The Aeroplane

by Claude Grahame-White; Harry Harper

Fig. 46.—The Farman Biplane.

The control was simple. At the pilot’s right hand there was a lever; this, when moved forward or backward, operated the elevating-plane; and a sideway action controlled the ailerons. At the pilot’s feet was a pivoted rod, and this, as he pressed upon it with one foot or the other, swung the twin rudders at the tail.

Such a system of hand-and-foot control has become general in aeroplanes. The pilot uses as a rule a hand-lever or wheel for governing the ascent or descent of his craft, and for sideway balancing, and employs his feet for operating the rudder. This leaves him a hand free for the manipulation of his engine throttle and switch.

A feature of Farman’s biplane was the landing gear, as shown in [Fig. 46]. It comprised two long skids, which projected in front of the main-planes beneath the machine, and continued some distance rearward; while mounted upon each of these skids, at a point below the front edge of the lower main-plane, was a short metal axle which bore two small bicycle wheels, fitted with pneumatic tyres. Holding the axle to the skid were thick india-rubber bands, and the working of this apparatus was as follows: when the machine moved across the ground, the bicycle wheels bore its weight, and the skids were prevented from making contact with the surface. But when alighting from a flight, should the biplane strike ground heavily, then the wheels were pushed up by the yielding of the elastic bands, and the skids took the shock of the impact. Light, and with no complications, this form of gear proved remarkably efficient; and by degrees it came to be used, not only in the Farman, but upon other types as well. The necessity in any such device was lightness; when the machine was in the air, and until it landed from its flight, the alighting gear was so much dead weight—and not only this, but the air-pressure on struts and stays acted as a check upon the speed of the machine. Any landing gear to be useful and efficient, therefore, must be light and yet strong, and have few parts which can offer resistance to the air.

PLATE VII.—A FARMAN IN FLIGHT.

Here, using the biplane with which he first flew in England, Mr. Grahame-White is seen ascending from a field near Rugby during his attempts to win the £10,000 London-Manchester prize.

Farman planned to win prizes at the Rheims flying meeting, and he succeeded. But the flights he made would hardly have been possible had not he obtained the use of a new motor—one destined to play a vital part in the development of flying. This was the Gnome; and to understand its triumph an explanation is necessary. Before Farman fitted the first of these motors to his biplane, engines in aeroplanes had been troublesome and unreliable. The difficulty was that they must be very light, and yet capable of running at high speeds and under heavy loads. Working, say, at 1000 revolutions a minute or even more, they drove the propeller of an aeroplane at full speed for the whole of the time it was in the air, and enjoyed no occasional rest, or slackening of power, as was the case with motor-car engines on the road. The result was that, being light and experimental—and at the same time so heavily worked—they either broke small but vital parts, such as a valve or connecting-rod, or became over-heated and failed to deliver their power.

To prevent overheating, there were two cooling systems available. In one, known as water-cooling, a stream of water flowed through metal chambers round the cylinders, and tended to reduce their heat. But this implied extra weight, and the carrying also of a radiator, or framework of thin pipes exposed to the air, through which the water was pumped, so as to cool it after it had passed round the heated cylinders. The second system, which obviated the use of water or radiators, was known as air-cooling. In this the tops of the cylinders were ringed with metal flanges, or fins, upon which the air impinged as the machine flew. This method is adopted in most motor-cycle engines, and answers admirably. But with aeroplane motors, in the early days, the high speed at which they worked, and the fact that they obtained no rest in flight, or slackening in the number of their revolutions, made them overheat very often, in spite of their cooling fins. One might liken their work to taking a motor-cycle and running it at top speed up a hill without end.