Hot air balloon flying in a still cloudless sky.Hotair balloons are 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.Propane inflation parachute vent passenger aeronautics rising flying morning aloft thermal inflating single solo alone one solitary sports airship airships aerostat propel traditional colorful burner human-carrying flight morning dark crew lift vents sport festival sky landscape holiday travel adventure interesting atmosphere happy njoy joy summer background ballooning freedom leisure summer transport activity extreme fly hobby multicolored UHD 4K 3840X2160