hovering in ground effect

hovering in ground effect (IGE)

hovering in ground effect (IGE)click for a larger image
hovering in ground effect (IGE)
A helicopter hovering at A requires 55% torque. It will require 58% if it were to hover at B.
A helicopter hovering at a height that is equal to or less than the span of its rotors. A helicopter can hover in ground effect at a higher density altitude than it can hover out of ground effect. A helicopter requires less power to hover in ground effect than hover out of ground effect. The power requirement varies directly with the height above ground level.