Leonardo da Vinci designed an aerial screw, a rotating helical device intended to lift people vertically.
His drawing from about 1489 shows a large screw-shaped surface wrapped around a central mast. Leonardo reasoned that if the helical sail rotated rapidly, it might “screw” itself upward through the air. The concept is one of his best-known studies of vertical flight.
The aerial screw was not a helicopter in the modern engineering sense. Leonardo proposed human-powered rotation, but people could not generate enough sustained power to lift the large structure. He also did not have a lightweight engine or modern rotor aerodynamics. For those reasons, the sketch remained a concept rather than a workable aircraft.
The design is frequently called an early helicopter idea, but “aerial screw” is the more precise historical name. Its rotating, spiral rotor influenced later discussions of vertical flight, even though practical helicopters required engines, improved materials, and very different rotor control systems.