Hot Air Balloons - How Do They Work?

Hot air ballooning is our first form of manned flight.to escape, reducing the temperature of the air within
How does it work? What allows a hot air balloon tothe balloon. This cooler air is lighter than the balloon
keep flying?weight and hence the balloon descends. The descent
There are some basics principles in play here, namely,can be controlled or reversed by releasing more
that hot air rises and cold air descends. So the hot airpropane gas and firing the burner.
that is released in to the balloon pushes it skywards3. Directional movement
and ensures it stays afloat.There are limitations in the direction a pilot can take a
There are three component parts to a hot airballoon as this is determined by the wind. However,
balloon, the envelope (which is the fabric which holdsthe wind blows in different directions at different
the air); the basket (which is where the pilot andheights so a degree of maneuverability is possible. So
passengers will stand); and the burner (which propelsto move horizontally, the pilot will go up or down to
the heat up in to the balloon). The pilot has the abilityfind a layer of air where the wind is blowing in the
to ascend, descend and move in a certain direction.desired direction.
1. Ascending4. Landing
To ascend, the pilot releases propane gas in to theWhere the balloon lands is very dependent on the
envelope, and this fires the burner, sending a flame inwind, but in the right conditions, an experienced pilot
to the envelope. The more gas that is released, thecan have considerable maneuverability. He will be in
greater the flame and the faster the balloon rises.regular radio contact with his ground crew and they
2. Descendingwill agree a landing site during the course of the flight.
To descend, the pilot has to allow the air in theAfter landing, the "chase" crew will pack away the
envelope to cool. He does this by pulling a cord whichballoon and everyone then generally returns to the
opens a valve at the top of the balloon. This is calledoriginal launch location.
the Parachute Valve and opening it allows the hot air