03/02/21
Message Overview:
Message Description:
The ARINC input from the FCU and analog input from the Flap Position Sensors are invalid or miscompare.
Possible Causes:
- Flap Control Unit (FPU) (A124)
- Stall Protection Computer (SPC) (A178)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- AW300-27-0058 - Flap Control Unit - CAS Messages Reset procedure (20501 - 20999)
Forum Articles/Infoservice/Newsletter: None
If Flap Control Unit (FCU) PN:2257A0000-02 is installed, reset procedure included in AW300-27-0058 may clear the fault.
Quick Links:
| Removal of the Junction Box JB3 | AMM 24-63-09-000-802 |
| Installation of the Junction Box JB3 | AMM 24-63-09-400-802 |
| Functional Test of Junction Box JB3 | AMM 24-63-09-720-801 |
| Operational Test of the Stall Protection System (SPS) | AMM 27-32-00-710-801 |
| Removal of the Stall Protection Computer | AMM 27-32-01-000-801 |
| Installation of the Stall Protection Computer | AMM 27-32-01-400-801 |
| Removal of the Flap Control Unit (FCU) | AMM 27-51-05-000-801 |
| Installation of the Flap Control Unit (FCU) | AMM 27-51-05-400-801 |
| Operational Test of the Flap Control Unit (FCU) | AMM 27-51-05-710-801 |
| Removal of the Flap Position Sensor | AMM 27-52-17-000-802 |
| Installation of the Flap Position Sensor | AMM 27-52-17-400-802 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Check in the MDC in the current faults and fault history pages for problems related to FLAP CONTROL UNIT.
- If one of the listed fault is found, continue with the troubleshooting of this failure.
- If none of the listed faults is recorded in the MDC, continue with next step.
- Reset the following circuit breakers.
STALL R PWR CB2-B10 STALL L PWR CB1-B10 FLAP R IND CB2-B12 FLAP L IND CB1-B13 FLAP CTRL CB1-B14 - Reset the FCU by pressing the FCU reset button on the MAINTENANCE TEST control panel.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Do wiring check between FCU connectors A124AP1/A124BP1 and SPC connectors A178AP1/A178BP1. Repair/replace as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace FCU.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace SPC.
- Do close out.