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This chapter presents an introduction to
ballooning’s history, physics, basic balloon terms,
balloon components, support equipment, and
choosing a balloon.
HISTORY
The first manned aircraft was a hot air balloon.
This balloon was built by the Montgolfier Brothers
and flown by Pilatre de Rozier and the Marquis
d’Arlandes on November 21, 1783, in France, over
120 years before the Wright Brothers’ first flight.
The balloon envelope was paper, and the fuel was
straw which was burned in the middle of a large
circular basket. Only 10 days later, Professor
Jacques Charles launched the first gas balloon made
of a varnished silk envelope filled with hydrogen.
Thus, the two kinds of balloons flown today—hot
air and gas—were developed in the same year.
Gas ballooning became a sport for the affluent and
flourished on a small scale in Europe and the United
States. Gas balloons were used by the military in
the Siege of Paris, the U.S. Civil War, and World
Wars I and II. In the last few decades, gas ballooning
has been practiced primarily in Europe, particularly
in the town of Augsburg, Germany, where an active
club has arranged with a local factory to purchase
hydrogen gas at a low price.
At the turn of the century, the smoke balloon—a
canvas envelope heated by a fire on the ground—
was a common county fair opening event. Today,
there are only a few people who have ridden on
the trapeze of a smoke balloon (called a hot air balloon without airborne heater). After the initial
climb—about 3,000 feet per minute (FPM)—the
hot air cools and the rider separates from the
balloon, deploying a parachute to return to earth.
Two chase crews were standard, one for the
performer and one for the envelope.
In the 1950s, the U.S. Navy contracted with the
General Mills Company to develop a small hot air
balloon for military purposes. The Navy never used
the balloon, but the project created the basis for
the modern hot air balloon.
With the use of modern materials and technology,
hot air ballooning has become an increasingly
popular sport.
PHYSICS
balloons and gas balloons. There is also the smoke
balloon, which is a hot air balloon without an
airborne heater, and the solar balloon, but they are
rare and almost nonexistent. This handbook
primarily covers hot air balloons.
Gas is defined as a substance possessing perfect
molecular mobility and the property of indefinite
expansion, as opposed to a solid or liquid.
The most popular gas used in ballooning is hot air.
As the air is heated, it expands making it less dense.
Because it has fewer molecules per given volume,
it weighs less than non-heated ambient air (air that
surrounds an object) and is lighter in weight.
As the air inside a balloon envelope is heated, it
becomes lighter than the outside air the envelope,
causing the balloon to rise. The greater the heat
differential between the air inside the envelope and
the air outside, the faster the balloon rises.
Hot air is constantly being lost from the top of the
envelope by leaking through the fabric, seams, and
deflation port. Heat is also being lost by radiation.
Only the best and newest fabrics are nearly airtight.
Some fabrics become increasingly porous with age
and some colors radiate heat faster than others do.
Under certain conditions, some dark-colored
envelopes may gain heat from the sun. To
compensate for heat loss, prolonged flight is
possible only if fuel is carried on board to make
heat.
To change altitude, the internal temperature of the
air in the envelope is raised to climb, or allowed
to cool to descend. Cooling of the envelope is also
possible by allowing hot air to escape through a
vent. This temporary opening closes and seals
automatically when it is not in use.
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