Helicopter Project

[Chris Fultz]

Originally Posted by KenWittlief

When the HC starts to hover the downdraft of the blades will push the air straight down. After a few seconds the air will start to swirl in a donut pattern, the air that was being pushed down goes outward, then back up, and is then sucked through the blades again.

Actually there are two phases of hover - HIGE and HOGE
Hover IN Ground Effect and Hover OUT of Ground Effect.

What Ken describes is IN ground effect - the ground is causing the air to recirculate and can cause turbulence, but it can also require less power to hover in this condition.

Hover OUT of ground effect means the helicopter is high enough that the air dissipates and the ground has no effect on the rotor system.