Ned Trumpet, Wallace Beery, is the brash Chief Aviation Pilot who commands a U.S. Navy K-class blimp stationed at the Lakehurst naval base in New Jersey. Known as “Old Gas Bag” for his tall tales, he regales his skeptical friend, Jimmy Shannon (James Gleason), with stories of a fictional son and the life heimagines for him. When the time comes to find someone to impersonate this pretend son, Trumpet soon crosses paths with Jess Weaver (Tom Drake), a young man recently made mobile again after an operation to repair his legs. Weaver agrees to the role, stepping into the part with a quiet resolve that will change both their lives, and he earns his Navy wings and a commission as an ensign as a result.
On a submarine patrol, Trumpet launches an unauthorized attack on a German submarine, ignoring orders to break off the engagement. Weaver’s bomb misses, the submarine returns fire, and the airship is struck. Trumpet seizes control and sinks the submarine, taking the heat for the act himself when a court-martial looms for disobeying orders. Weaver is recognized for his courage with the Distinguished Flying Cross, which he ceremonially hands back to his “father.” Afterward, Weaver heads to NAS Pensacola for pilot training, while Trumpet accepts a six-month grounding for his earlier defiance. The brass, however, wastes little time in reshaping careers: Trumpet is soon reassigned to help establish a new lighter-than-air base in Chittagong, on the Bay of Bengal, while Weaver advances to Ferry Command as his own career unfolds.
A new crisis soon draws them back together. Weaver’s aircraft crashes deep in Japanese-occupied Burma, prompting a bold rescue mission led by Trumpet from the Chittagong base. Battling hostile ground forces, the blimp crew manages to recover three survivors, though one crew member is found dead. As they prepare to lift off, the blimp comes under attack from three Japanese fighter planes. With the airship punctured and helium steadily escaping, the crew jettisons as much weight as possible to gain altitude; when clouds no longer offer a hiding place, Tim Shannon is forced to bail out as well. The danger escalates, and Allied P-38 Lightnings swing into action to rescue the downed flyers. In the aftermath, Trumpet and Shannon return to base amid victory and relief, while Weaver makes clear his intention to return to the Lakehurst lighter‑than‑air service to be with his “father” once more.
