DOC AIRBUS | TSM A320FFailure of the Yaw Damper System
TASK 27-26-00-810-801-A
Failure of the Yaw Damper System
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
[Rev.8 from Aug 2018]
2026.04.04 04:38:45 UTC
Failure of the Yaw Damper System
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| ESPM 2055500 | |
| AMM 22-66-34-000-002 | Removal of the FAC |
| AMM 22-66-34-400-002 | Installation of the FAC |
| ASM 226804 | |
| AMM 27-24-00-710-002 | Operational Test of the Rudder Servocontrols with Individual Hydraulic System |
| AMM 27-26-51-000-001 | Removal of the Yaw Damper Servo Actuator |
| AMM 27-26-51-400-001 | Installation of the Yaw Damper Servo Actuator |
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 27-26-00-710-050-A ** ON A/C NOT FOR ALL A. Test not applicable, you cannot confirm this fault on the ground.
4. Fault IsolationNOTE: This Fault Isolation is for the system 1, for the system 2, use the indications between the parentheses.
Subtask 27-26-00-810-050-A ** ON A/C NOT FOR ALL A. If the fault symptom is identified by the crew observation F/CTL - Yaw and roll jerk very hard:
(1) Remove the FAC related to the system which was active at the time of the event AMM 22-66-34-000-002.
1 Replace the FAC-1 [1CC1] ( FAC-2 [1CC2] ) AMM 22-66-34-000-002 and AMM 22-66-34-400-002.
2 If the fault continues:
(b) If the check is not correct:
1 Clean the connector A of the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) ESPM 2055500.
2 At the FAC receptacle, do again a check of the resistance and insulation of the LVDT.
a If the check is correct, no further maintenance action is necessary.
(3) At the yaw damper, do a check of the resistance and insulation between pins A/C and A/B, and between pins A/K and A/J ASM 226804.
(a) If the check is not correct, replace the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) AMM 27-26-51-000-001 and AMM 27-26-51-400-001
(b) If the check is correct, repair the wiring ASM 226804.
(1) Remove the FAC related to the system which was active at the time of the event AMM 22-66-34-000-002.
NOTE: In normal configuration, the FAC-1 [1CC1] servoes the Green yaw damper servo actuator (3CC1), the FAC-2 [1CC2] servoes the Yellow yaw damper servo actuator (3CC2).
(2) At the FAC receptacle, do a check of the resistance and insulation of the LVDT of SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) (COM) between pins AB/2E and AB/2F, and between pins AB/3E and AB/3F ASM 226804. NOTE: The resistance of the two secondary windings must be between 30 Ohms and 500 Ohms.
The insulation must be more than 100 Megohms.
(a) If the check is correct: The insulation must be more than 100 Megohms.
1 Replace the FAC-1 [1CC1] ( FAC-2 [1CC2] ) AMM 22-66-34-000-002 and AMM 22-66-34-400-002.
2 If the fault continues:
- Do a check of the wiring between the LVDT and the FAC ASM 226804 for correct connections.
- Replace the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) AMM 27-26-51-000-001 and AMM 27-26-51-400-001.
(b) If the check is not correct:
1 Clean the connector A of the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) ESPM 2055500.
2 At the FAC receptacle, do again a check of the resistance and insulation of the LVDT.
a If the check is correct, no further maintenance action is necessary.
NOTE: After the subsequent flight, if the fault continues, replace the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) AMM 27-26-51-000-001 and AMM 27-26-51-400-001.
b If the check is not correct, go to Para. (3). (3) At the yaw damper, do a check of the resistance and insulation between pins A/C and A/B, and between pins A/K and A/J ASM 226804.
(a) If the check is not correct, replace the SERVO ACTR-YAW DAMPER, 1 [3CC1] ( SERVO ACTR-YAW DAMPER, 2 [3CC2] ) AMM 27-26-51-000-001 and AMM 27-26-51-400-001
(b) If the check is correct, repair the wiring ASM 226804.