Leonardo da Vinci designed an ornithopter, a flying machine intended to fly by flapping wings like a bird.
The word ornithopter comes from Greek roots meaning bird and wing. Leonardo’s studies of bird flight led him to imagine machines whose wings would move through repeated mechanical strokes. His notebooks contain several flying-machine concepts, including devices that used human power and others inspired by bats or birds.
Leonardo carefully observed anatomy, wing structure, balance, and air movement. Even so, the human body cannot supply enough sustained power for a practical flapping aircraft of the size he envisioned. His ornithopter therefore remained a design study rather than a successful aircraft.
An ornithopter is not the same as a glider, which relies on aerodynamic lift without flapping, or a helicopter, which uses rotating blades. Leonardo explored all three broad ideas in different forms, but the flapping-wing category is specifically called an ornithopter.