04/09/25
Message Overview:
Message Name:
FGC USING STBY AIR SPEED
Message Code:
B3-280283
Associated CAS:
| Reporting LRU: | FGC 2 |
| System Description: | 22-11-00 - Automatic Flight-Control System (AFCS) |
| Schematic Diagram: | None |
| Wiring Diagram: | None |
Message Description:
The FGC has lost its primary source of airspeed from the R ADC. FGC is likely functioning correctly.
Possible Causes:
- Right-Air Data Computer (ADC 2) (A2)
- Right-Input/Output Concentrator Unit (IOC) (A4-IOC)
- Flight Guidance Computer (FGC) (A4-FGC)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
Fault Confirmation Procedure:
- Message# = 8
- Comp Id = A004
- Fault Logged = AIR, TAXI
- Status = FAILED/WIRING
- {Term Definitions}
- FGC2-16 2X 071 10 EXCT XXXX-XXXX XXXX-XXTX XXXX-XXXX 071: 18; (350: 13;)PRIMARY AIR SPEE
- ADC2-1 2X 350 10 ABSN XXXX-XXXX XXXX-XXXX XXXX-XXXX 350: (A) NO IOC 2X IN;
Quick Links:
| Standard Aircraft Configuration for Maintenance | AMM 12-00-00-867-803 |
| Cleaning Safety Precautions | AMM 12-21-00-910-801 |
| Removal of the Flight Guidance Computer (FGC) | AMM 22-11-01-000-801 |
| Installation of the Flight Guidance Computer (FGC) | AMM 22-11-01-400-801 |
| Removal of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-000-801 |
| Installation of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-400-801 |
| Removal of the Air Data Computer | AMM 34-13-01-000-801 |
| Installation of the Air Data Computer | AMM 34-13-01-400-801 |
Troubleshooting Recommendations:
- Suspect problem with the R-ADC, R-IOC or R-ADC-1 wiring. FGC is very likely not the failed device.