# SDR AALA202308217720

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 18, 2023
- Submitted: August 21, 2023
- Operation: Air carrier
- Aircraft: [N440AN](https://openairdocs.org/aircraft/N440AN), registered now
- Make and model: Airbus A321-253NX
- Registry model: [Airbus A321-253NX](https://openairdocs.org/model/airbus-a321-253nx) (OpenAirDocs)
- Aircraft serial: 10643
- Aircraft time: 7,060 hours, 1,888 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Battery
- Part number: 321431
- Condition: No Test
- Location: Zone 200 - Fuse
- Stage of operation: IN
- How discovered: C
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202308217720

## Discrepancy

AIRCRAFT WAS NOT GROUNDED: DURING OPERATIONAL TEST OF EMERGENCY LIGHTS, EMERGENCY POWER SUPPLY UNIT SYSTEM TEST GOT FAULT MESSAGE "BAT/EPSU (11WL) EXT L ". PERFORMED BUILT IN TEST EQUIPMENT TEST ON EMERGENCY POWER SUPPLY UNIT "BAT FAULT" MESSAGE. REPLACED EMERGENCY POWER SUPPLY UNIT BATTERY PER AMM 33-51-38.

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