Leonardo da Vinci designed an aerial screw with four angled wings arranged around a central shaft.
The drawing appears in a manuscript dated to about 1489 and shows a helical structure intended to rise by rotating. Leonardo seems to have reasoned that the screw might push against air in a way similar to a screw moving through a solid material. The concept is often discussed as an early helicopter or rotorcraft idea.
The aerial screw was not a practical helicopter. Its linen-covered frame would have been heavy, and Renaissance power sources could not provide the sustained mechanical power needed for vertical flight. It is also distinct from Leonardo's later parachute concept: the parachute slows descent, while the aerial screw was intended to produce upward lift. The drawing's importance lies in its bold mechanical analogy and its place in the history of flight.