Hot air ballooning balloon accidents are rare, according to statistics from the National Transportation Safety Board (NTSB). The first clearly recorded instance of a balloon carrying passengers used hot air to generate buoyancy and was built by the brothers Joseph-Michel and Jacques-Etienne Montgolfier in Annonay, France. After experimenting with unmanned balloons and flights with animals, the first "tethered" balloon flight with humans on board took place on October 19, 1783 with the scientist Jean-François Pilâtre de Rozier, the manufacture manager, Jean-Baptiste Réveillon and Giroud de Villette, at the "Folie Titon" in Paris. The first "free" flight with human passengers was on November 21,
Hot air balloon indicators would be useless) and direction. The combined mass of an average system can be calculated as follows: using a density of 0.9486 kg/m³ for dry air heated to 210 °F (99 °C). Increasing the air temperature inside the envelope makes it less dense than the surrounding (ambient) air. The balloon floats because of the buoyant force exerted on it. This force is the same force that acts on objects when they are in water and is described by Archimedes' principle. The amount of lift (or buoyancy) provided by a hot air balloon depends primarily upon the difference between the