Bowlus Bumblebee BBI
The Dragonfly, designed by Hawley Bowlus, was the first auxiliary-powered self-launching glider to be produced in the U.S.A. The designers nicknamed this design the Bumblebee but they sold the powered glider under the official moniker, Dragonfly. It featured 2-place, side-by-side seating, retractable tricycle landing gear and a Nelson engine. The marketing was sponsored by the Nelson Engine Company as a vehicle for their two-cycle four cylinder engine. The cockpit pod was molded plywood, aluminum boom, 2-spar wood wing with plywood D-tube, fabric cover aft of spar.
While the concept was good, the airplane never achieved real success, because it didn't perform well, and because Nelson took his engine and left the partnership. The beautiful wooden fuselage pod made up of layers of mahogany was very labour intensive and thus very expensive. Some Dragonflys had the engine removed, converting them to pure sailplanes. The Dragonfly features a fully retractable tricycle landing gear with stearable nosewheel, dual control and a ratchet-wire pull starter in the cockpit for engine starts in flight or on the ground.
Nelson Dragonfly / Bowlus Bumblebee BB1
Of less than 10 built, 2 survived in 2008 at the National Soaring Museum.
John Hess Auction Service Inc, Manheim, PA 17545, United States, consigned a Nelson-Bowlus BB-1 Dragonfly N33687 Glider and Culver Rigid Midge N215 jr. Racing Glider in May 2015.
Engine: 25 hp Nelson 4 cylinder engine (retractable)
Wing span: 14.42m / 47.3ft
Wing area: 15.7sq.m / 169sq.ft
Empty Weight: 263kg / 580lb
Payload: 163kg / 360lb
Gross Weight: 426kg / 940lb
Wing Load: 27.13kg/sq.m / 5.56lb/sq.ft
Max speed: 50 mph (80 km/h) (originally 70 mph (113 km/h) with power)
Empty weight: 580 lb (263 kg)
Gross weight: 940 lb (426 kg)
Span: 47 ft 4 in (14.4 m)
Height: 6ft 10 in (2.1 m)
Length: 20 ft 4 in (6.2 m)
No. of Seats: 2
No. Built: 7
Aspect ratio: 13.25