Take a trip in a hot air ballon


How Hot Air Balloons Work

Hot air balloons are one of the oldest flyingIt won't rise forever, though. The
machines ever invented, and they work on aatmosphere thins as it goes up, and
very  simple  principle:  hot  air  rises.eventually the air within the envelope is too
thin to support the weight of the balloon.
For practical purposes, hot air balloonsThe more air within the balloon, the greater
really can't compete with airplanes andthe buoyancy-so bigger balloons can go higher
helicopters. They're extremely difficult tothan  smaller  ones.
steer, and they can only move as quickly as
the surrounding winds. But as a recreationalA pilot can cause the balloon to rise by
activity, hot air ballooning can't be beat.turning on the propane burner and heating the
You're outside, feeling the wind in your hairair within the envelope. To bring the
and the sun on your face, drifting serenelyballoon down, the pilot releases the
over the earth. If you've ever been in a hotparachute valve. That's a vent in the top of
air balloon, you know it's an experience youthe envelope that allows some of the hot air
won't  soon  forget.to escape, cooling the temperature of the
remaining air within. This causes the
Hot air is less dense, and lighter, than coldballoon  to  sink  gradually.
air. Because it's lighter, it tends to rise.
If you've ever taken a dive into a pool, youThere are no horizontal controls in a
may have felt this effect in water: theballoon, but pilots can still control the
surface water is warm, but as you movehorizontal movement by raising and lowering
deeper, the water gets cooler. That'sthe altitude of the craft. Winds at
because warm water is lighter than cool waterdifferent altitudes move in different
and  tends  to  rise  to  the  top, like air.directions. If a pilot has a good working
knowledge of the wind currents in the area,
The air within a hot air balloon is heated,she can raise and lower the balloon to catch
and as it rises, it takes the balloon-anda  current  moving  in  the  right direction.
anything attached to it-with it. A cubic
foot of air within a balloon can lift aboutStill, piloting a balloon isn't an exact
seven grams of weight. This isn't a lot ofscience. It's impossible to target the
weight, which is why the balloon has to be soprecise location where you'll land. That's
big.why it's usually necessary for someone on the
ground to follow the balloon by car to meet
The balloon itself is called an "envelope."the balloon where it lands and transport the
It's usually made of nylon, which is theequipment.
perfect fabric for hot air balloons: it's
lightweight but sturdy, and it can withstandLaunching and landing generally take more
heat  without  melting  easily.work than actually flying a balloon. The
inflation process takes only about ten or
Below the balloon, a burner is positioned tofifteen minutes, and is done with a powerful
send a jet of flame upward into the envelope.fan. Once the balloon is full of air, it
The burner uses propane as a fuel. The fuelwill still lie on the ground until the burner
is stored as a highly compressed liquid inis fired, heating the air in the envelope and
canisters attached to the burner with a fuelcausing  it  to  rise.
hose. Because it's so highly compressed, the
liquid fuel flows quickly through the hose toA balloon descends gradually, but can still
the burner when the pilot turns it on.land with a bit of a bump if the pilot isn't
There, it's ignited by a pilot light. Theexperienced enough to know how to bump the
flame heats up the surrounding metal of thebasket along the ground to lessen the impact.
burner, which turns the fuel to gas before itThe wicker basket helps absorb the force of
gets lit. This makes the flame stronger andthe landing. Wicker is lightweight and
the  fuel  usage  more  efficient.flexible, and absorbs the energy of landing
better than a solid, less flexible basket
If you look at a hot air balloon, you'llwould. This way, riders aren't jarred when
notice a big hole in the bottom where thethe  ride  is  over.
burner is. So why doesn't the hot air escape
through the hole at the lower end? Simple:There's nothing like soaring over the earth
buoyancy. Hot air is buoyant, which means itin a balloon. Hot air balloons are exciting,
can only rise-it can't sink and drain out thefascinating, and pure fun. If you've never
bottom of the balloon. As long as the airtaken a ride in one, you're definitely
stays  hot,  it  will  continue  to  rise.missing out on an experience you'll never
forget.



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