i have one of these cubs and just maidened it this weekend .i'll have to say it flew but something is definately wrong and i suspect the engine mount is to blame it's way too flexable for the os 70 fs i put on it .i'm going to change to a gp adjustable mount off my gp cub and try again also the wheels that came with the cub were a little cheesy so i installed the 3 3/8 wheels from gp .i think that you can order that direct from graupner