# SDR ASAA2022040637919

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 6, 2022
- Submitted: April 8, 2022
- Operation: Air carrier
- Aircraft: [N481AS](https://openairdocs.org/aircraft/N481AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 44106
- Aircraft time: 24,778 hours, 7,816 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Valve
- Part number: 3989085
- Part serial: 23784
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 1,015 hours, 300 cycles
- Stage of operation: NR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2022040637919

## Discrepancy

CONT CAB ZONE TEMP LIGHT ILLUMINATES ON RECALL. EXTINGUISHES W/ MASTER CAUTION RESET. GROUNDED - YES. VERIFIED CONT CAB ZONE TEMP LIGHT ILLUMINATES ON RECALL. PERFORMED PACK/ZONE TEMP CONTROLLER BITE TEST REF B737-900 AMM 21-61-00. FOUND FLT DECK TRIM VALVE FAULT DURING BITE TEST. REMOVED AND REPLACED CONTROL COMPARTMENT ZONE TEMP CONTROL TRIM AR MODULATING VALVE REF AMM 21-61-21. OPS CHK GOOD.

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