Service difficulty report · Sensor · Boeing 737990ER

Difficulty date
June 24, 2020
Submitted
June 26, 2020
Operation
Air carrier
Aircraft
N440AS
Make and model
Boeing 737990ER
Aircraft serial
41705
Aircraft time
25,989 hours, 8,354 cycles
Part
Sensor
Condition
Failed
Location
Sliding Window
Part time
21,808 hours, 6,969 cycles
Stage of operation
NR
How discovered
O
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

RIGHT SIDE WINDOW HEAT OVERHEAT DID NOT REOCCUR AFTER RESET. GROUNDED - YES. WHCU BITE SHOWS SENSOR FAULT FOR EVERY FLT LEG HISTORY. WINDOW HAS SPARE SENSOR ACTIVE, BOTH SENSOR READS NML RESISTANCE WITH COLD WINDOW, HOWEVER WITH HEAT APPLIED, RESISTANCE READS EXTREMELY HIGH FOR BOTH SENSORS REF B737-900 FIM 30-41 TASK 811 & B737-900 WDM 30-41-11. REMOVED AND REPLACED #2 RH OPENABLE WINDOW. OPS AND LEAK CHECK PASSED. REF B737-900 AMM 56-12-11-400-801 AND 30-41-710-801.