The thing about 3D planes,and the difference from your trainer, is large control surfaces especially ailerons that extend all the way to the fuselage. The reason is very simple. 3D is flying the airplane in a stall condition. ie.. hovering, when the airplane is in this condition the only air moving accross the control sufaces and thus the only way to control the airplane is from the air coming off of your prop.
Take a look at planes like the Showtime and the U-Can-Do and you will see what I mean.