Nelson Dragonfly

The development of the Dragonfly was sponsored by the Nelson Engine Company to promote the use of their H-44 {{convert|25|hp|kW|0|abbr=on}} four cylinder two-stroke engine. The engine was mounted in the rear of the fuselage pod, in pusher configuration, with the wooden two bladed {{convert|42|in|cm|0|abbr=on}} propeller below the metal tail boom. The fuel tank holds {{convert|3|u.s.gal}}, enough for self-launching, but not for cross-country powered flight.

The Dragonfly shares the Baby Albatross's molded plywood fuselage pod, aluminium tube tail boom and strut-braced double spar wooden wing, covered in aircraft fabric aft of the spar. The leading edge is a plywood D-cell. The aircraft features dual controls and a retractable tricycle landing gear with a steerable nose wheel. The engine is started by a ratchet-wire recoil start system that allows restarts in flight, as well as on the ground.

Federal Aviation Administration certification of the type was achieved on 21 April 1947, with Nelson Aircraft Corporation as the certificate holder and the type officially known as Nelson Auxiliary Power Glider BB-1. The type certificate indicates that neither the engine nor the propeller need be certified. The type certificate specifies that the Nelson H-49 engine of {{convert|28|hp|kW|0|abbr=on}} may also be installed.{{Cite web|url = http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/8db86e618c946c038525673c00665b17/$FILE/ATTRYH3Y/GTC19.pdf|title = Aircraft Type Certificate Data Sheet GTC19 |accessdate = 10 March 2011|last = Federal Aviation Administration|authorlink = |date=April 1947}}

The Dragonfly was later replaced in production by the improved Nelson Hummingbird PG-185B.{{Cite web|url = http://www.sailplanedirectory.com/PlaneDetails.cfm?PlaneID=169|title = Hummingbird PG-185B Nelson|accessdate = 12 March 2011|last = Activate Media|year = 2006|url-status = dead|archiveurl = https://web.archive.org/web/20110715225244/http://www.sailplanedirectory.com/PlaneDetails.cfm?PlaneID=169|archivedate = 15 July 2011}}Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 123. Soaring Society of America, November 1983. USPS 499-920

In operational use the Nelson powerplant proved heavy and lacking in power and, as the Sailplane Directory terms it, "the result was an under-powered sailplane". The {{convert|25|hp|kW|0|abbr=on}} engine gave the Dragonfly a sea level climb rate of just 235 fpm (1.19 m/s) and a take-off run of {{convert|900|ft|m|0|abbr=on}}. As a result of the performance deficiencies only seven were produced. Three Dragonflys were sold to private owners in the Seattle region after having their engines removed.{{cite magazine |last=Bungey |first=Lloyd M. |title=Canada's Hidden Museum |magazine=Air International |date=May 1986 |volume=30 |issue=5 |pages=248–249 |issn=0306-5634}}

In March 2011 there were still four BB-1s registered in the US, two of which had been transferred to the National Soaring Museum.{{Cite web|url = http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=NELSON&Modeltxt=BB-1&PageNo=1|title = Make / Model Inquiry Results|accessdate = 10 March 2011|last = Federal Aviation Administration|authorlink = |date=March 2011}}

• Canadian Museum of Flight{{cite web|url=http://www.canadianflight.org/content/nelson-dragonfly|title=Nelson Dragonfly|work=canadianflight.org|accessdate=14 October 2015}}
• National Soaring Museum{{cite web|url = https://www.soaringmuseum.org/glider-collection.php|title = Sailplanes in Our Collection|access-date = 29 November 2021|last = National Soaring Museum|year = 2011|url-status = live|archiveurl = https://web.archive.org/web/20210509140257/https://www.soaringmuseum.org/glider-collection.php|archivedate = 9 May 2021}}{{Cite web|url = http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=4ND|title = Make / Model Inquiry Results|accessdate = 10 March 2011|last = Federal Aviation Administration|authorlink = |date=March 2011}}

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{{commons category|Bowlus/Nelson BB-1 Dragonfly}}

{{reflist}}

{{William Hawley Bowlus aircraft designs}}

{{Nelson Aircraft}}

{{DEFAULTSORT:Bowlus Nelson Dragonfly}}

Category:1940s United States sailplanes

Category:Bowlus aircraft

Category:Nelson aircraft

Category:Aircraft first flown in 1947

Category:Motor gliders

Category:Single-engined pusher aircraft