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]] CLASSES In one perspective there are three classes of Hang Glider :
The most used definitions have that Hang Glider s can be foot-launched, but landing some class-2 hang gliders is only possible on wheels. Beyond regulated hang gliding, a hang glider may be so constructed for alternative launching modes other than being foot launched; one practical avenue for this is for people who physically cannot foot-launch.Dan Buchanan: {Link without Title} In another perspective there are more than three classes of hang glider. Consider a multi-plane rigid-winged hang glider that does not "shape change" in virtue of shifted pilot weight; Otto Lilienthal (a German pioneer of hang gliding) introduced this class of hang glider. Further, the rotary-wing hang gliders, though not popular, are in a class by themselves. Paragliders can be seen simply as one class of hang glider in alternative perspectives. HISTORY See Also: History of hang gliding TRAINING & SAFETY
As a backup, pilots carry a Parachute in the harness. In case of serious problems the parachute is deployed and carries both pilot and glider down to earth. Pilots also wear helmets and generally carry other safety items such as hook knives (for cutting their parachute bridle after impact or cutting their harness lines and straps in case of a tree or water landing), light ropes (for lowering from trees to haul up tools or climbing ropes), radios (for calling for help) and first-aid equipment. Another issue that has dramatically improved the safety of the modern hang glider pilot is training. Early hang glider pilots learned their sport through trial and error. Many of those errors have led to effective training techniques and programs developed for today's pilot, with emphasis on flight well within safe limits, as well as the discipline to cease flying when conditions are unfavorable. LAUNCH Launch techniques include foot-launching from a hill, tow-launching from a ground-based tow system, aerotowing (behind a powered aircraft), and Powered Harnesses . Other, more exotic launch techniques have also been used successfully, such as Hot Air Balloon drops for very high altitude. Flights in non-soarable conditions are referred to as "sled runs". SOARING FLIGHT s, with darker bases, suggest active thermals and light winds.]] s with dark flat base.]] Glider pilots can stay airborne for hours. This is possible because they seek out rising air masses (lift) from the following sources: Thermals The most commonly used source of lift is created by the sun's energy heating the ground which in turn heats the air above it. This warm air rises in columns known as clouds, cloud streets, dust devils and haze domes. Also, nearly every glider contains an instrument known as a Variometer (a very sensitive vertical speed indicator) which shows visually (and often audibly) the presence of lift and sink. Having located a thermal, a glider pilot will circle within the area of rising air to gain height. In the case of a cloud street thermals can line up with the wind creating rows of thermals and sinking air. A pilot can use a cloud street to fly long straight-line distances by remaining in the row of rising air. Ridge lift Another form of lift occurs when the wind meets a mountain, cliff or hill. The air is deflected up the Windward face of the mountain forming lift. Gliders can climb in this rising air by flying along the feature. Another name for flying with ridge lift is Slope Soaring . Mountain wave The third main type of lift used by glider pilots is the Lee Waves that occur near mountains. The obstruction to the airflow can generate Standing Wave s with alternating areas of lift and sink. The top of each wave peak is often marked by Lenticular Cloud formations. Convergence Another form of lift results from the Convergence of air masses, as with a Sea-breeze Front . More exotic forms of lift are the polar vortexes which the has also been used by glider pilots in Australia. A Guide to the Morning Glory at www.dropbears.com Cross-country flying Once the skills of using thermals to gain altitude have been mastered, pilots can glide from one thermal to the next to go ‘cross-country’ (‘XC’). Potential thermals can be identified by land features which typically generate thermals, by soaring birds or by Cumulus Cloud s which mark the top of a rising column of warm, humid air as it reaches the Dew Point and Condenses to form a cloud. PERFORMANCE (2006) With each generation of materials and with the improvements in aerodynamics, the performance of hang gliders has increased. One measure of performance is the glide ratio. For example, a ratio of 12:1 means that in smooth air a glider can travel forward 12 meters while only losing 1 meter of altitude.
''Note:'' Glide Ratio is typically not provided by the manufacturers as it is nearly impossible to measure reliably and because the pilot is in the airstream (unlike in a sailplane) depends on many factors like pilot weight, pilot position, harness design, helmet, placement of instruments and so on. Ballast The extra weight provided by ballast is advantageous if the lift is likely to be strong. Although heavier gliders have a slight disadvantage when climbing in rising air, they achieve a higher speed at any given glide angle. This is an advantage in strong conditions when the gliders spend only little time climbing in thermals. COSTS (2003)
INSTRUMENTS In order to maximize a pilot's understanding of how the hang glider is flying, most pilots carry a series of instruments. The most basic being a variometer and altimeter--often combined. Some more advanced pilots also carry airspeed indicators and radios. When flying in competition or "cross country" pilots often also carry maps and/or GPS units. Hang gliders do not have instrument panels as such, so all the instruments are mounted to the control frame of the glider. Variometer People can sense the Acceleration when they first hit a thermal, but they cannot detect the difference between constant rising air and constant sinking air, so they turn to technology for help. A Variometer is a very sensitive vertical speed indicator; in other words, the variometer indicates climb rate or sink rate with audio signals (beeps) and/or a visual display. These units are generally electronic, vary in sophistication, and often include an Altimeter and an airspeed indicator. More advanced units often incorporate a Barograph for recording flight data and/or a built-in GPS. The main purpose of a variometer is in helping a pilot find and stay in the ‘core’ of a thermal to maximize height gain, and conversely indicating when he or she is in sinking air and needs to find rising air. Variometers are sometimes capable of electronic calculations based on the 'MacCready Speed Ring' to indicate the optimal speed to fly for given conditions. The Mac Cready theory solves the problem of how fast a pilot should cruise between thermals, given both the average lift the pilot expects in the next thermal climb, as well as the amount of lift or sink he encounters in cruise mode. Some electronic variometers make the calculations automatically, after allowing for factors such as the glider's theoretical performance (glide ratio), altitude, hook in weight and wind direction. Radio Pilots use radio for training purposes, and for communicating with other pilots in the air – particularly when traveling together on cross-country flights. Radios used are PTT ( Push-to-talk ) Transceiver s, normally operating in or around the FM VHF 2-metre Band (144–148 MHz). Usually a microphone is incorporated in the helmet, and the PTT switch is either fixed to the outside of the helmet, or strapped to a finger. GPS GPS (global positioning system) is a necessary accessory when flying competitions, where it has to be demonstrated that Way-points have been correctly passed. It can also be interesting to view a GPS track of a flight when back on the ground, to analyze flying technique. Computer Software is available which allows various different analyses of GPS tracks (e.g. CompeGPS ). Other uses include being able to determine drift due to the prevailing wind when flying at altitude, providing position information to allow restricted airspace to be avoided, and identifying one’s location for retrieval teams after landing-out in unfamiliar territory. More recently, the use of GPS data, linked to a computer, has enabled pilots to share 3D tracks of their flights on Google Earth . This fascinating insight allows comparisons between competing pilots to be made in a detailed 'post-flight' analysis. RECORDS Records fall into nearly the same categories as those for with 700.6 km (435.3 miles) in 2001, but Mike Barber has flown an uncertified distance of 704 km (437 miles) on June 19 2002 in Zapata Texas. COMPETITION Competitions started with "flying as long as possible" and spot landings. With increasing performance cross-country flying replaced them. Usually two to four waypoints have to be passed with a landing at a goal. In the late 90s low-power organized by Fédération Aéronautique Internationale (World Air Sports Federation - FAI). The FAI also has a chronology of the FAI World Hang Gliding Championships.Chronology of the FAI World Hang Gliding Championships {Link without Title} RELATED SPORTS The related sports are Gliding , in which the Gliders have full control surfaces and an enclosed cockpit, and Paragliding , where the pilot is sitting on a harness suspended below a fabric wing. COMPARISON WITH PARAGLIDERS Paragliding and hang gliding are closely related sports: foot-launched gliders with flexible wings, with options for tow launching and for powered flight and there is sometimes confusion about the differences. Beyond sport definitions and sporting association class definitions, there is a perspective that simply treats paragliders as a proper subset of hang gliders (as an over class of aircraft apart from the influence of sporting classes). The main differences between the two proper subsets of generalized hang gliders are: Q & A Q1. Is there hang gliding activity outside of organized and regulated sport? Yes. Some people build and fly experimental hang gliders and choose not to enter the sports arena. REFERENCES EXTERNAL LINKS
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