Leonardo da Vinci based an ornithopter concept on the flapping wings of birds.
An ornithopter is an aircraft intended to fly by flapping wings rather than by using fixed wings, propellers, or rotors. Leonardo studied birds, bats, and the mechanics of wing movement in several notebooks while investigating whether humans could imitate natural flight.
His drawings show wing structures, control ideas, and mechanisms that would transfer power from a person to the wings. He recognized that a human body could not simply flap bird-sized wings, so some designs used larger surfaces and mechanical assistance.
Leonardo’s ornithopters never achieved sustained flight. The concept remains important because it shows how closely his engineering observations were tied to biology. Modern ornithopters do exist, but their materials, motors, and control systems are far more advanced than Leonardo’s proposals.