# SDR ASAA2022071039081

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 10, 2022
- Submitted: July 18, 2022
- Operation: Air carrier
- Aircraft: [N973AK](https://openairdocs.org/aircraft/N973AK), registered now
- Make and model: Boeing 737-9
- Registry model: [Boeing 737-9](https://openairdocs.org/model/boeing-737-9) (OpenAirDocs)
- Aircraft serial: 43346
- Aircraft time: 889 hours, 270 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 34764
- Condition: Out Of Adjust
- Location: Left Ecs Bay
- Part time: 976 hours, 297 cycles
- Stage of operation: NR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2022071039081

## Discrepancy

MAINT LIGHT ON AFT OVERHEAD PANEL ILLUMINATED. GROUNDED - YES. PERFORMED AIR COND SYS TEST LEFT, FOUND FAULT 21-55090 LEFT TCV OUT OF RANGE. REPLACED LEFT PACK TCV IAW B737-9 AMM 21-51-10/401. OPS CHKD GOOD SYS TEST PASS.

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