rcpilotacro


Sir
Point b.
"(b) Wind milling Prop disturbs the air flow, beep , Saju, that is wrong too, wind milling prop produces drag, that is why a dead prop/turbo props engine is feathered "

We are talking about a model plane where we do not want to feather the prop using up energy. Hence it is more practical to have a smaller diameter prop creating a lesser drag not in the way of the wings. We are talking about gliders and UAVs and not WWII aircraft designed for dogfights.

Also
"Please  read this thread, a pusher config has an unconventional thrust drag couple, making it not so easy to control especially with an over powered engine."

In the earlier cited topic, you are talking about the Easy Star and an unconventional thrust drag couple. If you look at the thrust line of the Easy Star, you will notice that the moment arm of the thrust line falls very close to the CG of the plane. The motor thrust line is not parallel to the axis of the fuselage, but tipping downwards such that the thrust line passes pretty close to the CG and slightly above it. This is so as to not have appreciable thrust moment tipping the plane too nose down.. i.e calculated to prevent the plane nosing up too much because of the increased lift created by the thrust of the motor when powered on full. When one switches of the throttle in flight, immediately one sees the plane lifting up considerably.
Saju

What configuration is this, this is not a pusher but has the propeller mounted on top of the fuselage - http://www.pipistrel.si/plane/apisbee/gallery

TG,
i thing these leisure flying machines are a kind of powered gliders, where prop assembly collapses into the fuselage when u attain the desired height for gliding, for the sake of hindrance free smooth surface. this is what i can get from images.i thing it is a pusher yaar     i may be wrong