Based on the Popular PT40, Great Planes has Improved the Wing Construction and Instruction Manual for this PT40 MKII Trainer Plane. FEATURES: Stable, self-correcting flight characteristics Precision-cut, interlocking parts naturally assemble straight and strong Detailed, easy-to-follow instruction manual features step-by-step photos, expert tips, and helpful hints on building surfaces, flying, and covering Interlocking "I-beam" construction builds the wing straight & strong All balsa & ply construction and comes w/extensive hardware package Wing is built w/ailerons, but the ailerons may be locked for 3-channel use May be built with a rubber band-to-wing or a bolt-on wing (bolts included, rubber bands are not)