# SDR UALA2011010300039

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 2, 2011
- Submitted: January 6, 2011
- Operation: Air carrier
- Aircraft: [N771UA](https://openairdocs.org/aircraft/N771UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 26932
- Aircraft time: 61,301 hours, 11,338 cycles
- Engine: Pwa PW4077
- System (JASC): [2917 · Hydraulic Pressure Regulator, Main](https://openairdocs.org/jasc/2917)
- Part: Check Valve
- Part number: 71425
- Part serial: 30
- Condition: Faulty
- Location: Hyd System
- Stage of operation: IN
- How discovered: 9
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UALA2011010300039

## Discrepancy

CENTER ADP C1 MODULE RPL.  DUE TO PREVIOUS FAILURE OF THE PRESSURE TRANSDUCER CHECK VALVE IN THE FILTER MODULE, AS A PRECAUTION NEED TO REPLACE THE COMPLETE FILTER MODULE. NO LEAKS NOTED.

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