Which type of ice is considered the most dangerous?

Clear ice is considered the most dangerous type of ice that can form on an aircraft. This type develops when supercooled water droplets freeze upon contact with the aircraft's surface, creating a smooth, transparent layer of ice. Clear ice is particularly hazardous because it can significantly increase drag and alter the aerodynamic characteristics of the aircraft, leading to a reduction in lift and potential loss of control.

Moreover, clear ice tends to be heavier than other types of ice and can adhere strongly to surfaces, making it more difficult to remove once it forms. This makes it not only a threat during flight but also complicates pre-flight and in-flight de-icing efforts. Pilots must be particularly vigilant in avoiding conditions that promote the formation of clear ice, which is more severe than other types such as rime or frost. While rime ice has a less serious impact due to its rough surface and lower weight, and frost can generally be managed through preflight preparations, clear ice poses unique and significant threats to safety.