An airship or dirigible is a buoyant lighter-than-air aircraft that can be steered and propelled through the air. Unlike aerodynamic vehicles such as fixed-wing aircraft and helicopters which stay aloft by moving an airfoil through the air in order to produce lift, aerostatic craft such as airships and balloons stay aloft by filling a large cavity with lighter than air gas.
Airships were the first aircraft to make controlled, powered flight. They were widely used prior to the 1940s. Their use decreased over time as their capabilities were surpassed by those of airplanes. A series of high-profile accidents, including the 1937 burning of the hydrogen-filled Hindenburg at Lakehurst, New Jersey, furthered their decline. Airships are still used today in certain niche applications however, including advertising and sightseeing.