Spratt Model 107

Controlwing 107[1]
Role	Sport flying boat
National origin	United States
Manufacturer	homebuilt
Designer	George Spratt
First flight	1967
Number built	60 sets of plans sold by 1977[2]

The Spratt Controlwing 107 was an unorthodox controlwing flying boat designed in the United States in the 1960s and marketed for home building in the 1970s.[2]

The aircraft featured a flat, speedboat-like[3] hull with a square bow and with tailfins blended into each side.[4][5] The fins were angled to form a butterfly tail and included no moving surfaces.[5][6] The wings were mounted on struts, parasol-style, and also contained no moving surfaces.[3][6][7][8] Rather, each of the two wings could pivot independently to vary their angle of attack.[6][8] The pilot and a single passenger sat side by side in an open cockpit with a converted marine outboard motor mounted behind them that drove a pusher propeller.[3][6] The flight controls consisted of a helicopter-style collective that varied the angle of attack of both wings simultaneously,[6][8][9] and a control wheel that varied their angles of attack in relation to one another.[6][8][10] The hull was constructed from polyurethane foam and covered with fiberglass, and the wing panels were fiberglass throughout.[6]

Designer George Spratt claimed that the Model 107 could not stall or spin, and that it was 75% less affected by turbulence than a conventional airplane design.[2] With friend Elliot Dalland, Spratt began construction of the prototype (registered N2236) in 1962.[3] During the 1970s, Spratt marketed plans for the Model 107 to homebuilders.[2][11]

Specifications (Controlwing 107)

Data from Markowski 1979, p.384

General characteristics

• Crew: one pilot
• Capacity: one passenger
• Length: 17 ft 0 in (5.18 m)
• Wingspan: 24 ft 0 in (7.32 m)
• Height: 5 ft 0 in (1.52 m)
• Wing area: 96 sq ft (8.9 m^2)
• Empty weight: 500 lb (226 kg)
• Gross weight: 1,000 lb (543 kg)
• Powerplant: 1 × Mercury 800 converted marine engine , 80 hp (60 kW)

Performance

• Maximum speed: 98 mph (160 km/h, 85 kn)
• Service ceiling: 3,000 ft (910 m)
• Rate of climb: 800 ft/min (4.0 m/s)

Notes

1. "American airplanes: sk - ss". Aerofiles.com. 2009-03-16. Retrieved 2011-04-06.
2. Taylor 1977, p.563
3. Spratt 1962, p.25
4. Taylor 1977, p.565
5. Markowski 1979, p.384
6. Taylor 1977, p.564
7. Taylor 1989, p.839
8. Markowski 1979, p.380
9. Spratt 1962, p.25–26
10. Spratt 1962, p.26
11. Gunston 1993, p.290

References

• Gunston, Bill (1993). World Encyclopedia of Aircraft Manufacturers. Annapolis: Naval Institute Press.
• Markowski, Michael (1979). The Encyclopedia of Homebuilt Aircraft. Blue Ridge Summit: TAB Books.
• Spratt, George G. (July 1974). "The Controlwing Aircraft: Part 2 — Postwar Development". Sport Aviation: 24–30.
• Taylor, John W.R. (1977). Jane's All the World's Aircraft 1977–78. London: Jane's Yearbooks.
• Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions.

External links

• Aerofiles
• Spratt "Wingdinghy" in Popular Mechanics, June 1962