W DOC AIRBUS | AMM A320F

Deactivation of the Yaw Damper Servo-Actuator

TASK 27-26-00-040-001-A
Deactivation 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
Task Summary
Access Test Specific Tools Mhr E/T Nb Men
YESYESNO0.70.71
1. Reason for the Job
MMEL 22-60-04A
YAW DAMPER SYSTEM (FAA ONLY)
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
CAP - BLANKING (MS21914-4 TYPE)
No specific
1
CAP - BLANKING (MS21914-5 TYPE)
No specific
1
CONTAINER 5 L (1.32 USGAL)
No specific
1
PLUG - BLANKING (MS21913-4 TYPE)
No specific
1
PLUG - BLANKING (MS21913-5 TYPE)
No specific
AR
SAFETY CLIP - CIRCUIT BREAKER
No specific
AR
TIE WRAP
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 ) T
No specific
Torque wrench: range to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft ) T
 B. Work Zones and Access Panels
ZONE/ACCESS
ZONE DESCRIPTION
325
VERTICAL STABILIZER TRAILING EDGE
325BL, 325BR
 C. Referenced Information
REFERENCE
DESIGNATION
TASK 22-63-00-710-001-A
Operational Test of the Yaw Damper Function
TASK 24-42-00-861-001-A
Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A
De-energize the Ground Service Network Supplied from the External Power
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)
F Yaw Damper Servo-Actuator 3CC1 (3CC2)
3. Job Set-up
Subtask 27-26-00-860-050-A
A. Aircraft Maintenance Configuration
   (1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).
   (2) Make sure that the hydraulic systems are depressurized
(Ref. AMM TASK 29-10-00-864-001) (Ref. AMM TASK 29-10-00-864-002) (Ref. AMM TASK 29-10-00-864-003).
   (3) Put the WARNING NOTICE(S) in the cockpit to tell persons not to operate the flight controls.
Subtask 27-26-00-865-054-A
B. Open, safety and tag this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
FOR FIN: 3CC1 (SERVO ACTRYAW DAMPER, 1)
49VUAUTO FLT/FAC1/28VDC5CC1B04
49VUAUTO FLT/FAC1/26VAC14CC1B03
** ON A/C NOT FOR ALL
49VUAUTO FLT/FAC1/28VDC5CC1H10
49VUAUTO FLT/FAC1/26VAC14CC1H09
** ON A/C ALL
FOR FIN: 3CC2 (SERVO ACTRYAW DAMPER, 2)
121VUAUTO FLT/FAC2/28VDC5CC2M19
121VUAUTO FLT/FAC2/26VAC14CC2M18
Subtask 27-26-00-010-054-A
C. Get Access
   (1) Put an ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE in position at zone 325.
   (2) Open the access door 325BL ( 325BR).
4. Procedure
Subtask 27-26-00-040-050-A
A. Deactivation of the Yaw Damper Servo-Actuator 3CC1 (3CC2).
F Yaw Damper Servo-Actuator 3CC1 (3CC2)
   (1) Disconnect the electrical connectors (2) and (5) from the yaw damper servo-actuator (1).
   (2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
   (3) Attach the electrical connectors (2) and (5) with a TIE WRAP.
   (4) Make sure that there is no hydraulic leakage from the yaw damper servo-actuator (1).
If there are leaks:
     (a) Depressurize the Green (Yellow) hydraulic reservoir (Ref. AMM TASK 29-14-00-614-001).
     (b) Put a CONTAINER 5 L (1.32 USGAL) below the hydraulic connections of the yaw damper servo-actuator (1).
     (c) Disconnect the hydraulic pipes (3) and (4) from the yaw damper servo-actuator (1).
     (d) Drain the remaining hydraulic fluid into the container.
     (e) Remove the container.
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.
     (f) For hydraulic pipe (3) (pressure port):
       1 Put a CAP - BLANKING (MS21914-4 TYPE) on the unions of the yaw damper servo-actuator.
         a Torque it to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft ) T.
       2 Put a PLUG - BLANKING (MS21913-4 TYPE) on the disconnected line ends.
         a Torque it to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft ) T.
     (g) For hydraulic pipe (4) (return port):
       1 Put a CAP - BLANKING (MS21914-5 TYPE) on the unions of the yaw damper servo-actuator.
         a Torque it to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft ) T.
       2 Put a PLUG - BLANKING (MS21913-5 TYPE) on the disconnected line ends.
         a Torque it to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft ) T.
     (h) Attach the hydraulic pipes (3) and (4) to the adjacent area with TIE WRAP.
     (i) Pressurize the Green (Yellow) hydraulic reservoir (Ref. AMM TASK 29-14-00-614-002).
Subtask 27-26-00-865-055-A
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
FOR FIN: 3CC1 (SERVO ACTRYAW DAMPER, 1)
49VUAUTO FLT/FAC1/28VDC5CC1B04
49VUAUTO FLT/FAC1/26VAC14CC1B03
** ON A/C NOT FOR ALL
49VUAUTO FLT/FAC1/28VDC5CC1H10
49VUAUTO FLT/FAC1/26VAC14CC1H09
** ON A/C ALL
FOR FIN: 3CC2 (SERVO ACTRYAW DAMPER, 2)
121VUAUTO FLT/FAC2/28VDC5CC2M19
121VUAUTO FLT/FAC2/26VAC14CC2M18
Subtask 27-26-00-710-053-A
C. Tests
   (1) Do the operational test of the yaw damper function (Ref. AMM TASK 22-63-00-710-001).
NOTE: The yaw damper servo-actuator 3CC1 (3CC2) you deactivated does not operate.
5. Close-up
Subtask 27-26-00-941-053-A
A. Safety Precautions
   (1) Remove the WARNING NOTICE(S).
   (2) Put a WARNING NOTICE(S) in the cockpit to tell the crew that the yaw damper servo-actuator 3CC1 (3CC2) is deactivated.
   (3) Make an entry in the logbook.
Subtask 27-26-00-410-053-A
B. Close Access
   (1) Close the access doors 325BL ( 325BR).
   (2) Remove the access platform(s).
Subtask 27-26-00-860-051-A
C. Put the aircraft back to its initial configuration.
   (1) Make sure that the work area is clean and clear of tools and other items.
   (2) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
[Rev.10 from 2021] 2026.03.31 23:49:40 UTC
"Aviabrain" 2025