tt pros are ok the gp line sucked, I had a gp-42 on a lt-40 and the plane just sailed throu the air. allmost no accrobatics possible just sail around the field and try to not pump into any one else in the air. it needs allmost a 50 to do any thing like a tower hobbies trainer w/ a .46 bb engine will do, and then you got to remember you got more than twice the weight up there being flung around so that cramps a lot of style too.