Overheating Windshield Heater Prompts Japan Airlines Boeing 737 Diversion
Reports regarding the Japan Airlines incident note that the wires had become red hot, while windows fogged up.
While engine issues and smoke or fire indications seem to be the most common occurrences leading to aircraft diversions, an overheating windshield heater is even more infrequent. However, on Sunday, March 26th, a Japan Airlines Boeing 737-800 flying from Tokyo Haneda to Matsuyama had to divert to its origin airport after the crew began experiencing issues with the aircraft's windshield heater shortly after takeoff.
Red hot cables
The March 26th incident began with the Japan Airlines Boeing 737-800 taking off from Tokyo Haneda at 17:44. Performing flight JL439 to Matsuyama, FlightRadar24.com data indicates that the flight took off nearly an hour later than its scheduled time.
The Aviation Herald reports that the Japan Airlines jet, registered JA329J had begun to experience issues with the windshield heater at FL300. The crew stopped the climb after seeing sparks coming from the device. Equally as alarming, the cables of the windshield heater were turning red-hot while a window was turning "foggy."

Flying close to Mount Fuji, the issue prompted the crew to divert and return to Tokyo Haneda. The aircraft, with its 131 people onboard, touched down on Haneda's runway 34R safely and without further incident, 40 minutes after departing. Read More…