Icing decreases aircraft lift and increases drag and weight, while decreasing thrust. It can block pitot tubes and static inlets, obscure windscreens, cause control surface jamming, and interfere with radio transmission. Icing intensity ranges from trace to severe, with severe icing causing rapid, dangerous ice accumulation. Icing forms from supercooled water droplets and occurs as clear, rime, mixed, or rain ice above freezing levels. Pilots should be educated on anti-icing equipment, examine forecasts, clear ice from airframes, avoid known icing areas, and expect icing above freezing levels to avoid its effects.