# SDR DALA2020031001775

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 10, 2020
- Submitted: March 10, 2020
- Operation: Air carrier
- Aircraft: [N552NW](https://openairdocs.org/aircraft/N552NW), registered now
- Make and model: Boeing 757251
- Aircraft serial: 26499
- Aircraft time: 51,157 hours, 22,657 cycles
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Condition: Malfunctioned
- Location: Cabin Pressure
- Stage of operation: CR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: I
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DALA2020031001775

## Discrepancy

SHIP 5652 -PRES- CREW REPORTED HEARING A POP AND CABIN WOULD NOT PRESSURIZE. THE FLIGHT DESCENDED TO 10,000 FEET AND CONTINUED TO ATL. NO MASKS IN CABIN DROPPED. CORRECTIVE ACTION: FOUND UPPER POSITIVE PRESS RELIEF VALVE WITH INSULATION STUCK IN IT, REPLACED VALVE, CABIN PRESSURE CONTROLLER AND PRESSURE SEAL AT AFT P-DOME APU BLEED DUCT. PERFORMED HULL LEAK CHECK PER AMM OK FOR SERVICE.

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