A lifting gas or lighter-than-air gas is a gas that has a density lower than normal atmospheric gases and rises above them as a result, making it useful in lifting lighter-than-air aircraft. Only certain lighter-than-air gases are suitable as lifting gases. Dry air has a density of about 1.29 g/L (gram per liter) at standard conditions for temperature and pressure (STP) and an average molecular mass of 28.97 g/mol, and so lighter-than-air gases have a density lower than this.
>>>PUT SHARE BUTTONS HERE<<<
👉 Lifting gas in the context of Airship
An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the surrounding air to achieve the lift needed to stay airborne.
In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability, but the inherent flammability led to several fatal accidents that rendered hydrogen airships obsolete. The alternative lifting gas, helium, is not flammable, but is rare and relatively expensive. Significant amounts were first discovered in the United States and for a while helium was only available for airship usage in North America. Most airships built since the 1960s have used helium, though some have used hot air.
In this Dossier
Lifting gas in the context of Aerostat
An aerostat (from Ancient Greek ἀήρ (aḗr) 'air' and στατός (statós) 'standing', via French) or lighter-than-air aircraft is an aircraft that relies on buoyancy to maintain flight. Aerostats include unpowered balloons (free-flying or tethered) and powered airships.
The relative density of an aerostat as a whole is lower than that of the surrounding atmospheric air (hence the name "lighter-than-air"). Its main component is one or more gas capsules made of lightweight skins, containing a lifting gas (hot air, or any gas with lower density than air, typically hydrogen or helium) that displaces a large volume of air to generate enough buoyancy to overcome its own weight. Payload (passengers and cargo) can then be carried on attached components such as a basket, a gondola, a cabin or various hardpoints. With airships, which need to be able to fly against wind, the lifting gas capsules are often protected by a more rigid outer envelope or an airframe, with other gasbags such as ballonets to help modulate buoyancy.
Lifting gas in the context of Blimp
A non-rigid airship, commonly called a blimp (/blɪmp/), is an airship (dirigible) without an internal structural framework or a keel. Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of their lifting gas (usually helium, rather than flammable hydrogen) and the strength of the envelope to maintain their shape. Blimps are known for their use in advertising, surveillance, and observation due to their maneuverability, slow speeds and steady flight capabilities.
Lifting gas in the context of Thermal airship
A thermal airship is an airship that generates buoyancy by heating air in a large chamber or envelope. The lower density of the interior hot air compared to the cooler ambient air causes an upward force on the envelope. This is very similar to a hot air balloon, with the notable exception that an airship has a powered means of propulsion, whilst a hot air balloon relies on winds for navigation. An airship that uses steam would also qualify as a thermal airship.
Other types of airships use a gas that is lighter than air at ambient temperature, such as helium, as a lifting gas.
Lifting gas in the context of Goodyear Blimp
Goodyear built hundreds of airships throughout much of the 20th century, mostly for the United States Navy. Beginning with the Pilgrim in 1925, Goodyear also built blimps for its own commercial fleet. In 1987, a hostile takeover bid forced Goodyear to sell its subsidiary Goodyear Aerospace, eventually ending the company's construction of lighter-than-air craft. The last blimp built by Goodyear, Spirit of Innovation, was retired in 2017.
Lifting gas in the context of Rigid airship
A rigid airship is a type of airship (or dirigible) in which the envelope is supported by an internal framework rather than by being kept in shape by the pressure of the lifting gas within the envelope, as in blimps (also called pressure airships) and semi-rigid airships. Rigid airships are often commonly called Zeppelins, though this technically refers only to airships built by the Luftschiffbau Zeppelin company.
In 1900, Count Ferdinand von Zeppelin successfully performed the maiden flight of his first airship; further models quickly followed. Prior to the First World War, Germany was a world leader in the field, largely attributable to the work of von Zeppelin and his Luftschiffbau Zeppelin company. During the conflict, rigid airships were tasked with various military duties, which included their participation in Germany's strategic bombing campaign. Numerous rigid airships were produced and employed with relative commercial success between the 1900s and the late 1930s. The heyday of the rigid airship was abruptly ended by the destruction of the Hindenburg by fire on 6 May 1937. The disaster not only destroyed the biggest zeppelin in the world, but the film caused considerable reputation damage to rigid airships in general. Several nations had ended military rigid airship programs after serious accidents earlier in the decade, but widespread public safety concerns in the wake of the Hindenburg disaster led several nations to permanently ground their existing rigid airships and scrap them in subsequent years.