Leonardo da Vinci designed an aerial screw as an early ancestor of the modern helicopter.
Leonardo drew the aerial screw in the 1480s. The design showed a large helical rotor made from a reed frame covered with linen. He proposed that the rotating screw could press against the air and lift the machine upward, an idea that resembles the action of a helicopter rotor.
The design was never demonstrated as a practical aircraft. Its proposed structure was too large and heavy for the materials and power sources available in Renaissance Italy. Leonardo’s drawing therefore represents a conceptual investigation of vertical flight rather than a successful helicopter.
The aerial screw should not be confused with a propeller-driven aircraft. A propeller normally provides forward thrust, while a helicopter rotor produces lift and allows controlled vertical flight. Modern helicopters use engines, lightweight materials, and carefully shaped rotor blades, none of which Leonardo possessed.