# SDR 9506382291

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 20, 1995
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N291US](https://openairdocs.org/aircraft/N291US), registered now
- Make and model: Boeing 727251
- Aircraft serial: 21379
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Part number: 10328051
- Condition: Malfunctioned
- Location: Aft Fuselage
- Part time: 42,810 hours
- Stage of operation: CL
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/9506382291

## Discrepancy

DURING CLIMB AT FL210, CABIN PRESSURIZATION STARTED A SLOW UNCONTROLLABLE ASCENT.  UPON CABIN ALTITUDE REACHING 10,000 FEET, INITIATED AIRCRAFT DESCENT AND RETURNED TO PHX WITHOUT FURTHER INCIDENT.  MAINTENANCE REPLACED RIGHT OUTFLOW VALVE.  OPERATIONAL CHECK NORMAL.

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