Leonardo da Vinci’s proposed flying machine with flapping wings is an ornithopter.
An ornithopter is an aircraft designed to fly by flapping wings, imitating the action of birds or bats. Leonardo studied bird flight, wing structure, air currents, and the relationship between weight and lift. His notebooks contain several designs for machines in which a human pilot would operate wings through mechanical movement.
Leonardo’s ornithopters were ambitious concepts, but there is no reliable evidence that he successfully flew one. Human muscle power is generally insufficient to lift a person with the wing arrangements shown in his sketches. The drawings nevertheless helped connect observations of animals with systematic mechanical design.
An ornithopter is different from a helicopter, which uses rotating blades, and from a glider, which relies on lift while moving without powered flapping. Leonardo also drew a separate aerial screw concept, so not every Leonardo flying-machine sketch represents an ornithopter.