# SDR ASAA2021033034484

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 30, 2021
- Submitted: April 1, 2021
- Operation: Air carrier
- Aircraft: [N566AS](https://openairdocs.org/aircraft/N566AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35182
- Aircraft time: 52,611 hours, 15,562 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989083
- Part serial: 9354
- Condition: Inoperative
- Location: Left Ecs Bay
- Part time: 48,537 hours, 14,449 cycles
- Stage of operation: CL
- 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/ASAA2021033034484

## Discrepancy

CONT CAB ZONE TEMP LIGHT ILLUMINATED AFTER TAKEOFF. RAN QRH, LIGHT RESETS WITH MASTER CAUTION RESET. GROUNDED - YES. DUE TO PAST HISTORY REMOVED AND REPLACED CONTROL CABIN TRIM MODULATING VALVE IAW B737-800 AMM 21-61-21-000-801 AND AMM 21-61-21-400-801, ETOPS GROUND FUNCTIONAL CHECK GOOD IAW AMM 21-61-00-700-806-002.

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