Leonardo da Vinci developed ornithopter concepts, machines intended to fly by flapping wings like birds.
Leonardo studied birds, bats, and the mechanics of wing movement in notebooks devoted to flight. His designs placed a human pilot inside or beneath a framework connected to large wings. The pilot would operate pedals, levers, or other mechanisms to imitate the repeated motion of a bird’s wings.
These machines were not successfully flown. Human muscles cannot provide enough continuous power for a practical flapping aircraft of the size Leonardo imagined, and the proposed structures would also have been heavy. Later engineers created small ornithopters using engines, elastic power, or remote control.
An ornithopter is different from a glider, which remains airborne through aerodynamic lift without flapping its wings. It is also different from Leonardo’s aerial screw, whose proposed motion was rotational rather than birdlike. Leonardo’s studies nevertheless helped connect observation of nature with mechanical design.