Leonardo da Vinci designed an ornithopter with a large fabric wing inspired by bats.
An ornithopter is a flying machine intended to generate lift by flapping wings, just as birds, bats, and insects do. Leonardo studied bird flight extensively and produced several designs in which a human pilot would power wing movement with arms, legs, or both. His sketches combined observations of anatomy with mechanisms such as levers, pulleys, and frames.
Leonardo’s proposed machine was not a successful aircraft. Human muscles cannot supply enough power for a machine of the required size, and the design lacked a practical method for sustained control. Even so, his work helped make flight a subject of systematic mechanical study rather than only myth or speculation.
The term ornithopter applies broadly to flapping-wing aircraft, including later experimental machines. It should not be confused with Leonardo’s aerial screw, which used rotary motion rather than flapping wings.