# SDR ASAA2019070729960

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 7, 2019
- Submitted: July 9, 2019
- Operation: Air carrier
- Aircraft: [N566AS](https://openairdocs.org/aircraft/N566AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35182
- Aircraft time: 47,715 hours, 14,266 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 10415
- Condition: Failed
- Location: Ac Bay
- Part time: 42,576 hours, 12,912 cycles
- Stage of operation: TX
- 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/ASAA2019070729960

## Discrepancy

AFTER ENGINE START ON RECALL LEFT PACK LIGHT ILLUMINATED RESET ON MASTER CAUTION RESET. GROUNDED - YES. PERFORMED BITE TEST OF LEFT & RIGHT PACK/ZONE CONTROLLERS, REF AMM 21-61-00. FOUND LEFT TCV FAULTED. REMOVED & REPLACED LEFT PACK TCV. OPS CHECK GOOD REF AMM 21-51-10. BITE CHECK & VERIFY GOOD

---
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.