Nelson Dragonfly

Nelson BB-1 Dragonfly

 In 1945, William H. Bowlus and Ted Nelson formed the Nelson Aircraft Corporation to build a two-seat, motor glider version of the popular Bowlus BA-100 Baby Albatross. The designers nicknamed this design the Bumblebee but they sold the powered glider under the official name, Dragonfly. The men retained the basic Baby Albatross design but significantly widened the cockpit and added side-by-side seating and flight controls for each occupant. Other improvements included tricycle landing gear and a steerable nose landing gear, additional vertical fins mounted on the ends of the horizontal stabilizer, and a hinged canopy. 

The Dragonfly features a molded plywood fuselage pod, aluminum tube tail boom and strut-braced wooden wing. The engine is started by a ratchet-wire recoil system that allows ground and inflight starts.

While the concept was good, the airplane never achieved real success, because it didn't perform well. The beautiful wooden fuselage pod, made up of layers of mahogany, was very labour intensive and thus very expensive. Some Dragonflys (including the Museum's example) had the engine removed, converting them to pure sailplanes.

Once owned by Peter Bowers, well known designer, historian and glider enthusiast, the Museum’s aircraft was sold to Airplane Supply Centre in 1956, by which time its engine had been removed and it had been converted to a sailplane. It was later sold to Val Hinch of Victoria, who carried out necessary work to license the aircraft and who flew it on Vancouver Island in the early 1960's. It was then placed in storage, and finally donated to CMF in 1983 by Val Hinch. It is one of only seven built with four others known in the USA.

Technical details:

Serial 506, N34922, CF-IDB/CF-VFA
Manufactured: 1947
Engine: originally powered by a 25 hp (19 kW) Nelson H-44 4-cylinder 2-stroke engine
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)
Aspect ratio: 13.25
Propeller: 2-blade wooden 42 inch (1.07 m) diameter
Maximum Glide Ratio: 18:1

History of Hawley Bowlus and the Dragonfly

The seeds that would lead to the Baby Albatross and the post-war Dragonfly design were planted in January 1910 when Hawley Bowlus and his brother Glenn were spectators at the Los Angeles International Air Meet held in Rancho Dominguez, CA. For all ten days of the event, the brothers rode a trolley about 25 miles from the San Fernando Valley to attend the meet.

This was the experience that inspired Hawley Bowlus to begin designing and building gliders. His first glider was built around an old rocking chair. He experimented and made his first short glides with this craft in 1910 and 1911. His next glider of 1912 clearly shows some influence from both Curtiss and Wright airplane designs. His next thirteen gliders he built were mostly the biplane type hang gliders.

Bowlus continued designing gliders during World War I, while working as an aircraft mechanic in the U.S. Army Air Corps. After the war, Bowlus earned a reputation as an excellent aircraft builder, eventually becoming the first employee at the Ryan Airlines’ aircraft factory in San Diego, CA. Hawley Bowlus and T. Claud Ryan first met while learning to fly in 1917.

At Ryan, Hawley Bowlus was the Plant Manager, serving in that capacity in1927 when the Spirit of St. Louis was built for Charles Lindbergh. It was there that Bowlus and Lindbergh became friends. After Lindbergh’s flight, the world became “air minded,” and throughout the Great Depression Bowlus was convinced that gliders were the best way to teach people to fly, especially young people.

The Bowlus Sailplane Company was formed in 1928 in San Diego, California. The first of the famous Albatross series of sailplanes appeared shortly after Lindbergh’s transatlantic flight. This was Bowlus’ sixteenth glider design. There were about twenty Model A and SP-1 Albatross sailplanes built in San Diego.

Bowlus moved to San Fernando and was involved with several glider designs. His best-known design, well under way by 1936, was the BA-100, known as the Baby Albatross. This was an intermediate sailplane, loosely based on the German Grunau Baby designed in 1932. This design, first flown in April 1938, was intended to be a smaller and simpler addition to Bowlus’ series of Albatross sailplanes. The wooden wings were influenced by the Grunau Baby and were aerodynamically similar but were structurally very different. A streamlined wooden fuselage pod was molded in two halves over a concrete form. The tail boom was made of 5-inch diameter heat-treated aluminum. Bowlus pioneered the ‘pod and boom’ design that proved to be aerodynamically superior to other designs. The Baby was sold as a highly prefabricated homebuilder kit, or factory assembled and ready to fly. About 90 of these kits were sold with about 50 aircraft completed and flown.

During WW2, Bowlus designed gliders for the US Army Air Force. The largest of these, the XCG-8, was a 15-seat model with a lifting fuselage design that was by far the most aerodynamically efficient WW2 glider. None of his designs were put into production.

WW2 and the loss of friends had taken their toll on Hawley Bowlus. In August 1943, at the end of the XBM-5 project, he resigned from Bowlus Sailplanes to work with Douglas on the XCG-7 & 8 projects. In January 1944 Bowlus Sailplanes Inc. was sold to Laister-Kauffman and after the XCG-16 project Hawley Bowlus was without a company. In 1945 Hawley Bowlus and Ted Nelson (BTS-100 owner) teamed up and formed the Nelson Aircraft Corporation to build a two-seat, motor glider version of the Baby Albatross called the Bumble Bee.

For the Bumble Bee the Baby Albatross’ pod was widened to allow side-by-side seating and dual controls. The retractable tricycle landing gear kept the back of the pod high enough off the ground for an aft engine installation with adequate prop clearance.

The name was changed to Dragonfly as Republic Aviation intended to produce a line of civilian aircraft names all ending in “bee.” Seven BB-1s were produced, mostly with Nelson 24 hp engines. Today four of the Dragonflies are in museums, one is waiting to be rebuilt and one was wrecked, leaving the fate of one unknown. This was Hawley Bowlus’ final project after thirty-four years of creative and innovative aircraft designs. In 1949 he joined Hughes Aircraft; one of his projects he worked on was the Surveyor lunar lander program. He passed away in 1967 at the age of 71.

From On The Wings Of An Albatross by Jeff Byard.