# SDR 97UAL900696

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 10, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N544UA](https://openairdocs.org/aircraft/N544UA), registered now
- Make and model: Boeing 757222
- Aircraft serial: 25322
- Engine: Pwa PW2037
- System (JASC): [4950 · APU Bleed Air System](https://openairdocs.org/jasc/4950)
- Part: Sense Module
- Part number: 36144001
- Condition: Malfunctioned
- Location: Apu
- Stage of operation: NR
- Nature of condition: O
- Precautionary procedure: H
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97UAL900696

## Discrepancy

APU DUCT PRESSURE LOW AT ENGINE START, APU INOP.  *S/D*  SURGE CONTROL VALVE REPLACEMENT, DID NOT HELP.  REPLACED PNUEMATIC FLOW SENSING MODULE, AND OPERATION OF APU BACK TO NORMAL.

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