Service difficulty report · Sensor · Boeing 737990ER

Difficulty date
January 6, 2019
Submitted
January 11, 2019
Operation
Air carrier
Aircraft
N474AS
Make and model
Boeing 737990ER
Aircraft serial
40715
Aircraft time
14,031 hours, 4,643 cycles
Part
Sensor
Part number
56100025
Condition
Failed
Location
Windshield
Stage of operation
TX
How discovered
O
Nature of condition
N
Precautionary procedure
D

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

What was found

L2 WINDSHIELD HEAT OVERHEAT LIGHT ILLUMINATED. GROUNDED - YES. WINDOW HEAT CONTROLLER BITE TEST SHOWS PRIMARY SENSOR FAULT. CK RESISTANCE PRIMARY SENSOR OUT OF LIMITS AT 370 OHMS. REMOVED CAPT L2 SIDE WINDOW REF AMM 56-12-11-000-801. MOVED PRIMARY SENSOR TO SPARE SENSOR TERMINAL POSITION. REINSTALLED L2 SIDE WINDOW REF 56-12-11-400-801. RESISTANCE CK ON SPARE SENSOR 318 OHMS REF FIM TASK 30-41 TASK 811. PERFORM WHCU BITE CK TEST PASSED NO FAULTS NOTED NO OVERHEAT LIGHT INDICATION. WINDOW HEAT OP CK GOOD REF FIM 30-41-801.