USS Shenandoah (Airship)

The USS Shenandoah is a rigid airship built for the United States Navy, entering service in 1923 as the first American-built rigid airship and the first anywhere to be inflated with non-flammable helium gas rather than the more common but dangerously flammable hydrogen used by earlier rigid airships including Germany's wartime Zeppelins. Built closely modeled on a captured German wartime Zeppelin design, the Shenandoah was used by the Navy for long-distance training and demonstration flights, including a notable transcontinental flight across the United States, intended to showcase the rigid airship's potential for naval scouting and long-range patrol. The airship broke apart in a severe squall over Ohio in 1925, killing fourteen of its crew, a disaster that raised early doubts about the structural safety of large rigid airships that later accidents would reinforce.