Definition
In icing reports and forecasts, a category of aircraft icing in which both clear ice and rime ice form simultaneously, or in which the ice deposit shows characteristics of both types. The result is typically a rough, opaque-to-translucent accumulation that adheres firmly to airframe surfaces.
Plain English
Ice that is part smooth-and-glassy and part rough-and-milky, forming together on the aircraft. It combines the worst features of both kinds of ice.
Context Anchor
Seen in icing forecasts, pilot weather reports, and discussions of ice forming on an aircraft in flight.
Derivation
Mixed comes from an older word meaning blended or put together from more than one thing. That helps here because mixed ice is not one pure type of ice; it is a blend of two icing types.
Why Pilots Care
Mixed ice is difficult to remove and can quickly reduce lift and increase drag.
Grounding Statement
Picture ice on the wing that is not all smooth and not all rough, but a blend of both.
Intuition Check
Mixed does not just mean general or varied weather here. In icing reports, mixed means a specific blend of smooth hard ice and rough milky ice forming on the aircraft.
Example Sentence 1
The PIREP from a Cessna at 6,000 feet reported moderate mixed icing in the clouds north of the field.
Example Sentence 2
We turned back when mixed conditions started forming on the wings.