# SDR AALA202403218899

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 9, 2024
- Submitted: March 21, 2024
- Operation: Air carrier
- Aircraft: [N128AN](https://openairdocs.org/aircraft/N128AN), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 6346
- Aircraft time: 30,230 hours, 9,642 cycles
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Battery
- Part number: 321431
- 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/AALA202403218899

## Discrepancy

AIRCRAFT WAS IN BASE MAINTENANCE: DURING EPSU SYSTEM TEST, (13WL) AFT L FAULT IS DETECTED. DISPLACED EMERGENCY OXYGEN CONTAINER FROM THE SERVICE CHANNEL OF THE AFT UTILITY AREA IAW A321 AMM 35-21-41-000-001-A REMOVED THE BATTERY OF THE EMERGENCY POWER SUPPLY UNIT (EPSU) (13WL), INSTALLED SERVICEABLE BATTERY OF THE EMERGENCY POWER SUPPLY UNIT (EPSU) (13WL).  REINSTALLED EMERGENCY OXYGEN CONTAINER FROM THE SERVICE CHANNEL OF THE AFT UTILITY AREA.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.