Leonardo da Vinci’s bird-inspired flying-machine design was an ornithopter, an aircraft intended to fly by flapping wings.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo studied birds extensively and filled his notebooks with observations of their anatomy, balance, and wing movement. His proposed machine used a human pilot and large wings inspired by birds and bats.
Leonardo’s ornithopter was never successfully built as a practical aircraft. Human muscles cannot provide enough sustained power to flap wings of the proposed size, especially while carrying the machine and pilot. The design therefore remained an important theoretical study rather than a working invention.
An ornithopter differs from a glider, which stays aloft by using fixed wings, and from a helicopter, which gains lift from rotating blades. Leonardo also sketched gliding devices, so these terms should not be treated as interchangeable.