
Childhood
Both brothers received high school educations, but did not receive diplomas. The family's move in 1884 from Richmond, Indiana to Dayton (where the family had lived during the 1870s) prevented Wilbur from receiving his diploma after finishing four years of high school. Orville dropped out after his junior year to start a printing business in 1889, having designed and built his own printing press with Wilbur's help. Quietly starting a partnership with far-reaching consequences, Wilbur joined the print shop, serving as editor while Orville was publisher of the weekly newspaper the West Side News, followed, for only a few months, by the daily Evening Item. Capitalizing on the national bicycle craze, they opened a repair and sales shop in 1892 (the Wright Cycle Exchange, later the Wright Cycle Company) and began manufacturing their own brand in 1896. They used this endeavor to fund their growing interest in flight. In the early or mid-1890s they saw newspaper or magazine articles and probably photographs of the dramatic glides by Otto Lilienthal in Germany. The year 1896 brought three important aeronautical events. In May, Smithsonian Institution Secretary Samuel Langley successfully flew an unmanned steam-powered model aircraft. In the summer, Chicago engineer and aviation authority Octave Chanute brought together several men who tested various types of gliders over the sand dunes along the shore of Lake Michigan. In August, Lilienthal was killed in the plunge of his glider.These events lodged in the consciousness of the brothers. In May 1899 Wilbur wrote a letter to the Smithsonian Institution requesting information and publications about aeronautics.Drawing on the work of Sir George Cayley, Chanute, Lilienthal, Leonardo da Vinci, and Langley, they began their mechanical aeronautical experimentation that year.
The Wright brothers always presented a unified image to the public, sharing equally in the credit for their invention. Biographers note, however, that Wilbur took the initiative in 1899–1900, writing of "my" machine and "my" plans before Orville became deeply involved when the first person singular became the plural "we" and "our". Author James Tobin asserts, "it is impossible to imagine Orville, bright as he was, supplying the driving force that started their work and kept it going from the back room of a store in Ohio to conferences with capitalists, presidents, and kings. Will did that. He was the leader, from the beginning to the end."
The Wrights did all the theoretical work and most of the hands-on construction. Their bicycle shop employee Charlie Taylor became an important part of the team, building their first aircraft engine in close collaboration with the brothers.
Ideas about control
Despite Lilienthal's fate, the brothers favored his strategy: to practice gliding in order to master the art of control before attempting motor-driven flight. The death of British aeronaut Percy Pilcher in another hang gliding crash in 1899 only reinforced their opinion that a reliable method of pilot control was the key to successful—and safe—flight. At the outset of their experiments they regarded control as the unsolved third part of "the flying problem". They believed sufficiently promising knowledge of the other two issues—wings and engines—already existed. The Wright brothers thus differed sharply from more experienced practitioners of the day, notably Ader, Maxim and Langley who built powerful engines, attached them to airframes equipped with unproven control devices, and expected to take to the air with no previous flying experience. Though agreeing with Lilienthal's idea of practice, the Wrights saw that his method of balance and control—shifting his body weight—was fatally inadequate.They were determined to find something better.
Based on observation, Wilbur concluded that birds changed the angle of the ends of their wings to make their bodies roll right or left. The brothers decided this would also be a good way for a flying machine to turn—to "bank" or "lean" into the turn just like a bird—and just like a person riding a bicycle, an experience with which they were thoroughly familiar. Equally important, they hoped this method would enable recovery when the wind tilted the machine to one side (lateral balance). They puzzled over how to achieve the same effect with man-made wings and eventually discovered wing-warping when Wilbur idly twisted a long inner tube box at the bicycle shop.
Other aeronautical investigators regarded flight as if it were not so different from surface locomotion, except the surface would be elevated. They thought in terms of a ship's rudder for steering, while the flying machine remained essentially level in the air, as did a train or an automobile or a ship at the surface. The idea of deliberately leaning, or rolling, to one side either seemed undesirable or did not enter their thinking.Some of these other investigators, including Langley and Chanute, sought the elusive ideal of "inherent stability," believing the pilot of a flying machine would not be able to react quickly enough to wind disturbances to use mechanical controls effectively. The Wright brothers, on the other hand, wanted the pilot to have absolute control.For that reason, their early designs made no concessions toward built-in stability (such as dihedral wings). They deliberately designed their 1903 first powered flyer with anhedral (drooping) wings, which are inherently unstable, but less susceptible to upset by gusty sidewinds.
Flights
Toward flight
In July 1899 Wilbur put wing-warping to the test by building and flying a five-foot box kite in the approximate shape of a biplane. When the wings were warped, or twisted, one end would receive more lift and rise, starting a turn in the direction of the lower end. Warping was controlled by four lines attached to the kite. The lines led to two sticks held by the kite flyer, who tilted them in opposite directions to twist the wings and make the kite bank left or right. It worked.
In 1900 the brothers journeyed to Kitty Hawk, North Carolina to begin their manned gliding experiments. They chose the location based on advice from Octave Chanute (answering Wilbur's letter), who suggested a sandy coastal area for regular breezes and a soft landing surface. They selected Kitty Hawk after scrutinizing Weather Bureau data and writing to the government meteorologist stationed there. The location, although remote, was closer to Dayton than other places Chanute had suggested, including California and Florida. The spot also gave them privacy from reporters, who had turned the 1896 Chanute experiments at Lake Michigan into something of a circus. The trip required a train ride from Dayton to Cincinnati; change trains for an overnight ride to Old Point Comfort, Virginia (near Newport News); ferryboat to Norfolk; train to Elizabeth City, North Carolina; and boat ride to Kitty Hawk on the Outer Banks of North Carolina.
The gliders
They based the design of their first full-size glider on the work of their recent predecessors: the Chanute-Herring "double-decker," a biplane hang glider which flew well in the 1896 experiments near Chicago; and aeronautical data on lift that Lilienthal had published. The uprights between the wings of their glider were braced by wires in their own adaptation of Chanute's modified "Pratt truss," a bridge-building design he applied to his 1896 glider. The Wrights mounted the horizontal elevator in front of the wings rather than behind, apparently believing this feature would help avoid a nosedive and crash like the one that killed Lilienthal. (Later, when Santos-Dumont flew his 14-bis in Paris in 1906, the French dubbed the tail-first arrangement a "canard," due to the supposed resemblance to a duck in flight.) According to some Wright biographers, Wilbur probably did all the gliding until 1902, perhaps to exercise his authority as older brother and to protect Orville from harm.
1900 Glider
The brothers flew the glider only a few days in the early autumn of 1900 at Kitty Hawk. In the first tests, probably Oct. 3, Wilbur was aboard while the glider flew as a kite not far above the ground with men below holding tether ropes. Most of the kite tests were unpiloted with sandbags or chains (and even a local boy) as onboard ballast. They tested wing-warping using control ropes from the ground. The glider was also tested unmanned while suspended from a small homemade tower. Wilbur (but not Orville) made about a dozen free glides on only a single day. For those tests, the brothers trekked four miles (6 km) south to the Kill Devil Hills, a group of sand dunes up to 100 feet (30 m) high (where they made camp in each of the next three years). Although the glider's lift was less than expected (causing most tests to be unmanned), the brothers were encouraged because the craft's front elevator worked well and they had no accidents. However, the small number of free glides meant they were not able to give wing-warping a true test.
The pilot lay flat on the lower wing, as planned, to reduce aerodynamic drag. As a glide ended, the pilot was supposed to lower himself to a vertical position through an opening in the wing and land on his feet with his arms wrapped over the framework. Within a few glides, however, they discovered the pilot could remain prone on the wing, headfirst, without undue danger when landing. They made all their flights in that position for the next five years.
1901 Glider
Orville at Kitty Hawk with the 1901 glider, its nose pointed skyward; it had no tail.
Hoping to improve lift, they built the 1901 glider with a much larger wing area and made 50 to 100 flights in July and August for distances of 20 to 400 feet (120 m). The glider stalled a few times, but the parachute effect of the forward elevator allowed Wilbur to make a safe flat or "pancake" landing, instead of a nose-dive. These incidents wedded the Wrights even more strongly to the canard design, which they did not give up until 1910. The glider, however, delivered two major disappointments. It produced only about one-third the lift calculated and sometimes failed to respond properly to wing-warping, turning opposite the direction intended—a problem later known as adverse yaw. On the trip home after their second season, Wilbur, stung with disappointment, remarked to Orville that man would fly, but not in their lifetimes.
The poor lift of the gliders led the Wrights to question the accuracy of Lilienthal's data, as well as the "Smeaton coefficient" of air pressure, which had been used for over 100 years and was part of the accepted equation for lift.
The Wrights—and Lilienthal—used the equation to calculate the amount of lift that wings of various sizes would produce. Based on measurements of lift and wind during the 1901 glider's kite and free flights, Wilbur believed (correctly, as tests later showed) that the Smeaton number was very close to .0033, not the traditionally used 60% larger .0054, which would exaggerate predicted lift.
Back home, furiously pedaling a strange-looking bicycle on neighborhood streets, they conducted makeshift open-air tests with a miniature Lilienthal airfoil and a counter-acting flat plate, which were both attached to a freely rotating third bicycle wheel mounted horizontally in front of the handlebars. The results, based on which way the third wheel turned, confirmed their suspicion that published data on lift were unreliable and encouraged them to expand their investigation. They also realized that trial-and-error with different wings on full-size gliders was too costly and time-consuming. Putting aside the three-wheel bicycle, they built a six-foot wind tunnel in their shop and conducted systematic tests on miniature wings from October to December 1901. The "balances" they devised and mounted inside the tunnel to hold the wings looked crude, made of bicycle spokes and scrap metal, but were "as critical to the ultimate success of the Wright brothers as were the gliders." The devices allowed the brothers to balance lift against drag and accurately calculate the performance of each wing. They could also see which wings worked well as they looked through the viewing window in the top of the tunnel.
1902 Glider
A Big ImprovementAt left, 1901 glider flown by Wilbur (left) and Orville. At right, 1902 glider flown by Wilbur (right) and Dan Tate, their helper. Dramatic improvement in performance is apparent. The 1901 glider flies at a steep angle of attack due to poor lift and high drag. In contrast, the 1902 glider flies at a much flatter angle and holds up its tether lines almost vertically, clearly demonstrating a much better lift-to-drag ratio.
Lilienthal had made "whirling arm" tests on only a few wing shapes, and the Wrights mistakenly assumed the data would apply to their wings, which had a different shape. The Wrights took a huge step forward and made basic wind tunnel tests on 200 wings of many shapes and airfoil curves, followed by detailed tests on 38 of them. The tests, according to biographer Howard, "were the most crucial and fruitful aeronautical experiments ever conducted in so short a time with so few materials and at so little expense". A key discovery was the benefit of longer narrower wings: in aeronautical terms, wings with a larger aspect ratio (wingspan divided by chord—the wing's front-to-back dimension). Such shapes offered much better lift-to-drag ratio than the broader wings the brothers had tried so far.
With this knowledge, and a more accurate Smeaton number, the Wrights designed their 1902 glider. Using another crucial discovery from the wind tunnel, they made the airfoil flatter, reducing the camber (the depth of the wing's curvature divided by its chord). The 1901 wings had significantly greater curvature, a highly inefficient feature the Wrights copied directly from Lilienthal. Fully confident in their new wind tunnel results, the Wrights discarded Lilienthal's data, now basing their designs on their own calculations.
With characteristic caution, the brothers first flew the 1902 glider as an unmanned kite, as they had done with their two previous versions. Rewarding their wind tunnel work, the glider produced the expected lift. It also had a new structural feature: a fixed, rear vertical rudder, which the brothers hoped would eliminate turning problems.
By 1902 they realized that wing-warping created "differential drag" at the wingtips. Greater lift at one end of the wing also increased drag, which slowed that end of the wing, making the aircraft swivel—or "yaw"—so the nose pointed away from the turn. That was how the tailless 1901 glider behaved.
The improved wing design enabled consistently longer glides, and the rear rudder prevented adverse yaw—so effectively, that it introduced a new problem. Sometimes when the pilot attempted to level off from a turn, the glider failed to respond to corrective wing-warping and persisted into a tighter turn. The glider would slide toward the lower wing, which hit the ground, spinning the aircraft around. The Wrights called this "well digging"; modern aviators refer to a "ground loop".
Orville apparently visualized that the fixed rudder resisted the effect of corrective wing-warping when attempting to level off from a turn. He wrote in his diary that on the night of October 2, "I studied out a new vertical rudder". The brothers then decided to make the rear rudder movable to solve the problem. They hinged the rudder and connected it to the pilot's warping "cradle," so a single movement by the pilot simultaneously controlled wing-warping and rudder deflection. Tests while gliding proved that the trailing edge of the rudder should be turned away from whichever end of the wings had more drag (and lift) due to warping. The opposing pressure produced by turning the rudder enabled corrective wing-warping to reliably restore level flight after a turn or a wind disturbance. Furthermore, when the glider banked into a turn, rudder pressure overcame the effect of differential drag and pointed the nose of the aircraft in the direction of the turn, eliminating adverse yaw.
In short, the Wrights discovered the true purpose of the movable vertical rudder. Its role was not to change the direction of flight, but rather, to aim or align the aircraft correctly during banking turns and when leveling off from turns and wind disturbances. The actual turn—the change in direction—was done with roll control using wing-warping. The principles remained the same when ailerons superseded wing-warping.
With their new method the Wrights achieved true control in turns for the first time on October 8, 1902, a major milestone. During September and October they made between 700 and 1000 glides, the longest lasting 26 seconds and covering 622.5 feet (189.7 m). Hundreds of well-controlled glides after they made the rudder steerable convinced them they were ready to build a powered flying machine.
Thus, did three axis-control evolve: wing-warping for roll (lateral motion), forward elevator for pitch (up and down) and rear rudder for yaw (side to side). On March 23, 1903 the Wrights applied for their famous patent for a "Flying Machine," based on their successful 1902 glider. Some aviation historians believe that applying the system of three-axis flight control on the 1902 glider was equal to, or even more significant, than the addition of power to the 1903 Flyer. Peter Jakab of the Smithsonian asserts that perfection of the 1902 glider essentially represents invention of the airplane.
Adding power
In 1903, the brothers built the powered Wright Flyer I, using their preferred material for construction, spruce, a strong and lightweight wood. They also designed and carved their own wooden propellers, and had a purpose-built gasoline engine fabricated in their bicycle shop. They thought propeller design would be a simple matter and intended to adapt data from shipbuilding. However, their library research disclosed no established formulas for either marine or air propellers, and they found themselves with no sure starting point. They discussed and argued the question, sometimes heatedly, until they concluded that an aeronautical propeller is essentially a wing rotating in the vertical plane. On that basis, they used data from more wind tunnel tests to design their propellers. The finished blades were just over eight feet long, made of three laminations of glued spruce. The Wrights decided on twin "pusher" propellers (counter-rotating to cancel torque), which would act on a greater quantity of air than a single relatively slow propeller and not disturb airflow over the leading edge of the wings.
Wilbur made a March 1903 entry in his notebook indicating the prototype propeller was 66% efficient. Modern wind tunnel tests on reproduction 1903 propellers show they were more than 75% efficient under the conditions of the first flights, and actually had a peak efficiency of 82%. This is a remarkable achievement, considering that modern wooden propellers have a maximum efficiency of 85%.
While the early engines used by the Wright brothers are thought to no longer exist, a later example, serial number 17 from circa 1910, is on display at the New England Air Museum in Windsor Locks, Connecticut.
The Wrights wrote to several engine manufacturers, but none met their need for a sufficiently lightweight powerplant. They turned to their talented shop mechanic, Charlie Taylor (a largely unsung hero of the Wright aviation era), who built an engine in just six weeks in close consultation with the brothers. To keep the weight low enough, the engine block was cast from aluminum, a rare practice for the time. The Wright/Taylor engine was a primitive version of modern fuel-injection systems, having no carburetor or fuel pump. Gasoline was gravity-fed into the crankcase through a rubber tube from the fuel tank mounted on a wing strut.
The propeller drive chains, resembling those of bicycles, were actually supplied by a manufacturer of heavy-duty automobile chain-drives. The Flyer cost less than a thousand dollars to construct. It had a wingspan of 40 feet (12 m), weighed 625 pounds (283 kg), and sported a 12 hp (9 kW), 170 pound (77 kg) engine.
After weeks of delays at Kitty Hawk caused by broken propeller shafts during engine tests, Wilbur won a coin toss and made an unsuccessful three-second flight attempt on December 14, stalling after takeoff and causing minor damage to the Flyer. Following repairs, the Wrights finally took to the air on December 17, 1903, making two flights each from level ground into a freezing headwind gusting to 27 miles (43 km) an hour. The first flight, by Orville, of 120 feet (36.5 m) in 12 seconds, at a speed of only 6.8 mph over the ground, was recorded in a famous photograph. The next two flights covered approximately 175 and 200 feet (60 m), by Wilbur and Orville respectively. Their altitude was about ten feet above the ground.
"Wilbur started the fourth and last flight at just about 12 o'clock. The first few hundred feet were up and down, as before, but by the time three hundred feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when out about eight hundred feet the machine began pitching again, and, in one of its darts downward, struck the ground. The distance over the ground was measured to be 852 feet (260 m); the time of the flight was 59 seconds. The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all. We estimated that the machine could be put in condition for flight again in about a day or two.
The flights were witnessed by five people: Adam Etheridge, John Daniels and Will Dough of the coastal lifesaving crew; area businessman W.C. Brinkley; and Johnny Moore, a boy from the village, making these arguably the first public flights. A telegraph operator relaying a message to their father leaked the news against the brothers' wishes, and highly inaccurate reports ran in several newspapers the next day.
After the men hauled the Flyer back from its fourth flight, a powerful gust of wind flipped it over several times, despite the crew's attempt to hold it down. Severely damaged, the airplane never flew again. The brothers shipped it home, and years later Orville restored it, lending it to several U.S. locations for display, then to a British museum (see Smithsonian dispute below), before it was finally installed in the Smithsonian Institution in Washington, D.C. in 1948.
Trouble establishing legitimacy
Orville in flight over Huffman Prairie, in Wright Flyer II. Flight #85, approximately 1,760 feet (536 m) in 40 1/5 seconds, Nov. 16, 1904.
The Wrights were glad to be free from the distraction of reporters. The absence of newsmen also reduced the chance of competitors learning their methods. After the Kitty Hawk powered flights, the Wrights made a decision to begin withdrawing from the bicycle business so they could devote themselves to creating and marketing a practical airplane. The decision was financially risky, since they were neither wealthy nor government-funded (unlike other experimenters such as Ader, Maxim, Langley and Santos-Dumont). They did not have the luxury of giving away their invention; it was to be their livelihood. Thus, their secrecy intensified, encouraged by advice from their patent attorney not to reveal details of their machine.
Significantly, this patent illustrated a non-powered flying machine—namely, the 1902 glider. The patent's importance lies in its claim of a new and useful method of controlling a flying machine, powered or not. The technique of wing-warping is described, but the patent explicitly states that wing-warping need not be the only method that could be employed to vary the angle presented to the air by the outer portions of a machine's wings. The concept of varying the angle near the wingtips, by whatever means, is central to the patent. The broad protection intended by this language succeeded when the Wrights won patent infringement lawsuits against Glenn Curtiss and other early aviators, who adopted ailerons while the Wrights continued to use wing-warping. The courts decided that ailerons were also covered by the patent (see Patent War section below). The patent also describes the steerable rear vertical rudder and its innovative use in combination with wing-warping, enabling the airplane to make a coordinated turn, a technique that prevents hazardous adverse yaw, the problem Wilbur had when trying to turn the 1901 glider. Finally, the patent describes the forward elevator, used for ascending and descending.
Wright Model A Flyer flown by Wilbur 1908-09 and launching derrick, France, 1909
The Wrights traveled to Pau, in the south of France, where Wilbur made many more public flights, giving rides to a procession of officers, journalists and statesmen—and his sister Katharine on February 15. He trained two French pilots, then transferred the airplane to the French company. In April the Wrights went to Italy where Wilbur assembled another Flyer, giving demonstrations and training more pilots. A cameraman climbed aboard and made the first motion picture from an airplane.
Neither brother married. Wilbur once quipped that he did not have time for a wife and an airplane. Wilbur, age forty-five, died of typhoid fever on the morning of Thursday, May 30, 1912. Orville sold his interests in the plane company in 1915. He, Katharine and their father Milton moved to a mansion, Hawthorn Hill, Oakwooh, Ohio, which the newly wealthy family built. There, they lived quietly. Milton died in his sleep in 1917. Katharine married in 1926, which upset Orville. He cut her off, refusing to meet with or write to her. He finally agreed to see her just before she died of pneumonia in 1929.
Orvile Wright
Orville died in 1948, from a heart attack. Both brothers are buried at the family plot at Woodland Cemetery, Dayton, Ohio.
Legacy
The Flyer III, the only fixed-wing aircraft designated a National Historic Landmark, was dismantled after the 1905 flights, but rebuilt and flown in 1908 at Kitty Hawk, and was restored in the late 1940s with the help of Orville. It is on display at Dayton, Ohio in the John W. Berry Sr., Wright Brothers Aviation Center at Carillon Historical Park. The display space for the aircraft was designed by Orville Wright.
The Smithsonian feud
Samuel P. Langley, secretary of the Smithsonian Institution from 1887 until his death in 1906, experimented for years with model flying machines and successfully flew unmanned powered model aircraft in 1896 and 1903. Two tests of his manned full-size motor-driven Aerodrome in October and December 1903, however, were complete failures. Nevertheless, the Smithsonian later proudly displayed the Aerodrome in its museum as the first heavier-than-air craft "capable" of manned powered flight, relegating the Wright brothers' invention to secondary status and ironically triggering a decades-long feud with Orville Wright, whose brother had received help from the Smithsonian when beginning his own quest for flight.
Glenn Curtiss or an assistant coaxes the structurally modified Langley Aerodrome into the air above the surface of Keuka Lake near Hammondsport, N.Y., September 17, 1914.
The Smithsonian based its claim for the Aerodrome on short test flights Glenn Curtiss and his team made with it in 1914. The Smithsonian allowed Curtiss, in an unsavory alliance, to make major modifications to the craft before attempting to fly it. The Smithsonian hoped to salvage Langley's aeronautical reputation by proving the Aerodrome could fly; Curtiss wanted to prove the same thing to defeat the Wrights' patent lawsuits against him. The tests had no effect on the patent battle, but the Smithsonian made the most of them, honoring the Aerodrome in its museum and publications. The Institution did not reveal the extensive Curtiss modifications, but Orville Wright learned of them from his brother Lorin and a close friend, Griffith Brewer, who both witnessed and photographed some of the tests.
Competing claims
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