Hi everybody,

I stumbled upon the question how much lift a wing can create just by the airstream of the engines propeller. If you put enough propellers to the front of the wing (just like NASA´s LEAPTech does), can the airstream create lift although the airplane doesn´t move at all? In my first opinion there should be no difference - apart form the vortexes - if the airspeed is applied by propellers or by movement through the air. But on second thought the idea of an airplane taking off almost vertical just by its own propeller airstream seems odd..
Can somebody help here?