Enclosed is a pic I built back in 1970...made a new wing for it..differnet airfoil..design for RC....4 OS 25 2 strokes..flaps ,no retracts.....not enough right thrust on the engines...took off ,went left and couldn't save it....probably bigger ailerons would of helped too......made the size that the plans called for....4 engines running do make a nice sound of their own....