Mi-24 Flying Without Main Rotor!

Originally posted by Arbitrageur
The video is a real optical illusion, but you won't see that live in person unless your eyes have some bizarre defect that make them flicker the image at 24fps just like the video camera, and I doubt anyone has such a bizarre optical defect, hence, he made it up.

That is a real medical condition, I saw a discussion of it in New Scientist and I think one of the sufferers was the subject of a tv documentary (Maybe Body Shocks), it's the result of extreme trauma to the visual cortex, and results (if the trauma isn't fatal) in the sufferer seeing the world as a series of still scenes sometimes with a "framerate" as low as one frame every 5-10 seconds. It's not common (only 2-3 people in the world suffer from it), but it does exist.

It does not however cause helicopters to suddenly develop anti-gravity.