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While recreational glider enthusiasts enjoy the freedom, scenic views, and sheer enjoyment of controlling the planes, others concentrate on building their own craft, while still others fly in competitions, where the goal is to complete circuit around designated "turning-points", as quickly as possible. These competitions test the pilot's (and the co-pilot, in two-seater gliders) ability to recognise and make use of local weather conditions as well as their flying skills and navigational abilities. There are also glider aerobatics competitions.
All developments in heavier-than-air flight between 1853 ( Sir George Cayley's coachman), and 1903 ( Wright brothers) involved gliders (See History of Aviation). However, the sport of gliding only emerged after the First World War, and the reason for its development can be traced to the Treaty of Versailles. The peace settlement imposed severe restrictions on the manufacture and use of single-seater powered aeroplanes in Germany. Thus, in the 1920s and 1930s, while aviators and aircraft makers in the rest of the world were working to improve the performance of powered aeroplanes, the Germans were designing, developing and flying ever more efficient gliders, and discovering ways of using the natural forces in the atmosphere to make them fly further and faster. The first German gliding competition was held at the Wasserkuppe in 19201920 is a leap year starting on Thursday (link will take you to calendar) Events January January 7 Forces of Russian White admiral Kolchak surrender in Krasnoyarsk. January 9 Britain announces it will build 100,000 homes for war veterans. January 10 Leagu, organised by Oskar UrsinusCarl Oskar Ursinus ( March 11 1877 July 6 1952) was a pioneer of German aviation and is remembered mainly for his contributions to sailplane designs and the sport of gliding. He has been nicknamed the Rhonvater ("Rhon father") because he founded Germany’s, and ten years later had become an international event. The sport has since taken hold in many countries, not only those offering large areas of relatively flat land but also those where the terrain provides more challenging flying. Germany, however, remains the world centre of gliding, as evinced by the fact that all the major glider manufacturers are based in that country.
Good gliding weather. Well formed cumulusA cumulus cloud is a cloud belonging to a class characterized by dense individual elements in the form of puffs, mounds or towers, with flat bases and tops that often resemble cauliflower. They are formed in the troposphere at a lower altitude than altocu humilis with white bases suggests active thermalA thermal column is a column of rising warm air in the lower altitudes of the Earth's atmosphere, and are informally referred to as thermals''. Thermals are created by the uneven heating of the Earth's surface from solar radiation. The movement of air ors and light winds.
Soaring is usually achieved by flying through a mass of air that is ascending as fast or faster than the sailplane is descending, and thus gaining potential energyPotential energy U or E , a kind of scalar potential, is energy by virtue of matter being able to move to a lower-energy state, releasing energy in some form. For example a mass released above the Earth has energy resulting from the gravitational attracti. The most commonly exploited rising masses of air are thermalA thermal column is a column of rising warm air in the lower altitudes of the Earth's atmosphere, and are informally referred to as thermals''. Thermals are created by the uneven heating of the Earth's surface from solar radiation. The movement of air ors (updrafts of hot ground layer air caused by local differences in air temperature), ridge liftRidge lift (or slope lift) is created when a prevailing wind strikes a geologic obstacle that is large and steep enough to deflect the wind upward. If the wind is strong enough and the ridge high enough, it provides enough power for gliders to stay airbor (found where the wind blows against the face of a hill and is forced to rise), and wave lift ( standing waveA standing wave also known as a stationary wave is a wave that remains in a constant position. This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interferences in the atmosphereEarth's atmosphere is the layer of gases surrounding the planet Earth and retained by the Earth's gravity. It consists of nitrogen (78. 1% by volume) and oxygen (20. 9%), with small amounts of argon (0. 9%), carbon dioxide (variable, but around 0. 035%),, analogous to the ripples on the surface of a stream). Ridge lift rarely allows pilots to climb much higher than about 2,000 ft (600 m); thermals, depending on the climate and terrain, can exceed 10,000 ft (3 000 m) in flat country and much higher in the mountains; wave lift has allowed gliders to achieve altitudes approaching 50,000 ft (15 000 m).
On rare occasions, glider pilots have been able to use a technique called " dynamic soaring", where a sailplane can be made to gain kinetic energy by repeatedly crossing the boundary between air masses of different horizontal velocity. However, such zones of high " wind gradient" are usually much too low to be used safely by aircraft, and dynamic soaring is a technique only really useful to birds, notably to the albatrosses who during long flights can be seen repeatedly pulling up, turning, and diving back down through the wind gradient close to the surface of the ocean.
In thermal flight, the glider pilot attempts to find streams of air that are moving upwards as a result of being heated by contact with sun-lit earth. Typical spots to find thermals are over freshly ploughed fields and asphalt roads, however most of the time thermals are hard to associate with any feature on the ground. As it requires rising heated air, thermalling is typically only effective in mid-latitudes from spring through into late summer, other latitudes tend to have vertical air temperatures-gradients suppressing thermal convection, and during winter there is too little solar heat to start thermals. Once a thermal is encountered, the pilot banks sharply to keep the plane turning in a small circle within the thermal. This way gliders can ride upward until the thermal either enters the clouds base (see Visual Flight Rules) or a warmer air layer called a Capping inversion stops it from rising any further.
Ridge running instead looks for air that is being mechanically lifted as it flows up the sides of hills or other vertical changes in the landscape (including buildings in some cases). Ridge running works in any climate or weather, but can only be used in certain locations. Often a combination of ridge and thermal gliding is used. Ridge lift can kick off strong thermals.
Mountain wave flying is a variation of ridge-running allowing the glider to climb much higher. Most sailplane altitude records were set by flying large scale mountain waves in the top flow of long mountain ranges all over the world. The current world distance record of 3008 km by Klaus Ohlmann (on 21 jan 2003) was also flown in the mountain wave in South America.
Glider pilots learn to spot the characteristic cloud formations that usually accompany zones of rising air or "lift". Well-formed cumulus clouds (the fluffy, cotton-wool type of cloud) with sharply defined flat bases often form at the tops of strong thermals, and long, stationary lenticular (lens-shaped) clouds, perpendicular to the wind direction, frequently mark the crests of atmospheric waves.
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