DOC AIRBUS | AMM A320FInstallation of the Servovalve
TASK 27-26-51-400-002-A
Installation of the Servovalve
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 27-26-51-860-055-B
Subtask 27-26-51-420-051-A
Subtask 27-26-51-410-051-B
[Rev.10 from 2021]
2026.03.31 23:49:52 UTC
Installation of the Servovalve
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 | 1 | ACCESS PLATFORM 6M (20 FT) - ADJUSTABLE |
| No specific | 1 | CONTAINER - HYDRAULIC FLUID RESISTANT |
| No specific | 1 | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 0.66 and 0.54 m.daN (58.41 and 47.79 lbf.in )  | |
| 98D27207549000 | 1 | PIN-RIGGING |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.02ABA1) | Phosphate Ester Hydraulic Fluid-General Power - - |
| (Material No.06LCG9) | Non Hardening Jointing Putty-Medium Temp. Area - - |
| No specific | lockwire, corrosion-resistant steel, dia. 0.8 mm (0.032 in.) |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 325 | VERTICAL STABILIZER TRAILING EDGE |
| 325BL, 325BR |
| FIG.ITEM | DESIGNATION | IPC-CSN |
|---|---|---|
| 14 | O-RING | AIPC 27-26-51-01-040 |
| 10 | BASE PLATE | AIPC 27-26-51-01-060 |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 22-63-00-710-001-A | Operational Test of the Yaw Damper Function |
| 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 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 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 |
Yaw Damper - Servo ActuatorSubtask 27-26-51-860-055-B
A. Aircraft Maintenance Configuration
(2) Make sure that the ACCESS PLATFORM 6M (20 FT) - ADJUSTABLE is in position at zone 325.
(3) Make sure that the access panel 325BL (for the servovalve on 3CC1) or 325BR (for the servovalve on 3CC2) is open (Ref. AMM TASK 55-33-13-010-002).
(4) Make sure that the hydraulic systems are depressurized and put them in the maintenance configuration
(Ref. AMM TASK 29-00-00-864-001).
(5) Make sure that the reservoirs of the Green and Yellow hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) are in position to tell persons not to pressurize the Green, the Yellow and the Blue hydraulic systems:
(8) Make sure that the rigging pin 98D27207549000 PIN-RIGGING is in position in the yaw damper bellcrank.
Subtask 27-26-51-865-054-A WARNING:
OBEY THE HYDRAULIC SAFETY PROCEDURES.
(1) Obey the hydraulic safety procedures (Ref. AMM TASK 29-00-00-910-002). (2) Make sure that the ACCESS PLATFORM 6M (20 FT) - ADJUSTABLE is in position at zone 325.
(3) Make sure that the access panel 325BL (for the servovalve on 3CC1) or 325BR (for the servovalve on 3CC2) is open (Ref. AMM TASK 55-33-13-010-002).
(4) Make sure that the hydraulic systems are depressurized and put them in the maintenance configuration
(Ref. AMM TASK 29-00-00-864-001).
(5) Make sure that the reservoirs of the Green and Yellow hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(6) Make sure that the WARNING NOTICE(S) are in position to tell persons not to pressurize the Green, the Yellow and the 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.
(8) Make sure that the rigging pin 98D27207549000 PIN-RIGGING is in position in the yaw damper bellcrank.
B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
4. Procedure| 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 27-26-51-420-051-A
A. Installation of the Servovalve
(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 the anti-corrosion compound Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the threads of the screws (12).
(5) Lubricate the new AIPC 27-26-51-01-040 O-RING (14) with Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(6) Install the O-ring (14) in the port of the servovalve (13).
(7) Put the new AIPC 27-26-51-01-060 BASE PLATE (10) in its installation position on the yaw damper (7).
(9) Install the screws (12) with the washers (11) on the servovalve (13) and the yaw damper (7).
(10) TORQUE the screws (12) to between 0.66 and 0.54 m.daN (58.41 and 47.79 lbf.in ).
(11) Safety the screws (12) with lockwire, corrosion-resistant steel, dia. 0.8 mm (0.032 in.).
Subtask 27-26-51-865-055-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 the anti-corrosion compound Non Hardening Jointing Putty-Medium Temp. Area - - (Material No.06LCG9) to the threads of the screws (12).
(5) Lubricate the new AIPC 27-26-51-01-040 O-RING (14) with Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
(6) Install the O-ring (14) in the port of the servovalve (13).
(7) Put the new AIPC 27-26-51-01-060 BASE PLATE (10) in its installation position on the yaw damper (7).
NOTE: Do not lubricate the base plate. It must be clean and dry.
(8) Put the servovalve (13) on the base plate (10) and align the holes. (9) Install the screws (12) with the washers (11) on the servovalve (13) and the yaw damper (7).
(10) TORQUE the screws (12) to between 0.66 and 0.54 m.daN (58.41 and 47.79 lbf.in )
. (11) Safety the screws (12) with lockwire, corrosion-resistant steel, dia. 0.8 mm (0.032 in.).
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 27-26-51-080-051-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 |
C. Preparation for the Test
(1) Remove the rigging pin 98D27207549000 PIN-RIGGING from the yaw damper bellcrank.
(2) Remove the container.
(3) Pressurize the reservoir of the Green and the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-002).
Subtask 27-26-51-710-051-A (1) Remove the rigging pin 98D27207549000 PIN-RIGGING from the yaw damper bellcrank.
(2) Remove the container.
(3) Pressurize the reservoir of the Green and the Yellow hydraulic system (Ref. AMM TASK 29-14-00-614-002).
D. Test
(1) Do an operational test of the yaw damper (Ref. AMM TASK 22-63-00-710-001).
(2) Do a visual check and make sure that there are no hydraulic leaks at the yaw damper.
5. Close-up(1) Do an operational test of the yaw damper (Ref. AMM TASK 22-63-00-710-001).
(2) Do a visual check and make sure that there are no hydraulic leaks at the yaw damper.
Subtask 27-26-51-410-051-B
A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access panels 325BL (for the servovalve on 3CC1) and/or 325BR (for the servovalve on 3CC2) at the trailing edge of the vertical stabilizer (Ref. AMM TASK 55-33-13-410-002).
(3) Remove the WARNING NOTICE(S).
(4) 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 panels 325BL (for the servovalve on 3CC1) and/or 325BR (for the servovalve on 3CC2) at the trailing edge of the vertical stabilizer (Ref. AMM TASK 55-33-13-410-002).
(3) Remove the WARNING NOTICE(S).
(4) Remove the access platform(s).