Aeroplanes - Early history of Flying. Pages 1 2 3 4 Home
Of the two types of aeroplane in use, the biplane has only one advantage over the monoplane. From the nature
of its structure - a trussed girder - it is stronger and more rigid. Consequently, it is less likely to suffer serious
damage when subjected to a violent shock. From every other point of view, the monoplane is its superior. Since
recent advance in aeronautical engineering has succeed in providing methods of construction combining
strength and lightness to the requisite degree, the monoplane, by its vastly superior speed, equal carrying-power,
and smaller dimensions, has greatly gained in popularity, and offers better opportunities for ultimate perfection.
The biplane carries a loading of from 2 1/2 to 3 1/2 lbs. per sq. ft. of surface; the monoplane from 3 1/2 to 6 lbs.
per sq.ft. The load per horse-power in each case is from 30 to 40 lbs. In speed the biplane ranges from 35 to 45
miles per hour, as against 40 to 60 miles per hour attained by the monoplanes.
Image. Farman Biplane________________________________________________________________________________
Image. Blériot Monplane_______________________________________________________________________________
In neither type, however, has anything like finality in design been attained, so that any attempt to define their
respective capabilities would be premature. Nor is it possible to say whether the aeroplane will ultimately
prevail in its present form. The invention of gas turbines of other improved forms of motive power, the discovery
of another and more efficient means of propulsion than the screw propeller, may profoundly modify the design
or even the principle of flying-machines.
In spite of a series of fatal accidents, the principle of the aeroplane may be said to have proved essentially sound.
Such accidents as have occured have, in fact, been due not to fundamental defects, but to small imperfections
in design, and to constructional faults. The majority of fatal accidents have been caused by partial structural
weakness, usually in the tail members, which may be subjected to excessive strain during a sudden manoeuvre
of the machine. Faults in framework structure also account for several disasters. But save for these minor
faults, inseparable from the early days of any new departure in engineering, and easily remediable, the aeroplane
is radically safe. It suffers, of course, from the comparative disadvantage that its sustaining force is a direct
outcome of its forward motion, and must necessarily fail when the latter disappears. In other words, the aeroplane
must advance in order to keep up. But a breakdown of the motor does not therefore imply disaster; on the
contrary, a well-balanced aeroplane, when the motive-power fails, acts as a glider, with a gliding-angle not greater
than 1 in 8. Consequently, although, on the motor stopping, the machine assumes a descending trajectory, the
actual rate of fall is slow, so that the pilot, who preserves control over his machine, has time to choose a
suitable landing place. It is obvious, therefore, that when flying over difficult or densely-populated country it is
preferable to fly at a considerable altitude. From a height of 5,000ft., for instance, the aeroplane can land anywhere
within a radius of 8 miles.
In making flights it is necessary to take into account the action of the wind. A side-wind will cause an aeroplane to
make leeway in proportion to the speed at which it is blowing; similarly, a following wind will increase the speed of
flight. For the purpose of long-distance flights it may be possible to take advantage of the wind, or even of several
air currents, by suitable manouevring, and thus extend both the radius of action and the velocity of flight. The art of
navigation in the air is in its infancy, and offers severe difficulties as yet. In misty or cloudy weather the pilot has
recourse to the compass. This instrument is, however, extremely unreliable when fitted on an aeroplane, owing to
the disturbing effect of the magneto.
The altitude is measured by an aneroid barometer, usually self-recording. Special maps for aeronautical use are in
existance, indicating contours, land-marks, light-houses, dangerous areas for landing, etc. From the very first days
the value of the aeroplane, from a military point of view, has been realizes, not as a weapon of offence so much as of
intelligence. It would, in fact, be difficult to imagine a better means for scouting and reconnoitring than is afforded by
the flying machine. Its gradually increasing radius of action renders it available for strategical no less than for tactical
reconnaissance; its easy mode of progress and absence of vibration allow the most accurate observations to be made
and sketchmaps to be drawn. For despatch-carrying over difficult country its usefulness is also considerable. On the
question of it is employment for purposes of offence, it is impossible to pronounce definitely. On the other hand it is
practically immune from artillery or rifle fire from the land, especially when flying at a fair altitude.
Military aeroplane schools are established, and many officers trained as pilots, in several countries, notably in France;
and there is no reason to doubt that the aeroplane can be employed in naval warfare, especially if it be designed to land
on, and possibly to rise from, the surface of the water. Its use in conjunction with the less mobile dirigible also merits
attention. As a commercial vehicle, and for transport, the aeroplane, owing to its relatively low carrying power, is restric-
ted in its usefulness. With increasing reliability, however, it may well assume a portion of the functions of the motor car.
Such will certainly be the case with the flying-machine regarded as a pleasure craft and for sporting purposes. From
the fact that natural obstacles in the shape of mountains, rivers, forests, swollen torrents, impassable roads, do not
exist in the case of the aeroplane, its use as a means of communication in rough broken country is assured, and it
is designed to play an important part in exploration. The industry created by the aeroplane has grown at a very rapid
rate. In 1907 there were in existence at most three or four practicable machines; within three years the number had
grown to many hundreds. A large number of factories are exclusively engaged in the construction of these machines
and of light aerial engines.
The most important problems of which a solution is sought are the duplication of propelling mechanism, so that the
continuance of flight is not interrupted by the failure of the motor, and the attainment of automatic stability, independent
of the control of the pilot. Two solutions of the latter problem are possible: 1) the discovery of some form of surface that
shall be inherently stable; and 2) by regulating the controlling surfaces by some automatic means as the gyroscope.
Finally, there is a tendency to reduce the power required for flight to a much lower levelby improvements in design.
There seems no valid reason, in fact, why flight should not ultimately be achieved with a 3 or 4 H.P. engine, although
the achievement of flight by the muscular power of a man alone appears doubtful of realization.