Some Case Studies of Unusual Icing Conditions Encountered by Turbine Engine Powered Airplanes

Two cases of unusual inflight icing encountered by turbine engine-powered airplanes are discussed. The atmospheric conditions in which the apparent icing occurred are unusual in that in both cases the temperature was colder than that typically associated with icing (at the altitudes at which the events occurred). The pilots' accounts of the events suggest that large supercooled droplets were encountered. These conditions are rare at any temperature, but especially at the temperatures at which these events occurred.