What type of icing occurs when small droplets hit the airfoil and freeze instantly?

Rime icing occurs when small supercooled droplets of water come into contact with an object, such as an airfoil, and freeze almost instantly upon impact. This type of icing typically forms in conditions where there is a high concentration of small water droplets present in the atmosphere, often found in stratiform clouds, rain showers, or in low visibility situations. The rapid freezing leads to a rough, opaque layer of ice that does not build up as much weight as clear ice, which is formed from larger droplets that freeze more slowly and create a smooth, transparent surface.

Rime icing is particularly important for pilots and meteorologists to understand because it can significantly affect the performance of aircraft by altering airfoil shapes and increasing drag. Recognizing the conditions that lead to rime icing helps in forecasting and mitigating the hazards associated with flying in icing environments.