# SDR UALA2010070902452

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 9, 2010
- Submitted: July 9, 2010
- Operation: Air carrier
- Aircraft: [N660UA](https://openairdocs.org/aircraft/N660UA), registered now
- Make and model: Boeing 767322
- Aircraft serial: 27115
- Aircraft time: 74,832 hours, 12,096 cycles
- Engine: Pwa PW4060
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Shutoff Valve
- Part number: 7732887810
- Part serial: 880711
- Condition: Intermittent
- Location: Nr 1
- Stage of operation: IN
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UALA2010070902452

## Discrepancy

NR 1 PRSOV INTERMITTENT OPERATION WHEN CHECKING IDLE RUN AIR PRESSURE.  REMOVED NR2 PRSOV VALVE. RPLD NR 2 PRSOV.  ACCOMPLISHED POWER RUN. NR 2 BLEED OPS CHECKED GOOD AT POWER. OVERNIGHT TROUBLESHOOTING IDENTIFIES PROBLEM AS BLEED PRESSURE DROPPING OFF TO MINIMUM WHEN THROTTLE RETARDED: HPSOV APPEARS INOPERATIVE. LOCKED VALVE CLOSED, DEFERRED. REPLACED HPSOV AND HPC. DUCT PSI NORMAL, RT PACK OPS NORMAL.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.