# SDR ASAA2022120641039

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 6, 2022
- Submitted: December 8, 2022
- Operation: Air carrier
- Aircraft: [N423AS](https://openairdocs.org/aircraft/N423AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 35206
- Aircraft time: 34,917 hours, 11,087 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Filter
- Condition: Warning Message
- Location: Cockpit Temp
- 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/ASAA2022120641039

## Discrepancy

CONT CAB ZONE LIGHT ON RECALL. EXTINGUISHES ON RESET. GROUNDED - YES. RELEASED PER ASA MEL 21-21G FLIGHT DECK PRIMARY TEMP CONTROL INOP. BITE TEST OF R PZTC FAULTED FLT DECK/TRIM VALVE ON BIT & PREV FLT. VERIFY PASSES. RESET PZTC. REMOVED & REPLACED CABIN TEMP SENSOR ASSY FILTER IN FLIGHT DECK IAW B737-900 AMM 21-06-06. OPS TEST OF CABIN TEMP CONTROL & INDICATION GOOD. ACCOMPLISHED R PZTC BITE & ALL TESTS PASS. NO ZONE LIGHT ON RECALL. MEL 21-21G CLEARED.

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