Definition
An aircraft system designed to prevent the formation of ice on critical surfaces and components — such as wing leading edges, engine inlets, propellers, pitot tubes, and windshields — by heating, chemically treating, or otherwise protecting them before ice can accumulate.
Plain English
A system that stops ice from forming on the aircraft in the first place, rather than removing it after it has built up.
Context Anchor
Seen in aircraft systems, maintenance, preflight checks, and operations in cold weather, clouds, rain, or snow.
Derivation
‘Anti-’ comes from Greek, meaning ‘against’ or ‘before.’ So an anti-ice system works against ice forming — it acts before ice can take hold, not after.
Why Pilots Care
Ice changes wing shape and reduces lift while increasing drag, raising the risk of stall or loss of control; the system maintains normal flight performance.
Intuition Check
Anti-ice does not mean breaking off ice after it has already built up. It mainly means preventing ice from forming in the first place.
Example Sentence 1
Before entering the cloud layer, the pilot switched on the engine anti-ice system to keep ice from forming in the inlet.
Example Sentence 2
During the climb through freezing drizzle, the propeller anti-ice system kept the blades clear and maintained engine performance.