What flying-machine concept did Leonardo da Vinci equip with flapping wings?

Leonardo da Vinci equipped his ornithopter concept with flapping wings.

An ornithopter is an aircraft designed to fly by flapping wings, imitating the motion of birds or bats. Leonardo studied bird anatomy, wing movement, balance, and the forces acting on air in numerous notebooks. His proposed machines used a human operator to move or control large wings through mechanical linkages.

Leonardo understood that powered human flight would require more than simply copying a bird’s outline. He investigated lift, drag, weight, and the relationship between wing shape and motion. Even so, the materials and muscle power available in his era were insufficient for a practical human-powered aircraft.

An ornithopter is not the same as a glider. A glider depends on aerodynamic lift while moving through air, whereas an ornithopter’s defining feature is flapping propulsion. Leonardo also drew rotary flight concepts, but those belong to a different family of machines.