# SDR AALA202107190446

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 17, 2021
- Submitted: July 19, 2021
- Operation: Air carrier
- Aircraft: [N524UW](https://openairdocs.org/aircraft/N524UW), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 3977
- Aircraft time: 41,061 hours, 14,958 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Battery Pack
- Part number: AD321431
- Condition: No Test
- Location: Emergency Lights
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202107190446

## Discrepancy

AIRCRAFT IN BASE MAINTENANCE: FAILED OPERATIONAL CHECK OF EMERGENCY POWER SUPPLY UNITS BY BITE CHECK 14WL ON PASSENGER CABIN. REPLACED BATTERY PACK P/N:AD-3214-31 S/N: 265429 ON EPSU 14WL IAW AMM 33-51-38-400-002-A

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