Trivia: Leonardo’s aerial screw was an early version of what?
Correct Answer: Helicopter
So why is this answer correct? : Some 400 years before the first helicopter, Leonardo already had visions of a similar flying machine. His aerial screw was powered by a spiraling blade that, in theory, would push air downward to propel the vehicle upward. The lightweight screw would be made of linen and powered by a giant spring, wound up tightly to generate enough of an energy burst to spin the rotor.