# SDR AALA2020091429014

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 11, 2020
- Submitted: September 14, 2020
- Operation: Air carrier
- Aircraft: [N309PC](https://openairdocs.org/aircraft/N309PC), registered now
- Make and model: Boeing 737823
- Aircraft serial: 31258
- Aircraft time: 11,241 hours, 4,499 cycles
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Part number: 71211997101AC
- Part serial: 0019408
- Condition: Unserviceable
- Location: Cabin Pressure
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA2020091429014

## Discrepancy

AIRCRAFT NOT GROUNDED-DURING CRUISE FLIGHT, AT FL 370-50 DEG SAT, THE PRESSURIZATION OUTFLOW VALVE INDICATED A SUDDEN MOVE TO FULL OPEN THEN CLOSED, RESULTING IN 1000 FPM LIMIT THEN DESCENT OF CABIN PRESSURE.  MEL 09-499C-C ONE CABIN AUTO PRESSURE CONTROL, REF. 2110A AUTHORIZED.  REPLACED CABIN PRESSURE CONTROLLER NR 2, PER AMM 21-31-01, DCPC (DIGITAL CABIN PRESSURE CONTROLLER) SYSTEM TEST OKAY, CLEARED MEL.

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