# SDR ASAA2021103136475

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 31, 2021
- Submitted: November 3, 2021
- Operation: Air carrier
- Aircraft: [N562AS](https://openairdocs.org/aircraft/N562AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35091
- Aircraft time: 55,663 hours, 16,487 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 26495
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 16,749 hours, 4,982 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/ASAA2021103136475

## Discrepancy

CONT CAB ZONE TEMP LIGHT ILLUMINATED ON RECALL ZONE LIGHT CLEARS WITH MASTER CAUTION RESET. GROUNDED - YES. CONTROL CABIN TRIM MODULATING VALVE FAULTED DURING BITE. 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, CLEARS MEL 21-21G, CONTROL NUMBER 31018562 REMOVED, SEAMC DAVE NOTIFIED, NO AIRCRAFT CONFIGURATION CHANGE.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.