# SDR 20000718AP003

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 21, 2000
- Submitted: July 5, 2000
- Operation: Air carrier
- Aircraft: [N357QS](https://openairdocs.org/aircraft/N357QS), registered now
- Make and model: Boeing 727-21
- Registry model: [Boeing 727-21](https://openairdocs.org/model/boeing-727-21) (OpenAirDocs)
- Aircraft serial: 19259
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Valve
- Part number: 39270432
- Condition: Broken
- Location: Nr 3 Precooler
- Stage of operation: CL
- How discovered: O
- Nature of condition: B, J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/20000718AP003

## Discrepancy

FLT 649 - AIR RETURN TO OMA, ON CLIMB-OUT AT 1000 FEET AGL FLAPS 2 DEGREES WERE SELECTED AND A SPLIT FLAP CONDITION OCCURRED.  SMOKE BEGAN TO FILL THE COCKPIT, AND EMERGENCY WAS DECLARED AND AN IMMEDIATE RETURN INITIATED.  INSPECTED NR 1 AND NR 3 PRECOOLER REGULATOR AIR FLOW VALVES, FOUND NR 3 VALVE BROKEN.  REPLACED NR 3 PRECOOLER MODULATING VALVE.  (M)

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