# SDR AALA202507074158

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 5, 2025
- Submitted: July 7, 2025
- Operation: Air carrier
- Aircraft: [N155UW](https://openairdocs.org/aircraft/N155UW), registered now
- Make and model: Airbus A321-211
- Registry model: [Airbus A321-211](https://openairdocs.org/model/airbus-a321-211) (OpenAirDocs)
- Aircraft serial: 5659
- Aircraft time: 36,422 hours, 15,081 cycles
- System (JASC): [3460 · Flight Management Computing Hardware System](https://openairdocs.org/jasc/3460)
- Part: Fmc
- Part number: C13043AA05
- Part serial: 6675
- Condition: Frozen
- Location: Zone 100
- Part time: 70,438 hours, 34,081 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202507074158

## Discrepancy

AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT DIVERTED TO DEN DUE TO THE FLIGHT CREW REPORTING MULTIPLE FAILURE MESSAGES FOR AUTO THRUST, AUTOPILOT 1 AND 2, FMGC 1 AND 2 BEING FROZEN. THE AIRCRAFT WAS OVERWEIGHT AND LANDED SAFELY AT DEN. WHILE TAXING THE #1 AND #2 MAIN TIRES DEFLATED DUE TO THE FUSE PLUGS BEING MELTED DUIRNG THE EMERGENCY BRAKING UPON LANDING. PASSENGER WERE DEPLANED ON THE TAXIWAY AND BUSED TO THE GATE. MAINTENANCE REPLACED FMGC 1 (AALA202507074158) AND 2 (AALA202507070181) PER AMM 22-83-34 DUE BOTH UNITS BEING FROZEN. THE REPLACEMENT OF BOTH FMGC UNITS WERE DETERMINED TO BE THE CAUSE OF THE FAILURE MESSAGES FOR THE AUTOPILOT  1 AND 2, AS WELL AS THE AUTOHRUST. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO FAULTS NOTED.

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