Wright Glider

Gliders built by the Wright brothers

The Wright brothers designed, built and flew a series of three manned gliders in 1900–1902 as they worked towards achieving powered flight. They also made preliminary tests with a kite in 1899. In 1911 Orville conducted tests with a much more sophisticated glider. Neither the kite nor any of the gliders were preserved, but replicas of all have been built.

The 1899 kite, which Wilbur flew near his home in Dayton, Ohio had a wingspan of only 5 feet (1.5 m). This pine wood and shellacked craft, although too small to carry a pilot, tested the concept of wing warping for roll control that would prove essential to the brothers' solving the problem of controlled flight. The Wrights burned the craft along with other trash in 1905.

The 1900 Wright Glider was the brothers' first to be capable of carrying a human. Its overall structure was based on Octave Chanute's two surface glider of 1896. Its wing airfoil was derived from Otto Lilienthal's published tables of aerodynamic lift. The glider was designed with wing warping capability for full size testing of the concept first tried on the 1899 Wright Kite. On 23 September 1900, Wilbur wrote from Kitty Hawk, "My idea is merely to experiment and practice with a view to solving the problem of equilibrium. When once a machine is under proper control under all conditions, the motor problem will be quickly solved. I am constructing my machine to sustain about five times my weight trussed like a bridge." Weighing , the glider had a wingspan of 17.5 feet (5 m), a wing area of , while the wings were curved with a ratio of 1 in 22. In 1924, Orville wrote, " we retained the elevator in front for many years because it absolutely prevented a nose dive such as that in which Lilienthal and many others since have met their deaths." Harry B. Combs noted, " because the elevator was forward instead of behind, the aircraft, when it stalled, instead of spinning out and killing them the way a conventional aircraft would have done, simply parachuted to the ground in a flat position. The forward elevator also served as a visual indicator of the airplane's attitude in flight." The flyer would operate the craft from a prone position on the bottom wing, so as to reduce wind resistance. The glider was first flown as an unmanned kite on October 5, 1900 near Kitty Hawk, North Carolina. Next, Wilbur rode as pilot while men on the ground held tether ropes attached to the airborne craft. Subsequently, Wilbur made about a dozen free flights on a single day, concluding the season's test efforts. The brothers abandoned the glider when they broke camp on 23 October, and it eventually disappeared in the region's severe storms. The fabric covering of the wing components was given to the wife of helper Bill Tate, whose family Wilbur first stayed with at Kitty Hawk in 1900. Mrs. Tate allegedly used the material to make dresses for her daughters. Afterwards, Wilbur wrote, "longitudinal balancing and steering were effected by means of a horizontal rudder projecting in front of the planes. Lateral balancing and right and left steering were obtained by increasing the inclination of the wings at one end and decreasing their inclination at the other." The brothers had demonstrated two thirds of the eventual three dimension control system (the glider did not possess a vertical rudder). After testing concluded, the brothers stored the glider in their camp shed. The shed and glider were badly damaged later by windstorms. The wing uprights were salvaged for the 1902 Glider, but the rest was abandoned. According to Combs, "When the Wrights first tested their 1900 glider on Big Kill Devil Hill, they had observed their calculations to be in error. Actually, the glider, to their bitter disappointment, produced about one half the computed lift. They had observed that the drag, or resistance of the total frame when it was carrying no weight and was therefore flown at a very flat angle of attack, was very much less than they had anticipated, perhaps more than half less." The discrepancy was due to the Wrights using a published value of 0.005 for the pressure coefficient of air (Smeaton coefficient). Convinced this coefficient value was in error, they derived a smaller value 0.0033 from their experiments, explaining why the encountered less lift, and drag, than originally computed, and expected. the pilot was unable to stop turning and collided with the ground. "The addition of a fixed vertical vane in the rear increased the trouble, and made the machine absolutely dangerous." The brothers decided to remove one rudder, then make the remaining rudder steerable to achieve better control. The new rudder was ready by 6 October, measured 5 feet (2 m) high, wide, and had left or right movement of 30 degrees. Turns were coordinated by attaching the rudder to the same wires controlling wing warping. According to Combs, "In the last weeks of October at Kitty Hawk, they made more than a thousand gliding flights. They flew more than 600 feet on a number of occasions, and up to 26 seconds for a single flight. They flew in winds of more than 30 miles per hour." Most importantly, both brothers had flown, with Orville's first flight on 23 September. Wilbur noted, "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!!!"

A number of replicas of the gliders exist. Wright brothers historian Rick Young of Richmond, Virginia has built 9 accurate working replicas of all of the Wright gliders and the 1903 Flyer. Young's 1902 gliders have appeared in numerous films and television documentaries, including a 1986 IMAX film On the Wing. One of his 1902 replicas is on display at the Smithsonian National Air and Space Museum's Wright Brothers gallery. The Virginia Aviation Museum at Richmond International Airport is home to the Wright 1899 Kite, the 1900, 1901 and 1902 gliders and the 1903 Flyer, all built by Young. In 2011, Young researched and built a Wright 1911 glider replica that was displayed during the Soaring 100 event at the Wright Brothers National Monument to commemorate the 100th anniversary of Orville Wright's record setting glide. A replica of the 1902 glider is on display at the Dayton Aviation Heritage National Historic Park in Dayton Ohio. Another replica of the 1902 glider is also on display at the U. S. National Soaring Museum in Elmira, New York. A full scale replica of the 1902 glider was constructed and is on display at the San Diego Air & Space Museum in San Diego, California. Another replica, a half scale model, is on display at the Wings Over the Rockies Air and Space Museum in Denver, Colorado. A team led by Nick Engler of the Wright Brothers Aeroplane Company has also built replicas of all three gliders. A replica of the 1911 glider was built by Ernest Schweizer for the 75th anniversary of Orville's soaring flight. It has hung in the National Soaring Museum in Elmira, New York since 1986. Some replicas are flown in modern times.