What was Leonardo da Vinci’s 1489 rotating aircraft design called?

Leonardo da Vinci’s 1489 rotating aircraft design was called the aerial screw.

Leonardo sketched the aerial screw in the Codex Atlanticus. The machine had a large helical surface wrapped around a central mast. He reasoned that turning the screw rapidly could make it rise by pushing against the air, an idea often compared with the principle behind a helicopter rotor.

The aerial screw was a conceptual design, not a proven flying machine. Its proposed structure was too heavy and its human-powered mechanism could not have supplied enough lift. Even so, the drawing is frequently described as an early ancestor of the helicopter because it identifies vertical lift as the goal and uses a rotating air-moving surface.

Leonardo’s work should not be confused with a modern helicopter. The first successful powered helicopters appeared more than four centuries later, after engines and lightweight materials made vertical flight practical.