# SDR UIEA2020101202222

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 10, 2020
- Submitted: October 14, 2020
- Operation: Air carrier
- Aircraft: [N1997A](https://openairdocs.org/aircraft/N1997A), registered now
- Make and model: Boeing 767-33A
- Registry model: [Boeing 767-33A](https://openairdocs.org/model/boeing-767-33a) (OpenAirDocs)
- Aircraft serial: 27310
- Aircraft time: 98,919 hours, 20,438 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Condition: Malfunctioned
- Location: Cabin Pressure
- Stage of operation: CR
- 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/UIEA2020101202222

## Discrepancy

INFO ONLY: DURING CRUISE AT 390FL AT ABOUT 6 MIN INTERVALS, THE OUTFLOW VALVE WOUD MOVE FROM A QUARTER POSTION TO HALF POSITION CAUSING THE A/C TO SHUDDER.  IT HAPPENED CONTINUOUSLY.  PERFORMED CABIN PESS TEST, IAW AMM 05-51-24, SYSTEM TEST OK.  PERFORMED MANUAL MODE CONTACT TEST, IAW AMM 21-31-00, TEST OK.  PERFORMED BITE TEST ON CABIN PRESSURE CONTROLLERS, NO FAULTS FOUND.  A/C OK FOR SERVICE.

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