Terminology

This page will explain the most common terms used within the LTA-community.

- Lighter Than Air (LTA)
LTA-ships are buoyant in air because they have average densities lower than that of air, resulting in an upward lift.

- Airships
Airships are self-propelled, lighter-than-air aircraft with means of controlling the direction of flight, they are also known as dirigibles and they can be classified in multiple subtypes (see below.)

- Rigid-airships
The envelope of the airship is kept in shape by an internal framework, containing a number of ballonets or cells containing a lifting gas.

- Semi-rigid Airships
The envelope of the semi-rigid airship is supported by a truss or stiff keel along its length, located inside or outside the main evelope. The shape of the ship is primarily maintained by internal gas pressure.

- Non-rigid Airships (Also Known As Blimps)
Blimps are airships without an internal structure or keel. The shape of the envelope is maintained by internal gas pressure.

- Zeppelins
Originally, Zeppelins were rigid airships produced by the Zeppelin GmbH company during the end of the 19th century and the beginning of the 20th century.
Because of their incredible success, the word 'Zeppelin' has become a synonym for any rigid airship. The successor of the company, Zeppelin NT, now produces semi-rigid airships.

- Aerostats
Aerostats gain their lift due to the use of a buoyant gas. They include unpowered balloons as well as airships. The unpowered balloons can be free flying or tethered to a surface.

- Heavier Then Air (HTA)
HTA-crafts rely on aerodynamic lift created by air passing over an airfoil (wing). Examples HTA-crafts are airplanes, helicopters and gliders, but also hybrid airships that partly rely on buoyancy and partly rely on stationary or rotary wings to create aerodynamic lift, such as Dynastats and Rotastats.

- Dynastats
Dynastats are a type of HTA-ship that rely on additional lift by flying through the air. Configurations have included deltoid (triangular), lenticular (circular) or flattened hulls, or adding a stationary wing(s).

- Rotastats
Rotastats are a type of HTA-ship that rely on additional lift from powered rotors similar to a helicopters.

*Note - The term dirigible is a synonym for any type if airship.

More technical terms

- Envelope
The envelope of an aerostat is the outer surface or 'skin', often surrounding one or more gas-bags and/or ballonets within it.

- Ballonets
Ballonets are air bags inside the outer envelope of an airship which, when inflated, reduces the volume available for the lifting gas, making it more dense.

- Gondola
An external equipment or control/passenger compartments attached to an airship/dirigible.

- Buoyancy
The upward force exerted by the surrouding medium or fluid in which a body is immersed, Example: When you push a soccerball down into a body of water, the water will exert an upward force on the soccerball. Now replace the soccerball with an airship and the water with air and you got the same principle at work.

- Ballast
Weights that can be carried on LTA-ships in order to reduce the effects of buoyancy.

*Note - This page will be updated with time, by adding more terms and/or improving the existing definitions.