Adjustment of the Yaw Damper Actuation

TASK 27-26-00-820-001-A
Adjustment of the Yaw Damper Actuation

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: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

ZONE: 325

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	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
98D27207516000	2	PIN-RIGGING,SET
98D27207548000	1	PIN-RIGGING
98D27207549000	1	PIN-RIGGING

B. Consumable Materials

REFERENCE	DESIGNATION
No specific	lockwire corrosion resistant steel dia 0.8 mm (0.03 in.)

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
7	COTTER PIN	AIPC 27-21-47-01-210

E. Referenced Information

REFERENCE	DESIGNATION
TASK 22-63-00-710-001-A	Operational Test of the Yaw Damper Function
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
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 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 29-10-00-864-003-A	Depressurize the Blue Hydraulic System
TASK 29-23-00-863-001-A	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
TASK 29-23-00-864-001-A	Depressurize the Green and Yellow Hydraulic Systems after Operation of the PTU
TASK 29-24-00-863-001-A	Pressurize the Yellow Hydraulic System with the Electric Pump
TASK 29-24-00-864-001-A	Depressurize the Yellow Hydraulic System
Position of the Rigging Pins

3. Job Set-up
Subtask 27-26-00-861-051-A

A. Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 27-26-00-010-056-A

B. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at the access door 822.
(2) Open the access door 822.
(3) On the battery power center 105VU:

loosen the two screws and remove the protective cover.

(4) Put an ACCESS PLATFORM 10M (33 FT) - ADJUSTABLE in position at zone 325.
(5) Open the access doors 325BL 325BR.

Subtask 27-26-00-480-052-B

C. Not Applicable

Subtask 27-26-00-865-051-A

D. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/ELAC1/NORM/SPLY	15CE1	B11
49VU	FLIGHT CONTROLS/SEC1/NORM/SPLY	21CE1	B08
49VU	AUTO FLT/FAC1/28VDC	5CC1	B04
49VU	AUTO FLT/FAC1/26VAC	14CC1	B03
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/ELAC1/NORM/SPLY	15CE1	B06
49VU	FLIGHT CONTROLS/SEC1/NORM/SPLY	21CE1	B03
49VU	AUTO FLT/FAC1/28VDC	5CC1	H10
49VU	AUTO FLT/FAC1/26VAC	14CC1	H09
** ON A/C ALL
105VU	FLIGHT CONTROLS/ELAC2/STBY SPLY	16CE2	A02
105VU	FLT CTL/ELAC1/STBY SPLY	16CE1	A01
105VU	FLT CTL/SEC1/STBY SPLY	22CE	B01
121VU	AUTO FLT/RUDDER/TRIM/IND	15CC	M20
121VU	AUTO FLT/FAC2/28VDC	5CC2	M19
121VU	AUTO FLT/FAC2/26VAC	14CC2	M18
121VU	FLIGHT CONTROLS/SEC3/SPLY	21CE3	Q19
121VU	FLIGHT CONTROLS/SEC2/SPLY	21CE2	Q18
121VU	FLIGHT CONTROLS/ELAC2/NORM/SPLY	15CE2	R20

Subtask 27-26-00-860-057-A ** ON A/C NOT FOR ALL

E. Aircraft Maintenance Configuration
(1) On the overhead panel 23VU, make sure that:

The FLT CTL/ELAC1, FLT CTL/FAC1 and FLT CTL/SEC1 pushbutton switches are pushed (on these pushbutton switches, the FAULT and OFF legends are off).

(2) On the overhead panel 24VU, make sure that:

The FLT CTL/ELAC2, FLT CTL/FAC2, FLT CTL/SEC2 and FLT CTL/SEC3 pushbutton switches are pushed (on these pushbutton switches, the FAULT and OFF legends are off).

(3) On the overhead panel, on the ADIRS CDU:

Set the OFF/NAV/ATT selector switch related to IR3 to NAV.
Make sure that the OFF/NAV/ATT selector switches related to IR1 and IR2 are in the OFF position.

(4) Pressurize the aircraft hydraulic systems (Ref. AMM TASK 29-23-00-863-001) (Ref. AMM TASK 29-24-00-863-001) (Ref. AMM TASK 29-10-00-863-003).
(5) On the maintenance panel 50VU, make sure that:

The HYD/LEAK MEASUREMENT VALVES/B, HYD/LEAK MEASUREMENT VALVES/G and HYD/LEAK MEASUREMENT VALVES/Y pushbutton switches are pushed (on these pushbutton switches, the OFF legends are off).

(6) On the center pedestal, on the panel 110VU, make sure that the RUD TRIM indicator shows 0.
(7) Install the 98D27207548000 PIN-RIGGING (5) or 98D27207516000 PIN-RIGGING,SET pin (98D27207516330) on the mixer (4) of the artificial feel unit.

Position of the Rigging Pins ** ON A/C NOT FOR ALL

Subtask 27-26-00-860-057-B ** ON A/C NOT FOR ALL

E. Aircraft Maintenance Configuration
(1) On the overhead panel 23VU, make sure that:

The FLT CTL/ELAC1, FLT CTL/FAC1 and FLT CTL/SEC1 pushbutton switches are pushed (on these pushbutton switches, the FAULT and OFF legends are off).

(2) On the overhead panel 24VU, make sure that:

The FLT CTL/ELAC2, FLT CTL/FAC2, FLT CTL/SEC2 and FLT CTL/SEC3 pushbutton switches are pushed (on these pushbutton switches, the FAULT and OFF legends are off).

(3) On the overhead panel 41VU, on the ADIRS MSU:

Set the OFF/NAV/ATT selector switch related to IR3 to NAV.
Make sure that the OFF/NAV/ATT selector switches related to IR1 and IR2 are in the OFF position.

(4) Pressurize the aircraft hydraulic systems (Ref. AMM TASK 29-23-00-863-001) (Ref. AMM TASK 29-24-00-863-001) (Ref. AMM TASK 29-10-00-863-003).
(5) On the maintenance panel 50VU, make sure that:

The HYD/LEAK MEASUREMENT VALVES/B, HYD/LEAK MEASUREMENT VALVES/G and HYD/LEAK MEASUREMENT VALVES/Y pushbutton switches are pushed (on these pushbutton switches, the OFF legends are off).

Position of the Rigging Pins ** ON A/C NOT FOR ALL

4. Procedure
Subtask 27-26-00-820-052-A

A. Adjustment of the Yaw Damper Actuation
(1) Adjustment of the left yaw damper actuator
(a) Remove the cotter pin (7) and discard it.
(b) Remove the nut (8) and the washer (9).
(c) Remove the bolt (6) and disconnect the rod (11).
(d) On the maintenance panel 50VU, release the HYD/LEAK MEASUREMENT VALVES/Y pushbutton switch (on this pushbutton switch, the OFF legend comes on).
(e) Install the 98D27207549000 PIN-RIGGING (12) or 98D27207516000 PIN-RIGGING,SET pin (98D27207516330) on the output bellcrank (10) of the yaw damper. You must install and remove the rigging pin easily. If not, do the adjustment of the left yaw damper actuator (2):
1 Cut and remove the lockwire from the nuts.
2 Loosen the nuts.
3 Release the lockwashers.
4 Adjust the length of the actuator until you can install and remove the rigging pin (12) freely.
5 Engage the lockwashers.
6 Tighten the nuts.
7 Safety the nuts with lockwire corrosion resistant steel dia 0.8 mm (0.03 in.).
(f) Remove the rigging pin (12).
(2) Adjustment of the right yaw damper actuator.
(a) On the maintenance panel 50VU :
1 Release the HYD/LEAK MEASUREMENT VALVES/G pushbutton switch (on this pushbutton switch, the OFF legend comes on).
2 Push the HYD/LEAK MESUREMENT VALVES/Y pushbutton switch (on this pushbutton switch, the OFF legend goes off).
(b) On the overhead panel 23VU, release the FLT CTL/FAC1 pushbutton switch (on this pushbutton switch, the OFF legend comes on).
(c) Install the 98D27207549000 PIN-RIGGING (12) or 98D27207516000 PIN-RIGGING,SET pin (98D27207516330) on the output bellcrank (10) of the yaw damper. You must install and remove the rigging pin easily. If not, do the adjustment of the right yaw damper actuator(1):
1 Cut and remove the lockwire from the nuts.
2 Loosen the nuts.
3 Release the lockwashers.
4 Adjust the length of the actuator until you can install and remove the rigging pin (12) freely.
5 Engage the lockwashers.
6 Tighten the nuts.
7 Safety the nuts with lockwire corrosion resistant steel dia 0.8 mm (0.03 in.).
(d) Remove the rigging pin (12).
(3) Adjustment of the centering spring-rod
(a) On the maintenance panel 50VU, release the HYD/LEAK MEASUREMENT VALVES/Y pushbutton switch (on this pushbutton switch, the OFF legend comes on).
(b) Install the 98D27207549000 PIN-RIGGING (12) or 98D27207516000 PIN-RIGGING,SET pin (98D27207516330) on the output bellcrank (10) of the yaw damper. You must install and remove the rigging pin easily. If not, do the adjustment of the centering spring-rod (3):
1 Cut and remove the lockwire from the nuts.
2 Loosen the nuts.
3 Release the lockwashers.
4 Adjust the length of the centering spring-rod (3) until you can install and remove the rigging pin (12) freely.
5 Engage the lockwashers.
6 Tighten the nuts.
7 Safety the nuts with lockwire corrosion resistant steel dia 0.8 mm (0.03 in.).
(4) Adjustment of the length of the rod

CAUTION: BE CAREFUL WHEN YOU USE THE RIGGING PIN ON THE TRANSDUCER UNIT. DO NOT USE FORCE TO ENGAGE THE RIGGING PIN IN THE TRANSDUCER UNIT. IF YOU USE FORCE, THE RIGGING PIN WILL NOT DISENGAGE FREELY AND DAMAGE TO THE TRANSDUCER UNIT CAN OCCUR.

(a) Push the pin (14) of the transducer unit (15).

NOTE: The pin (14) is part of the transducer unit (15).

You must push the pin (14) in freely. If this is not the case, adjust the length of the rod (13) as follows:
1 Cut and remove the lockwire from the nuts.
2 Loosen the nuts.
3 Release the lockwashers.
4 Adjust the length of the rod (13) until you can push the pin (14) in freely.
5 Engage the lockwashers.
6 Tighten the nuts.
7 Make sure that the adjustment is correct after you have tightened the nuts.
8 Safety the nuts with lockwire corrosion resistant steel dia 0.8 mm (0.03 in.).
(b) Connect the rod (11) to the output bellcrank (10) of the yaw damper with the bolt (6).
(c) Install the washer (9), the nut (8) and the new AIPC 27-21-47-01-210 COTTER PIN (7).

Subtask 27-26-00-710-052-A

B. Operational Test
(1) Remove the rigging pin (12) of the output bellcrank (10) of the yaw damper.
(2) Remove the rigging pin (5) from the mixer (4) of the artificial feel unit.
(3) Make sure that the pin (14) is disengaged from the input lever of the transducer unit (15).
(4) On the maintenance panel 50VU:

Push the HYD/LEAK MEASUREMENT VALVES/G and HYD/LEAK MEASUREMENT VALVES/Y pushbutton switches (on these pushbutton switches, the OFF legends go off).

(5) On the overhead panel 23VU, push the FLT CTL/FAC1 pushbutton switch (on this pushbutton switch, the OFF legend goes off and the FAULT legend comes on then goes off).
(6) Do the operational test of the yaw damper (Ref. AMM TASK 22-63-00-710-001).

5. Close-up
Subtask 27-26-00-480-053-B

A. Not Applicable

Subtask 27-26-00-410-055-A

B. Close Access
(1) Close the access doors 325BL 325BR.
(2) Install the protective cover on the battery power center 105VU.
(3) Tighten the two screws.
(4) Close the access door 822.
(5) Remove the access platform(s).

Subtask 27-26-00-860-056-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Depressurize the aircraft hydraulic systems (Ref. AMM TASK 29-23-00-864-001) (Ref. AMM TASK 29-24-00-864-001) (Ref. AMM TASK 29-10-00-864-003).
(2) On the overhead panel, on the ADIRS CDU, set the OFF/NAV/ATT selector switch related to IR3 to OFF.
(3) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
(4) Make sure that the work area is clean and clear of tools and other items.

Subtask 27-26-00-860-056-B ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Depressurize the aircraft hydraulic systems (Ref. AMM TASK 29-23-00-864-001) (Ref. AMM TASK 29-24-00-864-001) (Ref. AMM TASK 29-10-00-864-003).
(2) On the overhead panel 41VU, on the ADIRS MSU, set the OFF/NAV/ATT selector switch related to IR3 to OFF.
(3) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
(4) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.03.31 23:49:43 UTC