Engineering:Marsden Gemini
| Gemini | |
|---|---|
| Role | Glider |
| National origin | Canada |
| Designer | David Marsden |
| First flight | 1973 |
| Status | unknown |
| Number built | one |
The Marsden Gemini is a Canadian mid-wing, T-tailed, two-seats in side-by-side configuration, experimental research glider that was designed and constructed by David Marsden at the University of Alberta, first flying in 1973.[1][2]
Design and development
The Gemini was designed to explore the use of flaps to create a variable geometry sailplane that would be optimized for both low speed thermalling flight and also high speed gliding between thermals.[1][2]
The aircraft was predominantly made from aluminium, with some stainless steel used for the wing ribs, controls and fittings. The two-place side-by-side cockpit was made from fibreglass. Its four-piece 60.75 ft (18.5 m) span high aspect ratio wing employed a modified Wortmann FX-61-163/35SF airfoil. The Fowler flaps occupied the entire trailing edge of the wing and accounted for 35% of the wing chord. In cruise the flaps were retracted, reducing the wing area. While climbing, the flaps were extended, producing a high lift coefficient of 2.2. For glidepath control when landing the flaps deployed to 80° to create aerodynamic drag. The outer flaps acted as slotted ailerons for roll control.[1][3]
Operational history
Only one Gemini was built.[1][2] The aircraft was still operational in August 2011, owned by William G. Osoba of Wichita, Kansas, United States , but was removed from the US register in April 2019 and its fate is unknown.[4][5]
The aircraft was flown to set seven Canadian multi-place records, including the record for speed over a 500 km (311 mi) triangle. It was also used to set the US national record for the 300 km (186 mi) of 94 mph (151 km/h).[1][2]
On July 2, 2011, Osoba and his wife Christine flew the Gemini on a 565 mi (909 km) free distance flight from Zapata, Texas to just east of Amarillo, Texas, a flight which won the 2011 Barringer Trophy.[6][7]
Specifications (Gemini)
Data from Sailplane Directory[1]
General characteristics
- Crew: one
- Capacity: one passenger
- Wingspan: 60 ft 8 in (18.49 m)
- Wing area: 124 sq ft (11.5 m2) with flaps retracted
- Aspect ratio: 29.8:1
- Airfoil: modified Wortmann FX-61-163/35SF
- Empty weight: 785 lb (356 kg)
- Gross weight: 1,240 lb (562 kg)
Performance
- Maximum glide ratio: 40:1 at 74 mph (119 km/h)
- Rate of sink: 124 ft/min (0.63 m/s)
- Wing loading: 10 lb/sq ft (49 kg/m2)
See also
Other gliders with Fowler flaps
- Beatty-Johl BJ-2 Assegai
- LET L-13 Blaník
- Sigma
- SZD Zefir series
Related lists
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Activate Media (2006). "Gemini Marsden". http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=118.
- ↑ 2.0 2.1 2.2 2.3 Armstrong, Ken (August 2011). "Capt. Ken's comments - July". Canadian Owners and Pilots Association. http://archive.copanational.org/non-members/KenArmstrong/2004/KenArmstrongJuly04.htm.
- ↑ Lednicer, David (2010). "The Incomplete Guide to Airfoil Usage". http://www.ae.illinois.edu/m-selig/ads/aircraft.html.
- ↑ "FAA Registry N Number Query Results - N77ZV". http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=77ZV&x=0&y=0.
- ↑ "FAA Registry N Number Query Results - N77ZV". https://registry.faa.gov/aircraftinquiry/Search/NNumberInquiry.
- ↑ "July 2 OLC". http://www.onlinecontest.org/olc-2.0/gliding/flightinfo.html?flightId=-177402969.
- ↑ "The Lewin B. Barringer Memorial Trophy". http://www.ssa.org/members/badgesandrecords/AwardDetail.asp?id=3.
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