Ranger 21 was designed in 1957 by Carl Goldberg and produced as a kit until the late 1970s.  It was intended to help new modelers achieve success in building model airplanes that also flew well.  The BMJR kit, designed by Paul Bradley, is a replica of the original.  Some structural changes have been made, but the plan is from that of the original.  Changes from the original include a larger prop, one piece fuselage sides, and a vacuum formed nose piece has been replaced with a removable laminated balsa nose block to aid in winding and add structural strength.  Model is of all sheet balsa construction and has a 21 in. wingspan with 76 sq. in of area.