Conmpleted a sturctural inspection on the aircraft. Noted that the lower ailerons with the two hinges were slightly bowed in the middle area due to the cable temsion at the aileron horns. Recomment considering adding a third hinge in the center of the lower ailerons. Also recommended that additional bracing be added to the wing tip sturctures to prevent warping during fabric covering. Noted that the throttle bolts were mounted with friction nuts and due to the torking during operation a cotter pin nut was recommented for that applicaion.
