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Rhön-Rossitten Gesellschaft
The Rhön-Rossitten Gesellschaft (RRG) or Rhön-Rossitten Society was a German gliding organization, the first one in the world that was officially recognised. The Rhön-Rossitten Gesellschaft was mainly responsible for establishing gliding as a sport, not only in Germany but eventually throughout the world. Because the Treaty of Versailles forbade any form of powered flight in Germany, many young pilots and aircraft designers turned to gliding as a sport. Under Oskar UrsinusReitsch, H., 1955, The Sky My Kingdom, London: Biddles Limited, Guildford and King's Lynn, and Theodore von Kármán, hobbyists and serious university study groups began building gliders. The first contest was held in 1920 on the mountain of the Wasserkuppe in the Rhön region of Hesse. While many of the entering designs were no more than kites and many of the 'flights' were no more than stumbles ending in a crash, Kármán and his team from the RWTH Aachen with their glider ''Schwarzer Teufel'' (Black Devil) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliding
Gliding is a recreational activity and competitive air sport in which pilots fly unpowered aircraft known as gliders or sailplanes using naturally occurring currents of rising air in the atmosphere to remain airborne. The word ''soaring'' is also used for the sport. Gliding as a sport began in the 1920s. Initially the objective was to increase the duration of flights but soon pilots attempted cross-country flights away from the place of launch. Improvements in aerodynamics and in the understanding of weather phenomena have allowed greater distances at higher average speeds. Long distances are now flown using any of the main sources of rising air: ridge lift, thermals and lee waves. When conditions are favourable, experienced pilots can now fly hundreds of kilometres before returning to their home airfields; occasionally flights of more than are achieved. Some competitive pilots fly in races around pre-defined courses. These gliding competitions test pilots' abilities to mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Lippisch
Alexander Martin Lippisch (November 2, 1894 – February 11, 1976) was a German aeronautical engineer, a pioneer of aerodynamics who made important contributions to the understanding of tailless aircraft, delta wings and the ground effect, and also worked in the U.S. Within the Opel-RAK program, he was the designer of the world's first rocket-powered glider. He developed and conceptualized delta wing designs which functioned practically in supersonic delta wing fighter aircraft as well as in hang gliders. People he worked with continued the development of the delta wing and supersonic flight concepts over the 20th century. His most famous designs are the Messerschmitt Me 163 rocket-powered interceptorReitsch, H., 1955, The Sky My Kingdom, London: Biddles Limited, Guildford and King's Lynn, and the Dornier Aerodyne. Early life Lippisch was born in Munich, Kingdom of Bavaria. He later recalled that his interest in aviation began with a demonstration conducted by Orville Wright ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliding In Germany
Gliding is a recreational activity and competitive air sport in which pilots fly unpowered aircraft known as gliders or sailplanes using naturally occurring currents of rising air in the atmosphere to remain airborne. The word ''soaring'' is also used for the sport. Gliding as a sport began in the 1920s. Initially the objective was to increase the duration of flights but soon pilots attempted cross-country flights away from the place of launch. Improvements in aerodynamics and in the understanding of weather phenomena have allowed greater distances at higher average speeds. Long distances are now flown using any of the main sources of rising air: ridge lift, thermals and lee waves. When conditions are favourable, experienced pilots can now fly hundreds of kilometres before returning to their home airfields; occasionally flights of more than are achieved. Some competitive pilots fly in races around pre-defined courses. These gliding competitions test pilots' abilities to mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanna Reitsch
Hanna Reitsch (29 March 1912 – 24 August 1979) was a German aviator and test pilot. Along with Melitta von Stauffenberg, she flight tested many of Germany's new aircraft during World War II and received many honors. Reitsch was among the very last people to meet Adolf Hitler alive in the in late April 1945. Reitsch set more than 40 flight altitude records and women's endurance records in gliding and unpowered flight, before and after World War II. In the 1960s, she was sponsored by the West German foreign office as a technical adviser in Ghana and elsewhere, and founded a gliding school in Ghana, where she worked for Kwame Nkrumah. Early life and education Reitsch was born in Hirschberg, Silesia, on 29 March 1912 to an upper-middle-class family. She was daughter of Dr. Wilhelm (Willy) Reitsch, who was an ophthalmology clinic manager, and his wife Emy Helff-Hibler von Alpenheim, who was a member of the Austrian nobility. Despite her mother being a devout Cathol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRG Professor
The RRG Professor was a very early soaring glider and the first to use a variometer for finding thermals. It was designed by Alexander Lippisch in Germany, first flying in 1928. The Professor was widely built by both flying clubs and factories. Design and development In early 1928 Professor Walter Georgii, an academic meteorologist and head of the Rhön-Rossitten Gesellschaft (RRG), began studies of thermals, previously assumed to be too weak to assist gliders. He directed flights of a light, powered aircraft which, with its engine idling, discovered uplifts of several metres per second. At about the same time Alexander Lippisch, who had earlier worked at Dornier on Zeppelins was considering the application of the variometer to gliding. These rapid response rate of climb instruments were known in lighter-than-air craft but had not been used on gliders. The two came together to produce a glider, designed by Lippisch and built at the RRG that had the performance to utilize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRG Falke
The RRG Falke ( en, Falcon) of 1930 was a secondary training glider designed by Alexander Lippisch in Germany and intended to provide better performance than his earlier RRG Prüfling whilst being easier to fly because of its inherent stability. It was sold as plans for both club and commercial production and was built in Germany and abroad. Design and development Secondary gliders were meant to be used by student pilots after an introduction to flight in primary gliders like Lippisch's Zögling. His first secondary glider, the 1926 RRG Prüfling, was disappointing, with a performance not much better than some contemporary primaries; lacking inherent stability its handling was not good either. After that design Lippisch had been working on aircraft which relied on wing sweep to provide stability in pitch, having no horizontal tail. The wing of the Storch IV was swept at about 17° and carried lobate ailerons which extended behind the rest of the trailing edge and were hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRG Prüfling
The 1926 German RRG Prüfling ( en, Examinee) of 1926 was a secondary training glider designed for club use. Plans were sold and it was built in Germany and across the world. Design and development Secondary gliders were meant to be used by student pilots after an introduction to flight on very simple primary gliders. Both types needed to be cheap to build, given the difficult financial position of many Germans after World War I and also simple enough that skilled amateur builders, both within and without gliding clubs, could successfully construct them from plans. The primary/secondary glider concept took shape shortly after the absorption of the Martens gliding school on the Wasserkuppe into Rhön-Rossitten Gesellschaft (RRG) at the end of 1925. Martens chief instructor Fritz Stamer and Alexander Lippisch were brought together to produce two such gliders and within a few days the Zögling ( en, Pupil) and the Prufling designs were complete. Some parts, for example the wing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. The onset of turbulence can be predicted by the dimensionless Rey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspect Ratio (aerodynamics)
In aeronautics, the aspect ratio of a wing is the ratio of its span to its mean chord. It is equal to the square of the wingspan divided by the wing area. Thus, a long, narrow wing has a high aspect ratio, whereas a short, wide wing has a low aspect ratio.Kermode, A.C. (1972), ''Mechanics of Flight'', Chapter 3, (p.103, eighth edition), Pitman Publishing Limited, London Aspect ratio and other features of the planform are often used to predict the aerodynamic efficiency of a wing because the lift-to-drag ratio increases with aspect ratio, improving the fuel economy in powered airplanes and the gliding angle of sailplanes. Definition The aspect ratio \text is the ratio of the square of the wingspan b to the projected wing area S, which is equal to the ratio of the wingspan b to the standard mean chord \text: \text \equiv \frac = \frac Mechanism As a useful simplification, an airplane in flight can be imagined to affect a circular cylinder of air with a diameter equal to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deutsche Forschungsanstalt Für Segelflug
The ''Deutsche Forschungsanstalt für Segelflug'' (), or DFS , was formed in 1933 to centralise all gliding activity in Germany, under the directorship of Professor Walter Georgii. It was formed by the nationalisation of the Rhön-Rossitten Gesellschaft (RRG) at Darmstadt.Reitsch, H., 1955, The Sky My Kingdom, London: Biddles Limited, Guildford and King's Lynn, The DFS was involved in producing training sailplanes for the Hitler Youth and Luftwaffe, as well as conducting research into advanced technologies such as flying wings and rocket propulsion. Notable DFS-produced aircraft include the DFS 230 transport glider (1600+ produced), the German counterpart to the British Airspeed Horsa glider, and the DFS 194, similar to the famous Messerschmitt Me 163 rocket fighter. In 1938, following a fatal accident at the Wasserkuppe, DFS held a competition to design a more effective speed brake for gliders. The final design, produced by Wolfgang and Ulrich Hütter of Schempp-Hirth, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitler Youth
The Hitler Youth (german: Hitlerjugend , often abbreviated as HJ, ) was the youth organisation of the Nazi Party in Germany. Its origins date back to 1922 and it received the name ("Hitler Youth, League of German Worker Youth") in July 1926. From 1936 until 1945, it was the sole official boys' youth organisation in Germany and it was partially a paramilitary organisation. It was composed of the Hitler Youth proper for male youths aged 14 to 18, and the German Youngsters in the Hitler Youth ( or "DJ", also "DJV") for younger boys aged 10 to 14. With the surrender of Nazi Germany in 1945, the organisation ''de facto'' ceased to exist. On 10 October 1945, the Hitler Youth and its subordinate units were outlawed by the Allied Control Council along with other Nazi Party organisations. Under Section 86 of the Criminal Code of the Federal Republic of Germany, the Hitler Youth is an "unconstitutional organisation" and the distribution or public use of its symbols, except for educ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
