GetWiki

{{Use dmy dates|date=March 2021}}{{short description|Unpowered glider air sport}}File:Hang gliding hyner.jpg|alt=|thumb|Hang glider just after launch from SalèveSalèveHang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised, heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered with synthetic sailclothWEB,weblink willswing.com, 30 April 2017, dead,weblink 22 May 2014, Hang Glider Sailcloth Information - Wills Wing, Inc, to form a wing. Typically the pilot is in a harness suspended from the airframe, and controls the aircraft by shifting body weight in opposition to a control frame.Early hang gliders had a low lift-to-drag ratio, so pilots were restricted to gliding down small hills. By the 1980s this ratio significantly improved, and since then pilots have been able to soar for hours, gain thousands of feet of altitude in thermal updrafts, perform aerobatics, and glide cross-country for hundreds of kilometers. The Federation Aeronautique Internationale and national airspace governing organisations control some regulatory aspects of hang gliding. Obtaining the safety benefits of being instructed is highly recommended and indeed a mandatory requirement in many countries.WEB, Meadows, G.W., How to buy a hang glider,weblink www.start-flying.com, 10 January 2014, live,weblink" title="web.archive.org/web/20140307042139weblink">weblink 7 March 2014, WEB, Learning to Hang Glide,weblink Hang Gliding Federation of Australia, 10 January 2014, dead,weblink" title="web.archive.org/web/20140126092605weblink">weblink 26 January 2014,

History

File:Lilienthal in flight.jpg|thumb|Otto LilienthalOtto LilienthalIn 1853, George Cayley invented a slope-launched, piloted glider.Most early glider designs did not ensure safe flight; the problem was that early flight pioneers did not sufficiently understand the underlying principles that made a bird's wing work. Starting in the 1880s, technical and scientific advancements were made that led to the first truly practical gliders, such as those developed in the United States by John Joseph Montgomery. Otto Lilienthal built controllable gliders in the 1890s, with which he could ridge soar. His rigorously documented work influenced later designers, making Lilienthal one of the most influential early aviation pioneers. His aircraft was controlled by weight shift and is similar to a modern hang glider.File:Lavezzari hang glider.jpg|thumb|left|Jan LavezzariJan LavezzariHang gliding saw a stiffened flexible wing hang glider in 1904, when Jan Lavezzari flew a double lateen sail hang glider off Berck Beach, France. In 1910 in Breslau, the triangle control frame with hang glider pilot hung behind the triangle in a hang glider, was evident in a gliding club's activity.WEB,weblink 1908 hang glider in Breslau territory with pilot hung by his left foot, a device used through 1900s (decade) up to today for natural bodily commute, 30 April 2017, live,weblink" title="web.archive.org/web/20160101030149weblink">weblink 1 January 2016, The biplane hang glider was very widely publicized in public magazines with plans for building;WEB,weblink spicerweb.org, Chanute Main Page, 30 April 2017, live,weblink" title="web.archive.org/web/20170607035110weblink">weblink 7 June 2017, such biplane hang gliders were constructed and flown in several nations since Octave Chanute and his tailed biplane hang gliders were demonstrated. In April 1909, a how-to article by Carl S. Bates proved to be a seminal hang glider article that seemingly affected builders even of contemporary times. Many builders would have their first hang glider made by following the plan in his article.WEB,weblink mywebpages.comcast.net, The Popular Mechanics Glider, 30 April 2017, dead,weblink" title="web.archive.org/web/20060207115532weblink">weblink 7 February 2006, Volmer Jensen with a biplane hang glider in 1940 called VJ-11 allowed safe three-axis control of a foot-launched hang glider.WEB,weblink sailplanehomebuilders.com, Home Builders of the Future | VJ-11 Information Page. The history of the VJ-11 hang glider., 30 April 2017, live,weblink" title="web.archive.org/web/20090312062320weblink">weblink 12 March 2009, File:Paresev 1-B in Tow Flight - GPN-2000-000212.jpg|thumb|NASA's (Paresev]] glider in flight with tow cable weblink" title="https:/-/web.archive.org/web/20070927120105weblink">weblink.)On 23 November 1948, Francis Rogallo and Gertrude Rogallo applied for a kite patentWEB,weblink Patent US2546078 - Flexible kite - Google Patents, 30 April 2017, for a fully flexible kited wing with approved claims for its stiffenings and gliding uses; the flexible wing or Rogallo wing, which in 1957 the American space agency NASA began testing in various flexible and semi-rigid configurations in order to use it as a recovery system for the Gemini space capsules. The various stiffening formats and the wing's simplicity of design and ease of construction, along with its capability of slow flight and its gentle landing characteristics, did not go unnoticed by hang glider enthusiasts. In 1960–1962 Barry Hill Palmer adapted the flexible wing concept to make foot-launched hang gliders with four different control arrangements.WEB,weblink Ralph S. Cooper, D.V.M., earlyaviators.com, Carl S. Bates, 30 April 2017, live,weblink" title="web.archive.org/web/20160305193020weblink">weblink 5 March 2016, In 1963 Mike Burns adapted the flexible wing to build a towable kite-hang glider he called Skiplane. In 1963, John W. Dickenson adapted the flexible wing airfoil concept to make another water-ski kite glider; for this, the Fédération Aéronautique Internationale vested Dickenson with the Hang Gliding Diploma (2006) for the invention of the "modern" hang glider.WEB,weblink fai.org, FAI Award: The FAI Hang Gliding Diploma, 30 April 2017, dead,weblink" title="web.archive.org/web/20110518115844weblink">weblink 18 May 2011, Since then, the Rogallo wing has been the most used airfoil of hang gliders.

Components

(File:Hang Gliding - My First Thermal.webm|thumb|Hang gliding)

Hang glider sailcloth

Hang glider sailcloth is normally made from woven or laminated fiber, such as dacron or mylar, respectively.Woven polyester sailcloth is a very tight weave of small diameter polyester fibers that has been stabilized by the hot-press impregnation of a polyester resin. The resin impregnation is required to provide resistance to distortion and stretch. This resistance is important in maintaining the aerodynamic shape of the sail. Woven polyester provides the best combination of light weight and durability in a sail, with the best overall handling qualities.Laminated sail materials using polyester film achieve superior performance by using a lower stretch material that is better at maintaining sail shape, but is still relatively light in weight. The disadvantages of polyester film fabrics are that the reduced elasticity under load generally results in stiffer and less responsive handling, and polyester laminated fabrics are generally not as durable or long-lasting as the woven fabrics.

Triangle control frame

In most hang gliders, the pilot is ensconced in a harness suspended from the airframe, and exercises control by shifting body weight in opposition to a stationary control frame, also known as a triangle control frame, or an A-frame. The control frame normally consists of 2 "down-tubes" and a control bar/base bar/base-tube. Either end of the control bar is attached to an upright tube or a more aerodynamic strut (a "down-tube"), where both extend from the base-tube and are connected to the apex of the control frame/ the keel of the glider. This creates the shape of a triangle or 'A-frame'. In many of these configurations additional wheels or other equipment can be suspended from the bottom bar or rod ends.Images showing a triangle control frame on Otto Lilienthal's 1892 hang glider shows that the technology of such frames has existed since the early design of gliders, but he did not mention it in his patents. A control frame for body weight shift was also shown in Octave Chanute's designs. It was a major part of the now common design of hang gliders by George A. Spratt from 1929.WEB,weblink Hang Glider Timeline EnterData, www.energykitesystems.net, 6 February 2018, live,weblink" title="web.archive.org/web/20180514000833weblink">weblink 14 May 2018, The most simple A-frame that is cable-stayed was demonstrated in a Breslau gliding club hang gliding meet in a battened wing foot-launchable hang glider in the year 1908 by W. Simon; hang glider historian Stephan Nitsch has collected instances also of the U control frame used in the first decade of the 1900s; the U is variant of the A-frame.

Training and safety

Due to the poor safety record of early hang gliding pioneers, the sport has traditionally been considered unsafe. Advances in pilot training and glider construction have led to a much improved safety record. Modern hang gliders are very sturdy when constructed to Hang Glider Manufacturers Association, BHPA, Deutscher Hängegleiterverband, or other certified standards using modern materials. Although lightweight, they can be easily damaged, either through misuse or by continued operation in unsafe wind and weather conditions. All modern gliders have built-in dive recovery mechanisms such as luff lines in kingposted gliders, or "sprogs" in topless gliders.Pilots fly in harnesses that support their bodies. Several different types of harnesses exist. Pod harnesses are put on like a jacket and the leg portion is behind the pilot during launch. Once in the air the feet are tucked into the bottom of the harness. They are zipped up in the air with a rope and unzipped before landing with a separate rope. A cocoon harness is slipped over the head and lies in front of the legs during launch. After takeoff, the feet are tucked into it and the back is left open. A knee hanger harness is also slipped over the head but the knee part is wrapped around the knees before launch and just pick up the pilots leg automatically after launch. A supine or suprone harness is a seated harness. The shoulder straps are put on before launch and after takeoff the pilot slides back into the seat and flies in a seated position.Pilots carry a parachute enclosed in the harness. In case of serious problems, the parachute is manually deployed (either by hand or with a ballistic assist) and carries both pilot and glider down to earth. Pilots also wear helmets and generally carry other safety items such as 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 communication with other pilots or ground crew), and first-aid equipment.The accident rate from hang glider flying has been dramatically decreased by pilot training. Early hang glider pilots learned their sport through trial and error and gliders were sometimes home-built. Training programs have been developed for today's pilot with emphasis on flight within safe limits, as well as the discipline to cease flying when weather conditions are unfavorable, for example: excess wind or risk cloud suck.In the UK, a 2011 study reported there is one death per 116,000 flights, a risk comparable to sudden cardiac death from running a marathon or playing tennis.{{Citation Most pilots learn at recognised courses which lead to the internationally recognised International Pilot Proficiency Information card issued by the FAIFAILaunch techniques include launching from a hill/cliff/mountain/sand dune/any raised terrain on foot, tow-launching from a ground-based tow system, aerotowing (behind a powered aircraft), powered harnesses, and being towed up by a boat. Modern winch tows typically utilize hydraulic systems designed to regulate line tension, this reduces scenarios for lock out as strong aerodynamic forces will result in additional rope spooling out rather than direct tension on the tow line. Other more exotic launch techniques have also been used successfully, such as hot air balloon drops from very high altitude. When weather conditions are unsuitable to sustain a soaring flight, this results in a top-to-bottom flight and is referred to as a "sled run". In addition to typical launch configurations, 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.WEB,weblink cableairport.com, Dan Buchanan, 30 April 2017, dead,weblink" title="web.archive.org/web/20070928095243weblink">weblink 28 September 2007, In 1983 Denis Cummings re-introduced a safe tow system that was designed to tow through the centre of mass and had a gauge that displayed the towing tension, it also integrated a 'weak link' that broke when the safe tow tension was exceeded. After initial testing, in the Hunter Valley, Denis Cummings, pilot, John Clark, (Redtruck), driver and Bob Silver, officianado, began the Flatlands Hang gliding competition at Parkes, NSW. The competition quickly grew, from 16 pilots the first year to hosting a World Championship with 160 pilots towing from several wheat paddocks in western NSW.In 1986 Denis and 'Redtruck' took a group of international pilots to Alice Springs to take advantage of the massive thermals. Using the new system many world records were set. With the growing use of the system, other launch methods were incorporated, static winch and towing behind an ultralight trike or an ultralight airplane.

Soaring flight and cross-country flying

GoldenMedows.jpg -