Hot air balloons are not only stunning to look at, but they’re also a lot of fun to ride in. If you’ve ever seen one fly overhead, you know they look like large colorful balloons floating through the air.
They’re also a lot like regular balloons, but instead of being filled with helium, they are filled with hot air. (The gas inside the balloon is heated by a propane burner, which is called a burner.)
“Hot air balloons” might be a misnomer to some people, as the hot air that keeps them afloat isn’t actually that hot.
In fact, it’s about the same temperature as the air in a room. What makes the air hot is the fact that it’s lighter than the cold air surrounding it, which makes it rise up into the sky.
That’s why a hot air balloon can move up and down on the wind without having to burn more gas.
A hot air balloon is a lighter than air aircraft which is propelled by heating the air inside the balloon and letting the warmer air rise, taking the balloon with it.
The basic principle is the same as that of a hot air balloon: the heated air inside the balloon is less dense than the cooler air in the surrounding air, so the balloon rises.
History of the hot air balloon
The first hot air balloons were created more than two hundred years ago. They were a very exciting invention and soon the hot air balloon became a common sight at fairs and at festivals.
In 1783, Frenchman, Dr. Jean-Pierre Blanchard, made the first manned flight in a hot air balloon.
He and his American co-pilot, John Jeffries, rose to an altitude of 1,800 feet (550 m) and flew for 5 minutes and 22 seconds.
This was just two years after the Montgolfier Brothers, Joseph-Michel and Jacques-Etienne, had made the first unmanned flight with a paper and hot air balloon.
In the following years these flights became more and more common but at the beginning of the 19th century they were still mostly viewed as a novelty act.
The hot air balloon (also called Montgolfier balloon) is a lighter than air aircraft that is propelled through the air by heated air.
In 1783, a French engineer, Jacques Charles, and an Italian aeronaut, Torquato Torelli, first demonstrated this principle to the French Academy of Sciences by using a large, light-weight, porous bag (called an envelope) filled with heated air.
The envelope was made of two layers of silk. The gas in the balloon expands, causing the balloon to float upwards, but the envelope is not able to stretch sufficiently to allow the gas to escape.
How it is controlled
The pilot makes sure that the air in the balloon is hot by using a propane burner to heat the air inside the balloon.
The burner heats the air inside the balloon, changing its density. The balloon gets more buoyant when it has less density, so it rises.
The burner also needs to be adjusted to keep the air hot. The temperature of the air inside the balloon must be kept within a narrow range.
This can be done by adjusting the burner. As the balloon rises, the air expands and cools, so the pilot must regulate the temperature by adjusting the burner to account for this expansion.
The balloon is filled with a lifting gas and lifted into the air as it is filled, the envelope is made of many joined panels that allow it to change shape. The panels are made from fabric such as latex, nylon or a cotton/polyester blend.
As the gas inside the envelope is less dense than the surrounding air, as the pressure is reduced the volume will increase.
The varying volume causes the balloon to take on different shapes. The amount of lift is controlled by releasing or pumping hot air into the envelope.
An inflated envelope, or bag, is heated by burning a fuel such as propane, butane, or a mixture of the two.
This produces hot air, which is then forced by the pilot through a vent at the top of the envelope. As the air expands and cools, it creates lift.
The lift force is directed in a direction opposite that of the Earth’s gravity, and the balloon rises. The pilot uses a burner to control the balloon’s altitude.
The pilot of a balloon must ensure that the balloon does not fly too high. If the balloon flies too high, the air pressure will be too low, and the balloon will lose lift.
Safety of hot air ballooning
Hot air ballooning is arguably a safe way to have an aerial view of a situation. However, pilots and passengers need to be aware of the inherent risks of this type of travel.
A hot air balloon is an aerial maze without any safeguard. A hot air balloon is a fragile balloon filled with air at high temperature. There is always a risk of fire and explosion.
Wind is the main enemy of hot air ballooning, because of the wind it can be stopped several times. This can make the journey longer than expected. Although the odds of a hot air balloon accident are low, there are still some safety measures you should take before getting in the basket.
Most hot air balloon accidents occur when the balloon hits a power line or tree, but you can greatly reduce your risks by being aware of your surroundings.
In hot air ballooning, there are the risks of injury from a landing accident or an accident during flight. On the ground, there is also the risk of a propane or natural gas leak, and there are always the dangers of fire and explosions.
To minimize these risks, hot air ballooners should always wear their seat belts, parachutes, and harnesses during flight and landing.