In general, scale model airplanes are constructed differently than the real planes, and different materials. Full scale engines are much heavier per hp than a nitro methane/alcohol fueled motor and are designed for much longer life. So it's not suprising that a design that works full scale needs help as a minature to meet flying criteria. Another example is in the airfoils. A scale 40 size mustang P-51 would have razorblade thick wings and stablizers. What "looks right" doesn't always" fly right". An example is a CG Tiger 60... They tend to build "tail heavy" . If you shortened the fusealage to fly right it would look funny. I prefer to add a little weight or move batteries, fuel tanks, servos, etc. and have a pretty plane... specially if its an model of a real aircraft. " Don't get me started on Profiles
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Mike