A crewman squeezes into the ball turret in the belly of a B-17E Flying Fortress in 1942. Isolated from the rest of the crew, cramped in a tiny space, and in a potentially fatal spot if the landing gear failed, the lower ball turret was one of the most dangerous -- and frightening -- places to be during the war, on land or in the sky.
Photo: Frank Scherschel./Time & Life Pictures/Getty Images