Would da Vinci's Helicopter have Worked?

PBS will be broadcasting a two-part show called “Leonardo’s Dream Machines,” which “follows the world’s leading experts as they attempt to build some of Leonardo da Vinci’s dream machines.” The shows will be broadcast on WVIZ Channel 25 from 9-11pm on Aug. 24 in Cleveland; check your local listings.

It’s a matter of judgment, but I’d say that a modern helicopter’s control system is not a short step.

With enough engine lots of otherwise hidiously un-aerodynamic things will fly.

That said, the “air screw” concept is a horrible way to propel any aircraft, and worse yet to try to support it’s weight.

Propellors, and helicopter rotors are just wings that chase each other. Long skinny wings always work better than short, fat wings. LdV’s “air screw” is such low aspect ratio that the chord takes up more than a full revolution.

To provide thrust, you have to move a cylinder of air. A couple of blades can move that whole cylinder of air pretty well.

Once the air cylinder’s motion has been started by the first part of the screw, all the last 90% does is waste power by causing drag.

I looked and wasn’t able to find this - can you tell me how to?