# SDR AALA202505164104

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 15, 2025
- Submitted: May 16, 2025
- Operation: Air carrier
- Aircraft: [N552UW](https://openairdocs.org/aircraft/N552UW), registered now
- Make and model: Airbus A321-231
- Registry model: [Airbus A321-231](https://openairdocs.org/model/airbus-a321-231) (OpenAirDocs)
- Aircraft serial: 4957
- Aircraft time: 42,890 hours, 16,966 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Oil System
- Condition: Overserviced
- Location: Apu
- Component: Apr, Hnywl
- Component part number: 38007081
- Stage of operation: AP
- How discovered: O
- Nature of condition: W, B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202505164104

## Discrepancy

AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANT REPORTED STRONG DIRTY SOCK SMELL IN THE MID CABIN ON APPROACH THRU LANDING. MAINTENANCE FOUND THE APU WAS OVERSERVICED AND DRAINED THE EXCESS OIL PER AMM 49-91-42. (AALA202505164104) MAINTENANCE ALSO FOUND THE APU GEARBOX VENT LINE HAD EVIDENCE OF COKING AND WAS CLOGGED. MAINTENANCE REPLACED THE VENT LINE PER AMM 49-26-55. (AALA202505165926) MAINTENANCE ACCOMPLISHED THE DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM PER TASK CARD 26L00021014. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO LEAKS OR ODORS NOTED.

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