# SDR 97UAL900027

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 3, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N781UA](https://openairdocs.org/aircraft/N781UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 26945
- Engine: Pwa PW4077
- System (JASC): [4900 · Airborne Auxiliary Power Unit (APU) System](https://openairdocs.org/jasc/4900)
- Part: Contactor
- Part number: BP4931
- Condition: Failed
- Location: Apu
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97UAL900027

## Discrepancy

APU SHUT DOWN AT GATE.  AIRCRAFT WILL NOT ACCEPT APU POWER.  INVESTIGATION REVEALS CONTACTOR (START RELAY) FAILED (WOULD NOT CLOSE).  REPLACED PN BP493-1.  OPERATIONAL CHECK OK.

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