Leonardo da Vinci sketched an ornithopter as an aircraft powered by flapping wings.
The word ornithopter comes from Greek words meaning “bird” and “wing.” Leonardo studied bird flight and designed machines in which a pilot would move wing mechanisms using arms, legs, or both. His drawings show that he was investigating lift, balance, and mechanical transmission rather than simply copying a bird’s shape.
Leonardo’s ornithopter was never built as a successful powered aircraft. Human muscles cannot provide enough continuous power to lift a person with flapping wings of the size he proposed. This is a common mix-up: Leonardo’s ornithopter was not the same concept as his separate aerial-screw design, which used a helical surface rather than flapping wings.
Modern ornithopters are real small aircraft and robotic devices, but they use lightweight materials and efficient motors. Leonardo’s sketches remain important because they show an early systematic attempt to connect observations of animals with aircraft engineering.