Soaring—also called “gliding” by some people—dates
from the 1800s. The two terms, however, are quite different. Both are practiced by individuals who either fly
for the sheer personal enjoyment of powerless flight
(gliding), or who compete as either individuals or
members of teams in local, regional, national, and international glider competition (soaring). Many pilots
do both.
History
In 1848 Sir George Cayley, an eminent British scientist,
is credited with having designed and built the first successful heavier-than-air device, a glider said to have
carried a 10-year-old boy several yards after its launching from a hill. From the 1890s onward, research and
development of gliders, flying techniques, and similar
subjects were being notably pursued in Germany, England, and the United States.
World War I halted glider development, but when
the Treaty of Versailles prohibited powered flight in
Germany, one result was enormous progress in the development of soaring flight. The first world championships were held at Wasserkuppe, Germany, in 1937.
Progress continued, but was slowed again during World
War II when military applications of gliding forced
sport flying into the background.
From then until now, the sport has flourished, and
several countries boast aggressive, healthy soaring programs. At least 5,500 pilots throughout the world have
earned diamond badges and over 150 have now flown
flights farther than 1,000 kilometers (620 miles).
Rules and Play
Air flows over the wings of a glider in much the same
way as it flows over the wings of a powered airplane,
which is propelled through the air by the force of its engine. Glider flight can be achieved only by descending
the glider, speeding it up, and causing air to flow
around its wings and tail surfaces. In gliding flight,
therefore, a glider (or sailplane, as it is often called) is
always descending, usually at a rate of between 45 and
90 meters (150 and 300 feet) per minute in still air.
The acceleration of air over the wings of the glider
produces a lifting force that counterbalances the weight
of the glider and actually slows down its rate of descent. Were it not for the force of “lift,” gliders would go
straight down. Instead, they follow predictable “glide
ratios.” Glide ratio is a measure of how far a sailplane
will travel forward (horizontal distance) for each foot
of altitude it loses (vertical distance).
What makes soaring a sport is the challenge to the
pilot of finding and using ascending air currents to
keep the glider aloft—to cause it to climb faster than it
is descending (which it always is)—and so achieve
height, distance, or flight durations impossible in “still
air.” Updrafts are the fuel of gliders.
Pilots who excel at finding and using the invisible
ascending currents are the champions and record holders, and the ones who reap the full enjoyment of solitary soaring flight.
Three classes of gliders are generally recognized in
world competition: Open, 15-meter, and Standard. A
fourth type of glider, the so-called “World Class” glider,
has been internationally classified but it has yet to be
built or compete on any widespread basis.
Except for motorgliders, which have engines that enable them to take off under their own power, other types
of gliders require some outside force to create airflow
over the wings. This gets the glider moving at sufficient
speed so adequate airflow passes around the wings to
overcome the force of gravity and cause it to fly.
Many different methods have been used to provide
this speed: pushing gliders down the slopes of hills until airflow over the wings is sufficient to produce flight;
dropping heavy weights on the ends of ropes to pull
them into the air; pulling them with elastic-like ropes
and “slingshotting” them to flying speed; pulling them
into the air on long cables reeled in by engine-driven
mechanical winches; pulling them into the air on ropes behind automobiles; and hooking them behind airplanes that take off and pull the glider to an altitude
from which gliding flight can begin. Most gliding in the
United States today starts with the glider being towed
by a rope attached to a powered airplane. The technique is called “aerotow.”
Types of Gliding
Glider pilots aim to soar, not glide. Soaring involves
finding parcels of air going up at a greater rate than the
glider is going down. The several methods of remaining aloft all involve pilot skill and knowledge in finding
these air currents. They are generally categorized as
thermaling, ridge flying, mountain wave flying, and
land and sea breeze flying. An additional source of lift
can be obtained by flying under or near newly developing cumulus clouds that owe their formation and sustenance to the updrafts found directly underneath
them.
Soaring Competition
The International Gliding Commission (IGC) is the
sport’s governing body.
The first world championship of soaring was conducted in 1937 at Wasserkuppe, Germany. Recently,
during every odd calendar year, the FAI sanctions a
World Gliding Championship for each of the three
classes of gliders (Open, 15-meter, and Standard). The
world contest is usually held over a three-week period,
with the first week devoted to official practice and the
last two weeks to actual competition.
Individual phases of soaring competition are called
“tasks.” Each day at the world championship competition, pilots fly around a specifically assigned course
composed of carefully selected and clearly defined turn
points on the ground. These turn points are the ends of
airfield runways, prominent road intersections, or
other distinctly identifiable geographical landmarks
over which competition pilots must precisely fly.
Win or lose, soaring pilots still score a victory: the
triumph, however temporary, of a nonmechanized
craft over the force of gravity.
—WALTER D. MILLER
Bibliography: Knauff, Thomas L. (1994) Glider Basics from
First Flight to Solo. Iceland: Prentsmidja Arna Valdemarssonar hf. Piggott, Derek. (1977) Understanding Gliding. New York: Barnes & Noble. Stewart, Ken. (1994) The
Glider Pilot’s Manual. UK: Airlife Publishing.Wills, Philip.
(1974) Free as a Bird. New York: Barnes & Noble.