# SDR ASAA2020093033243

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 30, 2020
- Submitted: October 1, 2020
- Operation: Air carrier
- Aircraft: [N538AS](https://openairdocs.org/aircraft/N538AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 41188
- Aircraft time: 31,924 hours, 9,344 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 20455
- Condition: Faulty
- Location: Rh Ecs Bay
- Part time: 8,558 hours, 2,550 cycles
- Stage of operation: IN
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2020093033243

## Discrepancy

RT PACK ZONE FAULTED ON CONTROLLER DURING BITE PROCEDURE.  GROUNDED-YES.  REPLACED RT PACK ZONE TRIM AIR MODULATING VALVE, PER B737-800 AMM 21-61-21-400-801.  PERFORMED BITE PROCEDURE B737-800 AMM 21-61-00, GREEN GO LIGHT ILLUMINATED.

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