Leonardo da Vinci designed an ornithopter as a birdlike flying machine powered by flapping wings.
His surviving notebooks show wing structures, frames, and mechanical ideas intended to imitate the flight of birds and bats. The proposed pilot would have supplied power through pedals, levers, or other body-driven mechanisms.
An ornithopter is a general aircraft category, not a single Leonardo model. Leonardo never built a successful human-carrying version, and the drawings reveal engineering problems involving weight, available power, and control. His studies nevertheless helped preserve important observations about wings, air resistance, and animal flight.
The word is sometimes confused with “helicopter,” but an ornithopter flies by flapping wings rather than rotating a rotor. Modern ornithopters, including small experimental aircraft, still use the same basic principle.