Definition
A clear, dense, hard layer of ice that forms when relatively large supercooled water droplets strike an aircraft surface and spread out before freezing. It typically appears smooth and glassy, follows the contour of the surface, and is the most difficult type of structural ice to remove.
Plain English
A clear, hard sheet of ice that forms on the aircraft when big, freezing-cold water drops hit the surface and flow along it before turning to ice. It looks shiny like glass and sticks tightly.
Context Anchor
Seen in icing discussions, preflight weather planning, and inspections of wings, propellers, windshields, antennas, and other exposed aircraft surfaces.
Derivation
From 'glaze,' meaning a smooth, glassy coating — the same word used for the shiny finish on pottery. The name describes how this ice looks: clear and polished, not white or rough.
Why Pilots Care
It adds weight and drag while changing airfoil shape, which can sharply reduce lift and increase stall speed.
Analogy
Like the clear, sheet-like ice that forms on a windshield during freezing rain.
Grounding Statement
Picture rain hitting a freezing windshield and spreading into a smooth, clear sheet before it sets — that same process happening on a wing in flight.
Intuition Check
Do not assume glaze ice is safe because it looks smooth or clear. In aviation, glaze ice is dangerous because it can be heavy, hard to see, and very hard to remove.
Example Sentence 1
After descending through a layer of freezing rain, the crew noticed glaze ice forming on the leading edges and activated the deice system.
Example Sentence 2
The crew activated the deice boots to shed the glaze ice that had accumulated on the wings.