Rime ice is described as

• A. Rough, milky, opaque ice formed by the instantaneous freezing of small supercooled water droplets.
• B. The four fundamental risk elements in aviation.
• C. See radio magnetic indicator.
• D. The future impact of a hazard that is not eliminated or controlled.

Answer: (A)

Rime ice forms when small supercooled water droplets strike the aircraft and freeze instantly, trapping air that makes the ice rough, milky, and opaque. This rapid freezing creates a light, porous layer that tends to build up on the leading edges and upper surfaces, altering the airfoil shape and increasing drag while reducing lift. It is distinct from clear ice, which forms from larger droplets that spread out and freeze slowly into a smooth, transparent layer. The other statements describe aviation risk management concepts or navigation indicators, not icing characteristics, so they don’t describe rime ice.