Glider

“ Why Kitty Hawk?
Wilbur and Orville now proposed to build a full-size, man-carrying glider on which to test their method of control. Highly enthusiastic with the idea of gliding as a sport, they started thinking of a place for testing it. To get practice in operating the glider, they would first fly it as a kite before making gliding flights. For kite flying, steady winds and flat, open country were needed; for the gliding, a sandy area for soft landings and sandhill slopes free of 14 trees and shrubs for low-level flights. ”

“ THE SLING-SHOT GLIDER. A fascinating field of experiment is opened by combining the sling-shot principle with the ordinary glider. The speed with which one can launch a glider from the hand is, of course, limited. Now use a small strand of rubber to launch the planes, and the increased speed will not only lengthen the flight surprisingly but make possible a really remarkable spectacular flight. A small glider may be made to return to the starting point or even loop the loop two or three times before touching the ground. ”

“ Take the glider to the top of a hill, step into the center of the main frame just a little back of the center of the wings. Put your arms around the arm pieces, face the wind and run a few steps. You will be lifted off the ground and carried down the slope. The balancing is done by shifting the legs. The glides should be short at first, but by daily practice, and, as the operator gains skill, glides can be made up to a length of several hundred feet. Do not attempt to fly in a wind having a velocity of more than 15 miles an hour. ”

“ The total forward resistance of a well-formed aërial glider, or bird, may be taken as one eighth of its weight; hence, if poised stationary in its normal attitude of flight, it will just be sustained by a direct head wind having a horizontal acceleration of one eighth that of gravity, or four feet per second. ”

“ The child will find it interesting to make a number of these gliders and then go one day to a window or high place and let them glide to the ground and thus find out the bird that has the longest flight. Or a number of children can have glider races and see who can make a glider that alights on the ground farthest from them. ”

“ For it must be distinctly understood that there is constant danger in such preliminary experiments. When this hazard has been eliminated by further evolution, gliding will become a most popular sport.'
Later experiments proved that the biplane type of glider gave better results than the rather cumbrous model consisting of five tiers of planes. Longer and more numerous glides, to the number of seven to eight hundred, were obtained, the rate of descent being about one in six. ”

“ One simply launches into the air, and concentrates his efforts upon balancing himself and the apparatus; not as two distinct bodies, however, but as a united whole. When practice has made perfect the ability to balance the glider instinctively, nine-tenths of the art of flying an aeroplane has been achieved. Not only this, but a new sport has been laid under contribution; one beside which coasting upon a snow-clad hillside is a crude form of enjoyment.
Fortunately for the multitude, a glider is easily made, and its cost is even less than that of a bicycle. ”

“ These experiments, however, led to the invention of the glider, which finally developed into the aeroplane or the heavier-than-air machine.
A glider consists of a rigid rectangular plane constructed of frail framework, similar to a kite, and covered with linen or cloth, much like the wing of a modern aeroplane. ”

“ Well, he’d proved how quickly you could get across the United States in an ordinary plane. Then he showed how you could cross with a glider, towed by an engined plane. Why, you ask. Well, in the first place, it attracted attention to gliders. And gliders are important in aviation. And then, if towed gliders are practical, they might solve the problem of carrying pay loads in cross-country flights. The glider could be loaded up, hitched to an airplane, and go from New York to any point west. That was the idea. Well, Hawks did attract attention. ”

“ We hadn't talked a minute before he handed me "pragmatism" and "zing-slingers." While I was rolling my eyes and clawing for a foothold he confessed that he was the best glider in college. When I remarked that I had been somewhat of a glider myself, but that I had preferred the twostep, he laughed and explained that he was captain of the aviation team—that they had three gliders and were finishing a monoplane that had a home-made engine with concentric cylinders.
Can you beat it? ”

“ A layer of liquid glue brushed between will help to make the joint firmer.
Otto Lilienthal in his single-plane glider. The swinging forward of his feet tends to turn the glider toward the ground, and increase its speed. ”

“ Many glider flights at Kitty Hawk preceded the first attempt to fly in a power-driven plane. Here the Wrights are flying a glider as a kite, controlling it from the ground. Later flights were made in man-carrying gliders. ”

“ All these grew out of kite experiments; and all gliders followed the kite construction, or the principles involved in them, so that, really, there is but one intervening step between the kite and the flying machine, as we know it, the latter being merely kites with power attached, as substitutes for the cords.
ONE OF THE USES OF GLIDER EXPERIMENTS.— There is one direction in which gliders are valuable to the boy and to the novice who are interested in aviation. He may spend a lifetime in gliding and not advance in the art. ”

“ With the multiple winged glider some two to three hundred glides were made without any accident either to the man or to the machine, and the action was found so effective, the principle so sound, that full plans were published for the benefit of any experimenters who might wish to improve on this apparatus. ”

“ They began coasting down the air from the tops of sand dunes, and after the first few glides were able to slide three hundred feet through the air against a wind blowing twenty-seven miles an hour. The reason their glider flights were made against the wind was because the wind passing swiftly under the planes had the same effect as if the machine was moving forward at a good clip, for the faster the machine moves, or the faster the air passes under it, the easier it remains aloft. ”

“ During six days of the practice season of that year, they made 375 gliding flights of various distances, most of them comparatively short, but each one of value in familiarizing the glider with the conditions to be met. It is not material whether gliding or manipulation of the control levers is taken up first, as both should be mastered as far as possible before attempting to fly a regular machine. ”

“ Down to the latter part of the nineteenth century only the gliders were successfully used in man flight. In reality they can scarcely be called flying machines for they could not lift their own weight, though late experiments prove that when once in air they may rise above their starting point under the influence of a strong wind. The glider, however, performed a most important part in the evolution of the aeroplane. ”

“ The glider shown in the sketch was worked out after considerable testing. With a toss it travels 20 to 30 ft., on a level keel, with a message slipped behind a pin, as shown in the upper sketch. The inventive boy may devise many play uses for the glider in tournaments, competitions, and for “military” flights, in which the “drivers” of the devices may “annihilate armies.” Practical use of the toy was made in a series of air-current tests. ”

“ In ascending, the glider and flying machine, like the bird, makes an angular, not a vertical flight. Just what this angle of ascension may be is difficult to determine. It is probable and in fact altogether likely, that it varies with the force of the wind, weight of the rising body, power of propulsion, etc. ”

“ Some of the best gliding flights made by Herring, Chanute's co-worker, were in a rudderless glider. After having mastered the rudiments of the art, the student may go as far as the dictates of his ambition impel him in the direction of improvements in his glider, by adding a rudder, elevator, and warping control. ”

“ Lilienthal in Germany, Pilcher in England, and Chanute in the United States are names eminent in 256 connection with the experiments with gliders which have been productive of discoveries of the greatest importance to the progress of aviation. The illustration of the Chanute glider shows its peculiarities plainly enough to enable any one to comprehend them.
The establishment of glider clubs in several parts of the country has created a demand for ready-made machines, so that an enthusiast who does not wish to build his own machine may purchase it ready made. ”

“ They found that in order to support a man on it the glider required an angle nearer twenty degrees than three, and even with the wind at thirty miles an hour they could not get down to the planned angle of three degrees. 'Later, when the wind was too light to support the machine with a man on it, they tested it as a kite, working the rudders by cords. Although they obtained satisfactory results in this way they realised fully that actual gliding experience was necessary before the tests could be considered practical. ”

“ In size the surface planes should be about twice as large as those of the 20-foot glider, viz: 40 feet spread instead of 20, and 6 feet deep instead of 3. The horizontal beams, struts, stanchions, ribs, etc., should also be increased in size proportionately.
While care in the selection of clear, straight-grained timber is important in the glider, it is still more important in the construction of a motor-equipped flying machine as the strain on the various parts will be much greater. ”

“ Gliding with a Chanute three-decker. A start with two assistants.
While it is necessary to make glides against the wind, it is not wise to attempt flights when the wind blows harder than 10 miles an hour. While the flight may be successful, the landing may be disastrous.
The accomplished glider operator is in line for the aeroplane, and it is safe to say that he will not 255 be long without one. The skilful and practised operator of a glider makes the very best aeroplane pilot. ”

“ If the motor and its appurtenances, and some of the purely auxiliary planes, be omitted, we have a glider. The glider is not a toy; some of the most important problems [Pg 130] of balancing may perhaps be some day solved by its aid. ”

“ Set your forward plane at an angle by inserting a block of wood between the stick. In the case of metal planes, bend up the front edge.
A very slight upward elevation will answer. Gradually increase this angle until the model sweeps upward and turns on itself. You will soon be able to make the glider describe a complete circle or loop the loop twice before landing. When traveling at such a high rate of speed, your glider is likely to be dangerous and might inflict a bad cut, and the flight should only be attempted where one has plenty of room. ”

“ Drag—A resistant force exerted in a direction opposite to the direction of motion and parallel to the relative gas or air Stream.
Dynamic lift—The lift given an airplane by the aerodynamic force produced from an adequately designed airfoil.
Glider—A fixed-wing aircraft having no power plant and constructed so as to glide and soar.
Gliding—The art, science, and activity of moving through the air in a glider.
Heavier-than-air aircraft—Any aircraft weighing more than the air it displaces. ”

“ The paper gliders form an excellent kindergarten preparation to the study of aviation, leading up to the construction of large model gliders. You will thus gain a skill in adjusting the planes and fixing the centers of gravity and of pressure, which will prove valuable later on. The possibilities of glider building come as a surprise to the laymen in such matters. ”

“ Like Lilienthal he realized that it would be useless to attempt a motor driven airplane until the principles of glider construction were fully understood. A glider is simply an airplane without an engine, and Lilienthal succeeded in giving it a certain motive power by starting from a high point, so that the force of gravity could draw him forward and downward. ”

“ Any flying machine without a motor is a glider and the latter is the basis of the successful aeroplane. In the building of an aeroplane the first thing constructed is the glider, i.e. the frame, main planes, stabilizing planes, elevators, rudders, etc. It is only by the installation of motive power that it becomes a flying machine. The biplane will be found the most satisfactory type of glider as it is more compact and therefore more easily handled, which is of great importance for practicing in a wind. ”

“ The higher the starting point the farther one may fly. Great care should be exercised in making landings; otherwise the operator might suffer a sprained ankle or perhaps a broken limb. The illustration shows two lines of flight from a hilltop, the glider travels on the upper line caused by the body of the operator taking a position a little back of the proper place, and on the lower line he changes his position from front to back while flying, which causes the dip in the line. ”