Leonardo da Vinci sketched an aerial screw, a rotating machine often described as an early helicopter concept.
The design appears in a manuscript dated to around 1489 and is commonly associated with Leonardo’s studies of flight. It shows a large helical surface made from reeds, linen, and other proposed materials, supported by a framework. Leonardo reasoned that turning the screw could press against the air and lift the structure, much as a screw moves through a material.
The aerial screw was not a helicopter and was never shown to fly. Its proposed human-powered mechanism could not generate enough lift, and the materials and aerodynamic assumptions were inadequate for practical vertical flight. The design also lacked the powered rotor, control system, and lightweight engine that later helicopters required.
It is called an early helicopter concept because it anticipates the use of a rotating helical lifting surface, not because it functioned as a working helicopter. Modern helicopters rely on aerodynamic rotor blades and powered rotation, while Leonardo’s drawing remains a remarkable theoretical exploration of vertical lift.