Airship

An airship or dirigible is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from large gas bags filled with a lifting gas that is less dense than the surrounding air.

In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability. Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive. Significant amounts were first discovered in the United States and for a while helium was only used for airships by the United States. Most airships built since the 1960s have used helium, though some have used hot air.

The envelope of an airship may form a single gas bag, or may contain a number of internal gas-filled cells. An airship also has engines and crew and/or payload accommodation, typically housed in one or more "gondolas" suspended below the envelope.

The main types of airship are non-rigid, semi-rigid, and rigid. Non-rigid airships, often called "blimps", rely on internal pressure to maintain the shape of the airship. Semi-rigid airships maintain the envelope shape by internal pressure, but have some form of supporting structure, such as a fixed keel, attached to it. Rigid airships have an outer structural framework which maintains the shape and carries all structural loads, while the lifting gas is contained in one or more internal gas bags or cells. Rigid airships were first flown by Count Zeppelin and the vast majority of rigid airships built were manufactured by the firm he founded. As a result, all rigid airships are sometimes called zeppelins.

Dirigible (film)

Dirigible is a 1931 American Pre-Code adventure film directed by Frank Capra for Columbia Pictures and starring Jack Holt, Ralph Graves and Fay Wray. The picture focuses on the competition between naval fixed-wing and airship pilots to reach the South Pole by air.

The female lead is assigned to Fay Wray, while the action scenes are handled by stars Jack Holt and Ralph Graves, who also played fliers two years earlier in Capra's 1929 airborne adventure, Flight. This film had been intended to emulate the success of 1927's Wings, another production with a very similar plot. Dirigible was characterized as "marginally science fictional" by scifilm.org. (Capra later planned to make a fully science fictional movie but was never able to.)

Plot

When famed explorer Louis Rondelle (Hobart Bosworth) requests the U.S. Navy's assistance in reaching the South Pole, officer Jack Bradon (Jack Holt) convinces Rear Admiral John S. Martin (Emmett Corrigan) to offer his dirigible, the USS Pensacola, for the attempt.