i have a EPP Viper combat glider, the problem is its very unstable, everyone else's has no nose weight and is smooth and sharp and stable in turns... with no nose weight mine is unflyable, i have added quite a bit, but it still wallows not sure which way is forwards, it wobbles around turns and can loose alot of speed getting into stalls easily, its like the CofG is miles back, but its forwards of most of the others on the slope. is this dutch roll? and how do i stop it. i don't want to add more lead, it already has the equivalent of another batt up front, i recently recovered and kept the back light, no difference. i also use less rates than most to keep it in control