# SDR AALA202605208192

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 18, 2026
- Submitted: May 21, 2026
- Operation: Air carrier
- Aircraft: [N815NN](https://openairdocs.org/aircraft/N815NN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 33208
- Aircraft time: 47,890 hours, 20,243 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Air Filter
- Part number: CD01068F2
- Condition: Contaminated
- Location: Zone 100
- Stage of operation: NR
- How discovered: O
- Nature of condition: B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202605208192

## Discrepancy

AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANT REPORT UNUSUAL ACRID AND BURNING ODOR SMELL NEAR MID CABIN WITH PACKS RUNNING. COMPLETED J/C 08L00021001, WHILE TROUBLESHOOTING FOUND THAT SMELL WOULD GET STRONGER WITH RIGHT HAND RECIRCULATION FAN ON, AND SUBSIDE WHEN RIGHT HAND RECIRCULATION FAN WAS OFF. WHILE RUNNING PACKS WITH NO RECIRCULATION FANS ON SMELL WOULD SUBSIDE. REMOVED AND REPLACED RIGHT HAND RECIRCULATION FAN (AALA202605203519), PER AMM 21-25-02. OPS CHECK GOOD. ALSO, REMOVED AND REPLACED BOTH CABIN AIR HEPA FILTERS (AALA202605208192) (AALA202605201060), PER AMM 21-25-01. RAN PACKS FOR OVER TWO HOURS WITH RECIRCULATION  FANS ON, NO SMELL NOTED.

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