# SDR AALA202407023482

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 18, 2024
- Submitted: July 2, 2024
- Operation: Air carrier
- Aircraft: [N163AA](https://openairdocs.org/aircraft/N163AA), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 6866
- Aircraft time: 24,240 hours, 9,646 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Lubrication Unit
- Part number: 41310204
- Part serial: 4326
- Condition: Leaking
- Location: Apu
- Part time: 17,088 hours, 21,070 cycles
- Component: Apu, Hnywl, 1319A
- Component part number: 38007081
- Stage of operation: DE
- How discovered: O
- Nature of condition: K, B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202407023482

## Discrepancy

AIRCRAFT WAS GROUNDED: DURING DESCENT THRU 10000, THERE WAS A STRONG ACRID SMELL THROUGHOUT THE CABIN. THE ODOR WAS SLIGHTLY BETTER AFTER TURNING PACK 1 OFF. THE STRONGEST SMELL WAS NOTICED IN THE AFT OF THE CABIN.  MAINTENANCE FOUND OIL LEAKING FROM THE APU DRAIN MAST FOR THE FUEL CONTROL UNIT / OIL LUBE MODULE. MAINTENANCE REPLACED THE APU OIL LUBE MODULE AND THE APU FUEL CONTROL UNIT (AALA202407021886). A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCO0MPLISHED WITH NO LEAKS OR DOSRS NOTED.

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