Ted Nelson sought to enhance performance of 1946 Dragonfly design. Improved engine, adding horsepower and making retractable within rear fuselage, sealed by doors. Hawley Bowlus no longer with project; most of the engineering fell to Harry Perl, with Don Mitchell helping. First version had new metal cantilever wings with solid styrofoam in D-tube and fabric aft of spar. Fuselage and tail were wood, with anti-servo-tab flying stabilizer. BB-1 pod used originally with side-by-side seating, retractable tricycle landing gear, and wide aft fuselage tapering to empennage. Quickly replaced by sleek tandem fuselage design (also wood), with 2-wheel gear (main and steerable nose) balanced during taxiing by wing tip outriggers. Production versions had similar configuration, but all wood replaced with metal except for rudder which had a radio antenna built in. Wing fabric replaced with thin magnesium sheet. Aircraft performed well but was priced considerably above existing 2-place aircraft, thus never sold well enough to proceed with volume production and certification. 2 Hummingbirds in National Soaring Museum collection. Charles Rhodes bought the aircraft and engine rights from Nelson and marketed 48 hp version of engine designated H-63 for light aircraft and helicopter use.