# SDR 99UAL900028

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 11, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N989UA
- Make and model: Boeing 737291
- Aircraft serial: 21751
- Engine: Pwa JT8D17
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Valve
- Condition: Failed
- Location: Right
- Component: Allied Signa, 39811611
- Stage of operation: NR
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99UAL900028

## Discrepancy

RIGHT MIX VALVE STUCK IN FULL COLD POSITION IN MANUAL AND AUTO SELECTIONS.  *S/D*  RIGHT HAND MIX VALVE FAILED IN THE FULL COLD POSITION.  REPLACED THE RIGHT HAND MIX VALVE ASSEMBLY, CHECKS GOOD.

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