United Arab Emirates (UAE). Dubai. Balloon Adventures Dubai. Two hot air balloons fly over the desert. A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket, which carries passengers and a source of heat, in most cases an open flame caused by burning liquid propane. The heated air inside the envelope makes it buoyant since it has a lower density than the colder air outside the envelope. As with all aircraft, hot air balloons cannot fly beyond the atmosphere. The envelope does not have to be sealed at the bottom, since the air inside the envelope there is at about the same pressure as the surrounding air. In modern sport balloons the envelope is generally made from nylon fabric and the inlet of the balloon (closest to the burner flame) is made from a fire resistant material such as Nomex. The United Arab Emirates (UAE) is a country in Western Asia at the northeast end of the Arabian Peninsula. 17.02.2020 © 2020 Didier Ruef