# SDR 2007UALA05294

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 25, 2007
- Submitted: December 26, 2007
- Operation: Air carrier
- Aircraft: N557UA
- Make and model: Boeing 757222
- Aircraft serial: 26653
- Aircraft time: 54,036 hours, 17,791 cycles
- Engine: Pwa PW2037
- System (JASC): [3510 · Crew Oxygen System](https://openairdocs.org/jasc/3510)
- Part: Oxygen Mask
- Part number: MC1019101
- Condition: Faulty
- Location: Cockpit
- Stage of operation: IN
- How discovered: C
- Nature of condition: W
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2007UALA05294

## Discrepancy

OBSERVER`S O2 MASK WILL NOT SHUT OFF.  FOUND 1ST OBS O2 MASK LEAKING AT HARNESS.  REPLACED FIRST OBS O2 MASK, OPS CHECKED NORMAL.


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