SAILPLANES

Sailplane, motorless aircraft used for soaring and gliding.

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Soaring and Gliding 
Article Outline 
Introduction; Craft; Flight Techniques; Competition; Hang Gliding 

I Introduction 

Soaring and Gliding, sport of flying a motorless aircraft known as a glider or sailplane. In the past, such a craft (except for trainer models) was built for one person. With today's advanced technology, two-place craft are becoming highly competitive. Flights are launched over terrain that produces the rising air currents necessary to gain or maintain altitude.

II Craft 


Otto Lilienthal 


The first gliders, made of wood and fiber, were developed by the German inventor Otto Lilienthal in the 1890s, and were subsequently improved upon by the American inventors Orville and Wilbur Wright. Later design modifications have produced the highly streamlined modern craft, made of fiberglass, with slender wings spanning 15 to 20 m (50 to 65 ft). Gliders are equipped with spoilers, dive brakes, or flaps to increase descent rate. Flight controls and instruments are similar to those of powered aircraft: a control stick to operate the ailerons and elevators; rudder pedals for rudder control; an airspeed indicator; an altimeter; a turn-and-bank indicator; a compass; and a variometer to register changes of altitude. A two-way radio and oxygen equipment may also be carried.

III Flight Techniques 


In the early days of the sport, gliders were towed by automobiles; today, craft are towed aloft by powered airplanes to a height of between 600 and 900 m (2000 to 3000 ft) above the ground. Flight depends on searching for updrafts found along mountain slopes, under or near cumulus clouds, or over arid terrain where thermals (hot rising air) occur.

IV Competition 

Since World War II recreational soaring has become increasingly popular in many parts of the world. The sport began in Germany about 1910, on the Wasserkuppe, a hill in the Rhön Mountains. Competition commenced in 1922, and the first world championship was held in Germany in 1937. International contests are now held every two years by the Fédération Aéronautique Internationale, which gives badges for various degrees of achievement in distance, altitude, and duration of flight. The Lilienthal Medal, named for the sport's originator, is its highest award. The longest straight distance flight so far recorded is that of the German pilot Hans Werner Grosse in 1972: 1460.8 km (907.7 mi). The altitude record of 14,938 m (49,009 ft) was set in 1986 by Robert Harris of the U.S. National groups, such as the Soaring Society of America, Inc., in Hobbs, New Mexico, conduct frequent local competitions.

V Hang Gliding 

A variation of soaring, hang gliding, has been popular since the 1970s. Hang gliders are constructions resembling kites, from which the flier is suspended by means of a harness and supported on a trapezelike frame. Maneuvering is done by shifting the body weight. International hang-gliding championships are also held.


How to cite this article:
"Soaring and Gliding," Microsoft® Encarta® Online Encyclopedia 2003
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