The Second Boys' Book of Model Aeroplanes

by Francis A. Collins

In the new Blackburn aeroplane, the fuselage is covered with wood as far back as the pilot's seat, and with cloth to its extreme end. The use of thin board for this purpose suggests interesting possibilities. One of the most novel features of this model is the light skid attached to the outer ends of the main plane. The skid is very light, adding little to the weight or head resistance, and prevents the end of the plane from digging into the ground on landing. Such an attachment may readily be added to model aeroplanes when they will save many a broken wing.

A novelty in plane-designing is shown in the Handley Page monoplane. The main plane, carried forward, as in the Bleriot, is cambered just back of the entering edge, flows back to a flat surface at the middle and then tilts upward toward the rear edge. The two sides, in turn, are set at a slight dihedral angle to the horizontal. This modeling is believed to secure automatic stability in two dimensions, both longitudinal and transverse. The planes are unusually broad in their fore and aft dimension, extending back nearly one-half the length of the motor base. The horizontal and vertical rudders are very small. The design should work well in models.

Builders of biplane models will find some interesting suggestions in the new Bristol biplane. The forward planes are of the biplane form, the lower surface being much narrower than the superimposed plane, the comparative width being one-third wider. Another original feature of this machine is that the planes are connected by only four struts instead of by rows of struts along both the front and rear edges. The planes are held rigid by a series of braces. It is believed that this arrangement decreases the head resistance, at the same time insuring considerable lateral automatic stability. The rear plane is of the monoplane type.

The friends of the Dunn monoplane believe that the question of automatic stability has been practically solved in this ingenious machine. The Dunn machine has flown on an even keel for five miles without the pilot once touching the controlling levers. The trick is in the design of the main wings.

The greater part of the wing, extending out from the central stick, has a slight camber and is slightly elevated, besides being set at a dihedral angle. Near the outer edge the wings are bent sharply down, much as the wings of a swallow are bent, and are given a considerable negative angle both forward and outward. The tips, therefore, form pockets at either end under the arched tips.

Wings modeled in this way are remarkably stable even when traveling across the wind. When a gust of wind strikes the outer edge of the plane, it tends to thrust it down rather than up, as is the case when a gust gets under a wing of the ordinary design. The wing quickly rights itself, however, since the angle of the plane tends to lift it. The pockets in turn by compressing the air tend to counteract this tipping tendency. These pockets are besides closed to an extent by ailerons or flaps, which may be pulled down, thus confining the air still further.

An effective device for securing lateral control appears in the new Grahame-White machine. Narrow ailerons are placed on the forward edge of the front plane near the outer tips. The tips at the opposite ends are hinged and so connected that as one is raised the corresponding tip is lowered, or the other way about. Now as one of these tips is lowered, tending to lift the machine, the opposite aileron working in the other direction tends to depress it.

The increased resistance offered by the lowered flap again tends to keep the machine from swinging around in the direction of the side on which the other aileron is lowered. The lateral control is thus much more quickly applied than in the case of the rear ailerons. In applying this principle to model construction, it must be borne in mind that the resistance of these forward tips is tending to retard the machine and must be used with care when the motive power is limited.

As far as general appearance is concerned, the Piggot monoplane is probably the greatest novelty of the year. It is the first aeroplane to carry a cabin, as it were, in which the pilot sits completely enclosed. In general appearance it suggests a great whale with exaggerated fins. The pilot looks out through elliptical windows at the sides and bottom, covered with mica, to protect him from the wind.

The wings of the Piggot aeroplane resemble the Bleriot machine, the propeller, or rather tractor, being carried forward. It is extremely interesting, however, since it suggests for the first time what the appearance of a cabined, passenger-carrying aeroplane of the future may be.