Technique: Inflating a balloon

Packed, the envelope for a typical hot air balloon fits into a bag about 3 by 3 by 3 feet—not much bigger than its basket, and both can be transported in many pickup trucks or a full-size van. Yet by liftoff that same balloon will grow to be 80 feet tall and 50 feet in diameter, holding around 77,000 cubic feet of air.

Let’s look at the transformation from empty envelope to inflated balloon. Aspiring hot air balloon pilots will have to master the inflation process—as well as deflation and packing—as part of their training process.

A hot air balloon also needs:

• An altimeter provides your height above sea level, and is adjustable like the one on your airplane.
• The variometer, also used by gliders, is a rate of climb meter, similar to the vertical speed indicator in an airplane or helicopter.
• The pyrometer is a sensor near the crown, or top, of the envelope and measures the air temperature. Like your tachometer, there is a red line that should not be exceeded.
• A fuel gauge shows how much propane is left in the balloon’s fuel tanks.
• Every U.S.-based balloon must be registered with the FAA, carries an N number, and receives an annual inspection—like almost every other aircraft.