# SDR 99UAL900268

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 9, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N557UA
- Make and model: Boeing 757222
- Aircraft serial: 26653
- Engine: Pwa PW2037
- System (JASC): [4920 · APU Core Engine](https://openairdocs.org/jasc/4920)
- Part: Seal
- Condition: Failed
- Location: Apu
- Stage of operation: NR
- Nature of condition: H
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99UAL900268

## Discrepancy

DIVERTED TO BOI DUE TO LOSS OF APU GENERATOR.  THE LEFT GENERATOR WAS LOST ON TAKEOFF.  *S/D*  APU SHUTDOWN WITH 'APU OIL QTY' MSG.   FOUND OIL DRIPPING FROM DRAIN MAST INDICATING A CARBON SEAL DEFECTIVE.  GENERATOR COULD NOT STAY ON LINE DUE TO AUTO SHUTDOWN FOR LOW OIL QUANTITY.  APU WAS REPLACED.  DURING SHOP VISIT, DISASSEMBLY REVEALED A DEFECTIVE CARBON SEAL.

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