# SDR QXEA0200796

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 9, 2002
- Submitted: May 10, 2002
- Operation: Air carrier
- Aircraft: N499US
- Make and model: Fokker F.28 MK4000
- Registry model: [Fokker F.28 MK4000](https://openairdocs.org/model/fokker-f-28-mk4000) (OpenAirDocs)
- Aircraft serial: 11182
- Aircraft time: 41,756 hours, 51,737 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Valve
- Part number: 39253021
- Part serial: 764
- Condition: Inoperative
- Location: Cabin
- Part time: 108,255 hours, 107,844 cycles
- Stage of operation: CL
- How discovered: V
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QXEA0200796

## Discrepancy

BOI- CLIMBING THROUGH 25,000 FEET CABIN PRESSURIZATION WAS CLIMBING 8,000 FEET. LEVELED OFF AT 26,000 FEET, CABIN PRESSURE CONTINUED TO CLIMB TO 10,000. (AIRFOIL ANTI-ICE WAS ON AND WING TEMPERATURE WAS IN YELLOWAND BACK-UP VALVE WAS CLOSED).AIRCRAFT RETURNED TO FEILD WITH OUT INCIDENT.ON DECENT TO BOI TURNED AIRFOIL OFF, BACK-UP VALVE OPENED AND PRESSURE RETURNED TO 55 PSI.REMOVED AND REPLACED #1 BACK-UP VALVE AND #2 MAIN VALVE. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.

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