# SDR USA2004F00014

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 14, 2004
- Submitted: March 18, 2004
- Operation: Air carrier
- Aircraft: N518AU
- Make and model: Boeing 737-3B7
- Registry model: [Boeing 737-3B7](https://openairdocs.org/model/boeing-737-3b7) (OpenAirDocs)
- Aircraft serial: 23704
- Engine: Ge CFM56*
- System (JASC): [2130 · Cabin Pressure Control System](https://openairdocs.org/jasc/2130)
- Part: Cabin Pressure
- Condition: Failed
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: B, G, A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/USA2004F00014

## Discrepancy

ENROUTE, WHILE LEVEL AT FL330, THE AIRCRAFT LOST PRESSURIZATION.  CREW ACCOMPLISHED A RAPID DESCENT TO 10,000 FT.  OXYGEN MASKS DID DEPLOY DURING DESCENT.  STANDBY AND MANUAL PRESSURIZATION MODES WERE USED BUT WERE NOT EFFECTIVE.  OUTFLOW VALVE WAS REPORTED TO BE FULLY CLOSED.  A RUMBLING SOUND WAS HEARD BENEATH THE FLOORBOARDS BY THE FORWARD AND AFT CABIN CREW MEMBERS.  FLIGHT DIVERTED AND LANDED WITHOUT FURTHER INCIDENT.  MAINTENANCE ACTION PENDING.

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