# SDR K11A2020072900004

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 29, 2020
- Submitted: July 29, 2020
- Operation: Air carrier
- Aircraft: [N724CK](https://openairdocs.org/aircraft/N724CK), registered now
- Make and model: Boeing 727225
- Aircraft serial: 20383
- Aircraft time: 63,732 hours, 48,789 cycles
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Control Valve
- Part number: 39608831
- Condition: Failed
- Location: Cabin Pressure
- Stage of operation: CL
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/K11A2020072900004

## Discrepancy

AIRCRAFT WILL NOT PRESSURIZE, CABIN ALTITUDE WARNING WENT OFF PASSING THROUGH 10000 AFL WITH AIRCRAFT AT 10000 CABIN ALTITUDE DESCENDED TO 9500. DUCT PRESSURE 38 PSI – R 32 PSI – L, MANUAL PNEUMATIC CONTROLLER APPEARED TO OPERATE NORMAL.  R & R NR 3 ENGINE SHUTOFF VALVE, IAW B727 AMM 36-10-10.  OPS CHECK GOOD.  R & R RT FLOW CONTROL VALVE.  OPS AND LEAK CHECK GOOD, IAW B727 AMM 36-12-61.  REPAIRED WIRES TO RT PACK, IAW SWPM 20-20-10 & 20-60-07.

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