Leonardo da Vinci’s cone-shaped design for a vertical-lift aircraft was called the aerial screw.
Leonardo drew the aerial screw in a manuscript traditionally dated to around 1489. The design showed a large helical surface wrapped around a central mast. Leonardo proposed that rotating this surface could cause it to “screw” upward through the air, making it an early conceptual ancestor of the helicopter.
The aerial screw was not a working helicopter. Its proposed linen-covered reed frame would have been too heavy and inefficient for the available human power. The design nevertheless demonstrates Leonardo’s interest in translating the action of a screw in water into a machine for air. It should not be confused with the ornithopter, which attempted to imitate flapping wings, or with a parachute, which was intended to slow a descent rather than create powered lift.