Delayed response

One of the tricks involved in flying a balloon is learning to deal with the delayed response. To slow or stop a descent requires the pilot to open a burner blast valve. This sends hot combustion exhaust through the mouth into the envelope where it expands and forces some cooler air out of the mouth. This lightens the total weight of the system and increases its buoyancy, but not immediately. From the time that the burner is lit until the balloon slows or stops its descent can take 30 seconds or more, depending on its rate of descent, how cold it has become, and how powerful the burner. This delay requires a great deal of anticipation on the part of the pilot.