Leonardo da Vinci’s bird-inspired flying-machine concept was an ornithopter.
An ornithopter is an aircraft designed to fly by flapping wings, rather than by using fixed wings or a helicopter rotor. Leonardo studied birds and bats closely and produced sketches of machines whose wings would move through human-powered mechanical systems.
His designs included a large wing structure and mechanisms intended to transmit force from the pilot’s arms and legs to the wings. Leonardo understood that a human would struggle to supply enough power for sustained flapping flight, but his studies still helped connect biological observation with engineering design.
Leonardo did not build a proven, airworthy ornithopter. The term applies to a broader class of aircraft, including later experimental machines. Modern ornithopters have flown, especially as small remotely controlled models, but they are not descendants of a successful Leonardo aircraft. His contribution was chiefly analytical: he investigated how wing shape, weight, balance, and movement could affect flight.