# SDR DALA2024120911525

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 5, 2024
- Submitted: December 9, 2024
- Operation: Air carrier
- Aircraft: [N957DZ](https://openairdocs.org/aircraft/N957DZ), registered now
- Make and model: Boeing 737-9GPER
- Registry model: [Boeing 737-9GPER](https://openairdocs.org/model/boeing-737-9gper) (OpenAirDocs)
- Aircraft serial: 38748
- Aircraft time: 26,107 hours, 16,150 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3966081
- Part serial: 7385
- Condition: Inoperative
- Location: Nr 1 A/C Pack
- Part time: 26,091 hours, 16,131 cycles
- Stage of operation: DE
- 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/DALA2024120911525

## Discrepancy

SHIP 3957 -PRES- CABIN ALTITUDE WARNING AT FL200 WITH RIGHT PACK ON MEL. FLIGHT CREW COMMENCED DECENT TO 10K FT PER QRH. CORRECTIVE ACTION: REPLACED LEFT PACK FLOW CONTROL VALVE AND RIGHT PACK TRIM AIR VALVE. ALL OPS CHECK GOOD.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.