# SDR DALA2026060403384

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 31, 2026
- Submitted: June 4, 2026
- Operation: Air carrier
- Aircraft: [N589DT](https://openairdocs.org/aircraft/N589DT), 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: 12417
- Aircraft time: 5,247 hours, 1,379 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Oil System
- Condition: Leaking
- Location: Apu
- 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/DALA2026060403384

## Discrepancy

FUMES - DESCENDING THRU FL190, CREW NOTICED A DIRTY SOCKS SMELL. O2 MASKS WERE DONNED AND AN EMERGENCY DECLARED. CORRECTIVE ACTION: INITIAL T/S FOUND OIL BEHIND NR 1 ENGINE SPINNER. NR 1 ENGINE FOAM WASH PERFORMED. FOLLOW UP BORESCOPE WAS GOOD. LEVEL C DECONTAMINATION PERFORMED. POST DECONTAMINATION ENGINE RUNS PERFORMED. P-TRAK RESULTS DEEMED APU AS SOURCE OF ODOR. APU BLEED DEFERRED TO MEL. INSPECTED APU COMPARTMENT FOUND CLEAN NO SIGN OF FLUID LEAKING PER  AMM 49-00-00. LATER, REPLACED NR 1 ENGINE. A/C RTS. (LP 7995595, 8319604 - AIRCRAFT WAS GROUNDED)

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