Installation of the Yaw Damper Servo Actuator

TASK 27-26-51-400-001-A
Installation 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.

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.

ZONE: 325
FIN: 3CC1
FIN: 3CC2

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 6M (20 FT) - ADJUSTABLE
No specific	AR	CAP - BLANKING
No specific	1	CONTAINER - HYDRAULIC FLUID RESISTANT
No specific	1	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 )
98D27207548000	1	PIN-RIGGING

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.02ABA1)	Phosphate Ester Hydraulic Fluid-General Power - -
(Material No.03GBD1)	Synthetic Oil base Grease-General Purpose Lithium Thickened -
(Material No.03HBD9)	Synthetic Ester base Grease-General Purpose Low Temp -
(Material No.04QAB2)	Coating_- Flexible Structure
(Material No.05ABF1)	Retaining adhesive-Cylindrical fitting Medium strength Low viscosity -
(Material No.06AAA1)	Polysulfide Sealant_General Purpose Brushable -
(Material No.12AGC2)	Corrosion Preventive Compound-- Soft Film System

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
325	VERTICAL STABILIZER TRAILING EDGE
325BL, 325BR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
10	COTTER PINS	AIPC 27-26-04-02-050
10	COTTER PINS	AIPC 27-26-84-02-010

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 22-63-00-710-001-A	Operational Test of the Yaw Damper Function
TASK 22-96-00-710-001-A	Operational Test of the AFS
TASK 22-97-00-710-001-A	Operational Test of the LAND CAT III Capability
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 27-26-00-820-001-A	Adjustment of the Yaw Damper Actuation
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
Position of the Rigging Pin (in the Mixer of the Artificial Feel Unit)
Yaw Damper - Servo Actuator

3. Job Set-up
Subtask 27-26-51-860-054-B

A. Aircraft Maintenance Configuration

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 3CC1) or 325BR (for 3CC2) is open (Ref. AMM TASK 55-33-13-010-002).
(4) Make sure that the rudder pedals are in the neutral position.
(5) Make sure that the RUD TRIM indicator on the center pedestal, on the panel 110VU shows 0.
(6) Make sure that the WARNING NOTICE(S) are in position in the cockpit to tell persons not to operate the flight controls.
(7) Make sure that the Green hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(8) Make sure that the Yellow hydraulic system is depressurized and put it in the maintenance configuration.
(Ref. AMM TASK 29-00-00-864-001).
(9) Make sure that the reservoirs of the Green and Yellow hydraulic systems are depressurized (Ref. AMM TASK 29-14-00-614-001).
(10) Make sure that the CONTAINER - HYDRAULIC FLUID RESISTANT is in position below the hydraulic pipes of the actuator.
(11) Make sure that the aircraft electrical circuits are de-energized (Ref. AMM TASK 24-41-00-862-002).
(12) Make sure that the warning notices are in position to tell persons not to pressurize the Green, Yellow and 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.

(13) Make sure that the PIN - RIGGING 98D27207548000 PIN-RIGGING (100) is in position in the mixer of the artificial feel unit (101).

Position of the Rigging Pin (in the Mixer of the Artificial Feel Unit)

Subtask 27-26-51-865-052-A

B. 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 27-26-51-210-050-A

C. Visual inspection of the work area and the attachment components

Yaw Damper - Servo Actuator

(1) Inspection of the work area
(a) Make sure that these areas and items are clean, show no corrosion and are not damaged:

The structure
The paintwork
The levers (5) and (11)
The electrical connectors (12) and (14)
The bonding straps (13)
The union nuts (15) and (18)
The hydraulic pipes (16) and (19).

(2) Inspection of the attachment components.
(a) Make sure that these items are clean and in good condition:

The bolts (3)
The bushes (4),(6) and (7)
The nuts (9).

(b) Make sure that the bushes (6) and (7) are tight in the levers (5) and (11).
(c) If the bushes (6) and (7) are not tight in the levers (5) and (11):
1 Apply Retaining adhesive-Cylindrical fitting Medium strength Low viscosity - (Material No.05ABF1) to the bushes (6) and (7) to safety them in the levers (5) and (11).
2 Seal the bushes (6) and (7) in the levers (5) and (11) with Polysulfide Sealant_General Purpose Brushable - (Material No.06AAA1) .
3 Apply Coating_- Flexible Structure (Material No.04QAB2) over the bushes (6) and (7) to protect them.

4. Procedure
Subtask 27-26-51-910-051-A

A. Preparation for Installation
(1) Preparation of the rod ends of the new actuator (1), (2):
(a) Compare the length of the replaced and new actuator.
(b) If necessary adjust the rod ends of the new actuator.
(2) 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 thread of the bolts (3) and to the interfaces of the bushes (4),(6),(7).
(3) Apply Corrosion Preventive Compound-- Soft Film System (Material No.12AGC2) to the shafts of the bolts (3).

Subtask 27-26-51-420-050-A

B. Installation of the Yaw Damper Servo Actuator 3CC1 and 3CC2

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.

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

(1) Connect the actuator (1),(2) to the lever (5).
(a) Support the actuator (1),(2).
(b) Put the sliding bush (4) into the flanged bush (6) of the lever (5).
(c) Put the connection of the actuator (1),(2) in position in the lever (5).
(d) Install the bolt (3), the washer (8) and the nut (9) at the connection of the lever (5) and the actuator (1),(2).
(2) Connect the actuator (1),(2) to the lever (11).
(a) Put the sliding bush (4) into the flanged bush (6) in the lever (11).
(b) Put the connection of the actuator (1),(2) in position in the lever (11).
(c) Install the bolt (3), the washer (8) and the nut (9) at the connection of the lever (11) and the actuator (1),(2).
(3) Tighten the nuts (9).
(a) Do not safety the nuts (9) with new cotter pins at this time.
(4) Remove the blanking caps from the unions (17),(20) of the actuator (1),(2).
(5) Remove the blanking caps from the ends of the pipes (16),(19).
(6) Apply Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) to the threads of the line end-fittings.
(7) Connect the union nut (18) of the pipe (19) to the union (20) at the pressure port of the actuator (1),(2).
(8) Connect the union nut (15) of the pipe (16) to the union (17) at the return port of the actuator (1),(2).

NOTE: Make sure that the pipes (16),(19) do not rub on the structure.

(9) TORQUE the union nut (18) to between 1.7 and 1.5 m.daN (12.54 and 11.06 lbf.ft )

.
(10) TORQUE the union nut (15) to between 2.3 and 2.0 m.daN (16.96 and 14.75 lbf.ft )

.
(11) Identify the the tightened union nuts with a red line (Ref. AMM TASK 20-23-22-910-001).
(12) Remove the drainage container.
(13) Remove all signs of hydraulic fluid from the components and the work area.
(14) Remove the CAP - BLANKING from the electrical connector (12),(14) and the plugs on the actuator (1),(2).
(15) Connect the electrical connectors (12),(14) to the actuator (1),(2).

Subtask 27-26-51-865-051-A

C. 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 27-26-51-080-050-A

D. Adjustment
(1) Do the adjustment of the new actuator (1),(2) (Ref. AMM TASK 27-26-00-820-001):
(a) Pressurize the reservoirs of the Green and the Yellow hydraulic systems (Ref. AMM TASK 29-14-00-614-002).
(b) Prepare to pressurize the hydraulic systems.
(2) After the correct adjustment: Safety the nuts (9) with new AIPC 27-26-04-02-050 COTTER PINS (10) or the AIPC 27-26-84-02-010 COTTER PINS (10).
(3) Make sure that you removed all the rigging pins.

Subtask 27-26-51-710-050-A

E. Test
(1) Do an operational test of the yaw damper (Ref. AMM TASK 22-63-00-710-001).

NOTE: If you operate the aircraft in actual CAT 3 conditions, do these tests:

AFS-Test (Ref. AMM TASK 22-96-00-710-001) and Land-Test (Ref. AMM TASK 22-97-00-710-001).

(2) Do a visual check and make sure that there are no hydraulic leaks at the yaw damper.

5. Close-up
Subtask 27-26-51-410-050-B

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access panel 325BL (for 3CC1) and/or 325BR (for 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).

[Rev.10 from 2021] 2026.03.31 23:49:50 UTC