Leonardo da Vinci studied an ornithopter, a flying machine intended to imitate the flapping wings of birds or bats.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo's drawings explore wing shapes, joints, frames, and human-powered mechanisms. Some designs place a pilot inside or beneath the machine, using pedals, levers, or arm movements to operate the wings.
Leonardo understood that birds do not fly simply by flapping rigid boards. His notebooks examine anatomy, balance, wind, and the difference between powered flight and gliding. However, a human pilot could not generate enough sustained power for a practical flapping aircraft of the type he imagined.
An ornithopter is a category of aircraft, not one single Leonardo model. Modern experimental ornithopters have flown, including small radio-controlled machines, but no Leonardo design became a working aircraft in his lifetime. His studies are valued for connecting biological observation with mechanical engineering.