The Wright brothers, Orville (August 19, 1871 – January 30, 1948) and Wilbur (April 16, 1867 – May 30, 1912), were two Americans who are generally credited[1][2][3] with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903. They are also officially credited worldwide through the Fédération Aéronautique Internationale, the standard-setting and record-keeping body for aeronautics and astronautics, as "the first sustained and controlled heavier-than-air powered flight." In the two years afterward, the brothers developed their flying machine into the first practical fixed-wing aircraft. Although not the first to build and fly experimental aircraft, the Wright brothers were the first to invent aircraft controls that made fixed-wing flight possible. The brothers' fundamental breakthrough was their invention of three-axis control, which enabled the pilot to steer the aircraft effectively and to maintain its equilibrium.[4] This method became standard and remains standard on fixed-wing aircraft of all kinds.[5][6] From the beginning of their aeronautical work, the Wright brothers focused on unlocking the secrets of control to conquer "the flying problem," rather than developing more powerful engines as some other experimenters did. Their careful wind tunnel tests produced better aeronautical data than any before, enabling them to design and build wings and propellers more effective than any before.[7][8] Their U.S. patent 821,393 claims the invention of a system of aerodynamic control that manipulates a flying machine's surfaces.[9] They gained the mechanical skills essential for their success by working for years in their shop with printing presses, bicycles, motors, and other machinery. Their work with bicycles in particular influenced their belief that an unstable vehicle like a flying machine could be controlled and balanced with practice.[10] From 1900 until their first powered flights in late 1903, they conducted extensive glider tests that also developed their skills as pilots. Their bicycle shop employee Charlie Taylor became an important part of the team, building their first aircraft engine in close collaboration with the brothers. The Wright brothers' status as inventors of the airplane has been subject to counter-claims by various parties. Much controversy persists over the many competing claims of early aviators. The Wright brothers were two of seven children born to Milton Wright (1828–1917) and Susan Catherine Koerner (1831–1889). Wilbur Wright was born near Millville, Indiana in 1867; Orville in Dayton, Ohio in 1871. The brothers never married. The other Wright siblings were named Reuchlin (1861–1920), Lorin (1862–1939), Katharine (1874–1929), and twins Otis and Ida (born 1870, died in infancy). In elementary school, Orville was given to mischief and was once expelled.[11] In 1878 their father, who traveled often as a bishop in the Church of the United Brethren in Christ, brought home a toy "helicopter" for his two younger sons. The device was based on an invention of French aeronautical pioneer Alphonse Penaud. Made of paper, bamboo and cork with a rubber band to twirl its rotor, it was about a foot long. Wilbur and Orville played with it until it broke, and then built their own.[12] In later years, they pointed to their experience with the toy as the initial spark of their interest in flying.[13] Both brothers attended high school, but did not receive diplomas. The family's abrupt 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. In the winter of 1885–86 Wilbur was accidentally struck in the face by a hockey stick while playing an ice-skating game with friends, resulting in the loss of his front teeth. He had been vigorous and athletic until then, and although his injuries did not appear especially severe, he became withdrawn, and did not attend Yale as planned. Had he enrolled, his career might have taken a very different path than the extraordinary one he eventually followed with Orville. Instead, he spent the next few years largely housebound, caring for his mother who was terminally ill with tuberculosis and reading extensively in his father's library. He ably assisted his father during times of controversy within the Brethren Church[14] but also expressed unease over his own lack of ambition.[15] Orville dropped out of high school after his junior year to start a printing business in 1889, having designed and built his own printing press with Wilbur's help. Wilbur shook off the lingering depression caused by his accident and 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. One of their clients for printing jobs was Orville's friend and classmate in high school, Paul Laurence Dunbar, who rose to international acclaim as a ground-breaking African-American poet and writer. The Wrights printed the Dayton Tattler, a weekly newspaper that Dunbar edited for a brief period.[16] Capitalizing on the national bicycle craze, the brothers opened a repair and sales shop in 1892 (the Wright Cycle Exchange, later the Wright Cycle Company) and began manufacturing their own brand[17] 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.[18] These events lodged in the consciousness of the brothers. In May 1899 Wilbur wrote a letter[19] to the Smithsonian Institution requesting information and publications about aeronautics.[20] 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."[21] 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.[22] 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.[23] 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.[24] 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.[25] 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 seemed either undesirable or did not enter their thinking.[26] 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.[27] 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. 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.