The Wright brothers spent years in learning the art of balancing in the air before they appeared in public as aviators. And their method of teaching pupils is evidence that they believe the only road to successful aviation is through progressive experience, leading up from the use of gliders for short flights to the actual machines with motors only after one has become an instinctive equilibrist.
At the Plum Island school of the Herring-Burgess Company the learner is compelled to begin at the beginning and work the thing out for himself. He is placed in a glider which rests on the ground. The glider is locked down by a catch which may be released by pulling a string. To the front end of the glider is attached a long elastic which may be stretched more or less, according to the pull desired. The beginner starts with the elastic stretched but a little. When all is ready he pulls the catch free, and is thrown forward for a few feet. As practice gains for him better control, he makes a longer flight; and when he can show a perfect mastery of his craft for a flight of 300 feet, and not till then, he is permitted to begin practice with a motor-driven machine.
A French apparatus for instructing pupils in aviation.
The lamented Otto Lilienthal, whose experience in more than 2,000 flights gives his instructions unquestionable weight, urges that the “gradual development of flight should begin with the simplest apparatus and movements, and without the complication of dynamic means. With simple wing surfaces ... man can carry out limited flights ... by gliding through the air from elevated points in paths more or less descending. The peculiarities of wind effects can best be learned by such exercises.... The maintenance of equilibrium in forward flight is a matter of practice, and can be learned only by repeated personal experiment.... Actual practice in individual flight presents the best prospects for developing our capacity until it leads to perfected free flight.”
The essential importance of thorough preparation in the school of experience could scarcely be made plainer or stronger. If it seems that undue emphasis has been laid upon this point, the explanation must be found in the deplorable death record among aviators from accidents in the air. With few exceptions, the cause of accident has been reported as, “The aviator seemed to lose control of his machine.” If this is the case with professional flyers, the need for thorough preliminary training cannot be too strongly insisted upon.
Having attained the art of balancing, the aviator has to learn the mechanism by which he may control his machine. While all of the principal machines are but different embodiments of the same principles, there is a diversity of design in the arrangement of the means of control. We shall describe that of the Curtiss biplane, as largely typical of them all.
In general, the biplane consists of two large sustaining planes, one above the other. Between the planes is the motor which operates a propeller located in the rear of the planes. Projecting behind the planes, and held by a framework of bamboo rods, is a small horizontal plane, called the tail. The rudder which guides the aeroplane to the right or the left is partially bisected by the tail. This rudder is worked by wires which run to a steering wheel located in front of the pilot’s seat. This wheel is similar in size and appearance to the steering wheel of an automobile, and is used in the same way for guiding the aeroplane to the right or left. (See [illustration of the Curtiss machine in Chapter V].)
In front of the planes, supported on a shorter projecting framework, is the altitude rudder, a pair of planes hinged horizontally, so that their front edges may tip up or down. When they tilt up, the air through which the machine is passing catches on the under sides and lifts them up, thus elevating the front of the whole aeroplane and causing it to glide upward. The opposite action takes place when these altitude planes are tilted downward. This altitude rudder is controlled by a long rod which runs to the steering wheel. By pushing on the wheel the rod is shoved forward and turns the altitude planes upward. Pulling the wheel turns the rudder planes downward. This rod has a backward and forward thrust of over two feet, but the usual movement in ordinary wind currents is rarely more than an inch. In climbing to high levels or swooping down rapidly the extreme play of the rod is about four or five inches.
Thus the steering wheel controls both the horizontal and vertical movements of the aeroplane. More than this, it is a feeler to the aviator, warning him of the condition of the air currents, and for this reason must not be grasped too firmly. It is to be held steady, yet loosely enough to transmit any wavering force in the air to the sensitive touch of the pilot, enabling him instinctively to rise or dip as the current compels.