# SDR ASAA2018100826393

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 5, 2018
- Submitted: October 9, 2018
- Operation: Air carrier
- Aircraft: [N433AS](https://openairdocs.org/aircraft/N433AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41704
- Aircraft time: 19,744 hours, 6,504 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989083
- Part serial: 19237
- Condition: Inoperative
- Location: Ac Bay
- Part time: 21,024 hours, 6,951 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/ASAA2018100826393

## Discrepancy

CONT CAB ZONE TEMP LIGHT COMES ON WITH RECALL. TEMP CONTROLLABLE IN MANUAL. TEMP RUNS AWAY IN AUTO. GROUNDED - YES. REMOVED AND REPLACED CONTROL CABIN TRIM MODULATING VALVE IAW AMM 21-61-21-000-801 AND 21-61-21-400-801, OPS CHECK GOOD IAW AMM 21-61-00-700-806-002. CLEARS MEL 21-21G.

---
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.