FAA Ground School Practice Test

The correct choice of "Light to moderate rime" indicates a specific type of icing that is characterized by the formation of ice crystals on the aircraft's surfaces. Rime ice occurs when supercooled water droplets freeze rapidly upon contact with the aircraft, resulting in a milky-white appearance and a rough texture.

The distinction of it being "light to moderate" provides valuable context for pilots, as this classification helps assess the potential impact on aircraft performance and safety. Light to moderate rime icing suggests that while there may be some accumulation of ice, it is not extreme, meaning that typical operations can continue with caution, although de-icing measures may be necessary.

In contrast, severe clear icing would indicate a more dangerous situation where ice forms in a clear manner, potentially leading to rapid accumulation and serious performance issues. Moderate mixed icing implies the presence of both clear and rime ice, which can create a complex situation requiring more significant attention and management by pilots. Light hoarfrost usually doesn’t present the same level of risk as it is often formed on clear, calm nights and can be removed through normal preflight procedures. Each type of icing contributes uniquely to operational risks, making the correct identification of icing type crucial for safe flight operations.