June 1970 | Volume 21, Issue 4
It seemed, as the year 1903 drew to a close, that man was not quite ready to fly. Many had tried, but so far all had failed to get off the ground in a powered machine that could do more than just return to earth right away. Twice that very year, on October 7 and again on December 8, Charles M. Manly had taken off in self-propelled, gasoline-powered flying machines designed and built by the distinguished head of the Smithsonian Institution, Dr. Samuel Pierpont Langley. Twice Manly had crashed into the Potomac River; twice he had narrowly escaped drowning before managing to free himself from the wreckage. After the second failure thé New York Times urged Langley to give the whole idea up as a waste of time. “Life is short,” the newspaper said, “and his is capable of services to humanity incomparably greater than can be expected to result from trying to fly.”
Not all the early test pilots had been as fortunate as the intrepid Manly. The great German glider pilot Otto Lilienthal was dead, his back broken in a glider crash in 1896. And in England, Percy Pilcher, a promising young disciple of Lilienthal’s, had also been killed in a glider accident. The others had simply given up when the solution ultimately eluded them.
Then, on December 17, 1903, only nine days after Langley’s last failure, came this startling telegram from an obscure sand spit off the North Carolina coast named Kitty Hawk:
SUCCESS FOUR FLIGHTS THURSDAY MORNING ALL AGAINST TWENTY ONE MILE WIND STARTED FROM LEVEL WITH ENGINE POWER ALONE AVERAGE SPEED THROUGH AIR THIRTY ONE MILES LONGEST 57 SECONDS INFORM PRESS HOME CHRISTMAS. OREVELLE WRIGHT The message was addressed to Bishop Milton Wright of Dayton, Ohio, and it was from his sons Orville—whose name got garbled in transmission—and Wilbur.
The homemade gasoline engine aboard the Wrights’ airplane didn’t run very well. The aircraft was also hard to control and had a habit of diving abruptly into the sand. It couldn’t make a turn yet, much less a precision landing; it was uncomfortable, dangerous, and easily damaged.
But the two shy, strait-laced Wright brothers were the first people in the world to achieve powered flight. On December 17 they made four flights—of 120, 175, 180, and 852 feet—and they took photographs to prove it, including perhaps the most dramatic aviation picture of all time (see page 65), showing the first flight just an instant after it became airborne with Orville at the controls.
The first Wright powered machine may have left a lot to be desired as far as performance went, but it was a thing of unique beauty and grace. And in its lines it foreshadowed all that was to follow until man began to send wingless, unstreamlined machines into space. Looking back over sixty years, it may seem that the family resemblance between the Wright machine and today’s sleek, modern aircraft is somewhat vague and indistinct. But the resemblance is real enough, for the underlying principles of flight discovered by the Wrights and applied to the design of their aircraft are the same immutable principles that apply today.
With their first flights on December 17, 1903, the Wright brothers demonstrated that they had mastered the three essential elements of flight. First, they had designed wings with sufficient lifting power to sustain their machine in the air. Next, they had built themselves a power plant consisting of engine and propeller that was capable of moving the craft through the air fast enough so that air rushing over the wings generated enough lift to keep the machine airborne. Finally, they had developed a system of controlling the movement of their machine so that once it was off the ground they could keep it off the ground until they were ready to land or—as in the case of the first few flights—until their engine quit.
Others before them, such as Langley, had developed wings with lifting power and power plants capable of driving a machine through the air. In these two areas the Wrights improved substantially on existing technology. But in the field of aircraft control the Wrights, at the very beginning of their interest in flying, came up with a method of controlling the motion of their aircraft that permitted them to succeed where all others had failed. Arguing, debating, discussing things between themselves as the nineteenth century drew to a close, the two brothers made one of those rare intuitive mental leaps that, just when a situation seems stagnant, suddenly sends the human race surging ahead into undreamed-of realms. The Wrights’ breakthrough was profound—their control system is used on every fixed-wing aircraft that flies today. And, like most great scientific advances, it was simple. It had to be, for neither brother had gone to college. In fact, neither had finished high school.
Prior to the Wrights the most successful flying machines had been the gliders of Lilienthal in Germany and Octave Chanute in the United States. Between 1891 and 1896 Lilienthal made some two thousand flights in batlike gliders which he launched from a manmade hill near Berlin and controlled by shifting his weight. In some of these he covered distances of nearly one thousand feet. The Chanute glider looked more like a conventional biplane. As in the Lilienthal machine, the pilot dangled below the wings and attempted to control his craft by swinging the lower part of his body. With test pilot A. M. Herring aboard, Chanute tested his designs on the sand hills bordering Lake Michigan near Miller, Indiana, in 1896.
In neither case did control by weight shifting work very well. Lilienthal was fatally injured on a routine flight on August 9, 1896, when a gust of wind threw his glider out of control. Despite the fact that Herring once made a flight of 359 feet in the Chanute machine, experiments with it in the fall of 1896 were generally inconclusive and were soon discontinued.
The problem lay in the fact that a shift of weight—even a large one—was not sufficient to counteract gusts of wind once the Lilienthal and Chanute gliders tipped over beyond a certain point. The balance of these gliders was something like that of a bicycle. As long as they were upright, level, and moving ahead, they were steady. But once they started leaning to one side or the other, they tended to keep right on going over like a leaning bicycle until they passed the point where the shifting of weight would do any good.
The first thing the Wrights did was solve the problem of control. Many years later Orville Wright recalled the chain of events that led to their remarkable piece of deductive reasoning:
“Our first interest began when we were children. Father brought home to us a small toy actuated by a rubber spring which would lift itself into the air. We built a number of copies of this toy, which flew successfully. … But when we undertook to build the toy on a much larger scale it failed to work so well. The reason for this was not understood by us at the time, so we finally abandoned the experiments. In 1896 we read in the daily papers, or in some of the magazines, of the experiments of Otto Lilienthal. … His death a few months later … increased our interest in the subject and we began looking for books pertaining to flight. We found a work written by Professor [Étienne] Marey on animal mechanism which treated of the bird mechanism as applied to flight, but other than this, so far as I can remember, we found little.
“In the spring of the year 1899 our interest in the subject was again aroused through the reading of a book on ornithology. We could not understand that there was anything about a bird that would enable it to fly that could not be built on a larger scale and used by man. … We knew that the Smithsonian Institution had been interested in some work on the problem of flight, and accordingly, on the 30th of May 1899, my brother Wilbur wrote a letter to the Smithsonian inquiring about publications on the subject.”
Dr. Langley had done considerable work of his own by this time, had already flown a steam-powered model, and was well up on the work of other people. Thus the Smithsonian sent the Wrights several monographs by Langley as well as papers by Lilienthal, Chanute, and other scientific writers of this period who had explored the problem of flight. The Wrights studied this material and were immediately struck by a fact that everyone else had missed.
They reasoned that if a gust of wind struck a glider and tilted it over to the point of instability, the thing to do was to increase the lift of the low wing so that it would rise, while simultaneously decreasing the lift of the high wing so that it would drop back to a stable level position. This was the breakthrough that was needed. The next step was to figure out a practical way to apply this solution to the control problem. Orville tells how Wilbur worked it out:
“Wilbur … demonstrated the method by means of a small pasteboard box, which had two of the opposite ends removed. By holding the top forward corner and rear lower corner of one end of the box between his thumb and forefinger and the rear upper corner and the lower forward corner of the other end of the box in like manner, and by pressing the corners together the upper and lower surface of the box were given a helicoidal twist, presenting the top and bottom surfaces of the box at different angles on the right and left sides. From this it was apparent that the wings of a machine of the Chanute double-deck type, with the fore-and-aft trussing removed, could be warped in like manner so that in flying the wings on the right and left sides could be warped so as to present their surfaces to the air at different angles of incidence and thus secure unequal lifts on the two sides.”
That was in late July, 1899. Wilbur was then thirty-two years old and Orville almost twenty-eight. Up until this time they had led serene but somewhat threadbare lives as part of a midwestern minister’s large, close-knit family. Bishop Wright was one of the leaders of the United Brethren Church. For almost fifty years since his ordination in 1850 he had taught in church schools or preached in a string of small communities in southeastern Indiana. The three older Wright sons—Reuchlin, Lorin, and Wilbur—were all born in Indiana. Orville and his sister Katherine were born in Dayton, where the family had moved in 1869. The Wrights moved back to Indiana once more after that and then settled permanently in Dayton in 1884.
The first time Wilbur and his younger brother Orville teamed up on a major enterprise was in the publication of a Dayton neighborhood newspaper, The West Side News , which made its debut in March, 1889. Then, in 1892, sensing the potential of the new “safety” bicycle, the brothers went into the business of selling several well-known makes in Dayton. In their first year in their new enterprise they also added a repair shop to their salesroom. Before long they were manufacturing their own line of bikes, the most popular of which was the Wright Special, which sold for eighteen dollars. As a foundation for the brothers’ aeronautical researches, the bicycle business was to prove ideal, for it provided them with the income they needed to support their experiments and a well-equipped machine shop that could turn out just about anything they needed to make an airplane.
The Wrights’ first attempt at flight was decidedly casual. A day or two after Wilbur conceived his wing-warping idea, the two brothers began building a large kite to test their new theory. Its design was simple enough: two 5-foot wings were mounted in biplane fashion, one above the other, and were trussed and braced in such a way that they could be warped in the desired fashion by control lines leading to sticks held in either hand. The kite also had a small rigid wooden tail which was supposed to steady it in the air. According to Wilbur’s accounts to his family, the model responded very well to the warping control. “We felt,” said Orville later, “that the model had demonstrated the efficiency of our system of control.”
With this intriguing experience behind them, the brothers began hatching more ambitious plans during the long winter days they spent in the bicycle shop building up their inventory for the heavy spring sales season. “We decided to experiment with a man-carrying machine embodying the principle of lateral control used in the kite model already flown,” said Orville. “We expected to fly the machine as a kite and in this way we thought we would be able to stay in the air for hours at a time, getting in this way a maximum of practice with a minimum of effort.”
Figuring correctly that a man-carrying kite would require quite a breeze to keep it aloft, the brothers began making inquiries about locations where strong, dependable winds prevailed. After consulting the U.S. Weather Bureau and Octave Chanute, they finally decided upon Kitty hawk, on the Outer Banks of North Carolina; and on September 6, 1900, Wilbur set out from Dayton, carrying with him all the material needed for a man-carrying glider except some spruce spars which he hoped to purchase en route. Orville planned to follow as soon as the kite was ready to test.
The low, thin sand spits that make up the Outer Banks begin a few miles to the southeast of Norfolk, Virginia, and continue down the North Carolina coast in a meandering line that in places sticks close to the mainland and in others sweeps far out into the ocean. In spots, The Banks are high and wide enough to support sizable towns; in others the beach is barely above water at high tide. The easternmost limit of The Banks is Cape Hatteras, which juts out into the warm water of the Gulf Stream and is so temperate in climate that such southern flora as Spanish moss and scrub palmetto trees flourish there despite the fact that they normally do not occur north of South Carolina. In the summertime, a strong prevailing wind sweeps in off the ocean from the southeast and drives the sand across the dunes in stinging, shifting swirls during the day. When the wind dies down there are mosquitoes.
Arriving at Elizabeth City on the North Carolina coast, Wilbur spent several days trying to book passage to Kitty Hawk, and after a perilous voyage in a leaky fishing boat finally reached the island at nine o’clock in the evening of September 12, more than seven days outbound from Dayton. He boarded at the home of the Kitty Hawk postmaster, William J. Täte, until Orville arrived on September 28. After this the brothers pitched a tent among the dunes.
Almost a year had gone by since Wilbur had tested the controllable kite in Dayton, and the brothers’ concept of what the next step should be had undergone an important modification. Instead of simply experimenting further with a larger, man-carrying kite, they planned and built a craft which they hoped would not require a line to hold it into the wind as a kite does, but which would be capable of gliding freely for short distances in a good breeze. And in their thinking they went even beyond this development. A letter from Wilbur to his father, written shortly before Orville arrived in Kitty Hawk, provides the first hint that the brothers had at least considered the problems of powered flight.
“I have my machine nearly finished,” Wilbur wrote home. “It is not to have a motor and is not expected to fly in the true sense of the word. My idea is merely to experiment and practice with a view to solving the problem of equilibrium. I have plans which I hope to find much in advance of the methods tried by previous experimenters.” He added confidently: “When once a machine is under proper control under all conditions, the motcr problem will be quickly solved.”
The first Kitty Hawk glider was a biplane design like the Dayton kite and had two ly-foot wings. The ribs of the wings were made of ash and provided a gentle curvature to the upper surfaces; this, the brothers knew from reading about Lilienthal’s experiments, would enhance the lifting power of the wings. Both wings were covered with panels of French sateen which had been sewn to size in Dayton ahead of time.
In this early glider, the control problem was not completely solved. The wings and their struts and braces were designed so that they could be warped and the glider tilted, or banked, to counteract any gusts that threatened to upset its equilibrium. But in addition the Wrights anticipated, correctly, that some sort of control would be needed over the up-and-down motion of the craft in order to make the transition between tethered kite and free-flying glider. Once again they rejected the method used by Lilienthal and Chanute of control by shifting the weight of the pilot. Instead, they designed a movable “rudder,” which they placed out in front on a separate frame. This rudder (in modern aviation terminology it would be called an elevator) resembled a small wing and when tilted downward tended to force the craft toward the ground. Conversely, when tilted upward it pointed the craft toward the sky.
The forward rudder was operated by a wire which ran back to the center section of the lower wing, where the pilot stretched out on his stomach. As bicycle experts the brothers well knew the value of reducing the amount of air resistance offered by a body sitting upright. Wing warping was also controlled by a wire that led in to where the pilot lay. The brothers quickly discovered when they actually began testing the glider that the pilot couldn’t manipulate both wires and still have one hand free to hang on with unless he clenched one of the wires in his teeth. “As we had neither the material nor the tools to change these so as to correct the trouble, we were compelled to test them separately,” Wilbur later reported to Octave Chanute in a long, detailed letter. “Two minutes trial was sufficient to prove the efficiency of twisting the planes to obtain lateral balance. We also found our system of fore-and-aft balancing quite effective, but it was only when we came to gliding that we became positive of this.”
The new craft was first flown as a kite a few feet off the ground. The brothers conducted several experiments with different loads in different winds and found that it took a fairly stiff breeze of about twenty-five miles per hour to keep their craft in the air with a man aboard. They were somewhat puzzled by the inability of their new wings to generate as much lift as some of Lilienthal’s theoretical tables said they should, but their vacation ended on an eminently satisfying note. As Wilbur wrote to Chanute:
“After we found the difficulty of simultaneously maintaining both fore-and-aft and lateral balance we almost gave up the idea of attempting to glide, but just before returning we went down to the big hill which was about ,three miles from our camp and spent a day in gliding. Our plan of operation was for the aeronaut to lie down on the lower plane while two assistants grasped the ends of the machine and ran forward till the machine was supported on the air. The fore-and-aft equilibrium was in entire control of the rider, but the assistants ran beside the machine and pressed down the end which attempted to rise. We soon found that the machine could soar on a less angle than one in six [a descent of one foot for every six feet of forward motion] and that if the machine was kept close to the slope (which was one in six by measurement) the speed rapidly increased until the runners could no longer keep up. The man on the machine then brought the machine slowly to the ground. … We had intended to have the operator turn his body to an upright position before landing but a few preliminary tests having shown that it was feasible to let the machine settle down upon its lower surface with the operator maintaining his recumbent position, we used this method of landing entirely. … The distance glided was between three and four hundred feet at an angle of one in six and the speed at landing was more than double that of starting. The wind was blowing about twelve miles. We found no difficulty in maintaining fore-and-aft balance. The ease with which it was accomplished was a matter of great astonishment to us. It was so different from what the writings of other experimenters led us to expect.”
Octave Chanute was impressed at Wilbur’s report of their successful gliding flights and wrote back a week later to ask for more details and to get the brothers’ permission to use the information they furnished him in a magazine article he was working on. A lively correspondence then ensued between Chanute and Wilbur Wright. Acting as a sounding board, the old engineer drew out the ideas of the brothers, constantly testing and querying and supplying them with information from his own gliding experience and the studies he had made of the works of others, such as Lilienthal. Wilbur, in turn, took full advantage of Chanute’s interest and reported on their work and problems at great length in letters that reveal a considerable talent for clarity, interest, and exciting descriptions of the highlights of their experiments.
By the end of October, 1900, the brothers were back in Dayton again. They left their glider behind at Kitty Hawk, where it was soon destroyed by the elements and by Mrs. Täte, wife of the postmaster, who made dresses for her daughters out of the sateen that covered the wings. But this was no great loss; already the Wrights had begun thinking about the next aircraft they would build.
Chanute was graciously included in the brothers’ plans for the next session at Kitty Hawk and visited the Wright family in Dayton on June 25 and 26. The return to Kitty Hawk was imminent, and Chanute made arrangements to visit the Wright camp during the summer and to have an experimental machine of his own tested by two protégés, Edward C. Huffaker, who had formerly worked with Langley, and George A. Spratt. On Sunday, July 7, 1901, Wilbur and Orville left together for the Carolina beaches. The trip was much easier this time, and within four days they had begun making a camp at Kill Devil Hills, near Kitty Hawk. The biggest of the dunes there was about one hundred feet high; it was from this “big hill” that the Wrights had made their successful glider flights just before returning home in 1900.
Since they were expecting company, the Wrights’ camp was a bit more elaborate this time. For living quarters, they had a large tent. They also built a wooden shed to house their new glider. “The building is a grand institution, with awnings at both ends; that is, with big doors hinged at the top, which we swing open and prop up,” Orville wrote home to his sister Katherine. “We keep both ends open almost all the time and let the breezes have full sway.”
But this arrangement left them defenseless against a natural hazard—mosquitoes. On this subject Orville waxed eloquent in his letter to Katherine:
“Mr. Huffaker arrived Thursday afternoon, and with him a swarm of mosquitoes which became a mighty cloud, almost darkening the sun. This was the beginning of the most miserable existence I ever passed through. The agonies of typhoid fever with its attending starvation are as nothing in comparison. But there was no escape. The sand and grass and trees and hills and everything was fairly covered with them. They chewed us clear through our underwear and socks. Lumps began swelling up all over my body like hen’s eggs. We attempted to escape by going to bed, which we did at a little after five o’clock. We put our cots out under the awnings and wrapped up in our blankets with only our noses protruding from the folds, thus exposing the least possible surface to attack. Alas! Here nature’s complicity in the conspiracy against us became evident. The wind, which until now had been blowing over twenty miles an hour, dropped off entirely. Our blankets then became unbearable. The perspiration would roll off us in torrents. We would partly uncover and the mosquitoes would swoop down upon us in vast multitudes. We would make a few desperate and vain slaps, and again retire behind our blankets. Misery! Misery!…
“The next night we constructed mosquito frames and nets over our cots, thinking in our childish error we could fix the bloody beasts. We put our cots on the sand twenty or thirty feet from the tent and house, and crawled in under the netting and bedclothes, and lay there on our backs smiling at the way in which we had gotten the best of them. The tops of the canopies were covered with mosquitoes till there was hardly standing room for another one; the buzzing was like that of a mighty buzz saw. But what was our astonishment when in a few minutes we heard a terrific slap and a cry from Mr. Huffaker announcing that the enemy had gained the outer works and he was engaged in a hand-to-hand conflict with them. All our forces were put to complete rout. … Affairs had now become so desperate that it began to look as if camp would have to be abandoned or we perish in the attempt to maintain it.”
Next they tried building bonfires around the camp, and these helped somewhat, but apparently relief came in a natural way: in a day or two the mosquitoes simply went away. “Yesterday,” Orville wrote to Katherine, “most of the mosquitoes had disappeared and we had a fine day and wind for testing the new machine. We took it off to the Big Hill, about a thousand feet distant, and began our experiments. Our first experiments were rather disappointing. The machine refused to act like our machine last year and at times seemed to be entirely beyond our control.”
The 1901 glider was similar in design to the aircraft that had been such a success the previous year, but slightly larger. Its biplane wings had a span of twenty-two feet and a total area of roughly three hundred square feet. (The earlier glider had a wingspan of seventeen feet and a total wing area of 165 feet.) The system of control was the same, in principle, as on the earlier craft. Despite its apparent success, the previous year’s glider had failed to produce as much lift as Lilienthal’s tables indicated it should have; thus the Wrights gave the wings of their 1901 machine a greater curvature to produce a shape more nearly like that used by Lilienthal. All in all, the 1901 glider was a well-built, carefully thought-out aircraft, and it should have performed well.
But it didn’t. The first time the brothers tried it out on the big dune at Kill Devil Hills it nosed into the sand after going only a few yards. A second test flight yielded the same results. Believing that there was too much weight forward, the Wrights tried shifting the position of the pilot farther aft for their third attempt. “The machine then sailed off and made an undulating flight of a little more than 300 feet,” Wilbur noted. “To the onlookers, this flight seemed very successful, but to the operator it was known that the full power of the rudder had been required to keep the machine from either running into the ground or rising so high as to lose all headway. In the 1900 machine one fourth as much rudder action had been sufficient to give much better control. It was apparent that something was radically wrong, though we were for some time unable to locate the trouble.”
The brothers resumed experiments with the machine tethered as a kite in winds of approximately seventeen miles per hour. Even though they had meticulously designed the wings to correspond with the design used by Lilienthal when he worked out his tables, they found that the lifting power was far less than it should have been. They reasoned that the curvature, or camber, of their wings was too great, despite the fact that it was exactly what Lilienthal recommended. But the Wrights figured that if the top surface of a wing was curved too much, the air flow over the top surface would strike the forward, or leading, edge of the wing at such an angle as to force it down.
So they changed the shape of the wings on their glider and flattened out the curvature of the top surface.
“On resuming our gliding, we found that the old conditions of the previous year had returned; and after a few trials, made a glide of 389 feet. The machine with its new curvature never failed to respond promptly to even small movements of the rudder. … And thereafter we made glide after glide, sometimes following the ground closely, and sometimes sailing high in the air.”
The weather turned rainy and unpleasant as the end of August approached, and camp was abandoned; but their experience with the 1901 glider’s poor performance in its first few flights made them thoroughly skeptical of the data developed by Lilienthal, and they returned to Dayton determined to run some tests and find out for themselves what kind of wing produced the greatest lift. After experimenting with various testing devices, they finally built a wind tunnel in their Dayton workshop. It was small, measuring six feet in length and having a cross section of sixteen inches square. At one end, a two-bladed fan, driven by a gasoline engine used in their bicycle shop to power a lathe, drill press, and band saw, developed a wind of twenty-five to thirty-five miles per hour. This blast passed through a honeycomb which straightened out the air current generated by the whirling blades of the fan. The wing section to be tested was mounted in the other end of the wind tunnel so that it could move back and forth in the air stream, the amount of movement indicating the amount of lift a particular shape developed. A direct reading of the amount of drag, or resistance to the air flow, was also possible.
The Wright wind tunnel was not the first ever used to test wing shapes, but none had achieved results so spectacular. In their work with their homemade wind tunnel, these two untrained, self-educated engineers demonstrated a gift for pure scientific research that made the more eminent scientists who had studied the problems of flight look almost like bumbling amateurs.
By early October, 1901, the Wrights had their wind tunnel set up and operating well. In the next month they tried out more than one hundred miniature wings of various shapes, including models of bird wings. The letters between Wilbur and Octave Chanute flew thick and fast as Wilbur went into detail on the experiments, ancl the older man, somewhat doubtful at first, was gradually won over to the Wrights’ conviction that previous research on wing design was misleading.
“I am now absolutely certain that Lilienthal’s table is very seriously in error, but that the error is not so great as I had previously estimated,” Wilbur wrote to Chanute on October 6.
The Wrights emerged from this series of experiments with several notebooks full of data, mankind’s first good grasp of the complex theoretical formulas required to predict the lifting power and behavior of different types of wings, and a clear idea of which wing designs would work and which ones were useless. As their busy bicycle-manufacturing season wore on, they completed their plans for an improved glider for the next trip to Kitty Hawk.
The brothers arrived at the site of their previous camp on Thursday, August 28, 1902, and began drilling a well and tidying up their old storage shed. They cannibalized their old 1901 glider, which they had left behind in the shed, to make a new and bigger one, with wings that measured 32 feet 1 inch. It was more graceful-looking due to the fact that the wings were narrower. The curvature of the upper surfaces was also much less pronounced than in the previous year’s model, as a direct result of the Wrights’ wind tunnel experiments; the new glider incorporated the most efficient wing design that they had developed so far. The design of the control system was refined somewhat in order to permit the pilot, again lying prone, to handle everything and still have a hand left over to hang on with. Up-and-down control was once again effected with a forward horizontal “rudder” that could be tilted by working handles jutting back just in front of the pilot. However, the wing-warping wires were led into a wooden cradle which fitted around the pilot’s hips as he lay on the lower wing. By moving his hips from side to side he also moved the cradle from side to side and manipulated the wires that warped the wings of the aircraft.
In their last flights in 1901 the Wrights had experienced some difficulty with the glider’s tendency to slew around when the wing-warping controls were used. Now they reasoned that the addition of a fixed vertical tail would stabilize the aircraft when the wings were banked. It did, but a new problem had developed: every time the glider got into a steep bank, its nose pitched up.
After one potentially disastrous crash, which reduced their craft to what Orville described as “a heap of flying machine, cloth, and sticks … with me in the center without a bruise or a scratch,” Orville had an inspired thought. Why not make the vertical tail movable, instead of fixed? He noted, simply, in his diary: “While lying awake last night, I studied out a new vertical rudder.” The Wrights rebuilt their machine, and as October, 1902, drew to a close they made more than 375 flights, including their best: a breathtaking flight of 622½ feet that lasted twenty-six seconds. Control was no longer a problem; the wings they had designed on the basis of scientific data from their wind tunnel experiments proved to be powerful lifting surfaces, and time and time again they soared out from the top of the big hill.
Orville wrote home to Katherine:
“The past five days have been the most satisfactory for gliding that we have had. In two days we made over 250 glides. … We have gained considerable proficiency in the handling of the machine now, so that we are able to take it out in any kind of weather. Day before yesterday we had a wind of sixteen meters per second or about 30 miles per hour, and glided in it without any trouble. That was the highest wind a gliding machine was ever in, so that we now hold all the records! The largest machine we handled in any kind of weather, made the longest distance glide (American), the longest time in the air, the smallest angle of descent, and the highest wind!!! Well, I’ll leave the rest of the ‘blow’ till we get home.…”
Now all the Wrights needed to do was obtain a lightweight engine, hook it up to a set of propellers, and, in addition to the other records Orville was so proud of, they would have the world’s first self-propelled aircraft. In all the world, no one had yet come as close to attaining man’s age-old desire to fly as these two self-taught scientists. There had been a flurry of activity in France at about the same time the Wrights began their glider work, but it was not related to the experiments at Kitty Hawk and had been spectacularly unsuccessful. In the United States, Langley was moving steadily and happily toward the disasters of 1903, completely in the dark, as was everyone except Octave Chanute and the Wrights’ immediate family, about the significance of the developments on the remote North Carolina beach.
Within a few weeks after their return to Dayton the Wrights V T began trying to locate a small engine, weighing around 180 pounds, that might develop eight or nine horsepower. They wrote to at least ten well-known American engine manufacturers, but nothing promising turned up. So the brothers decided to build their own engine, counting heavily on the skill and ingenuity of Charles E. Taylor, the top mechanic in their bicycle factory. Here, in Taylor’s words, is the way they went about it:
“The first thing We did as an experiment was to construct a sort of skeleton model in order that we might watch the functioning of the various vital parts before venturing with anything more substantial.…
“When we had the skeleton motor set up we hooked it up to our shop power, smeared the cylinder with a paint brush dipped in oil and watched the various parts in action. It looked good so we went ahead immediately with the construction of a four cylinder engine. I cut the crank shaft from a solid block of steel weighing over a hundred pounds. When finished it weighed about 19 pounds. We didn’t have spark plugs but used the old ‘make and break’ system of ignition [in which a spark is produced by the opening and closing of contact points inside the combustion chamber]. The gas pump was geared on to the cam shaft and the gas was led in and made to spread over the chamber above the heated water jackets and this immediately vaporized it. … I must admit there wasn’t much to that first motor—no carburetor, no spark plugs, not much of anything but cylinders, pistons and connecting rods, but it worked.” By May of 1903 they had an engine that tested successfully.
Meanwhile, they went to work on the ribs and spars for the wings of their next machine. They had already decided to make it bigger than anything they had tried before. The wings were to be 40 feet 4 inches long and 6 feet 6 inches wide. Instead of making the larger wing ribs out of one solid piece of wood they made them out of two thin strips with the long spars sandwiched in between in order to save weight. They also conducted wind tunnel experiments to see what shape they should use for the struts and braces to cut drag to a minimum. To their surprise a square cross section with the corners slightly rounded off proved to be the design that would slow down their aircraft the least.
Propellers to drive the new craft were expected to present little trouble. Since 1816, when the British experimenter Sir George Cayley thought of the idea of using them on steerable balloons, propellers had become part of the design of every powered aircraft, fanciful and otherwise, that had been seriously advanced, except for the flapping wing, or ornithopter, variety. The only difficulty was that none of the Wrights’ predecessors, including Langley, seemed to understand what the problems were when they designed their propellers. Consequently, the Wrights soon discovered that all the previous designs were little more than windmills of various sizes and shapes that beat the air ineffectually, generating little thrust, or pull, despite the horsepower that made them turn. Again they were forced to work out a theory of their own.
From the first the Wrights realized something that previous experimenters had missed. For decades seagoing ships had been pushed through the water by the action of the rear surfaces of their propellers shoving the water behind them. But the Wrights reasoned that aircraft propellers would have to behave differently. They felt that the propeller should be designed like a set of whirling wings in which the forward surface, like the top surface of a wing, developed lift—or in this case, thrust—along the aircraft’s flight path.
This piece of reasoning was every bit as important as the thinking that had produced the wing-warping idea and the movable rudder concept of 1902. But the Wrights were in a hurry now. There was much to do before the next summer and too little time to devote to recording the mental process by which they grasped a fact that had eluded many others. So they simply jotted down in a notebook the results of two tests, worked out a formula on the basis of this data that enabled them to predict propeller performance with amazing accuracy, and then made themselves a pair of propellers consisting of three pieces of carved spruce laminated with glue. Rough shaping was done with a hatchet. The brothers used a drawknife to whittle the blades to the final degree of precision.
It was almost the end of September before all was packed up and ready for the return to Kitty Hawk. The Wrights were aware from the newspapers that Langley was about to make his first attempt at flight with his big man-carrying machine, but they weren’t particularly concerned. Earlier, Wilbur had even expressed some doubt that the Langley machine would work. “Prof. Langley seems to be having rather more than his share of trouble just now with pestiferous reporters and windstorms,” he commented^in a letter to Chanute. “It would be interesting to attempt a computation of the possible performance of his machine in advance of his trial, but the data of the machine as given in the newspapers are so evidently erroneous that it seems hopeless to attempt it.…”
As October wore on at Kill Devil Hills, the clear days and steady winds prevailed that were ideal for glider flights with the 1902 machine. Instead of going for distance, the Wrights added a new twist to their glider work and began trying to see how long they could remain airborne by “soaring.” By this they meant taking off into a wind strong enough to sustain them in a hovering position a few feet from their point of take-off. In previous summers at Kitty Hawk they had marvelled at the ability of buzzards and hawks to do this and had spent many hours watching them hover almost motionless above the dunes. Orville finally set the record with a flight of 1 minute 11 4/5 seconds. This, of course, was a world record —and one which stood unchallenged until October 24, 1911, when Orville again broke the record, with a soaring flight of 9¾ minutes. The 1911 record was not broken for ten years.
Meanwhile, the new aircraft that would soon change history was beginning to take shape. By October 15, with the assistance of their friend George Spratt, the Wrights had completed the upper wing and covered it with cloth. Another friend sent them a sobering account of Langley’s first disastrous attempt at a man-carrying flight, and Wilbur commented in a letter to Chanute: “I see that Langley has had his fling and failed. It seems our luck to throw now, and I wonder what our luck will be.”
The transition from glider to powered flying machine was a tremendous step; the 1903 airplane reflected this in almost every detail. The pilot was still going to lie prone on the bottom wing, but when he was stretched out like this, the only place for the engine was to one side of him. However, the engine weighed thirty-four pounds more than either potential pilot; thus the airplane was unbalanced. The Wrights corrected this by adding four inches more to the wing on the heavy side to create additional lift.
Instead of a single propeller, the brothers decided to use a pair of them rotating in opposite directions. For in addition to producing thrust, a whirling propeller also produces torque, a twisting force that tends to pull an airplane to one side. The Wrights figured correctly that they could cancel out this sidewise pull by mounting two propellers that would turn, and thus pull, in opposite directions. Connecting the propellers to the engine was a chain-and-sprocket drive—the only feature on the machine that betrayed its humble bicycle-shop origin.
As in the 1902 glider, a hip cradle controlled the warping of the wings and caused the aircraft to bank. The movable tail was also connected to the hip cradle. The front horizontal rudder, which made the plane climb and dive, was once again controlled by a wire that ran back to a lever within reach of the pilot. The engine was essentially uncontrollable. Once it was started and adjusted on the ground, the only thing the pilot could do to it was to stop it by pulling on a lever that interrupted the ignition.
The lower wing, rudder, and tail surfaces were completed toward the end of October, and most of the uprights and wire braces had been installed between the two wings. On November 2 the Wrights began hooking up the engine and the propellers. Two days later Orville optimistically noted in his diary: “Have machine now within half day of completion.” But now, after such a long period of success, they ran into a frustrating series of setbacks.
First, two propellers came loose on their shafts the first time the engine was started up. The shafts were sent via Spratt back to Charley Taylor in Dayton. The new shafts arrived on November 20. This time the sprockets for the chain drives from the engine began to slip. No amount of tightening seemed to help. In desperation the two men turned to a tire cement known as Arnstein’s, which Orville claimed would fix anything from a stop watch to a threshing machine. It must have been a remarkable compound, for after they had filled the threads of the sprocket screws with Arnstein’s and let it set awhile, they had no more difficulty with loose sprockets.
On November 25, just as the brothers were getting ready to take the new machine out for their first trial flight, it began to rain. Before the skies cleared up again, a crack developed in one of the propeller shafts. Orville left for Dayton on November 30 to make new and, he hoped, foolproof shafts. He arrived back at the camp on Friday, December ll. The shafts were installed, and the machine was hauled out on Saturday for another attempt at flight, but the brothers judged that there was not sufficient wind to take off from the level ground right near their camp and not enough time to try for a launching down the big hill, almost half a mile away. The next day the weather was perfect, but it was Sunday, and that, to the bishop’s jons, meant no flying.
The Wrights’ activities in four seasons at Kitty Hawk had generated considerable interest among the few residents there. The brothers had consequently acquired a set of loyal fans who didn’t want to miss the final act. They arranged to hoist a signal on a small flagstaff when they were about to make their first attempt at flight so that the men at the Kill Devil Hills lifesaving station just about a mile away would have enough notice to walk over in time for the attempt.
At half past one on the afternoon of Monday, December 14, the Wrights hoisted their signal and started walking their machine toward the big hill. There they were met by six men from the lifesaving station, who helped them lug the 605-pound aircraft to the top. The brothers tossed a coin to decide who was to go first, and Wilbur won.
Since the new plane was so heavy—the 1902 glider had weighed only 112 pounds—the Wrights were concerned about the possibility that its skids would dig into the sand during the take-off run and prevent a lift-off. So they built a sixty-foot wooden track made of four 15-foot two-by-fours placed end to end on the sand. To the top surface they nailed a metal strip. A small wooden dolly or “truck” ran along this track on two rollers made from bicycle hubs. The sledlike skids of the aircraft rested on this dolly.
Unfortunately the attempt on Monday, with Wilbur at the controls, was a flop. “The machine turned up in front and rose to a height of about 15 feet from ground at a point somewhere in the neighborhood of 60 feet from end of track,” Orville wrote. “After thus losing most of its headway it gradually sank to the ground turned up at an angle of probably 20° incidence.”
Some early aviators might have been tempted to call this first sixty-foot hop a “flight,” but not the Wrights. However, they were now confident of ultimate success. They got off a telegram to their father telling him, “Success assured keep quiet.”
It took them a day to repair the damaged plane. Then the weather failed to co-operate again. Thursday, December 17, was perfect for flying, though seasonably cold. The wind was blowing from the north at twenty to twenty-five miles an hour, and the puddles near camp were covered with ice. The two brothers waited awhile to see whether the wind would hold. By this time they had been at their camp eighty-four days, their food was mostly beans, and it was beginning to be bitterly cold. But they knew their machine would work. So they hoisted their signal and were soon joined by several men from the lifesaving station. They must have been moved by an uncanny sense of history that morning, for they painstakingly adjusted their cumbersome glass-plate camera so that it could snap a picture at the precise moment of lift-off.
Again Orville’s diary preserves the flavor of the historic occasion:
“After running the engine and propellers a few minutes to get them in working order, I got on the machine at 10:35 for the first trial. The wind … was blowing … 27 miles [per hour] according to the Government anemometer at Kitty Hawk. On slipping the rope the machine started off increasing speed to probably 7 or 8 miles. The machine lifted from the truck just as it was entering on the fourth rail. Mr. Daniels [from the Kill Devil Hill Life Saving Station] took a picture just as it left the tracks. I found the control of the front rudder quite difficult on account of its being balanced too near the center and thus [it] had a tendency to turn itself when started so that the rudder was turned too far on one side and then too far on the other. As a result the machine would rise suddenly to about 10 ft. and then as suddenly, on turning the rudder, dart for .the ground. A sudden dart when out about 100 feet from the tracks ended the flight. Time about 12 seconds (not known exactly as watch was not promptly stopped).…”
Then it was Wilbur’s turn again. Orville continues his narrative:
“After repairs, at 20 min. after 11 o’clock Will made the second trial. The course was like mine, up and down but a little longer over the ground though about the same in time. Dist. not measured but about 175 ft. Wind speed not quite so strong. With the aid of the station men present, we picked the machine up and carried it back to the starting ways. At about 20 minutes till 12 o’clock I made the third trial. When out about the same distance as Will’s, I met with a strong gust from the left which raised the left wing and sidled the machine off to the right in a lively manner. I immediately turned the rudder to bring the machine down and then worked the end control. Much to our surprise, on reaching the ground the left wing struck first, showing the lateral control of this machine much more effective than on any of our former ones. At the time of its sidling it had raised to a height of probably 12 to 14 feet.”
The third flight was a short hop by Orville. The fourth and last flight, made by Wilbur, was the most spectacular and satisfying of all. Again Orville describes it in his diary:
“At just 12 o’clock Will started on the fourth and last trip. The machine started off with its ups and downs as it had done before, but by the time he had gone over three or four hundred feet he had it under much” better control, and was traveling on a fairly even course. It proceeded in this manner till it reached a small hummock out about 800 feet from the starting ways, when it began its pitching again and suddenly darted into the ground. The front rudder frame was badly broken up, but the main frame suffered none at all. The distance over the ground was 852 feet in 59 seconds. The engine turns was 1071, but this included several seconds while on the starting ways and probably about half a second after landing. The jar of landing set the watch on the machine back so that we have no exact record for the 1071 turns. Will took a picture of my third flight just before the gust struck the machine. The machine left the ways successfully at every trial, and the tail was never caught by the truck as we had feared.
“After removing the front rudder, we carried the machine back to camp. We set the machine down a few feet west of the building and while standing about discussing the last flight, a sudden gust of wind struck the machine and started to turn it over. All rushed to stop it. Will who was near one end ran to the front, but too late to do any good. Mr. Daniels and myself seized the spars at the rear, but to no purpose. The machine gradually turned over on us. Mr. Daniels, having had no experience in handling a machine of this kind, hung onto it from the inside, and as a result was knocked down and turned over and over with it as it went. His escape was miraculous as he was in with the engine and chains. The engine legs were all broken off, the chain guides badly bent, a number of uprights and nearly all the rear ends of the ribs were broken. One spar only was broken.”
The historic first successful airplane was never to fly again. The brothers packed it up and brought it back to Dayton with them as they hurried home for Christmas. It was later reassembled and exhibited a couple of times in New York and once at M.I.T. For many years it languished in a shed at Dayton; then, in 1928 it was sent to the Science Museum in London after the Smithsonian Institution refused to recognize it as the first successful airplane, giving Langley’s machine that honor. In 1942, after many years of controversy, the Smithsonian belatedly reversed its position, and Orville Wright asked the Science Museum to return the aircraft to the United States when it would be safe to do so after the war. After Orville Wright’s death in January, 1948, the 1903 machine came back from twenty years’ exile. It was refurbished and placed on exhibit on December 17, 1948, the forty-fifth anniversary of its first flight.