Failure of the FAC 1

TASK 22-66-00-810-801-A
Failure of the FAC 1

1. Possible Causes

FAC-1 [1CC1]
wiring of the 28VDC signal from the circuit breaker (5CC1) to the FAC 1 (1CC1)
wiring of the ground signal at the FAC 1 (1CC1)
C/B-AUTO FLT/FAC1/28VDC [5CC1]
RELAY-RUD TRIM 1 [7CC1]
RELAY-RTL SYS1 [13CC1]
ACTUATOR-RUDDER TRIM [10CC]
LIMITATION UNIT-RUDDER TRAVEL [4CC]
short to ground between the circuit breaker 5CC1 and the three units

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 22-63-00-810-801-A	Loss of the Yaw Damper Function on the FAC 1
AMM 22-66-34-000-002	Removal of the FAC
AMM 22-66-34-400-002	Installation of the FAC
ASM 226701
AMM 22-96-00-710-001	Operational Test of the AFS
AMM 27-22-51-000-001	Removal of the Rudder Trim Actuator
AMM 27-22-51-400-001	Installation of the Rudder Trim Actuator
AMM 27-23-51-000-001	Removal of the Rudder Travel Limitation Unit
AMM 27-23-51-400-001	Installation of the Rudder Travel-Limitation Unit

3. Fault Confirmation
Subtask 22-66-00-865-088-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AUTO FLT/FAC1/28VDC	5CC1	B04

Subtask 22-66-00-710-050-A

B. Test
(1) Do the operational test of the AFS AMM 22-96-00-710-001 and read the result for the FAC 1.
(a) If the circuit breaker 5CC1 is open refer to Para. 4.B.

4. Fault Isolation
Subtask 22-66-00-810-050-A

A. If the circuit breaker 5CC1 is closed, and if the test gives the maintenance message AFS: FAC1:

Do a check for 28VDC at the FAC 1 (1CC1).

(1) If there is 28VDC:

Replace the FAC-1 [1CC1] , AMM 22-66-34-000-002 and AMM 22-66-34-400-002.

(2) If there is no 28VDC:

Do a check of the wiring of the 28VDC signal from the circuit breaker (5CC1) to the FAC 1 (1CC1).
Do a check of the wiring of the ground signal at the FAC 1 (1CC1) pin AC/3.
ASM 226701.

(a) If there is no continuity:

Repair the above wirings.

(b) If there is continuity:

Replace the C/B-AUTO FLT/FAC1/28VDC [5CC1] .

Subtask 22-66-00-810-097-A

B. If the circuit breaker 5CC1 is open:

Close this circuit breaker.

(1) If this circuit breaker opens again:

Disconnect these three units:
FAC-1 [1CC1]
RELAY-RUD TRIM 1 [7CC1]
RELAY-RTL SYS1 [13CC1]
Close the circuit breaker 5CC1.

(a) If the circuit breaker 5CC1 opens again:

Go to Para. 4. D.

(b) If the circuit breaker 5CC1 stays closed:

Connect the FAC-1 [1CC1] .

1 If the circuit breaker 5CC1 opens again:

Do the troubleshooting procedure (Ref. TSM TASK 22-63-00-810-801) Para. 4. A.

a If the circuit breaker 5CC1 opens again:

Replace the FAC-1 [1CC1] AMM 22-66-34-000-002 and AMM 22-66-34-400-002.
Go to Para. 4. E.

2 If the circuit breaker 5CC1 stays closed:

Continues the troubleshooting.

Subtask 22-66-00-810-179-A

C. If the circuit breaker 5CC1 stays closed:

Connect the RELAY-RUD TRIM 1 [7CC1] .

(1) If the circuit breaker 5CC1 opens again:

Replace the ACTUATOR-RUDDER TRIM [10CC] AMM 27-22-51-000-001 and AMM 27-22-51-400-001.
Go to Para. 4. E.

(2) If the circuit breaker 5CC1 stays closed:

Connect the RELAY-RTL SYS1 [13CC1] .

(a) If the circuit breaker 5CC1 opens again:

Replace the LIMITATION UNIT-RUDDER TRAVEL [4CC] AMM 27-23-51-000-001 and AMM 27-23-51-400-001.
Go to Para. 4. E.

Subtask 22-66-00-810-180-A

D. If the circuit breaker 5CC1 opens again:
(1) Do a check for a short to ground between the circuit breaker 5CC1 and the three units , ASM 226701.
(a) If there is a short to ground:

Repair the related wiring.

(b) If there is no short to ground:

Replace the C/B-AUTO FLT/FAC1/28VDC [5CC1] .

Subtask 22-66-00-710-131-A

E. Put the aircraft back to its initial configuration.
(1) Connect all the units.
(2) Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:15 UTC