Leonardo da Vinci's machine attempting human flight with flapping wings was an ornithopter.
An ornithopter is an aircraft intended to fly by flapping wings, imitating birds or bats. Leonardo studied bird anatomy, wing motion, and the flow of air while developing several human-flight designs in the late 15th and early 16th centuries.
His sketches included machines with large wings operated by a pilot through pedals, levers, and cranks. Leonardo understood that the pilot would need to generate lift and thrust, but human muscles could not provide enough power for a practical flapping aircraft of the proposed size.
Leonardo's ornithopters never achieved controlled flight. They are nevertheless important in aviation history because they combine observation of nature with mechanical experimentation. They should not be confused with his aerial screw, which sought lift from a rotating helical structure rather than flapping wings.