An airplane by its nature wants to fly....A helicopter does not want to fly. There is no such thing as a gliding helicopter.
—Harry Reasoner, US broadcast journalist
There is something amazing when you really look at a helicopter hovering in the sky. Airplanes must keep moving forward so that the airflow over the wings provides lift and keeps it in the sky. But helicopters behave differently, don’t they?
What can we observe about a hovering helicopter?