Definition
A lighter-than-air aircraft consisting of a large fabric envelope open at the bottom, a burner that heats the air inside the envelope, and a basket suspended below for the pilot and passengers. The heated air inside the envelope is less dense than the cooler outside air, producing the lift that allows the balloon to rise and stay aloft. Altitude is controlled by adjusting the temperature of the air inside the envelope; horizontal direction is determined by the wind.
Plain English
A balloon that floats because the air inside it is heated and becomes lighter than the air outside. A burner heats the air, the balloon rises, and the wind carries it along.
Context Anchor
Seen in aviation history, basic aircraft categories, and balloon flight discussions.
Derivation
Balloon comes from the Italian 'pallone,' meaning a large ball. The 'hot air' part simply describes how lift is produced — by heating the air inside the envelope so it becomes lighter than the surrounding air.
Why Pilots Care
Hot air balloons are the starting point of powered human flight and are still flown today under FAA regulations as a category of aircraft. Understanding how they generate lift introduces the basic principle that warmer air is less dense than cooler air — a concept that reappears throughout aviation in topics like density altitude and aircraft performance.
Grounding Statement
Picture a large fabric bag of warmed air lifting a basket because the warm air inside is lighter than the cooler air around it.
Intuition Check
A hot air balloon is not held up by smoke, helium, or an engine pushing it upward. It floats because warm air inside the balloon is lighter than the cooler outside air.
Example Sentence 1
The earliest recorded human flight took place in a hot air balloon built by the Montgolfier brothers in France.
Example Sentence 2
Early experiments with the hot air balloon demonstrated that heated air could lift objects into the sky.