Rotating wings

The idea of flying on rotating wings is old. As long ago as 1400, European children played with flying toys with whirring blades. Indeed, up until the Wright brothers' Flyer, many felt the future of flight lay with rotating rather than fixed wings. Spinning wings, they knew, would slice through the air to provide lift like fixed wing. But while a fixed wing plane must keep moving, a rotating wing plane could hover in one place. In early 1900s, many whirling wing contraptions did lift some way off the ground. Yet the chances of controlled flight seemed remote until Juan de la Cierva created "autogiro".

Helicopter
Of all flying machine, none is quite so versatile as the helicopters. Its whirling rotor blades enable it to shoot straight up in the air, hover for minute after minute over the same spot, and land on an area little bigger than a bus. It burns up fuel at a frightening rate because the engine, via the rotors, provides all the lifting force. It also takes great skill to fly, for the pilot has three flight controls to handle-rudder, "collective pitch", and "cycle pitch" controls- one more than conventional aircraft. But it has proved its worth in many situations, from traffic monitoring to dramatic rescues from sinking ships.