Loss of FAC 2
TASK 22-66-00-810-891-A
Loss of FAC 2
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 22-66-00-865-094-A
[Rev.8 from Aug 2018]
2026.04.04 04:25:24 UTC
Loss of FAC 2
1. Possible Causes
- 28VDC FAC2 Power Supply wiring
- SERVO ACTR-YAW DAMPER, 2 [3CC2]
- FAC-2 [1CC2]
- RELAY-RTL SYS2 [13CC2]
- RELAY-RUD TRIM 2 [7CC2]
- ACTUATOR-RUDDER TRIM [10CC]
- LIMITATION UNIT-RUDDER TRAVEL [4CC]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 22-63-00-810-802-A | Loss of the Yaw Damper Function on the FAC 2 |
| 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 |
CAUTION:
DO NOT SWAP FLIGHT AUGMENTATION COMPUTERS. IF THERE IS A SHORT CIRCUIT, YOU WILL CAUSE DAMAGE TO A SERVICEABLE COMPUTER WHEN YOU SWAP THEM.
Subtask 22-66-00-710-217-A A. Not applicable.
4. Fault IsolationSubtask 22-66-00-865-094-A
A. Table of the circuit breakers used in this procedure:
Subtask 22-66-00-810-170-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 121VU | AUTO FLT/FAC2/28VDC | 5CC2 | M19 |
B. If the fault symptom is identified by the trip of the 28VDC FAC2 circuit breaker:
(4) If the fault continues:
Subtask 22-66-00-810-170-B ** ON A/C NOT FOR ALL - do a check for short circuit of the 28VDC FAC2 Power Supply wiring between:
. the pin 2 of the AUTO FLT/FAC2 circuit breaker (5CC2) and respectively:
.. the pin AC/2 of the FAC2 (1CC2)
.. the pin A/A2 of the RTL SYS 2 relay (13CC2)
.. the pin A/A2 of the RUD TRIM 2 relay (7CC2)
. the pin A/A1 of the RTL SYS 2 relay (13CC2) and the pin B/A of the RUDDER TRAVEL limitation unit (4CC)
. the pin A/A1 of the RUD TRIM 2 relay (7CC2) and the pin A/T of the RUDDER TRIM actuator (10CC)
ASM 226701.
- repair it.
- do a check of the integrity of the SERVO ACTR-YAW DAMPER, 2 [3CC2] and FAC-2 [1CC2] by the following trouble shooting procedure (Ref. TSM TASK 22-63-00-810-802).
NOTE: Disregard the maintenance message.
(3) If the fault continues: (4) If the fault continues:
- replace the ACTUATOR-RUDDER TRIM [10CC] AMM 27-22-51-000-001 and AMM 27-22-51-400-001.
- replace the LIMITATION UNIT-RUDDER TRAVEL [4CC] AMM 27-23-51-000-001 and AMM 27-23-51-400-001.
- replace the FAC-2 [1CC2] AMM 22-66-34-000-002 and AMM 22-66-34-400-002.
B. If the fault symptom is identified by the trip of the 28VDC FAC2 circuit breaker:
(4) If the fault continues:
Subtask 22-66-00-810-178-A - do a check for short circuit of the 28VDC FAC2 Power Supply wiring between:
. the pin 2 of the AUTO FLT/FAC2 circuit breaker (5CC2) and respectively:
.. the pin AC/7 of the FAC2 (1CC2)
.. the pin A/A2 of the RTL SYS 2 relay (13CC2)
.. the pin A/A2 of the RUD TRIM 2 relay (7CC2)
. the pin A/A1 of the RTL SYS 2 relay (13CC2) and the pin B/A of the RUDDER TRAVEL limitation unit (4CC)
. the pin A/A1 of the RUD TRIM 2 relay (7CC2) and the pin A/T of the RUDDER TRIM actuator (10CC)
ASM 226701.
- repair it.
- do a check of the integrity of the SERVO ACTR-YAW DAMPER, 2 [3CC2] and FAC-2 [1CC2] by the following trouble shooting procedure (Ref. TSM TASK 22-63-00-810-802).
NOTE: Disregard the maintenance message.
(3) If the fault continues: (4) If the fault continues:
- replace the ACTUATOR-RUDDER TRIM [10CC] AMM 27-22-51-000-001 and AMM 27-22-51-400-001.
- replace the LIMITATION UNIT-RUDDER TRAVEL [4CC] AMM 27-23-51-000-001 and AMM 27-23-51-400-001.
- replace the FAC-2 [1CC2] AMM 22-66-34-000-002 and AMM 22-66-34-400-002.
C. If the fault symptom is not identified by the trip of the 28VDC FAC2 circuit breaker:
(2) If the fault continues:
Subtask 22-66-00-710-218-A - do a check of the integrity of the SERVO ACTR-YAW DAMPER, 2 [3CC2] and FAC-2 [1CC2] by the following trouble shooting procedure (Ref. TSM TASK 22-63-00-810-802).
NOTE: Disregard the maintenance message.
(1) If the fault continues: (2) If the fault continues:
- replace the ACTUATOR-RUDDER TRIM [10CC] AMM 27-22-51-000-001 and AMM 27-22-51-400-001.
- replace the LIMITATION UNIT-RUDDER TRAVEL [4CC] AMM 27-23-51-000-001 and AMM 27-23-51-400-001.
- replace the FAC-2 [1CC2] AMM 22-66-34-000-002 and AMM 22-66-34-400-002.