Leonardo da Vinci designed an ornithopter, an aircraft intended to fly by flapping wings like a bird.
Leonardo studied bird anatomy, wing movement, and the mechanics of flight in numerous notebooks. His proposed machines transferred power from a pilot’s legs and arms to large wings. The designs reveal careful observation, but a human pilot could not produce enough sustained power to lift the machine by flapping alone.
The word ornithopter means a craft propelled by flapping wings. Leonardo’s machines therefore belong to a wider class of experimental aircraft rather than to the helicopter family. Some modern ornithopters have flown, but they use lightweight materials and powered mechanisms.
Leonardo also explored gliders and the aerial screw. These ideas are often blended together in popular illustrations, although they rely on different principles: flapping, fixed-wing lift, and rotary lift.