Leonardo da Vinci’s human-powered flapping-wing aircraft concept is an ornithopter.
The word ornithopter comes from Greek roots meaning “bird wing.” Leonardo studied birds, bats, and the mechanics of flight, then produced many sketches of machines with wings intended to flap rather than remain fixed. Some designs placed the pilot in a prone position and used pedals, levers, or hand controls to drive the wings.
Leonardo understood that simply copying a bird’s outline would not be enough. His notes examine wing structure, air resistance, balance, and the different functions of the downstroke and upstroke. Even so, the materials and power available in the fifteenth century could not provide enough energy for a person to fly by flapping large mechanical wings.
An ornithopter is different from Leonardo’s glider ideas, which use fixed wings, and from his aerial screw, which seeks vertical lift through a rotating spiral. No Leonardo ornithopter is known to have flown successfully.