# SDR ASAA2017052420855

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 24, 2017
- Submitted: May 25, 2017
- Operation: Air carrier
- Aircraft: [N461AS](https://openairdocs.org/aircraft/N461AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36363
- Aircraft time: 12,663 hours, 4,161 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989083
- Part serial: 10459
- Condition: Failed
- Location: Cockpit Temp
- Part time: 31,983 hours, 10,566 cycles
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2017052420855

## Discrepancy

WHILE PERFORMING A PACK, ZONE TEMP CONTROLLER BITE TEST,  FOUND THE FLIGHT DECK TAV FAILED ON THE NR 2 CONTROLLER.  ACFT GROUNDED. REMOVED AND REPLACED FLIGHT DECK TAV IAW AMM 21-61-21-400-801. OPS AND LEAK CHECKED OK.

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