What kind of motion did Leonardo da Vinci’s ornithopter use to imitate a bird’s flight?

Leonardo da Vinci’s ornithopter used flapping wings to imitate a bird’s flight.

An ornithopter is an aircraft designed to fly by moving wings up and down. Leonardo studied birds and bats and filled his notebooks with observations about wing structure, balance, air resistance, and the mechanics of flight. His proposed machines transferred power from a pilot’s arms or legs to large artificial wings.

Leonardo understood that a flying machine needed both lift and control. Several of his designs included frameworks, straps, pedals, and mechanisms intended to coordinate the wing movement. The machines were imaginative engineering studies, not practical aircraft.

The term ornithopter comes from Greek words meaning bird and wing. Unlike an airplane, which normally uses fixed wings, or a helicopter, which uses rotating blades, an ornithopter relies on oscillating wings. Modern experimental ornithopters continue to use this principle.