The hot air balloons

The hot air balloon is the oldest successful human-carrying flight technology. On November 21, 1783, in Paris, France, the first manned flight was made by Jean-Francois Pilatre de Rozier and Francois Laurent d’Arlandes in a hot air balloon created by the Montgolfier brothers.
Modern hot air ballons, with an onboard heat source, were pioneered by Ed Yost, beginning in the 1950s. His work resulted in his first successful flight, on October 22, 1960.

The first modern-day hot air balloon to be built in the United Kingdom (UK) was the Bristol Belle in 1967. A range of envelope sizes is available. The smallest, one-person, basket-less balloons (called “Hoppers” or “Cloudhoppers”) have as little as 21,000 ft (595 m) of envelope volume (for a perfect sphere this would mean a radius of around 5.22 m (17 ft)). At the other end of the scale are the balloons used by large commercial sightseeing operations that carry well over two dozen people and have envelope volumes of up to 600,000 ft (16,990 m). However, most balloons are roughly 100,000 ft (2,832 m) and carry 3 to 5 people.

First manned flight

Hot air balloons are able to fly to extremely high altitudes. On November 26, 2005, Vijaypat Singhania set the world altitude record for highest hot air balloon flight, reaching 21,027 meters (68,986 feet). He took off from downtown Bombay, India, and landed 240 kilometers (149 miles) south in Panchale. The previous record of 19,811 m (64,997 ft) had been set by Per Lindstrand on June 6, 1988 in Plano, Texas. As with all unpressurized aircraft, oxygen is needed for all crew and passengers on any flight that exceeds an altitude of about 12,500 ft (3,810 m).

Today

Today, hot air balloons are used primarily for recreation, and there are some 7,500 hot air balloons operating in the United States. Recently, balloon envelopes have been made in all kinds of shapes, such as hot dogs, rocket ships, and the shapes of commercial products, like you can see in these pictures. To help ensure the safety of pilot and passengers, a hot air balloon may carry several pieces of safety equipment. In order to relight the burner, in case the pilot light goes out and the optional piezo ignition fails, the pilot should have ready access to a flint spark lighter.
Many systems, especially those that carry passengers have completely redundant fuel and burner systems: two fuel tanks, connected to two separate hoses, which feed two distinct burners. This enables a safe landing in the case of a clog somewhere in one system or if a system must be disabled because of a fuel leak.Hot air balloons that can be propelled through the air rather than just being pushed along by the wind are known as airships or, more specifically, thermal airships.

Construction

A hot air balloon for manned flight uses a single-layered, fabric gas bag (lifting “envelope”), with an opening at the bottom called the mouth or throat. Attached to the envelope is a basket, or gondola, for carrying the passengers. Mounted above the basket and centered in the mouth is the “burner” which injects a flame into the envelope, heating the air within. The heater or burner is fueled by propane, a liquefied gas stored in pressure vessels, similar to high pressure forklift cylinders.