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 fabric needs to be replaced. Many balloon pilots operate their envelopes at temperatures significantly less than the maximum to extend envelope fabric life. The lift generated by 100,000 ft³ (2831.7 m³) of dry air heated to various temperatures may be calculated as follows: The density of air at 20 °C, 68 °F is about 1.2 kg/m³. The total lift for a balloon of 100,000 ft³ heated to (99 °C, 210 °F) would be 1595 lb, 723.5 kg. This is just enough to generate neutral buoyancy for the total system mass (not including the heated air trapped in the envelope, of