Definition
A glossy, transparent or translucent layer of ice that forms when large supercooled water droplets strike an aircraft surface and spread out before freezing, producing a smooth, hard, and tightly adhering coating. It typically forms in temperatures near freezing, often within cumuliform clouds or freezing rain.
Plain English
A clear, glass-like ice that builds up on the aircraft when big, very cold water drops hit the surface and spread before they freeze. It is hard, smooth, and sticks firmly.
Context Anchor
Pilots encounter this term in icing forecasts, weather reports, pilot reports, and discussions of ice forming on wings, propellers, windshields, or other aircraft surfaces.
Derivation
Called 'clear' because the ice forms slowly enough for trapped air to escape, leaving the layer transparent rather than white. The visual property names the hazard.
Why Pilots Care
Clear ice adds weight, destroys lift, increases drag, and sticks tightly to surfaces, making it one of the most hazardous icing types.
Analogy
Clear ice is like a smooth glaze of ice on a car windshield: it may look thin or almost invisible at first, but it can still block vision and be hard to remove.
Grounding Statement
Picture flying through cold visible moisture and seeing a smooth, glassy layer begin to build on the leading edge of the wing.
Intuition Check
“Clear” does not mean safe here. It means the ice is mostly transparent, which can actually make it harder to notice.
Example Sentence 1
The pilot reported clear ice forming on the wing leading edges shortly after entering the cloud layer at 6,000 feet.
Example Sentence 2
Pneumatic boots cycled repeatedly to shed the clear ice that had built up on the wings.