# SDR UALA2010121604600

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 16, 2010
- Submitted: January 31, 2011
- Operation: Air carrier
- Aircraft: [N778UA](https://openairdocs.org/aircraft/N778UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 26940
- Aircraft time: 59,092 hours, 10,656 cycles
- Engine: Pwa PW4077
- System (JASC): [4950 · APU Bleed Air System](https://openairdocs.org/jasc/4950)
- Part: Check Valve
- Part number: 32026105
- Condition: Faulty
- Location: Apu
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UALA2010121604600

## Discrepancy

3 START ATTEMPTS APU FAILED TO START.  STARTED APU USING ACFT PNEUMATIC. DEFERRED ISSUE FOR FURTHER T/S IAW MEL 4942A AND COMPLIED WITH MAINT MSG 49-11290. CHECK VALVE, REF: FIM 49-52-00-810 TASK 808 "APU CHECK VALVE FAILED OPEN".  REPLACED 2EA APU PNEU CLUSTER SENSORS: 'TOTAL PRESS' & 'INLET PRESS' SENSORS IAW MM.  NEED REPAIR CONF CK IAW REF FIM TASK ITM 'E'.  OPS CHECK GOOD IAW FIM.

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