Hi annmarie this is larryboccio I'm sending you my plane you will see that the spar did sperate due to lack of glue. I follow all steps to the tee. i use the fpe 2.4 engine and had 7 flights in three weekends without mishap. myself and others wintess the failure of the upper wing. and the cement use in the construction isn't epoxy . please tell me what kind of glue. i'm a carpenter and it looks like hot glue. i'm sorry if its not. but whatever it is there wasn't enought apply in my opinon. I been using your products for years and i am happy custormer. please look at my plane , it sure be there by thursday. thanks a bunch .