# SDR SWAA991606

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 24, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N687SW
- Make and model: Boeing 737-3H4
- Registry model: [Boeing 737-3H4](https://openairdocs.org/model/boeing-737-3h4) (OpenAirDocs)
- Aircraft serial: 23388
- System (JASC): [2131 · Cabin Pressure Controller](https://openairdocs.org/jasc/2131)
- Part: Controller
- Part number: 7638101
- Condition: Malfunctioned
- Location: E&E Compt
- Stage of operation: CR
- Nature of condition: J
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SWAA991606

## Discrepancy

AIR TURNBACK, DURING FLIGHT AT 37,000 FEET, CABIN ALTITUDE WARNING HORN SOUNDED ALERTING THE CABIN ALTITUDE WAS 10,000 FT.  DECLARED EMERGENCY LANDING.  CABIN ALTITUDE NEVER GOT ABOVE 10,000 FT AND THE DESCENT WAS NORMAL.  INSPECTED ALL DOOR PRESS SEALS, PRESS DUCTINGS, C/W BITE CHECK ON PRESS CONTROLLER, PRESSURIZED ACFT AND PERFORMED LEAK CHECK.  NO LEAKS FOUND AND PRESS SYSTEM OP CHECKED GOOD.  LATER AT HOU, REMOVED AND REPLACED PRESS RATIO AUTO CONTROLLER PER MM.

---
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.