that plane is a contender?Looks like my contender.but mine has a cowl built on it.they track really nice.I have a os 61FX on it unlimited vertical with it.flies like its on rails.Avery nice windy day plane cut right through it.I made mine very tail heavy plane loves it.Have to use the flap for landing comes in real hot without it.Did you put the strate wing tips on it?It flys better with the angled tips .My friend angled them is much more stable it a flat turn,or i might say it yaws better doesnt yaw to good with straight tips.
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joel