Planes, Gliders and Paper Rockets

Chapter 1. Helicopters

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?

• Its largest blade is parallel to the ground, as opposed to an airplane’s propeller being perpendicular.
• The small blade on the rear of the helicopter is perpendicular to the ground, but it points away from the side of the helicopter instead of to the front like an airplane. ...