Unit 2  Wright brothers

 American brothers, inventors, and aviation pioneers who achieved the first powered, sustained, and controlled airplane flight (1903). Wilbur Wright (April 16, 1867, near Millville, Indiana, U. S. —May 30, 1912, Dayton, Ohio) and his brother Orville Wright (August 19, 1871, Dayton—January 30, 1948, Dayton) also built and flew the first fully practical airplane (1905).

Wilbur and Orville were the only members of the Wright family who did not attend college or marry. Orville, who had spent several summers learning the printing trade, persuaded Wilbur to join him in establishing a print shop. In addition to normal printing services, the brothers edited and published two local newspapers, and they also developed a local reputation for the quality of the presses that they designed, built, and sold to other printers. These printing presses were one of the first indications of the Wright brothers’ extraordinary technical ability and their unique approach to the solution of problems in mechanical design.

In 1892 the brothers opened a bicycle sales and repair shop, and they began to build bicycles on a small scale in 1896. They developed their own self-oiling bicycle wheel hub and installed a number of light machine tools in the shop. Profits from the print shop and the bicycle operation eventually were to fund the Wright brothers’ aeronautical experiments from 1899 to 1905. In addition, the experience of designing and building lightweight, precision machines of wood, wire, and metal tubing was ideal preparation for the construction of flying machines.

In later years the Wrights dated their fascination with flight to a small helicopter toy that their father had brought home from his travels when the family was living in Iowa. A decade later, they had read accounts of the work of the German glider pioneer Otto Lilienthal. By 1899 the brothers had exhausted the resources of the local library and had written to the Smithsonian Institution for suggestions as to further reading in aeronautics. The following year they wrote to introduce themselves to Octave Chanute, a leading civil engineer and an authority on aviation who would remain a confidant of the brothers from 1900 to 1905.

Their first experiments with “wing warping, ” as the system would be called, were made with a small biplane kite flown in Dayton in the summer of 1899. Discovering that they could cause the kite to climb, dive, and bank to the right or left at will, the brothers began to design their first full-scale glider using Lilienthal’s data to calculate the amount of wing surface area required to lift the estimated weight of the machine and pilot in a wind of given velocity.

They selected Kitty Hawk, an isolated village on the Outer Banks of North Carolina, which offered high average winds, tall dunes from which to glide, and soft sand for landings.

Tested in October 1900, the first Wright glider was a biplane featuring 165 square feet (15 square metres) of wing area and a forward elevator for pitch control. The glider developed less lift than expected, however, and very few free flights were made with a pilot on board. The brothers flew the glider as a kite, gathering information on the performance of the machine that would be critically important in the design of future aircraft.

Eager to improve on the disappointing performance of their 1900 glider, the Wrights increased the wing area of their next machine to 290 square feet (26 square metres). Establishing their camp at the foot of the Kill Devil Hills, 4 miles (6. 5 km) south of Kitty Hawk, the brothers completed 50 to 100 glides in July and August of 1901. As in 1900, Wilbur made all the glides, the best of which covered nearly 400 feet (120 metres). The 1901 Wright aircraft was an improvement over its predecessor, but it still did not perform as well as their calculations had predicted. Moreover, the experience of 1901 suggested that the problems of control were not fully resolved.

They designed and built a four-cylinder internal-combustion engine with the assistance of Charles Taylor, a machinist whom they employed in the bicycle shop. Recognizing that propeller blades could be understood as rotary wings, the Wrights were able to design twin pusher propellers on the basis of their wind-tunnel data.

The brothers returned to their camp near the Kill Devil Hills in September 1903. They spent the next seven weeks assembling, testing, and repairing their powered machine and conducting new flight tests with the 1902 glider. Then, at about 10: 35 on the morning of December 17, 1903, Orville made the first successful flight, covering 120 feet (36 metres) through the air in 12 seconds. Wilbur flew 175 feet (53 metres) in 12 seconds on his first attempt, followed by Orville’s second effort of 200 feet (60 metres) in 15 seconds. During the fourth and final flight of the day, Wilbur flew 852 feet (259 metres) over the sand in 59 seconds. The four flights were witnessed by five local citizens. For the first time in history, a heavier-than-air machine had demonstrated powered and sustained flight under the complete control of the pilot.

Determined to move from the success of 1903 to a practical airplane, the Wrights in 1904 and 1905 built and flew two more aircraft from Huffman Prairie, a pasture near Dayton. They continued to improve the design of their machine during these years, gaining skill and confidence in the air. By October 1905 the brothers could remain aloft for up to 39 minutes at a time, performing circles and other maneuvers.