It does not require much ice to make a difference in the flight of an aircraft, a thin, almost invisible coating. The latter risk was put into focus when a twin-engine Bombardier Challenger 600 business jet crashed on takeoff in Bangor International Airport, Maine, when winter weather hit the area. The federal authorities reported that the aircraft crashed at approximately 7:45 pm local time and that there was a massive fire after the crash. Federal Aviation Authority indicated that it was launching an inquiry that would be carried out together with the National Transportation Safety Board.
The minutes preceding and immediately following the accident are given a grainy detail with publicly posted air-traffic audio. Some thirty minutes before, another flight crew had radioed the tower requesting it to halt its attempt to take off, on a ground that it had a de-icing fluid problem and the visibility was getting worse; to which the controller replied that the visibility was only about three-quarters of a mile. At around the same time, the pilot of the Challenger could be heard asking to have the wings and tail of the plane treated and the jet was waiting on the de-icing pad approximately 20 minutes before take-off as recorded on audio by LiveATC.net audio. The recording during the moments after takeoff clearance had a controller saying, Aircraft upside down. Our passenger plane was inverted and the airport authorities reported that it took less than a minute to have first responders there.
To the traveling people, de-icing may seem like ordinary winter housekeeping. In the case of flight operations, it is more like a hard safety gate: wings and control surfaces have to be clean enough to produce predictable lift and handling. Aviation safety consultant Jeff Guzzetti who was a former federal crash investigator, stated that the Challenger 600 model has a background of icing during takeoff and that any amount of contamination can count. The plane of the incident in Bangor had already arrived the same evening, which is quite capable of leaving a jet in the ramp when it gets cold and the rain has started. Such an environment, where fuel in wing tanks can maintain parts of the wing at cold temperatures to allow ice to be formed more rapidly, is an aspect that the NTSB has noted in winter operations investigations of the past.
The context of airport weather is also important due to its influence on the decision-making pressure. Bangor is used to winter climate and it encourages operational posture in that its runways are ready in both snow and rain. According to the office of the National Weather Service at Caribou, the airport eventually got almost 10 inches of snow during the storm and only accumulation was in the offing when the crash occurred. The officials in charge of landing and take-off at the airports also reported that other planes were landing and leaving around the same time frame, a crucial fact that can give one a false impression that all things are equally under control even when micro-environment factors such as visibility drop in a specific area, the type of precipitation or a drop in aircraft surface temperature occur between one landing and another.
The next thing is deliberate and gradual in nature. The investigators usually recreate the pre-takeoff preparations of the aircraft, such as whether the aircraft was de-iced, which fluids were deployed, and how long the aircraft remained after the process, which took place later, as time is a factor determining the duration of protection. They also evaluate performance data, cockpit procedures and environmental conditions to identify whether lift or control was impaired at rotation and the spread of fire after impact.
To the common person, the most straightforward lesson learnt is that winter flying safety is frequently determined not by the storm itself but by the well-trained professionalism of ground rules that make the concept of clean wings non-negotiable.
