# SDR CALA2025031302786

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 12, 2025
- Submitted: March 13, 2025
- Operation: Air carrier
- Aircraft: [N73445](https://openairdocs.org/aircraft/N73445), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 40000
- Aircraft time: 43,749 hours, 15,891 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Filter
- Part number: P199753
- Condition: Dirty
- Location: Zone 100
- Stage of operation: DE
- 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/CALA2025031302786

## Discrepancy

MOLDLY OLD SOCK SMELL AT LOW ALTITUDES AND HIGH POWER SETTINGS OPERATED APU AND PACKS. NOTICED THERE WAS A STRONG OIL ODOR THROUGHOUT CABIN AND COCKPIT. PERFORMED FIM TASK 05-51-26-800-801-C1, SMOKE/ODOR IN FLIGHT DECK/ CABIN. FOUND RIGHT RECIRCULATION FILTER DIRTIER THAN LEFT, BUT SEEMED LIKE NORMAL DIRT AND NOT OIL CONTAMINATION. REPLACED BOTH FILTERS PER A.M.M. 21-25-01. RAN ENGINES AT 70% N1 WITH PACKS ISOLATED ON EACH SIDE FOR 10 MINUTES. ISOLATED APU BLEED DURING COOL DOWN. NO ODORS NOTED. REINSPECTED RECIRCULATION FILTERS AND FOUND NO CONTAMINATION. AIRCRAFT OKAY FOR SERVICE.

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