# SDR ASAA2022110440627

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 4, 2022
- Submitted: November 7, 2022
- Operation: Air carrier
- Aircraft: [N493AS](https://openairdocs.org/aircraft/N493AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41727
- Aircraft time: 23,873 hours, 7,504 cycles
- System (JASC): [2133 · Pressure Regulator/Outflow Valve](https://openairdocs.org/jasc/2133)
- Part: Outflow Valve
- Part number: 2123010BA
- Part serial: 14115186
- Condition: Leaking
- Location: Cabin Pressure
- Part time: 10 hours, 2 cycles
- Stage of operation: NR
- 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/ASAA2022110440627

## Discrepancy

FLIGHT ATTENDANTS REPORT LOUD SQUEALING SOUND ENROUTE AT ALTITUDE. PRESSURIZATION NORMAL. SQUEAL DIMINISHED @ 4 PSI DIFFERENTIAL. GROUNDED - YES. REMOVED AND REPLACED OUTFLOW VALVE WITH NEWER STYLE REF B737-900 AMM 21-31-03.

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