE GOGGLES WHEN YOU REMOVE OR INSTALL A COTTER PIN. EACH TIME YOU REMOVE A COTTER PIN DURING THE TASK, DISCARD IT IMMEDIATELY. A LOOSE COTTER PIN CAN CUT YOU OR MAKE YOU BLIND.
(e) Safety the nut (9) with the AIPC 27-26-04-01-050 COTTER PIN (10) or AIPC 27-26-84-01-010 COTTER PIN (10).(2) Connect the spring rod (2) to the lever (3) as follows:
(a) Put the spring rod (2) in position in the lever (3).
(b) Put the bush (16) in the flanged bush (17) of the lever (3).
(c) Install the bolt (15).
1 If you cannot install the bolt (15) smoothly, adjust the length of the spring rod (2) as follows:
WARNING:
USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
a Remove and discard the lockwire from the locknut (14).b Release the locknut (14).
c Turn the rod eye-end of the spring rod (2) until you can install the bolt (15) smoothly.
d Put a piece of lockwire through the inspection hole in the spring rod (2). This is to make sure that the thread of the rod eye-end engages sufficiently through the body of the spring rod (2).
e Remove and discard the piece of lockwire.
f Tighten the locknut (14).
WARNING:
USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
g Safety the locknut (14) on the locking device (13) with the (d) Install the washer (19) and the nut (20).
(e) Tighten the nut (20).
WARNING:
USE PROTECTIVE GOGGLES WHEN YOU REMOVE OR INSTALL A COTTER PIN. EACH TIME YOU REMOVE A COTTER PIN DURING THE TASK, DISCARD IT IMMEDIATELY. A LOOSE COTTER PIN CAN CUT YOU OR MAKE YOU BLIND.
(f) Safety the nut (20) with the new AIPC 27-26-04-01-050 COTTER PIN (21) or AIPC 27-26-84-01-010 COTTER PIN (21). WARNING:
USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
(3) Make sure that the locknut (11) is tight and safetied on the locking device (12) with the C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 27-26-41-710-050-A | 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 |
D. Test
(1) Remove the rigging pin 98D27207549000 from the yaw damper bellcrank.
(2) Remove the WARNING NOTICE(S).
(3) Do the operational test of the rudder hydraulic actuation (Ref. AMM TASK 27-24-00-710-001).
5. Close-up(1) Remove the rigging pin 98D27207549000 from the yaw damper bellcrank.
(2) Remove the WARNING NOTICE(S).
(3) Do the operational test of the rudder hydraulic actuation (Ref. AMM TASK 27-24-00-710-001).
Subtask 27-26-41-860-053-A
A. Put the aircraft back to the serviceable condition.
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Apply a layer of Corrosion Preventive Compound-Water Displacing Oily Film System (Material No.12ABE2) to the adjacent structure.
(3) Make sure that the drain holes in the adjacent structure are not blocked.
Subtask 27-26-41-410-050-B (1) Make sure that the work area is clean and clear of tools and other items.
(2) Apply a layer of Corrosion Preventive Compound-Water Displacing Oily Film System (Material No.12ABE2) to the adjacent structure.
(3) Make sure that the drain holes in the adjacent structure are not blocked.
B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access panel 325BL (Ref. AMM TASK 55-33-13-410-002).
(3) Remove the access platform(s).
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access panel 325BL (Ref. AMM TASK 55-33-13-410-002).
(3) Remove the access platform(s).
Centering Spring Rod