# SDR SWAA2013041514836

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 10, 2013
- Submitted: April 15, 2013
- Operation: Air carrier
- Aircraft: N394SW
- Make and model: Boeing 737-3H4
- Registry model: [Boeing 737-3H4](https://openairdocs.org/model/boeing-737-3h4) (OpenAirDocs)
- Aircraft serial: 27380
- Aircraft time: 60,590 hours, 49,498 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Regulator
- Part number: 1074926
- Part serial: 1400C
- Condition: Failed
- Location: Bleed Air Sys
- Stage of operation: DE
- 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/SWAA2013041514836

## Discrepancy

DECLARED EMERGENCY - AT INITIAL DESCENT FM FL350 CABIN ALT WARNING HORN SOUNDED & CABIN ALT LIGHT CAME ON COULD NOT CONTROL ALT IN AUTO OR MANUAL PER QRH.  REMOVED AND REPLACED NR 1 ENGINE BLEED AIR REGULATOR, NR 1 ENGINE PRECOOLER CONTROL VALVE, NR 2 ENGINE HIGH STAGE PRESSURE REGULATOR PER AMM.

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