Question: The Derwitzer Glider was a glider that was developed by Otto Lilienthal, a German pioneer of aviation who became known as the "flying man", and on which date, his glider stalled and he was unable to regain control?

full_context: Document 1: Wright brothers: The Wright brothers, Orville (August 19, 1871 – January 30, 1948) and Wilbur (April 16, 1867 – May 30, 1912), were two American brothers, inventors, and aviation pioneers who are generally credited with inventing, building, and flying the world's first successful airplane. They made the first controlled, sustained flight of a powered, heavier-than-air aircraft on December 17, 1903, four miles south of Kitty Hawk, North Carolina. In 1904–05 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 powered flight possible.
Document 2: Octave Chanute: Octave Chanute (February 18, 1832, Paris – November 23, 1910, Chicago, Illinois) was an American civil engineer and aviation pioneer, born in France. He provided many budding enthusiasts, including the Wright brothers, with help and advice, and helped to publicize their flying experiments. At his death he was hailed as the father of aviation and the heavier-than-air flying machine.
Document 3: Horten brothers: Walter Horten (born 13 November 1913; died 9 December 1998 in Baden-Baden, Germany) and Reimar Horten (born 12 March 1915; died 14 March 1994 in Villa General Belgrano, Argentina), sometimes credited as the Horten Brothers, were German aircraft pilots and enthusiasts. Although they had little, if any, formal training in aeronautics or related fields, the Hortens designed some of the most revolutionary aircraft of the 1940s, including the world's first jet-powered flying wing, the Horten Ho 229.
Document 4: Wright Flyer: The Wright Flyer (often retrospectively referred to as Flyer I or 1903 Flyer) was the first successful heavier-than-air powered aircraft. It was designed and built by the Wright brothers. They flew it four times on December 17, 1903, near Kill Devil Hills, about four miles south of Kitty Hawk, North Carolina, US. Today, the airplane is exhibited in the National Air and Space Museum in Washington D.C. The U.S. Smithsonian Institution describes the aircraft as "the first powered, heavier-than-air machine to achieve controlled, sustained flight with a pilot aboard". The flight of "Flyer I" marks the beginning of the "pioneer era" of aviation.
Document 5: Lincoln J. Beachey: Lincoln J. Beachey (March 3, 1887 – March 14, 1915) was a pioneer American aviator and barnstormer. He became famous and wealthy from flying exhibitions, staging aerial stunts, helping invent aerobatics, and setting aviation records.
Document 6: Otto Lilienthal Museum: The Otto Lilienthal Museum in Anklam (Germany) is a museum about the "glider king" Otto Lilienthal, the flight pioneer, as well as a pioneer in technical, social and cultural projects.
Document 7: Lilienthal Normalsegelapparat: The Lilienthal "Normalsegelapparat" ( German: "Normal soaring apparatus") is a glider designed by Otto Lilienthal in Germany in the late 19th century. It is considered to be the first aeroplane to be serially produced, examples being made between 1893 and 1896.
Document 8: Max Immelmann: Max Immelmann (21 September 1890 – 18 June 1916) "PLM" was the first German World War I flying ace. He was a pioneer in fighter aviation and is often mistakenly credited with the first aerial victory using a synchronized gun. He was the first aviator to win the "Pour le Mérite", and was awarded it at the same time as Oswald Boelcke. His name has become attached to a common flying tactic, the Immelmann turn, and remains a byword in aviation. He is credited with 15 aerial victories.
Document 9: Otto Lilienthal: Otto Lilienthal (23 May 1848 – 10 August 1896) was a German pioneer of aviation who became known as the "flying man". He was the first person to make well-documented, repeated, successful flights with unpowered airplanes. Newspapers and magazines published photographs of Lilienthal gliding, favorably influencing public and scientific opinion about the possibility of flying machines becoming practical. On 9 August 1896, his glider stalled and he was unable to regain control. Falling from about 15 m (50 ft), he broke his neck and died the next day, 10 August 1896.
Document 10: Gustav Lilienthal: Gustav Lilienthal (October 9, 1849 – February 1, 1933) was a German social reformer, a pioneer in building and construction technology (Prefabricated buildings), inventor of different Construction sets (e. g. Anchor Stone Blocks) and involved in the pioneering work of his brother, Otto Lilienthal in aviation.
Document 11: Jan Wnęk: Jan Wnęk (1828 – 10 July 1869) was a Polish carver of religious statues who is claimed to have constructed and flown a glider (aircraft) in the 1860s, predating the flights of Otto Lilienthal. There is a speculative "reconstruction" of Wnek's glider in the Kraków Museum of Ethnography.
Document 12: Derwitzer Glider: The Derwitzer Glider was a glider that was developed by Otto Lilienthal, so named because it was tested near Derwitz in Brandenburg. When flown in 1891, it became his a very early successful design able to carry a person and the one of the first successful manned aircraft in the world. He made flights of up to 25 metres (80 feet) in it.
Document 13: Lilienthal Glacier: Lilienthal Glacier ( ) is a glacier flowing west into Cayley Glacier between Pilcher Peak and Baldwin Peak, on the west coast of Graham Land, Antarctica. It was photographed by the Falkland Islands and Dependencies Aerial Survey Expedition in 1956–57, and mapped from these photos by the Falkland Islands Dependencies Survey. It was named by the UK Antarctic Place-Names Committee in 1960 for Otto Lilienthal, a German pioneer of flight in gliders.
Document 14: John Joseph Montgomery: John Joseph Montgomery (February 15, 1858 – October 31, 1911) was an American inventor, physicist, engineer, and professor at Santa Clara University in Santa Clara, California who is best known for his invention of controlled heavier-than-air flying machines.
Document 15: Lilienthal Gliding Medal: Lilienthal Gliding Medal – the highest soaring award in the world, established by Fédération Aéronautique Internationale (FAI) in 1938 in honor of Otto Lilienthal, a German pioneer of human aviation. It aims "to reward a particularly remarkable performance in gliding, or eminent services to the sport of gliding over a long period of time". The award is made at the annual FAI General Conference. Medal was designed by Austrian artist Josef Humplik.
ground_truth: 9 August 1896