Leonardo da Vinci’s flapping-wing flying machine was an ornithopter.
An ornithopter is an aircraft designed to fly by flapping wings, rather than by using fixed wings or a rotor. Leonardo studied birds extensively and made several drawings of mechanical wings, including designs intended to be powered by a person’s arms and legs.
Leonardo’s ornithopter was never successfully built as a practical aircraft. The main difficulty was power: human muscles cannot provide enough sustained energy to lift a person using wings of the proposed size. His studies nevertheless helped connect the observation of animal flight with mechanical design.
An ornithopter is different from Leonardo’s aerial screw, which used a rotating helical surface, and from his parachute, which was intended for controlled descent rather than powered flight.