Duties of the crew typically include launch preparation, following the balloon flight in the chase vehicle, obtaining permission of the landowner for the balloon landing and retrieval, keeping spectators out of the landing area, and insuring that gates are left as they are found and that property is not damaged. In the air, the complete system, including the weight of the air inside the envelope, will weigh about 2 tons. It is carried in liquid form, under pressure in the tanks, and supplied to the burners through flexible hoses. The burner flame may shoot out 6 to 8 feet in the blast that the pilot controls. A typical flight lasting 1 hour, with 3 people aloft, will consume about 20 gallons of propane.
Some balloons have two independent burner and fuel systems for added safety.
Since a balloon travels with the wind, it is not possible to determine an exact landing site prior to launch. However, a pilot is able, through the study of wind currents, to determine the general direction of the flight. Balloon pilots must have an aircraft pilot's license especially for balloons. Currently there are more than 3,200 balloons in the United States. Generally speaking, they don't.