Soar to New Heights with the 2025 Commercial Pilot License (CPL) Practice Exam – Ready for Takeoff!

Rime ice accumulation on an aircraft primarily occurs due to the impact of small liquid water droplets that freeze quickly upon contact with the cold surfaces of the aircraft. This process happens in conditions where the aircraft is flying through clouds or precipitation that contains supercooled water droplets. When these small droplets strike the aircraft, especially at lower temperatures, they do not have enough time to spread out and form a smooth layer before freezing, resulting in the characteristic rough texture of rime ice.

While large droplets can lead to clear ice formation, small droplets are specifically associated with rime ice. The rapid freezing that happens upon impact is crucial to this ice type, as it solidifies before the water droplets can flow and create a gradual buildup. Consequently, the emphasis on small droplet impacts leading to slow freezing accurately reflects the dynamics of rime ice accumulation, distinguishing it from other types of icing that may involve larger droplets or different mechanisms of freezing.