HOT AIR BALLOON
Curiosity Questions
• How many layers of atmosphere does Earth have? (Six.)
• Why is it that hot air rises? (Buoyancy. Hot air is less dense, because it expands, so it “floats” on cooler, denser air.)
• What’s the highest a hot air balloon has ever gone? (21,027 metres above sea level, set by 67-year-old Vijaypat Singhania
in 2005; gas-filled balloons can go a lot higher.)
Science Themes
Ballooning is flight, and flight is science. Humans have been using hot air balloons to fly since the Montgolfier brothers in 1783.
The oldest recorded hot air balloons, sky lanterns, were unpiloted and used for sending messages and for celebrations as far back
as the 3rd Century CE. Balloons have been used for numerous purposes, ranging from entertainment to weather monitoring to
military applications.
The hot air balloon in use here at Beakerhead is small by hot air balloon standards, at about 2.5 million litres. A normal balloon
used for moving humans will range from 900,000 litres to about 21 million litres. The average person breathes about 11,000 litres
of air in a day, so if one of the big balloons was full of normal air, you could breathe in it for more than five years.
The “balloon” part of the balloon is called the envelope. This one is made from ripstop Nylon and has a bottom
layer made of Nomex, a flame-resistant material used in firefighting apparel. The Montgolfiers made their early
balloons out of fabric, and the first balloon to carry a person was made of simple silk taffeta, with a layer of
alum -- a chemical similar to what is found in fire extinguishers -- to protect against flame. The basket is made
of wood and aluminum, covered in wicker, and held to the envelope with steel cables.
The “engine” of the balloon is called a burner. A burner is a propane flame that can put out 10 million BTUs (3 megawatts) of heat
energy. A home barbecue might put out 20,000-80,000 BTU, and a home furnace as much as 200,000 BTU. Bigger balloons will use
multiple burners in arrays. Interview.
HOT AIR BALLOON
Science Themes
The materials for ballooning haven’t changed much since the 1960s, when the US Navy
started their ballooning program and introduced modern materials.
Going up in a hot air balloon is distinct from powered flight, like in an airplane or
helicopter.
In a balloon, the pilot can’t steer the vessel directly, but can make it rise or fall,
either by adding heat to the air or by opening a release valve and letting some
hot air out.
To guide the balloon, the pilot must know what the air currents are doing above and
below the balloon. Air is a gas, but acts like a liquid, in that it has different currents at
different altitudes.
The air at one level might be moving east, but the air just above it might be moving west.
By moving the balloon up or down, the pilot will guide the balloon into air currents that
are moving in the direction they want to go.
Because the balloon is moving at the same speed as the surrounding air, a passenger
won’t feel any wind. The average height the Beakerhead balloon will rise to is
approximately 300-600 metres.
Makers and Making
PUBLIC SPEAKER | Gary “The Balloon Guy” Fehr – Gary joined a balloon ground chase crew in 1995. Ground crews are required to
follow the balloon in the air and subsequently pack up and return to base at the end of the flight. Gary completed his training and
certification as a pilot in 1997, and has been licensed by Transport Canada to fly balloons ever since. Fehr operates Air-Ristocrats
Balloon Rides and Promotions out of Alix, Alberta, just east of Red Deer.