"The tragic story of the British airship R101-which went down in a spectacular hydrogen-fueled fireball in 1930, killing more people than died in the Hindenburg disaster seven years later-has been largely forgotten. In His Majesty's Airship, historian S.C. Gwynne resurrects it in vivid detail, telling the epic story of great ambition gone terribly wrong. Airships, those airborne leviathans that occupied center stage in the world in the first half...