US Navy ONR Personal Flying platform VTOL - Close look at the counter rotating propellers.
ONR - Office of Naval Research
The world's first ducted fan vertical takeoff and landing aircraft -- 1955
Air drawn over the rim of the duct which surrounds the counter rotating propellers provide 40% of the aircrafts' thrust.
The propellers inside the duct generate the remaining thrust.
The craft was controlled by means of the pilot leaning in the direction of desired movement or by power changes for up and down movement.
The Flying Platform accomplished its first flight on January 27, 1955.
Hiller Aviation Museum San Carlos California http://hiller.org/
TilTul http://tiltul.com LinksYouWantToRemember