Science Fair Project Encyclopedia
Paragliding (known in some countries as parapenting) is a recreational and competitive sport that is best described as a hybrid of hang gliding and parachuting. A paraglider is free-flying, unlike the parachutes used in parasailing, which is generally a passive amusement ride rather than an active sport.
A paraglider closely resembles the modern parachutes used in parachuting competitions, but with a higher aspect ratio (to increase its glide angle) and a lighter construction (it does not have to deal with the sudden opening shock when deployed at terminal velocity). These paragliders have reasonable gliding characteristics and are quite controllable by use of cords which are held in the pilot's hand as he or she sits in the harness. Shifting one's weight also steers the paraglider. Typically, paragliders are launched from slopes at, or close to, the summit of hills.
Launching is only possible in anabatic (uphill) breezes, or zero wind. Generally speaking, a tail-wind launch is not possible.
The paraglider wing is an inflatable structure. It consists of a row of cells, open at the front and closed at the back, joined together side by side. Moving through the air keeps them inflated because air goes in the front but can't get out the back. The cells are cut into the same cross-sectional shape as an aeroplane wing and it is this "aerofoil" section that produces the lift. The pilot is supported underneath the wing from a web of lines, each with the strength to support the pilot. The lines are then attached to risers, straplike devices, that are attached to the pilot's harness.
Paragliding offers many of the joys of hang gliding and parachuting in perhaps a less intimidating and more accessible package, avoiding the initial fright (but perhaps also some of the thrill) of the plane-jump of parachuting, and giving much of the exhilaration of the controllable gliding of hang gliding. There is a greater ease of control (due to the lower speeds, greater stability, lower stall speeds and lesser physical demands) but with correspondingly less acrobatic manoeuvrability and range. A paraglider can also be landed in a much smaller space than a glider or hang glider and can easily be carried in a car, unlike a glider that requires a large trailer, or a hang glider that requires, at least, a roofrack. It is also easy to climb a mountain carrying a paraglider to fly from the top to the bottom.
Solo paragliders typically have an area of 25-30m2 and weigh 6-7kg. Glide angles range from 7:1 to 10:1 and top speeds from 45 to 65km/h.
Paragliders (or "Parapentes" in French) have a low top speed, hence are suited to light winds of under 25 km/h and smooth air conditions. The non-rigid structure of paragliders relies on a constant angle of attack to maintain the shape and profile of the wing section. Turbulent air changes the angle of attack and can deflate part or all of a wing while in flight. "Collapses" are typically easy to deal with but require some training to deal with correctly.
Paragliders are suitable for mountain flying in low-wind conditions, and are best suited to thermally active areas or coastal locations where a sea-breeze is prevalent.
Although paragliding is classed as a high-risk sport, technological advances in the design of paraglider canopies have significantly reduced the number of recorded incidents since the pioneering days of the 1980s. On average there are between one and three fatalities a year in Britain, most of which involve experienced pilots using faster, high-performance wings that are less stable in the air. The most common minor injuries are twisted ankles and back injuries sustained during take-off and landing.
Ninety percent of all injuries occur in the first 10 flights and are, typically, to the lower leg. Once a pilot has achieved a full licence (after 40 to 60 high-altitude flights) the injury rate drops significantly until 500 to 1000 flights have been completed. Then the injury rate spikes again and, typically, the injuries are very serious or fatal.
Learning to fly
A beginner should learn from a fully-qualified instructor. One of the 9 fatalities in the USA in 2003 was a self-taught pilot attempting to fly in high winds by tethering to a fixed object on the ground. A bystander was also seriously injured in this accident. Fixed-rope towing and tethering with fixed ropes to objects is extremely dangerous and has resulted in several other serious injuries and fatalities in the US. Training is essential in any form of aviation. Pilots should not sell used equipment to people who do not have proper training.
Safe towing requires a weak link, a proper tow device and training for both the pilot and the tow operator.
The origin of paragliding has roots in the sport of parachuting. In the early 1960’s, American parachutist Pierre Lemoigne was successful in cutting slots in the round parachute canopy to allow for air to flow through the canopy. This had a dramatic effect on the lift to drag ratio and allowed the pilot to steer the chute in a predictable manner.
In 1962, Walter Newmark of England took note of Lemoigne’s design and modified it so that the chute could be towed aloft. During the 60’s, parascending became a popular sport among the English. Newmark was responsible for the creation of the British Association of Parascending in the early 1970’s.
In 1964, Domina Jalbert of Florida invented a square canopy called the Ram Air Para Foil. The Ram Air worked by allowing air to pass through the double surface glider allowing for better maneuverability and increased lift. Walter Newmark soon adopted this canopy for his parascending activities. Using specially designed ram-air parachute canopies, instead of wings of aluminium and dacron, paraglider pilots launch, glide and soar in much the same way that hang-glider pilots do.
Not until the 1970’s did the sport take off. Gerard Bosson introduced paragliding at the 1979 World Hang Gliding Championships.
- Para2000.org - An excellent paragliding info site in English and French
- paragliding365.com - The most complete flying site database in German
- Gravsports.com - Loosely edited by Will Gadd
- Paragliding Courses
- Acrobatic Paragliding Shows and Equipment
- / Current paragliding records
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