SDR ASAA2020061642799

Service difficulty report · Controller · Boeing 737990ER

Difficulty date: June 14, 2020
Submitted: June 16, 2020
Operation: Air carrier
Aircraft: N442AS
Make and model: Boeing 737990ER
Aircraft serial: 43293
Aircraft time: 25,435 hours, 8,168 cycles
System (JASC): 2160 · Cabin Temperature Control System
Part: Controller
Condition: Malfunctioned
Location: Cockpit Temp
Stage of operation: DE
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

ON RECALL, AT TOP OF DESCENT, CONT CAB ZONE TEMP ILLUMINATED, RESET WITH PUSHING MASTER CAUTION. GROUNDED - YES. VERIFIED FAULT, ACCOMPLISHED A PACK/ ZONE TEMP CONTROL BITE, BOTH CONTROLLERS SHOW TRIM VALVE FOR FLT DECK FAULT. ACCOMPLISHED A CONTROLLER RESET. REPLACED ALL 3 TEMP SENSORS FILTERS WITH NEW ONES. ACCOMPLISHED A PACK/ ZONE TEMP CONTROL. BITE AGAIN NO FAULTS. ACCOMPLISHED CABIN SELECTOR TEST, TEST PASSED, NO FAULTS. IAW AMM 21-61-06-400-801, 21-61-00-700-806-002, & 21-61-07-400-803-003.