Leonardo da Vinci designed an ornithopter as a flying machine powered by flapping wings.
An ornithopter is an aircraft that flies by moving wings up and down, rather than by using fixed wings or a conventional rotor. Leonardo studied birds and bats carefully and filled notebooks with observations about their wings, muscles, balance, and air movement.
His designs included wings connected to pedals and hand-operated mechanisms. The machine was intended to imitate the muscular action of a bird, but the available materials and human strength would not have been sufficient for sustained flight. Leonardo did not build a successful flying ornithopter.
The design is sometimes confused with Leonardo's aerial screw, which used a helical rotor concept rather than flapping wings. Ornithopters were later built experimentally by other inventors, including modern radio-controlled aircraft designers.