Hot air balloon

Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and a source of heat, in most cases an open flame caused by burning liquid propane.

In the 18th century the Portuguese Jesuit priest Bartolomeu de Gusmão in colonial Brazil envisioned an aerial apparatus named Passarola, which was the predecessor of the hot air balloon.

[5] In 1709 John V of Portugal decided to fund Bartolomeu de Gusmão's project following a petition made by the Jesuit priest,[6] and an unmanned demonstration was performed at Casa da Índia in the presence of John V and the queen, Maria Anna of Austria, with the Italian cardinal Michelangelo Conti, two members of the Portuguese Royal Academy of History, one Portuguese diplomat and one chronicler serving as witnesses.

[7] To support this theory, in 1975 he designed and piloted the Nazca Prehistoric Balloon, claiming to have used only methods and materials available to the Pre-Inca Peruvians 1,000 years ago.

[8][9] The French brothers Joseph-Michel and Jacques-Étienne Montgolfier developed a hot-air balloon in Annonay, Ardèche, France, and demonstrated it publicly on September 19, 1783, making an unmanned flight lasting 10 minutes.

[2] King Louis XVI had originally decreed that condemned criminals would be the first pilots, but de Rozier, along with Marquis François d'Arlandes, petitioned successfully for the honor.

[15] Modern hot air balloons, with an onboard heat source, were developed by Ed Yost and Jim Winker, beginning during the 1950s; their work resulted in his a first successful flight on October 22, 1960.

On November 26, 2005 Vijaypat Singhania set the world altitude record for highest hot air balloon flight, reaching 21,027 m (68,986 ft).

Designed to fly in the trans-oceanic jet streams, the Pacific Flyer recorded the fastest ground speed for a manned balloon at 394 km/h (245 mph).

Steve Fossett, flying solo, exceeded the record for briefest time traveling around the world on 3 July 2002 on his sixth attempt,[18] in 320 h 33 min.

[19] 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.

The heater or burner is fueled by propane, a liquefied gas stored in pressure vessels, similar to high-pressure forklift cylinders.

[23] During the manufacturing process, the material is cut into panels and sewn together, along with structural load tapes that carry the weight of the gondola or basket.

At the other end of the scale, balloons used by commercial sightseeing operations may be able to carry well over two dozen people, with envelope volumes of up to 17,000 m3 (600,000 cu ft).

[34] Finally, some specialized balloons are designed to minimize aerodynamic drag (in the vertical direction) to improve flight performance in competitions.

The burner unit gasifies liquid propane,[40] mixes it with air, ignites the mixture, and directs the flame and exhaust into the mouth of the envelope.

Propane fuel tanks are usually cylindrical pressure vessels made from aluminium, stainless steel, or titanium with a valve at one end to feed the burner and to refuel.

This is just enough to generate neutral buoyancy for the total system mass (not including the heated air trapped in the envelope, of course) stated in the previous section.

For typical atmospheric conditions (20 °C or 68 °F), a hot air balloon heated to 99 °C (210 °F) requires about 3.91 m3 of envelope volume to lift 1 kilogram (equivalently, 62.5 cu ft/lb).

[58] Observation balloon usage skyrocketed in Britain by the Royal Engineers at the end of the 19th Century, deploying to Sudan in 1885 and to South Africa during the Second Boer War from 1899 to 1902.

This consists of a hip belt and a webbing line that together allow for some movement while preventing the pilot from being ejected from the basket during a hard landing.

At a minimum, the pilot should wear leather or flame-retardant fiber (such as nomex) gloves, so that they may shut off a gas valve in the case of a leak, even if there is a flame present; quick action in this regard can turn a potential catastrophe into a mere inconvenience.

This makes such fabrics very much unsuitable to wear near high temperatures, since non-flame-retardant thermoplastics will melt onto the wearer, and most hydrocarbons, whether fibrous or not, are suitable to use as fuels.

Many pilots also advise their passengers to wear similar protective clothing that covers their arms and legs, as well as strong shoes or boots that offer good ankle support.

Finally, some balloon systems, especially those that hang the burner from the envelope instead of supporting it rigidly from the basket, require the use of helmets by the pilot and passengers.

As aircraft made of fabric and that lack direct horizontal control, hot air balloons may occasionally require repairs to rips or snags.

This prevents mold and mildew from forming on the fabric and abrasion from occurring during packing, transport, and unpacking due to contact with foreign particles.

In the event of a landing in a wet (because of precipitation or early morning or late evening dew) or muddy location (farmer's field), the envelope should be cleaned and laid out or hung to dry.

[65] In the UK, the person in command must hold a valid Private Pilot's Licence issued by the Civil Aviation Authority specifically for ballooning; this is known as the PPL(B).

A pilot does not need a license to fly an ultralight aircraft, but training is highly advised, and some hot-air balloons meet the criteria.