# SDR DALA2021042202363

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 22, 2021
- Submitted: April 22, 2021
- Operation: Air carrier
- Aircraft: [N3771K](https://openairdocs.org/aircraft/N3771K), registered now
- Make and model: Boeing 737832
- Aircraft serial: 29632
- Aircraft time: 63,134 hours, 23,477 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Condition: Damaged
- Location: Cabin Pressure
- Stage of operation: CL
- How discovered: O
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DALA2021042202363

## Discrepancy

SHIP 3771 -ATB/PRESS- RETURNED TO BOS DUE TO UNABLE TO CONTROL PRESSURIZATION AFTER TAKEOFF. CORRECTIVE ACTION: MAINTENANCE REPLACED THE GROUND AIR INLET VALVE PER 737 AMM 21-31. OPS TEST OK, AIRCRAFT RETURNED TO SERVICE.

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