AN ORNITHOPTER IS A DEVICE THAT FLIES BY FLAPPING ITS WINGS.
How is it different from an airplane or helicopter? Those machines are driven by rotating airfoils. In an ornithopter, the driving airfoils have an oscillating motion instead. This imitates nature, because no animals have any rotating parts.
SOME MANNED ORNITHOPTERS HAVE MADE SUCCESSFUL FLIGHTS.
Ornithopters have been around a long time. The first ornithopter, the size of a pigeon, was flown in 1870. Ornithopters require more sophisticated technology than airplanes, so it was not until 1942 that a manned, engine-powered ornithopter was successfully flown (more info). Flapping wings are potentially more fuel-efficient than rotary-driven aircraft.
