Hot-Air Balloon

A hot-air balloon is an aircraft that rises because heated air is less dense than the cooler air around it. Its large fabric envelope contains air warmed by burners, while a basket beneath it carries passengers and equipment. The principle is based on buoyancy: when the air inside the envelope becomes warmer, the balloon can become lighter than the surrounding air and rise.

The burners are usually powered by propane and allow the pilot to control the temperature of the air inside the envelope. The first successful manned free flight took place in France in 1783, carried out by Jean-François Pilâtre de Rozier and François d'Arlandes in a balloon built by the Montgolfier brothers.

Unlike an airplane, a hot-air balloon does not have an engine that provides forward thrust. Once airborne, it generally moves with the wind, while the pilot controls the altitude by heating the air or allowing it to cool. To descend more quickly, the pilot can also release hot air through an opening near the top of the envelope.

Because the balloon's horizontal movement depends largely on the wind, choosing the flight direction is limited. Modern balloons are mainly used for leisure flights, tourism and sporting events, although they also have scientific and educational uses. Their simple operating principle makes them a clear example of how differences in air density can produce lift.