Part 2

The Wright Brothers were not only inspired mechanics (as many people still believe today) but serious scientists, working along the soundest lines. In their keen desire to know what air pressure on wings really was, they cleared a corner of their bicycle shop and built a small wind tunnel with spare lumber and an old electric fan. They built small wing sections of various shapes and experimented with them in their wind tunnel. The electric fan was used to create the moving air around the wing section. By attaching the wing sections to a supporting frame and connecting the frame with a pointer and dial, they were able to keep a record of the effect of moving air on each experimental wing section. Through their wind tunnel research the Wright Brothers discovered the four forces that control all heavier-than-air flight: _lift_, _thrust_, _weight_, and _drag_. They found that a slight curve or camber in the wing section would cause the moving air to travel farther over the top of the wing surface than along the under side. This made the air pressure greater under the wing, gave a suction effect above the wing, and caused it to rise, creating _lift_. They discovered that a wing section of the proper camber would counteract the _weight_ of gravity. Thus, a wing must be so designed that, with a certain amount of air flowing around it, it would lift a certain _weight_. They also discovered that air flow against any surface attached to the wing would cause a resistance or _drag_. Hundreds of experiments in their wind tunnel with various types of wing shapes gave the Wrights a series of tables from which to design a wing that would create the _lift_ for a designed weight.

Then, after testing more than 200 wing designs and plane surfaces in their wind tunnel, the Wright Brothers found out how to figure correctly the amount of curve, or camber, that was essential to weight-carrying wings. They discovered, too, that before man could be flown through the air, he must have his wings attached firmly to a body or platform which was firm and controllable. The Wrights in their earliest experiments had realized that to be practical their machine must be built not only to fly in a straight line, but also in order that it could be steered to the right or to the left. One day, Orville was twisting a cardboard box in his hand when Wilbur noticed it. Immediately he saw the solution to the problem of steering their airplane. The result was a design which changed the _lift_ of either end of the wing by warping its surface. If one end of the wing was warped to give it more _lift_, the machine would _lift_ on that side and fall off into a turn. Thus the problem of steering was solved by the Wrights.

FIRST FLIGHT

After a year of exhaustive study and experiments with models in their wind tunnel, the Wright Brothers were ready to experiment with a man-carrying glider. With the thoroughness that was typical of every move of the Wrights, the brothers asked the government to let them have information on meteorological conditions all over the country. By studying the weather charts they were able to find a locality where there was a continual flow of wind. This would be nature’s wind tunnel where they could test their glider day after day. Through their study of the charts they found that the wind conditions at Kitty Hawk, on the North Carolina coast, seemed to offer the best possibilities for their glider test.

Orville and Wilbur Wright began their experiments with a small man-carrying glider at Kitty Hawk in 1900. From that time until 1903 they made hundreds of successful glider flights and kept accurate records of each flight. They recorded wind velocity, angle of flight, duration of flight, time of day, temperature, humidity, and sky conditions overhead with the typical Wright attention to detail. Each year the Wrights constructed new gliders which embodied principles they had discovered for themselves during their flights at Kitty Hawk. Each glider was larger and had longer and narrower wings than the one before. During the fall of 1902 the brothers recorded nearly a thousand flights in a glider with a wingspan of thirty-two feet. It had a front elevator and a vertical tail which helped to maintain lateral stability.

By 1903 the Wright Brothers were ready to build a powered man-carrying flying machine. Their experiments had shown them just how much moving air was necessary to create lift in such a machine. To create the needed thrust, an engine having eight horsepower and weighing not over 200 pounds had to be fitted into the machine. Such an engine was not available, so the Wrights built one in their shop at Dayton, Ohio. They were ready to ship their airplane to Kitty Hawk, N. C., in the fall of 1903.

A cold wind whipped across those buff stretches of Kitty Hawk on Thursday, December 17. A coin was tossed into the air between Orville and Wilbur Wright. Orville won the toss, climbed up and stretched prone on the wing of the flying machine. He clutched the controls.

There were no cheering crowds; a mere handful of people were there. Running along its launching track, the 750 pounds of plane, engine, and passenger shot up into the air so fast that Wilbur, at the wing-tip, could not keep up. For three and one-half seconds the plane was in the air. It came to rest 105 feet from the take-off. Powered flight was born!

WRIGHT BROTHERS’ AIRPLANE

Three more flights were made on that epochal day at Kitty Hawk. The last flight of the day, with Wilbur at the controls, proved to be a breath-taking adventure. For fifty-nine seconds the roaring, white-winged craft pitched and rolled in the fitful wind. Flying low with its pilot tense at the controls, it covered a distance of 852 feet. There was no question now in the minds of Orville and Wilbur. They had proved conclusively their theory and were anxious to get back to their shop to continue improving their first flying machine.

Except for the handful of spectators who were present, the world treated the first powered flight coldly. Only a few days before the first flight of the Wright Brothers the highly publicized Langley _Aerodrome_ had crashed into the Potomac for the second time. People just would not believe that the Wrights actually had flown. The newspapers refused even to print the story. Had not most newspaper editors just proved conclusively from Langley’s disaster that the heavier-than-air flying machine could never work? Most scientists agreed with the newspaper editors, and the Wright Brothers were ignored by both press and public.

Immediately after their initial flight, the Wrights offered their invention to the government. The criticism aroused by the government’s investment of $50,000 in the disastrous Langley experiment was too fresh in the minds of the authorities, and no encouragement was given to the brothers’ offer. The Wrights returned to Dayton, where they housed their machine in a closed barn on the flat land a few miles east of the city. They admitted that they had flown, but they were among the first to state that they had only uncovered the barest physical facts associated with flight.

The brothers continued to make flights over the flat lands. They made 105 flights during the year 1904 and gained a considerable amount of experience and skill. They mastered the art of flying in a complete circle and landing the plane in the same field from which it had taken off.

Early in the winter of 1905 the Wrights began work on a new machine, incorporating many improvements resulting from their flying experience. They continued to work quietly, and the only news of them that reached the world came from the reports of farmers who lived near the flat-land flying field. Confirmed reports showed that the Wrights had now covered a distance of twenty-four miles in thirty-eight minutes.

THE FIRST AIRPLANE

Many people speak of the Wright Brothers’ first airplane as a flimsy contraption of sticks, cloth, and wire. Although it was indeed built of wood, cloth and wire, it was, like everything else the Wrights built, thoughtfully and painstakingly constructed. Its wings were efficient lifting surfaces and the entire airplane was sound structurally. The main force that went into it was the result of years of sound research in aëronautical science. Orville and Wilbur Wright had solved all the fundamental problems of flight before they built their first powered, man-carrying airplane. They discovered the basic forces that control all heavier-than-air flight: _lift_, _thrust_, _drag_, and _weight_. Today, little more than forty years after the first flight at Kitty Hawk, those _four forces_ discovered by the Wright Brothers still control the design of every airplane built.

Equally important was their solution of the problem of controlled flight. Their knowledge of the effect of air on the surfaces of the wings helped the Wrights solve the problem of control. By warping the wings they were able to turn the plane to the right or to the left. When a wing-tip was warped downward it increased the lift of the wing, causing it to rise. The opposite wing-tip warped upward lost lift and the plane would fall off toward the low side. The effect was that of dragging one oar of a boat in the water. To aid in turning the plane, the machine was provided with a vertical rudder attached to the lateral control. When the wings were warped, the rudder automatically swung to enforce the turn.

The pilot’s right hand was on the lever which controlled the wing warping and rudder. His left was on the lever which raised and lowered the elevators. The lever at the extreme left also was attached to the elevators, providing dual control. All movements of the controls were in the direction of the desired attitude of the plane.

The story of American aviation began in a bicycle shop in Dayton, Ohio. It continued in the shop of a daredevil motorcycle racer and gasoline engine builder at Hammondsport, New York.

While the Wright Brothers were quietly flying their plane on the flat lands in Ohio, another self-taught, young Yankee was combining bicycles and gasoline engines to create speedy motorcycles. Speed fascinated this young man. He had started to build motorcycle engines of his own design in order to win races and break speed records.

It was not long before the name of this young mechanic began to appear repeatedly in connection with new motorcycle speed records. His name was Glenn H. Curtiss, and he won race after race. His prize money was not spent foolishly, but put into his experiments with gasoline engines.

In 1904, the pioneer American dirigible balloon builder, Captain Tom Baldwin, saw a Curtiss motorcycle in California. One look at the engine sent him scurrying to Hammondsport, New York, where he begged Glenn Curtiss to build him an engine for a new dirigible he was building. Curtiss built the engine, the first Curtiss engine to function in the skies. He also flew Tom Baldwin’s dirigible, but he was not enthusiastic over the idea of flying. “Not bad sport,” he remarked the first time he flew the dirigible, “but there’s no place to go.” Curtiss had heard of the flights of the Wright Brothers, but he was skeptical.

Before long Glenn Curtiss had another visitor. Dr. Alexander Graham Bell, the inventor of the telephone, had long been interested in the problems of flight, and had organized the Aërial Experiments Association to encourage aëronautical efforts in this country. After talking for hours, Dr. Bell converted Curtiss to a belief in the future of flying and persuaded him to join the experimental group.

In November, 1907, Glenn H. Curtiss, in company with two young Canadian engineers, F. W. Baldwin and J. A. D. McCurdy of Dr. Bell’s group, and an official Army observer, Lieutenant Tom Selfridge, started to work on a new airplane. Using all of the available existing flight research and the ingenuity of Glenn H. Curtiss, the group finished their first plane in March, 1908. On March 12 Baldwin flew it 300 feet. Curtiss then designed an improved plane, the _June Bug_. With it he won the _Scientific American_ contest by flying over a measured kilometer course on July 4.

AMERICA’S SECOND PLANE

In 1909, Glenn H. Curtiss, in a plane of his own design, again won the _Scientific American_ award, by flying 24.7 miles over a closed course. The plane he flew was built on order for the New York Aëronautical Society. This was the first airplane order ever received by an American aircraft manufacturer.

On July 25, 1909, a Frenchman, Louis Bleriot, flew his monoplane twenty-five miles to cross the English Channel. Immediately there was furor in Europe and golden prizes were posted for new airplane developments and designs. The first big air race, the James Gordon Bennett Cup race, was held at Rheims, France, in 1909. Glenn Curtiss flew his machine against the pick of foreign pilots including Bleriot, whom he beat by six seconds to win the Cup. His speed was forty-six miles an hour.

Glenn Curtiss had the benefit of the aëronautical research of the Wright Brothers to aid him in designing his first airplanes, but he could not use the wing warping method of control invented by them. This was thoroughly protected by patents. As a result, Curtiss was forced to work out a new system of lateral controls. He developed the aileron method of control for use in turns or circular flight. He did this by mounting small winglike planes on the rear struts of the plane, between the upper and lower wings. These ailerons were hinged to swing up or down and were attached by cables to a yoke which encircled the pilot’s shoulders. The banking of the plane was produced by the movement of the flier as he leaned against the yoke, pushing it in the direction of the desired bank. Vertical motion was achieved by a fore and aft pressure on the control column by the flier. The wheel on the control column was attached to the vertical rudder by cables. Right or left steering was produced by turning the wheel in the desired direction. To make a climbing turn to the right, the flier would lean against the yoke, pushing to the right. At the same time he would turn his wheel gently to the right and pull the control slightly toward himself. Curtiss’ method of control led the way to the modern type of wing aileron and the general system of control was basically the same as that in use today.

POWER FOR THE AIRPLANE

Going back to the four forces that govern the flight of a plane, we find _thrust_ pulling the plane forward. _Thrust_ is the force that keeps the plane in the air; without it the airplane could not leave the ground for sustained flight. _Thrust_ is created by the propeller. The propeller blades function in the same manner as the wings. Just as the wing of a plane bites into the air to cause _lift_, the propeller blades, patterned after wing camber, bite into the air to create _thrust_. Their action on the air is similar to a screw biting its way into wood.

The propeller is whirled by the engine. Without the engine to whirl it the propeller is useless, for without _thrust_ we would have no _lift_. That makes the engine the governing factor in flight. _Weight_ also is a serious force in flight, and the Wrights and Curtiss found from the beginning that the four-cycle gasoline engine would give greater power for its weight than would a steam or electric engine.

The principle of the airplane engine is the same as the one used in the automobile engine. However, weight always has been a problem to aircraft designers. The automobile engine always has been too heavy for use in a plane. When the Wrights built their first plane, automobile engines weighed 25 to 35 pounds per horsepower. The Wrights built one that weighed 13 pounds per horsepower and produced 12 horsepower. They used this engine in 1903 to power their first plane. Since that time all practical airplanes have been powered with gasoline engines, designed specifically for use in heavier-than-air machines. Since the first flight, engineers constantly have strived to produce engines with greater power and less weight per horsepower. How well they have succeeded is proved by the progress of the airplane.

It was in 1905 that the Wright Brothers had first offered to the Army a license to use their patents; but nothing came of it. Reports coming from Dayton during the next two years, concerning their flying activities, caused the newspapers to publish a number of articles about them.

Theodore Roosevelt, then our President, was a diligent reader, and several articles about the Wrights attracted his attention. One day he clipped one of these articles from a newspaper and scribbled across it one word: “Investigate!” He passed it along to his Secretary of War, William Howard Taft. In a short time the almost forgotten Wright Brothers had a call from Brigadier General James Allen, U. S. Army Signal Corps. In the autumn of 1907 Wilbur Wright appeared in Washington to confer with the War Department.

A few months later, in July, 1907, an aëronautical division was established in the Office of the Chief Signal Officer of the Army. In December of that year the Army asked for bids on the construction of an airplane. The specifications called for a machine that could carry a weight of 350 pounds. It had to be able to remain in the air continuously for one hour with two passengers. During the flight the machine was required to remain under perfect control and to be capable of being steered in all directions. Its speed should be 40 miles per hour. The machine had to be built so that it could be taken apart and packed for transportation in army wagons. Then it had to be reassembled and put in flying condition in one hour.

By this time inventors everywhere were working on flying machines, but the Wright Brothers were the only ones who put in an appearance with an airplane for the Army trials in September, 1908.

Unfortunately the trial was a failure. The huge crowd gathered at Fort Meyer, Virginia, was horrified to see a propeller fly off and the machine crash, killing Lieutenant Tom Selfridge, the Army observer, and injuring Orville Wright. Tom Selfridge thus became the first American air martyr, and the future dimmed for the Wright Brothers and the airplane.

FIRST ARMY AIRPLANE