# SDR CALA2025021102280

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 10, 2025
- Submitted: February 11, 2025
- Operation: Air carrier
- Aircraft: [N39463](https://openairdocs.org/aircraft/N39463), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 37208
- Aircraft time: 38,168 hours, 13,698 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Filter
- Part number: P199753
- Condition: Contaminated
- Location: Zone 100
- Stage of operation: NR
- How discovered: 9
- Nature of condition: B
- Precautionary procedure: H
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2025021102280

## Discrepancy

AFTER TO STRONG SMELL OF BURNT OIL IN THE AIR CON SYSTEM THROUGH OUT THE CABIN PERF AMM TASK 05-51-26-800-801-C1 AND HAD CREW COMPLETE SMOKE/OD OR FORMS, FORWARDED TO MX CTL. CREW INDICATED THAT IT WAS AN  OILY/CHEMICAL SMELL. PERF ENG RUN AT PART PWR PER MM TASK, NO OD ORS NOTED WITH EITHER ENG BLEED OR PACK. HOWEVER,WHEN ENG BLEEDS WERE SWITCHED OFF AND APU BLEED WAS SWITCHED ON, A FAINT SMELL W AS NOTED WITH APU SUPPLYING BOTH PACKS, TWO TIMES. AS PER DIS- POSITION PARAGRAPH, DIP CREATED TO REPLACE RECIRC FILTERS, REF L OG 3828557. DEFERRAL REQUESTED TO INOP APU PER MEL. INSPECTIONS HAVE BEEN COMPLETED PER MM 05-51-26, NO OTHER FINDINGS/DEFECTS N OTED.  APU INOP DUE TO REPORT OF OIL SMELL ACFT IS OK FOR SERVICE. UPDATED SDR REPORT COMPLETED PART USAGE ON SDR UPDATE SDR REPLACED RE CIRCULATION FILTERS 2 EACH REF LOG PAGE 3828557 AND AMM 21-25-01.  RAN APU WITH LEFT PACK IN AUTO AND HIGH, THEN RIGHT PACK IN AUTO AND HIGH, THEN BOTH PACKS IN AUTO AND HIGH FOR A TOTAL OF 1 HOUR.  NO SMELL OF OIL CABIN REF AMM 05-51-26-800-801-C1.

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