If you look closely at the outer edge of the ailerons, you will see it gets progressively thicker on the top portion. This is a rather crude attempt to create washout at the tip of the wing. Washout forces the center of the wing to stall first, allowing a controlled and level descent of the aircraft as the tips of the wing contine to generate lift while the stalled, center section of the wing causes descent. Before you attach the ailerons, maually add true washout by bending each tip upwards and using a hot ar gun, shrink out the resulting wrinkles. Do both sides!!! The amount is usually 1/4 to 3/8ths per panel. Sight along the trailing edge to assure your efforts are uniform.

I learned this when I was real young and flew free-flight. My Gee Bee had an incident-free maiden flight. Standard servos, reccomended balance point, using a SuperTiger 2300, it required no balance weights. The servos were mounted at the center section of the fuselage. The ST 2300 is only a few cc's larger than the optional 1.2 fourstroke. I used a 16x6 prop. Tried a 16x8 on the second flight and the landing was more difficult. The aerobraking of the lower pitched prop was helpful.