# SDR CALA2026092119557

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 19, 2026
- Submitted: September 21, 2026
- Operation: Air carrier
- Aircraft: [N77536](https://openairdocs.org/aircraft/N77536), registered now
- Make and model: Boeing 737824
- Aircraft serial: 62766
- Aircraft time: 31,507 hours, 11,756 cycles
- Engine: Cfmint CFM567B27
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Filter
- Part number: 21FA407G
- Condition: Clogged
- Location: Zone 100
- Stage of operation: CR
- 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/CALA2026092119557

## Discrepancy

MUSTY ODOR FROM PACKS ON TAKEOFF/CLIMB. DISAPPEAR ED IN CRUISE. CAME BACK ON DESCENT. REMOVED AND REPLACED RECIRCULATOIN AIR FILTERS IAW AMM TASK21-25-01-400-801. CONFIRMED WITH TOMC ENGINE WASH ACCOMPLISHED ON SNA ON 09/19/26 OPERATED PACKS NO MUSTY SMELL NOTED.PARTS USED:  29-2124-3-0006, QTY :1 ADD EMP:U354710

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