# SDR DALA2026080804586

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 5, 2026
- Submitted: August 8, 2026
- Operation: Air carrier
- Aircraft: [N549DN](https://openairdocs.org/aircraft/N549DN), registered now
- Make and model: Airbus A321-271NX
- Registry model: [Airbus A321-271NX](https://openairdocs.org/model/airbus-s-a-s-a321-271nx) (OpenAirDocs)
- Aircraft serial: 11693
- Aircraft time: 11,467 hours, 2,777 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Oil System
- Condition: Leaking
- Location: Apu
- Stage of operation: IN
- How discovered: V
- Nature of condition: K, B
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DALA2026080804586

## Discrepancy

FLIGHT ATTENDENTS REPORTED DIRTY SOCK SMELL AT GEAR DOWN THRU ENGINE SHUTDOWN, ODOR CAME AND WENT IN THE FRONT, BACK FA'S REPORTED SIMILAR ODOR AT 8000 AGL.  FOUND APU OIL OVERSERVICED. DRAINED OIL IAW AMM 49-90. INSPECTED APU BLEED DUCT, NO OIL WETTING NOTED IAW AMM 49-51. AFTER APU RUN, FOUND APU OIL LEVEL LOW. INSPECTED BOTH ENG INLET CONES, NO WETTING NOTED. IAW AMM72-15. DURING WC 4900-2001 NO OIL FOUND IN APU BLEED DUCT. FOUND OIL AT APU LOAD COMPRESSOR DRAIN LINE, REPLACED APU. (LP 9583621, 1742877  AIRCRAFT WAS GROUNDED)

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