# SDR ASAA2021060935063

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 9, 2021
- Submitted: June 10, 2021
- Operation: Air carrier
- Aircraft: [N477AS](https://openairdocs.org/aircraft/N477AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 40716
- Aircraft time: 21,327 hours, 6,705 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 4533
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 63,029 hours, 24,591 cycles
- Stage of operation: IN
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021060935063

## Discrepancy

WHILE PERFORMING T/C NG-21EA-23228-1 FOUND TCV FAULT ON ZONE TEMP CONT #1 GROUNDED - YES. REMOVED AND REPLACED L/H TCV REF B737-900 MM 21-51-10-400-801, OPS AND LEAK CHECK OK.

---
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.