# SDR AALA202509057172

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 3, 2025
- Submitted: September 5, 2025
- Operation: Air carrier
- Aircraft: [N450AN](https://openairdocs.org/aircraft/N450AN), registered now
- Make and model: Airbus A321-253NX
- Registry model: [Airbus A321-253NX](https://openairdocs.org/model/airbus-a321-253nx) (OpenAirDocs)
- Aircraft serial: 10810
- Aircraft time: 13,603 hours, 3,681 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Power Supply
- Part number: 32146210
- Part serial: 178636
- Condition: Faulted
- Location: Zone 200
- Part time: 13,603 hours, 3,681 cycles
- Stage of operation: TX
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202509057172

## Discrepancy

AIRCRAFT WAS NOT GROUNDED: FLIGHT ATTENDANT REPORTS EMERGENCY LIGHTS CAME ON IN TAXI OUT THEN WENT OFF INFLIGHT, THE LIGHTS CAME BACK ON IN DESCENT AND STAYED ON. MAINTENANCE FOUND FAULT MESSAGE EPSU(16WL) OWD R AND REPLACED EMERGENCY POWER SUPPLY UNIT 16WL PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO FAULTS NOTED.

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