Piloting a balloon takes skill, but the controls are actually very simple.
To lift the balloon, the pilot moves a control that opens up the propane
valve. This lever works just like the knobs on a gas grill or stove: As
you turn it, the flow of gas increases, so the flame grows in size. The
pilot can increase the vertical speed by blasting a larger flame to heat
the air more rapidly.
To blast the burner, the pilot
opens the propane valve
Additionally, many hot air
balloons have a control that opens a second propane valve. This valve
sends propane through a hose that bypasses the heating coils. This lets
the pilot burn liquid propane, instead of propane in gas form. Burning
liquid propane produces a less efficient, weaker flame, but is much
quieter than burning gas. Pilots often use this second valve over
livestock farms, to keep from scaring the animals.
Hot air balloons also have
a cord to open the parachute valve at the top of the envelope. When
the pilot pulls the attached cord, some hot air can escape from the
envelope, decreasing the inner air temperature. This causes the balloon to
slow its ascent. If the pilot keeps the valve open long enough, the
balloon will sink.
The parachute valve, from the inside of the balloon. A Kevlar cord runs
from the valve at the top of the balloon, down to the basket, through the
centre of the envelope
Essentially, these are the
only controls -- heat to make the balloon rise and venting to make it
sink. This raises an interesting question: If pilots can only move hot air
balloons up and down, how do they get the balloon from place to place? As
it turns out, pilots can manoeuvre horizontally by changing their vertical
position, because wind blows in different directions at different
altitudes. To move in a particular direction, a pilot ascends and descends
to the appropriate level, and rides with the wind. Since wind speed
generally increases as you get higher in the atmosphere, pilots can also
control horizontal speed by changing altitude.
To manoeuvre the balloon horizontally, the pilot ascends or descends in
altitude, catching different wind currents
Of course, even the most experienced pilot doesn't have complete
control over the balloon's flight path. Usually, wind conditions
give the pilot very few options. Consequently, you can't really
pilot a hot air balloon along an exact course. And it's very rare
that you would be able to pilot the balloon back to your starting
point. So, unlike flying an airplane, hot air balloon piloting is
largely improvised, moment to moment. For this reason, some members
of a hot air balloon crew have to stay on the ground, following the
balloon by car to see where it lands. Then, they can be there to
collect the passengers and equipment.
Launching and Landing
A lot of the work in hot air ballooning comes
at the beginning and the end of the flight, when the crew inflates and
deflates the balloon. For the spectator, this is a much more spectacular
show than the actual balloon flight.
Once the crew has found a
suitable launching point, they attach the burner system to the basket.
Then they attach the balloon envelope and begin laying it out on the
Once the envelope is laid out, the crew
begins inflating it, using a powerful fan at the base of the envelope.
When there is enough air
in the balloon, the crew blasts the burner flame into the envelope mouth.
This heats the air, building pressure until the balloon inflates all the
way and starts to lift off the ground.
The ground crew members
hold the basket down until the launch crew is on board. The balloon basket
is also attached to the ground crew vehicle until the last minute, so the
balloon won't be blown away before it is ready to launch. When everything
is set, the ground crew releases the balloon and the pilot fires a steady
flame from the burner. As the air heats up, the balloon lifts right off
entire process only takes 10 or 15 minutes! The landing process, combined
with deflating and re-packing the balloon envelope, takes a while longer.
When the pilot is ready to land, he or she
discusses possible landing sites with the ground crew (via an onboard
radio). They need to find a wide open space, where there are no power
lines and plenty of room to lay out the balloon. As soon as the balloon is
in the air, the pilot is constantly looking for suitable landing sites, in
case there is an emergency.
The balloon landing can be
a little rough, but an experienced pilot will bump along the ground to
stop the balloon gradually, minimizing the impact. If the ground crew has
made it to the landing site, they will hold the basket down once it has
landed. If the balloon isn't in a good position, the crew pulls it along
the ground to a better spot.
Click on the images for a high-resolution
The ground crew sets out a
ground tarp, to protect the balloon from wear and tear. Then the pilot
opens the parachute valve all the way, so the air can escape out the top
of the balloon. The ground crew grabs a cord attached to the top of the
balloon, and pulls the envelope over onto the tarp.
Once the balloon envelope
is down on the ground, the crew begins pushing the air out. When the
balloon is flattened, the crew packs it into a stuff sack. This whole
process is a lot like packing up a giant sleeping bag.