Hello, I was reading somewhere about how to control Rudders in RC planes. The basic equation here is the drag equation: F=0.5*ρ*v^2*C*A (take ρ=1Kg/m3) where v is the velocity, C is the Drag coefficient of the control surface (Rudder in this case) and A is the area. I am wondering if we have a flat plate, what would its Drag coeff. be if its area is A and it is deflected θ° to either directions? According to Wikipedia, if it is parallel, C=0.005, if it is perpendicular, C~2. I am not sure how these numbers were calculated.