SDR ASAA2019020428031

Service difficulty report · Filter · Boeing 737990ER

Difficulty date: February 4, 2019
Submitted: February 6, 2019
Operation: Air carrier
Aircraft: N474AS
Make and model: Boeing 737990ER
Aircraft serial: 40715
Aircraft time: 14,324 hours, 4,732 cycles
System (JASC): 2160 · Cabin Temperature Control System
Part: Filter
Condition: Dirty
Location: Cabin Temp
Stage of operation: TX
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 MASTER CAUTION RECALL AFTER START AIR COND. ZONE TEMP CONT CAB, ILLUMINATED. FOLLOWED QRH VERIFIED VALVE WORKED W/ PROCEDURE. GROUNDED - YES. RELEASED PER MEL 21-21G FLIGHT DECK PRIMARY TEMP CONT INOP. CLEANED CONT CABIN TEMP SENSOR FILTER. ACCOMP ZONE TEMP CONT BITE. NR 1 SHOWS NO FAULTS. NR 2 SHOWS TRIM VALVE (V143) FLT DECK FAULT. CLEARED FAULT RERAN BITE TEST, TEST PASS NO FAULTS NOW ON NR 2 CONTLR. A/C RELEASED PER MEL 21-21G REMOVED. REF FIM 21-62 TASK 801 & AMM 21-61-06-400-801.