Return to the heady days of the 1920s, when the strategic bombers of World War I were still seen as a viable alternative to the rickety airplanes of the day. While the acting is wooden and stereotypical (brave fly boy, conservative large "ship" commander, frail stay at home wife), just seeing the footage of the long-gone rigid airships is worth the tariff.
The best shot is near the beginning, when the camera pans upward, past round naval observation balloons, surprisingly modern non-rigid 'blimps' flying in formation, and then (above them all) the massive (larger by a factor of five or more) dirigible of the title.
Scenes of the real dirigible flying, landing, dropping naval "parachute men", and hooking up to the mooring mast are also worth the time.
Not so much the rest of the movie. Period special effects do not hold up well under modern scrutiny, and the silly pining away of Fay Wray really gets in the way.
(Odd too is the fact that the Review Board passed on a plot line involving an obviously cheating on her husband woman, including a racy scene at the beach where the two have been sharing an afternoon swimming, barely clad by 1930s standards). Perhaps this was during the Hays to Breen transition period, and it slipped under the radar.)
Note that the poor USS Pensacola (a mythical Navy airship; there was a cruiser by that name but never an aircraft) doesn't catch fire, despite the dramatic breakup of the structure. US airship were filled with helium (due to the almost monopolistic corner of the world's supply of helium by the US), and although they suffered through a series of dramatic crashes (Shenandoah, Akron, Macon), none of them caught fire a la the Hindenburg.
Buy it in the newly released DVD for the flying, and try to ignore the rest. (Oh, and Fay Wray looks far better as a brunette than she ever did as a blonde.)
