# SDR AALA202404259737

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 23, 2024
- Submitted: April 25, 2024
- Operation: Air carrier
- Aircraft: [N129AA](https://openairdocs.org/aircraft/N129AA), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 6401
- Aircraft time: 30,392 hours, 9,639 cycles
- System (JASC): [4930 · APU Engine Fuel and Control](https://openairdocs.org/jasc/4930)
- Part: O-Ring
- Part number: UNKNOWN
- Condition: Leaking
- Location: Apu Fule
- 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/AALA202404259737

## Discrepancy

AIRCRAFT WAS GROUNDED: DESCENDING THROUGH 18000 FT FLIGHT CREW REPORTED A STRONG MUSTY DIRTY SOCK FUMES, CONTINUED TO LANDING. MAINTENANCE FOUND OIL LEAKING OUT OF THE APU FUEL CONTROL UNIT DRAIN. MAINTENANCE REPLACED THE O-RING ON THE APU FUEL CONTROL UNIT SEAL TO GEAR BOX PER AMM 49-32-11. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.

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