# SDR ASAA2019081963408

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 16, 2019
- Submitted: August 19, 2019
- Operation: Air carrier
- Aircraft: [N402AS](https://openairdocs.org/aircraft/N402AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41189
- Aircraft time: 26,876 hours, 8,769 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Sensor
- Part number: 11500021
- Condition: Inoperative
- Location: Lt A/C Pack
- 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/ASAA2019081963408

## Discrepancy

LEFT PACK LIGHT ILLUMINATES ON RECALL. EXTINGUISHES UPON MASTER CAUTION RESET. GROUNDED - YES. REF B737-900 FIM 21-62 TASK 801, 837 PERFORMED BITE OF PACK/ZONE TEMPERATURE CONTROLLER. LEFT CONTROLLER HAS FAULT RAM AIR ACT. VERIFY SHOWS NO FAULTS. FAULT NOT ACTIVE. HAS HISTORY. LEFT RAM AIR ACTUATOR REPLACED 3 DAYS PRIOR ON DEFECT 12179744. CHECK OPERATION OF FLAPS UP SWITCH PER FIM 21-51 TASK 803. MODULATION DOORS OPERATED CORRECTLY. AIRPLANE TEMP PUT IN AIR MODE PER B737-900 AMM 32-09-00. AS A PRECAUTION REMOVED AND REPLACED LEFT PACK RAM AIR CONTROL TEMP SENSOR IAW AMM 21-51-50. PZTC BITE NO FAULTS.

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