SDR ASAA2022120641039

Service difficulty report · Filter · Boeing 737990ER

Difficulty date: December 6, 2022
Submitted: December 8, 2022
Operation: Air carrier
Aircraft: N423AS
Make and model: Boeing 737990ER
Aircraft serial: 35206
Aircraft time: 34,917 hours, 11,087 cycles
System (JASC): 2160 · Cabin Temperature Control System
Part: Filter
Condition: Warning Message
Location: Cockpit Temp
Stage of operation: NR
How discovered: O
Nature of condition: J
Precautionary procedure: O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

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.