SDR ASAA2018020723450

Service difficulty report · Warning Message · Boeing 737890

Difficulty date: February 7, 2018
Submitted: February 8, 2018
Operation: Air carrier
Aircraft: N566AS
Make and model: Boeing 737890
Aircraft serial: 35182
Aircraft time: 42,606 hours, 12,774 cycles
System (JASC): 2150 · Cabin Cooling System
Part: Warning Message
Condition: False Activation
Location: Lt A/C Pack
Stage of operation: NR
How discovered: 9
Nature of condition: N
Precautionary procedure: O

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

What was found

LEFT PACK SINGLE CHANNEL FAIL. ACFT GROUNDED. INITIAL EVALUATION FOUND THE NR 1 ZONE TEMP CONTROLLER, SHOWING TCV FAILED. PERFORMED PACK/ZONE TEMP CONTROLLER BITE TEST IAW AMM 21-61-00-700-806-002, NO FAULTS DETECTED, RESET FAULT. RAN BITE TEST, THREE MORE TIMES, NO DEFECTS NOTED.