Plain English Meaning

Equipment that stops ice from building up on the front cockpit window so the pilot can still see out when flying in icy conditions.

Full Definition

A system that prevents ice from forming on the cockpit windscreen, keeping the pilot's forward view clear in icing conditions. On most general aviation aircraft this is done by spraying or pumping a freezing-point-depressant fluid (typically isopropyl alcohol) onto the outside of the windscreen. Larger and turbine aircraft commonly use electrically heated windscreen panels, while some use heated bleed air directed against the inside of the glass.