Leonardo da Vinci designed an ornithopter, a flying machine intended to imitate the flapping wings of birds.
The word ornithopter comes from Greek roots meaning bird and wing. Leonardo studied bird anatomy, wing movement, and the relationship between weight and lift while developing several concepts for human flight. His drawings show a pilot using mechanical systems to move large wings.
Leonardo's ornithopters were never proven to fly. A human does not have enough muscle power to flap wings of the required size, and the proposed mechanisms could not supply the necessary energy. The designs remain important because they show Leonardo treating flight as an engineering and observational problem.
An ornithopter is not the same as an airplane or helicopter. An airplane uses fixed wings and forward motion, while a helicopter uses powered rotary blades. An ornithopter produces lift through flapping wings, whether those wings are powered by a person, an engine, or another mechanism.