# SDR ASAA2016021415440

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 14, 2016
- Submitted: February 18, 2016
- Operation: Air carrier
- Aircraft: [N478AS](https://openairdocs.org/aircraft/N478AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 44105
- Aircraft time: 2,400 hours, 786 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 8930
- Condition: Failed
- Location: Lt A/C Pack
- Part time: 35,405 hours, 10,730 cycles
- Stage of operation: NR
- How discovered: 9
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2016021415440

## Discrepancy

LEFT PACK LIGHT ILLUMINATES WITH MASTER CAUTION RECALL. EXTINGUISHES WITH PRESS OF MASTER CAUTION LIGHT.  ACFT GROUNDED.  R & R LT PACK TEMPERATURE CONTROL VALVE (TCV), REF AMM 21-51-10, OPS AND LEAK CHECK GOOD.  BITE TEST ON LT CONTROLLER, NO DEFECTS NOTED, AMM 24-22-00-860-811.

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