# SDR CALA2025112411431

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 21, 2025
- Submitted: November 24, 2025
- Operation: Air carrier
- Aircraft: [N33264](https://openairdocs.org/aircraft/N33264), registered now
- Make and model: Boeing 737824
- Aircraft serial: 31584
- Aircraft time: 75,741 hours, 26,826 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: A/C Pack
- Condition: Faulted
- Location: Zone 100
- Stage of operation: CL
- How discovered: O
- Nature of condition: B
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2025112411431

## Discrepancy

AIR RETURN PGUM - PGUM UPDATE FROM CREW: BURNING OIL SMELL IN CABIN, VERY DISTINCT OIL SMELL CLIMBING THROUGH 22K GOT WORSE ON DECENT. ALL INDICATIONS WERE NORMAL. FLIGHT CREW REPORTS STRONG SMELL OF BURNING OIL AT FLIGHT LEVEL 220 AND SMELL  INCREASED ON DESCENT ENGINE RUN PERFORMED FOR FLUSHING THE LUBE, SUMPS, AND BLEED SYSTEMS PER AMM 72-00-00-100-803-F00 (4)(H)(2). OPERATED ENGINE AT IDLE WITH NO FUMES OR ODOR DETECTED IN THE COCKPIT OR CABIN. PERFORMED INSPECTION PER AMM 05-51-26-800-801-C1 COMPLETED UP TO ITEM L. NO FAULTS OR EVIDENCE OF ANY FUILD IN  PNEUMATIC DUCT SYSTEM OR SMOKE FROM ELECTRICAL COMPONENTS FOUND DURING COMPLETED INSPECTION.   UPDATED WORK PERFORM PER AMM 05-51-26-800-801-C1 PERFORMED WORK UP TO DETAILED INSPECTION PARAGRAPH D ITEM (1) STEP (K) NEED TO CONTUINE AT STEP (L) CONT'D W/ MM 05-51-26, ITEM (1) TO DETERMINE SOURCE OF SMOKE/ODORS C/W.  C/W ITEM (2) DETAILED OPERATION CHECKS W/ NO FINDINGS.  RAN NR 1 & 2 AT HIGH POWER W/ ENG BLEEDS ON, APU BLEED OFF, PACKS ON & ISOLATION VALVE CLOSED W/ NO EVIDENCE OF SMOKE OR UNUSUAL ODOR IN COCKPIT OR CABIN, REF MM 71-00-00, NEED DISPOSITION FROM TOMC AS PER ITEM D.(3) OF MM 05-51-26. CONFIRMED W/ TOMC OK TO CLEAR THIS LOG PAGE W/ NO ADDITIONAL MAINTENANCE REQUIRED, OK TO CONTINUE.

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