What type of icing occurs when small water droplets freeze instantaneously?

Rime icing occurs when small water droplets come into contact with a surface and freeze instantaneously. This can happen in conditions where the air is saturated with supercooled water droplets, such as in cloud formations or during precipitation in freezing conditions. When these supercooled droplets hit the aircraft, they create a rough and opaque layer of ice, known as rime ice, which typically has a white or frosted appearance. This type of icing tends to form at lower temperatures and is characterized by its crystalline structure and lower density compared to other types of icing.

In contrast, clear icing, which is another type of icing, forms when larger supercooled droplets freeze more slowly, resulting in a smooth and glossy layer of ice. Mixed icing consists of both rime and clear icing characteristics, while fog icing isn't a recognized type of icing in aviation meteorology, as it refers more to conditions rather than a specific icing type.