Leonardo da Vinci sketched an aerial screw with a helical linen sail intended to lift a machine into the air.
In a drawing usually dated to about 1489, Leonardo imagined a large spiral structure supported by a frame. He reasoned that if the helical surface rotated rapidly, it might screw upward through the air in a way comparable to a screw moving through wood or water. The concept is one of the earliest famous attempts to describe vertical flight with a rotor-like device.
Leonardo’s aerial screw was not a helicopter and was never shown to fly. The proposal lacked a practical engine and did not fully solve problems of weight, torque, and aerodynamic lift. Modern helicopters use rotating blades that generate lift through airfoils, a principle more efficient than the broad linen helix Leonardo drew.
The design is sometimes called Leonardo’s helicopter, but “aerial screw” is the more historically precise name. It demonstrates an important early association between rotary motion and vertical flight.