Leonardo da Vinci called his large rotating lifting device an aerial screw.
Leonardo sketched the aerial screw around 1489. The design used a helical surface made from linen and supported by reeds. He believed that rapid rotation would make the screw press against the air and lift the machine, in much the same way that a screw advances through a solid material.
The device is often described as a conceptual ancestor of the helicopter, but it was not a helicopter in the modern engineering sense. Leonardo did not provide a practical power source capable of rotating the large rotor fast enough, and the structure would have been difficult to stabilize.
The drawing is important because it shows Leonardo thinking about vertical flight rather than only flapping wings or gliding. Modern helicopters use powered rotors, aerodynamic blades, and control systems that solve problems the Renaissance sketch left unresolved.