Leonardo da Vinci’s aerial screw was a helical flying-machine design intended to rise vertically. Drawn around 1489, it is often described as an early conceptual ancestor of the helicopter.
The sketch shows a large spiral rotor made from reed, linen, and wire. Leonardo reasoned that turning the screw would force air downward and lift the structure upward, borrowing the idea of a screw moving through water. His notes do not provide a practical engine or a complete mechanism for producing enough power.
The aerial screw was never built or flown in Renaissance Italy. Modern engineers regard it as an imaginative but physically limited concept because human muscles could not have supplied the necessary power. Its historical importance lies in recognizing vertical lift centuries before powered helicopters became possible.