| 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]
Data from Markowski 1979, p.384
General characteristics
Performance