# SDR ASAA2020122033731

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 20, 2020
- Submitted: December 23, 2020
- Operation: Air carrier
- Aircraft: [N516AS](https://openairdocs.org/aircraft/N516AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 39044
- Aircraft time: 43,832 hours, 13,213 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 18518
- Condition: Failed
- Location: Rt A/C Pack
- Part time: 27,818 hours, 8,745 cycles
- Stage of operation: NR
- 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/ASAA2020122033731

## Discrepancy

RT PACK LIGHT ON MASTER CAUTION RECALL EXTINGUISHED ON RESET.  GROUNDED-YES.  PERFORMED BITE CHECK, REF B737-800 FIM 21-62 TASK 801/802, TRIM VALVE LIGHT ILLUMINATED.  REMOVED & REPLACED ZONE TRIM VALVE OPERATIONS CHECK GOOD, REF B737-800 AMM 21-61-21.

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