If the development of model aeroplanes leads the way in perfecting heavier-than-air machines, as many believe, the monoplane form seems destined to replace all multiplane types. During the past year practically all of the biplane forms have been abandoned by model builders. As a result of wide experiments, it has been found that the monoplane exerts more sustension per unit of surface than any two or three-plane machines. In theory, it is, of course, possible to increase the sustained force by setting one plane above another, but in practice it has been found that the planes must be set so far apart that the arrangement is impracticable. When planes are separated, they must, of course, be stayed and trussed to keep them rigid, and all this adds to the weight and complexity of the machine.
[Illustration: A good specimen of plane building.]
[Illustration: "Finish one end of the blade before cutting away the opposite end."]
[Illustration: Model aeroplane. Designed by Cecil Peoli.]
The builder of model aeroplanes has a great advantage over the designer of man-carrying crafts. The spread of the wings of his model is comparatively small, and the problem of staying and trussing is greatly simplified. The monoplane, especially in a model, requires practically no staying at all. Then again the skin friction is greatly reduced in the monoplane form. Simple as it is, there are great possibilities in the arrangement of these surfaces. The effect of outline upon resistance again may be more closely observed in the monoplane than in the multiplane forms. In other words, if your model goes wrong, it is far easier to locate the fault and rectify it than in the more complicated arrangement of planes.
The flights of the English models this year are longer than those made in America, but, on the other hand, we are solving many practical problems of aviation, in our model building, which the English have not attempted. Even in the case of our single-stick frames built in America, the tendency is toward more stable construction than abroad. The best English models would not qualify for an American model tournament, since they could not rise from the ground.
The best American models, on the other hand, would be outdistanced in an English meet, but their flights would show them to have far greater automatic stability than their English rivals. It is extremely interesting to speculate whether the American or English types of model aeroplanes will survive, and which is contributing more to the solving of the great mysteries of aviation, but, after all, it is a question which only time can answer.