Leonardo da Vinci sketched an aerial screw in 1489 as a possible machine for rising vertically into the air.
The drawing shows a large helical rotor made from reeds, linen, and wire. Leonardo reasoned that the screw-shaped surface might push against the air and lift the machine if it were turned quickly enough. The concept resembles a very large, rotating corkscrew.
The aerial screw is frequently described as an ancestor of the helicopter, but it was not a helicopter and was never built by Leonardo as a functioning aircraft. Its major challenge was power: human muscles and the materials available in the Renaissance could not provide enough energy to rotate such a large rotor.
Later engineers developed powered vertical flight using lighter materials, engines, and improved rotor designs. Leonardo’s idea remains important because it identified the central lifting principle of rotary-wing aircraft centuries before practical helicopters appeared.