õhulaeva

õhulaev is the Estonian word for airship. An airship is a type of lighter-than-air aircraft that can be steered and propelled through the air by means of engines and rudders. Unlike balloons, which are at the mercy of the wind, airships can be directed to a specific destination.

The principal structural element of an airship is its envelope, which contains a lifting gas. Historically, hydrogen was widely used due to its excellent lifting capacity, but its extreme flammability led to a preference for helium, a non-flammable gas, in later designs. The envelope is typically a large, elongated bag, often shaped to reduce aerodynamic drag.

Beneath the envelope, a hull or gondola is suspended, which houses the crew, passengers, cargo, and propulsion systems. These propulsion systems typically consist of engines driving propellers. Control surfaces, such as rudders and elevators, are also attached to the airship to allow for directional control and changes in altitude.

Airships were prominent in the early 20th century for transportation and military purposes, particularly for reconnaissance and bombing. Famous examples include the German Zeppelin airships. However, a series of accidents, most notably the Hindenburg disaster, significantly curtailed their widespread use. Despite this, there is ongoing interest in airships for various applications, including cargo transport, surveillance, and tourism, owing to their potential for long endurance, low operating costs, and environmental benefits.