Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Human Factors
Prior to departing de-ice was required. After deicing during taxi out I noticed a slight odor which I attributed to the de-ice effects. During the flight the odor at times increased. It had a somewhat dirty sock smell with a trace of plastic. We looked for but did not see any signs of smoke. The odor was unpleasant and as we were neared the top of descent I decided to have Maintenance determine its origin upon arrival. After shutdown we discussed the odor with Maintenance. They initially thought it may have come from the de-ice process. After they had left the cockpit to attend to another minor write-up my First Officer stood up to go to the back of the aircraft when he noticed sparking and flame coming from the wire bundle leading to the left lateral window. He went to get a fire extinguisher. I shook the bundle and turned off the window heat and pitot heat switches. The flame went out. I could have been more conservative in my assumptions of the odor coming from the de-ice process and investigated the cause more thoroughly before takeoff. Maintenance will have to offer solutions to prevent the shorting/arcing from occurring without any fault lights or circuit breakers popping.
[No additional information was included in the secondary narrative.]
The flight crew of an A310 continued their flight to destination believing an odor continuing through the flight was the result of residual fluid from de-icing prior to departure. As they got up to depart the aircraft at the gate they were confronted by a flaming wire bundle powering the window heat.