Leonardo da Vinci’s flapping-wing flying-machine designs are called ornithopters.
An ornithopter is an aircraft intended to fly by moving wings up and down, imitating birds or bats. Leonardo studied bird anatomy, wing motion, and air resistance while developing several human-powered flight concepts. His drawings show a pilot lying or standing inside a framework connected to wings, with pedals, levers, or other mechanisms supplying movement.
Leonardo correctly recognized that flight depended on interacting forces such as lift, weight, thrust, and drag. However, human muscles could not provide enough power to flap a large aircraft’s wings efficiently. No evidence shows that Leonardo built a successful man-carrying ornithopter.
The term is broader than Leonardo’s work: modern experimental ornithopters may use motors, remote controls, or flexible wings. Leonardo’s designs are historically important because they represent a systematic Renaissance investigation of powered flight, even though they were not practical aircraft. His studies also led him toward gliding and rotor-based ideas.