# SDR ASAA2023102345812

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 23, 2023
- Submitted: October 25, 2023
- Operation: Air carrier
- Aircraft: [N459AS](https://openairdocs.org/aircraft/N459AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36352
- Aircraft time: 35,848 hours, 11,235 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 20930
- Condition: Faulty
- Location: Rh Ecs Bay
- Part time: 33,689 hours, 10,655 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/ASAA2023102345812

## Discrepancy

CONT CAB ZONE TEMP LIGHT ILLUMINATES ON RECALL & RESETS. GROUNDED - YES. (RESOLVED ON W/O: 1971707 TASKCARD: N/R-00003 ) REMOVED OLD AND INSTALLED NEW R/H PRIMARY ZONE TRIM AIR MODULATING VALVE PER MM 21-61-21/401, OPS NORMAL. OPENED, COLLARD, RESET 1 C/B. GROUND VERIFICATION SUCCESSFUL. PLACARDS REMOVED. THIS CLEARS MEL 21-21G. SEAMC ASHRAF NOTIFIED.

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