Leonardo da Vinci studied an ornithopter, a flying machine intended to imitate a bird’s flapping wings.
Leonardo’s notebooks contain many observations of birds, bats, and the mechanics of flight. His ornithopter concepts used large wings moved by a human operator through levers and pedals. He hoped that understanding wing motion, balance, and air resistance could lead to controlled human flight.
The designs remained theoretical because a human could not generate enough power to flap wings of the necessary size. Leonardo eventually explored gliding and other aerodynamic ideas as well. An ornithopter is defined by flapping wings, unlike a helicopter, which uses rotating blades, or a glider, which has fixed wings and depends on forward motion through the air.