# SDR 95ZZZW421

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 16, 1995
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N448US](https://openairdocs.org/aircraft/N448US), registered now
- Make and model: Boeing 737-4B7
- Registry model: [Boeing 737-4B7](https://openairdocs.org/model/boeing-737-4b7) (OpenAirDocs)
- Aircraft serial: 24892
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3964981
- Condition: Failed
- Location: Right
- 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/95ZZZW421

## Discrepancy

PIT - FLT 670 - UNABLE TO PRESSURIZE AIRCRAFT AFTER TAKEOFF.  RIGHT PACK ON MEL AND LEFT PACK VERY WEAK.  FLIGHT RETURNED TO PIT WHERE LANDING WAS WITHOUT FURTHER INCIDENT.  MAINTENANCE REPLACED RIGHT TURBO FAN VALVE AND FLOW CONTROL VALVE.  REFERENCE USAA950247.

---
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.