Plain English Meaning
A bumpy, frosty-looking layer of ice that builds up on the aircraft when tiny cold water drops hit it and freeze straight away, trapping air bubbles that make it look white and rough.
Full Definition
A rough, opaque, milky-white deposit of ice that forms on aircraft surfaces when small, supercooled water droplets freeze almost instantly on contact, trapping air between the frozen droplets. It typically forms in stratiform clouds at colder temperatures and accumulates on leading edges, probes, and antennas.
Context Anchor
Seen in aircraft icing discussions, preflight inspections, deicing work, and reports of ice on , , , antennas, or other exposed surfaces.