Leonardo da Vinci studied an ornithopter, a flying machine intended to copy the wing movements of birds and bats.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo investigated flapping-wing flight in several notebooks, examining bird anatomy, wing structure, balance, and the action of air. His designs generally placed a human pilot inside a frame connected to movable wings.
Leonardo understood that human muscles alone would probably not supply enough power for a large flapping aircraft. He nevertheless continued studying the idea because bird flight offered clues about lift and control. His work helped make systematic observation central to later studies of aviation.
An ornithopter is not the same as a glider, which flies with fixed wings, or an aerial screw, which uses rotary motion. Modern experimental ornithopters have flown, but Leonardo’s proposed machines were never documented as successful manned aircraft.