In five major U.S. airline jet crashes of the past 20 years caused by icing just before takeoff, the weather conditions were remarkably similar except for an eightfold variation in visibility. This finding emerged from a study by researchers Roy Rasmussen, Jeffrey Cole, and Kevin Knight (National... Show moreIn five major U.S. airline jet crashes of the past 20 years caused by icing just before takeoff, the weather conditions were remarkably similar except for an eightfold variation in visibility. This finding emerged from a study by researchers Roy Rasmussen, Jeffrey Cole, and Kevin Knight (National Center for Atmospheric Research, or NCAR), along with R. K. Moore and Murray Kuperman (United Airlines). The study implicates snowfall rate (specifically the amount of water in the snow) as a major variable in aircraft icing and cautions pilots not to rely on visibility as an indicator of icing hazard. Show less
