# SDR ASAA2020112233581

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 22, 2020
- Submitted: December 1, 2020
- Operation: Air carrier
- Aircraft: [N464AS](https://openairdocs.org/aircraft/N464AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 40714
- Aircraft time: 25,311 hours, 7,965 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 21359
- Condition: Inoperative
- Location: Lt A/C Pack
- Part time: 22,933 hours, 6,967 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/ASAA2020112233581

## Discrepancy

CONT CABIN 'ZONE TEMP' LIGHT ILLUMINATES DURING MASTER CAUTION RECALL.  GROUNDED-YES.  REMOVED & REPLACED CONT CABIN TRIM AIR MODULATING VALVE, REF B737-900 AMM 21-61-21.  OPERATIONS CHECK GOOD.  NO LEAKS NOTED.

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