Leonardo da Vinci’s ornithopter used winglike flapping surfaces to imitate a bird’s flight.
Leonardo studied birds extensively and designed several machines based on their wings. An ornithopter is an aircraft intended to fly by flapping wings, rather than by using fixed wings or a rotating rotor. Leonardo’s sketches show human pilots attached to frameworks with large movable wings.
His designs included mechanisms using the pilot’s arms, legs, or body to drive the wings. Leonardo recognized that birds used complex movements and that simply copying their shape would not be enough. Nevertheless, human muscles cannot provide the power-to-weight ratio needed to lift a person with flapping wings of the proposed type.
No Leonardo ornithopter is known to have flown. The designs remain important in the history of aviation because they represent systematic observation of animal flight and an attempt to convert that observation into mechanical engineering. Modern experimental ornithopters use motors and lightweight materials.