Leonardo da Vinci envisioned an ornithopter, a flying machine intended to rise by flapping wings like a bird.
Leonardo studied bird flight extensively and filled notebooks with observations about wings, muscles, balance, and air resistance. His proposed ornithopters generally placed a human pilot inside or beneath a winged framework. Some drawings show wings operated by pedals, levers, or other mechanical linkages.
An ornithopter is different from a glider, which stays aloft with fixed wings, and from a helicopter, which uses rotating blades. Leonardo’s designs tried to reproduce the active wingbeat of birds, but the human body could not supply enough power to make such a craft fly effectively.
The drawings remain important because they show Leonardo analyzing flight as an engineering problem rather than treating it only as an artistic fantasy. Modern ornithopters have flown, especially small remote-controlled models, but Leonardo’s full-scale human-powered proposals were never known to have flown.