# SDR ASAA2023012041605

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 20, 2023
- Submitted: February 1, 2023
- Operation: Air carrier
- Aircraft: [N517AS](https://openairdocs.org/aircraft/N517AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35197
- Aircraft time: 50,662 hours, 14,761 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 22348
- Condition: Faulted
- Location: Lt Ac Pack
- Part time: 3,833 hours, 1,083 cycles
- Stage of operation: NR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2023012041605

## Discrepancy

FLIGHT DECK TEMP CONTROL INOP. ZONE TEMP CAUTION EXTINGUISHES ON RESET. GROUNDED - YES. REMOVED AND REPLACED ZONE TRIM AIR MODULATING VALVE (V143). REF. B737-800 AMM 21-61-21.  ORIG SUB DATE: 1/24/2023

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