Which of the following lists the recognized types of icing and their intensities?

• A. Clear, Rime, Mixed; Light, Moderate, Severe
• B. Rime, Clear; Trace, Moderate, Severe
• C. Clear, Mixed; Light, Severe
• D. Rime, Clear, Mixed; Trace, Light, Moderate, Severe

Answer: (D)

Understanding icing terminology involves two parts: the types of ice that can form on aircraft surfaces and the amounts or intensities of that icing. The three recognized icing types describe how the ice forms: Rime icing results from small supercooled droplets freezing rapidly on contact, giving a rough, opaque coating; Clear icing comes from larger droplets that flow before freezing, creating a smooth, glassy layer; Mixed icing is a combination of both forms. The four intensity levels describe how much ice is present and how it affects flight: Trace means a very small amount detected or observed; Light icing is noticeable and may affect performance but is usually manageable; Moderate icing is more pronounced and often requires operational changes; Severe icing is hazardous and can significantly degrade handling or control.

The best answer lists all three icing types and all four intensity levels, which is why it’s correct: Rime, Clear, Mixed alongside Trace, Light, Moderate, Severe. Other options miss one or more categories, so they don’t fully reflect the standard terminology.