# SDR ASAA2020081042998

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 4, 2020
- Submitted: August 10, 2020
- Operation: Air carrier
- Aircraft: [N440AS](https://openairdocs.org/aircraft/N440AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41705
- Aircraft time: 26,233 hours, 8,437 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989085
- Part serial: 20140
- Condition: Inoperative
- Location: Lt A/C Pack
- Part time: 22,117 hours, 7,352 cycles
- Stage of operation: DE
- 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/ASAA2020081042998

## Discrepancy

ON DESCENT WHEN RECALL WAS DEPRESSED THE LEFT PACK LIGHT ILLUMINATED. LIGHT EXTINGUISHED WHEN MASTER CAUTION LIGHT WAS RESET. GROUNDED - YES. CURRENTLY SYSTEM CHECKS GOOD AND THERE WERE NO LIGHTS AFTER HITTING RECALL. BUT THERE IS HISTORY SO REMOVED AND REPLACED TRIM MODULATING VALVE IAW B737-900 AMM 21-61-21-000-801 AND B737-900 AMM 21-61-21-400-801. ETOPS GROUND FUNCTIONAL CHECK GOOD IAW B737-900 AMM 21-61-00-700-806-002.

---
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.