Leonardo da Vinci sketched what he called a helixpteron (“screw wing”), which would ave been made of startched linen. It was intended to be a screw that would “bore up” into the air when rotated rapidly. More than once I’ve seen the claim made that it would have worked, if he had a motor to drive the screw (instead of the humans often shown in sketches or models). This page points out the need for something like a moder helicopter’s tail rotor to resist the tendency of the machine to counter-rotate:
My question : I’ve never really bought this. Nobody else has ever designed or built a helicopter looking remotely like this (except for another early dreamer, whose ideas never got beyond the drawing board. But i forget his name). Modern heluicopters have relatively narrow blades that get tilted with variable pitch. this thing has an enormous area of non-variable pitch, and I think it would have a phenomenal amount of drag. Modern helicopters don’t exactly “bore up into the air”, anyway. Even with a powerful motor and a tail stabilizer, I don’t see this as working.
What do you think? Has anyone heard of any critiques or Discovery-Channel or PBS-style recreations of this one?