Leonardo da Vinci’s 1489 machine with a rotating screw intended to rise into the air is commonly called the aerial screw.
The sketch shows a helical rotor made from reeds, linen, and wire, supported by a circular frame. Leonardo reasoned that the screw might press against the air and produce upward motion, an idea sometimes compared with a modern helicopter rotor.
However, the machine was not a helicopter in the modern engineering sense, and there is no evidence that Leonardo built or flew it. The design also lacked a practical power source capable of turning the large rotor.
The aerial screw belongs to Leonardo’s wider study of flight. He examined birds, wings, air resistance, and mechanisms for lifting humans. Its historical importance lies mainly in the early expression of a vertical-lift concept, not in demonstrated operation.