What Are the Different Pieces of a Hot Air Balloon?

A hot air balloon is so much more than the balloon itself and the basket. Knowing what the various parts of a balloon are can help you better appreciate this flying vessel as well as feel more prepared for your flight. What are all the parts? 

These are the different pieces of a hot air balloon:

  • Envelope
  • Burners
  • Blast valve
  • Basket
  • Sparker
  • Fuel gauge
  • Pyrometer
  • Variometer
  • Altimeter
  • Maneuvering vent 

In this extensive guide, we’ll go through piece by piece, defining and explaining what makes a hot air balloon. There’s lots of great information coming up ahead, so make sure you keep reading! 

These Are the Pieces of a Hot Air Balloon


You were probably a little confused to see the term “envelope” here, right? It’s not like you’re mailing out a letter to a friend. You’re going on a hot air balloon ride. Yet that’s exactly what the balloon is technically called, the envelope. Of all the parts, this is by far the most important. Without the envelope, your hot air balloon won’t fly. 

Hot air balloons are built from durable ripstop nylon fabric with fire resistance. Although the nylon itself is not UV-resistant, most envelope manufacturers will add a coating of tough polyurethane to strengthen the nylon from the damaging, fading effects of sunlight. 

You’ve probably noticed that hot air balloons are segmented, right? This isn’t merely for decoration, as those segments have a name: gores. Gores are vertical panels or fabric sections. Each panel is woven together and, when interconnected, comprises the envelope. Even if the envelope is a single color, it’s not one piece of fabric. 

If yours is a standard-sized hot air balloon, then it may have as many as 24 panels or gores. So what keeps the gores attached? It’s not stitching, right? No, as that wouldn’t be durable enough to stand up to wind and everyday use. Instead, envelope manufacturers will use a type of webbing known as load tape. Load tape is not just installed vertically along the lengths of the gores, but horizontally as well.

The reason this webbing is known as load tape is how it’s made to hold the envelope’s load, lessening stress. With its load-bearing capabilities, the load tape can extend the longevity of the envelope. 

At the top of the envelope is a crown, also referred to as a top cap. The cap has a deflation port covered by a panel and then secured with a hook and loop attachment. If the balloon needs to be deflated, such as for landing, the balloon pilot could use the deflation port at the envelope’s crown. Starting from the crown and running downwards is the rip line. This red port line is a means of deflating that pulls air from the envelope. 


The second most important piece of a hot air balloon is the burner system, which houses one to two burners, sometimes more. While the envelope holds the air and gives you lift when hot air ballooning, the burners are what provide the hot air. Since hot air rises, you wouldn’t have buoyancy without the burner system.

Whether a hot air balloon has one burner or several, all burners point in the same direction, which is upwards towards the center of the envelope. The burners are fueled by propane much like what you use when grilling outside. 

The propane starts as a liquid when it first enters the burner system. As the liquid propane pressurizes in the internal hoses of the burner system, it soon reaches a series of coils. The coils make the propane from a liquid to a vapor. Then the pilot light sets the vapor alight, causing a tall flame (we’re talking over six feet here) to rise quickly into the envelope.

The rate of heat that this flame produces is astronomical. It’s about 12 million British thermal units or BTUs per hour. For example’s sake, your furnace at home runs on 100,000 BTUs and you know how hot that gets. Now imagine 12 million BTUs. Yes, this flame is hot! 

The balloon pilot will likely have spare propane on the balloon that’s stored in fuel tanks weighing between 10 and 20 gallons.  

Blast Valve

Now that you know how propane behaves as it travels through the internal components of the burner system, you’re probably wondering something else. Where does the propane come from? Does the balloon pilot add the propane continuously and how?

Yes, the balloon pilot controls the amount of propane in the burner system at any one time, and they do this through a handy part of the burner system known as the blast valve. When the balloon pilot engages the blast valve, they can send fuel into the burner system. Through the blast valve, the pilot also can reduce propane flow but not stop the flow altogether. They can also cease propane flow.

Your balloon pilot will use the blast valve throughout your trip to the skies. Since the burner system produces heated air, the pilot will need to keep the propane coming so you can reach a desirable altitude when ballooning and then stay there.

When the time comes to land, one method the balloon pilot will use is pressing the blast valve intermittently. This on-off pattern keeps some hot air in the envelope so you don’t come out of the sky quickly yet provides enough cool air that you can start your descent.

Interestingly, this method also allows the balloon pilot to steer, as lowering the positioning of the balloon and then angling it in the preferred direction is a safe means of travel. 


When you go to take a hot air balloon ride, you sit in the basket, also referred to as the gondola. Like a real basket, hot air balloon baskets may be made of wicker, specifically rattan. Fiberglass and aluminum are other common materials. These baskets weigh less than rattan ones. 

The shape of the basket may be rectangular for roominess. Triangular shapes are less common but still available, and square shapes are popular as well. Some hot air balloon companies may have enclosed gondolas, but the unenclosed ones provide a more authentic experience when ballooning. That’s the only way to feel the wind in your hair, after all! 

Attached to your basket are cables that connect to the envelope via cable attachment blocks. There are upwards of 24 of these cables, all made of burly stainless steel. Encircling the basket at the top is the framework, which in part reinforces the burner system. The framework is also installed for your protection, raising the lip of the basket so you feel secure when sitting.

Also, when you land, the stability of the framework is such that you might have a lower likelihood of tipping. 


The blast valve can provide hot air to the envelope, but what if the pilot light that heats the propane happens to go out? It can happen, and in that case, the balloon pilot would use the sparker.

The sparker, as the name tells you, will quickly get the pilot light burning again so the balloon can continuously have warm air. To be ultra-safe, your balloon pilot will usually have not only one sparker on their person, but two. Some pilots even bring dry matches and a cigarette lighter in case they lose both sparkers or if the sparkers fail. 

Fuel Gauge

Although hot air balloons are about the farthest thing from a car as you can get, balloons and the vehicle you drive every day do share one thing in common. They both have a fuel gauge that indicates when the tank is running empty. Or, in the case of hot air balloons, tanks.

The balloon pilot will watch the fuel gauge periodically as you fly. Before the tank is empty, they’ll refuel with more propane from one of the spare tanks.


Up at the top of the envelope near the crown is the pyrometer. This is a sensor that reads the air temperature as you float through the air. A line, often red, is the limit for which the temperature should be to continue ballooning. At that point, the fabric of the envelope could degrade, which would make ballooning unsafe.  


How does the balloon pilot know the direction you’re traveling in the hot air balloon? They rely on the variometer, which is an indication of whether the balloon is moving downward or upward. Since you’re surrounded by sky at your height, there are no visual references the balloon pilot can rely on, so the variometer certainly comes in handy. 

Variometers produce a reading of vertical speed in feet per second or minute. 


If you’ve read our other blog posts on hot air ballooning lately, then you know there’s a recommended height by the Federal Aviation Administration or FAA that your hot air balloon can legally travel. That height is no greater than 12,500 feet. 

Again, without a frame of reference, it can get pretty difficult to determine your height in a hot air balloon without the guidance of an altimeter. Measuring altitude is important not only for staying within FAA regulations, but for avoiding the onset of altitude sickness. This illness can lead to symptoms such as nausea and headache in its mildest form and only gets worse as altitude increases. 

Maneuvering Vent

The last piece of a hot air balloon is the maneuvering vent on the envelope. Connected to the vent is a maneuvering vent line that extends to the basket. When the balloon pilot wants to open the vent, they give a tug on this line. 

Why would the pilot want to open the maneuvering vent? We talked before about how pressing the blast valve off and on is one way to bring the hot air balloon down for a landing. So too is releasing air through the maneuvering vent. With less hot air in the envelope, the balloon will naturally begin lowering. 

Final Thoughts

The pieces of a hot air balloon work in tandem to create a safe, enjoyable riding experience. We hope you enjoyed learning more about how balloons work so the next time you go ballooning, you can appreciate it even more! 

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

Recent Posts

outdoortroop-21 outdoortroop-20