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How a hot-air balloon works: a journey to the heart of the skies
Hot-air balloons fascinate young and old with their majestic ascent and smooth flight. But how exactly does a hot-air balloon work? Marie (8) and Grégoire (9) put the question to Gaël, hot-air balloon pilot and founder of Ballons du Léman. Discover, in simple words, the principle of flight, the different parts of a hot-air balloon and how a flight in Switzerland works.
How does a hot-air balloon work? The principle of hot air
Marie: What makes a hot-air balloon fly?
Gaël: A hot-air balloon works on a simple principle.Hot air is lighter than cold air. By heating the air inside the envelope (the balloon) with propane-fuelled burners, the balloon becomes lighter than the surrounding air and rises into the sky. To ascend, the pilot activates the burners, heating the air inside the balloon. To descend, the pilot simply allows the air to cool naturally, or opens a valve at the top of the envelope. This opening, also known as the “parachute”, allows the hot air to escape and the balloon to lose altitude. It’s this subtle interplay between warm and cooler air that enables the pilot to control the balloon’s altitude throughout the flight.
The key elements of a hot-air balloon
Grégoire: What are the important elements of a balloon?
Gaël: A hot-air balloon is made up of several essential elements that work together.
- The envelope: This large, strong fabric balloon contains the hot air. It is designed to withstand heat and pressure during Flight.
- The nacelle: The wicker basket housing the pilot and passengers. It’s sturdy, cushions landing shocks and offers warm contact with the material.
- Burners: These produce a powerful flame to heat the air inside the envelope. The pilot operates them to climb or maintain altitude.
- Propane tanks: These supply gas to the burners, and are securely fixed in the nacelle.
- The parachute or valve: An opening at the top of the envelope that the pilot can operate to let the hot air out and lower the balloon.
All these elements are controlled by a trained and certified pilot. To find out more about our team and our way of flying, you can discover the founding pillars of Ballons du Léman and our team.
The main stages of a hot-air balloon Flight
Marie: What’s a balloon flight like, from start to finish?
Gaël : A hot-air balloon flight is a complete adventure that begins long before you leave the ground.
- Preparation and inflation
The team deploys the envelope on the ground and begins by inflating it with a cold-air blower. Once the balloon is partially inflated, the burners take over to heat the air and gradually straighten out the balloon. It’s a spectacular moment that passengers can watch up close. - Take-off
When the air is sufficiently warm, the balloon becomes fully erect and the basket gently detaches from the ground. The floating sensation is very different from that of a plane. Everything happens slowly and smoothly. - Flight
A hot-air balloon is not steered like a car or a plane. It moves with the wind. The pilot chooses his altitude to take advantage of different wind layers and adjust the trajectory slightly. The result is a unique panorama of lakes, villages and the Alps. To help you prepare for this step, read our article “Getting ready for a hot-air balloon flight”. - Landing
After about an hour in the air, the pilot finds a clear spot. He gradually reduces altitude and gently lands the balloon. The ground crew follows the balloon throughout the flight to help with the landing. - Folding and sharing
Once on the ground, it’s time to fold the envelope and put the equipment away. This is a convivial moment in which passengers can participate. The experience often ends with a toast or snack. We talk more about this in our article “And after the flight? the little extras that make all the difference”.
Can anyone fly in a hot-air balloon?
Grégoire: Would you recommend a balloon flight to everyone?
Gaël : Yes, as long as the safety conditions are respected, it’s an experience you should have at least once in your life. A hot-air balloon Flight is generally accessible to a wide public. You simply need to be able to stand upright for the duration of the flight and climb into the basket. If you have any questions about health, age or special requirements, please consult our Practical info page and our Frequently asked questions section.
At Ballons du Léman, we are committed to making the experience as inclusive as possible. That’s why we’ve developed gondolas and Flights adapted to welcome everyone, including people with reduced mobility. If you’re in any doubt, just get in touch with our team. We’ll be happy to advise you on the most suitable formula.
A hot-air balloon flight is a timeless, magical way to discover the French-speaking part of Switzerland from the sky, between lakes and mountains, in complete serenity.
FAQ : How does a hot-air balloon work?
A hot-air balloon rises thanks to the principle of hot air. Air heated by burners becomes lighter than the surrounding air. By heating the air inside the envelope, the balloon becomes lighter than the surrounding air and rises. To descend, the pilot allows the air to cool, or opens a valve to evacuate some of the hot air.
No, a hot-air balloon is not steered like a plane or a car. It moves with the wind. The pilot can, however, adjust the altitude to take advantage of different wind layers and slightly influence the trajectory. The choice of take-off zone is also very important to anticipate the general direction of the flight.
The average duration of a hot-air balloon Flight is about one hour in the air. Including preparation, inflation, landing, balloon folding and socializing, you should allow between three and four hours for the whole experience. Practical details are specified when booking.
Yes, hot-air ballooning is a highly supervised activity. Pilots are trained and certified, equipment is regularly inspected, and flights are organized only in favorable weather conditions. In Switzerland, Ballons du Léman applies strict safety standards to guarantee a comfortable and serene flight for all passengers.