Expert: Paul Soderman - 6/28/2003

Question
This is a kind of nutty question maybe but,if you have two wings facing each other,(attached to the same base)each wing has it's own prop facing it.Will this produce lift for both wings enough to lift the whole thing?Before I go to the model airplane shop and buy anything thought I would ask.Hope you understand what I'm saying.
                         Thanks
                         Rob L.  

Answer
Yes, if you blow air over a wing you will get lift (and drag and pitching moment).  In principle, the lift could be enough to lift the wings off the ground.  Most wings require forward speed to fly, because the propeller washes only a small section of the wing, but if you had a very light wing and motor and big enough propeller, maybe it will fly....but stability and control is going to be quite difficult.  If one wing lifts more than the other, the whole thing will rotate and crash.  And there is the torque from each propeller that will have to exactly balance out or be countered by ailerons.   Any pertubation will have to be responded to. Sounds tricky.

Paul