# SDR ASAA2023012641661

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 24, 2023
- Submitted: January 27, 2023
- Operation: Air carrier
- Aircraft: [N491AS](https://openairdocs.org/aircraft/N491AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 44109
- Aircraft time: 26,801 hours, 8,417 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Modulating Valve
- Part number: 3989083
- Part serial: 8891
- Condition: Faulted
- Location: Lt Acm
- Part time: 1,758 hours, 515 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/ASAA2023012641661

## Discrepancy

LEFT PACK LIGHT ILLUMINATES ON RECALL AND EXTINGUISHES WITH MASTER CAUTION RESET. GROUNDED - YES. REMOVED AND REPLACED LH PACK TEMP CONTROL VALVE REF B737-900 AMM 21-51-10-400-801 (ASA L/P 60116284).

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