# SDR ASAA2019123081713

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 28, 2019
- Submitted: December 31, 2019
- Operation: Air carrier
- Aircraft: [N559AS](https://openairdocs.org/aircraft/N559AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35178
- Aircraft time: 49,416 hours, 14,637 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 6700
- Condition: Intermittent
- Location: Lt A/C Pack
- Part time: 52,733 hours, 22,503 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2019123081713

## Discrepancy

LEFT PACK ILLUMINATED IN FLIGHT. GROUNDED - YES.  PERFORMED PACK/ZONE TEMP CONTROLLER BITE IAW AMM 21-61-00-700-806-002. THIS PACK - TCV LIGHT ON DURING BITE OF LEFT CONTROLLER, OFF FOR PREV FLIGHT AND VERIFY TESTS. 2 OTHER OCCURRENCES LAST 60 DAYS. REMOVED AND REPLACED TCV, OPS CHECKED GOOD. IAW AMM 21-51-10.

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