The outstanding accomplishments during World War II of the U.S. Navy’s twin-engine flying boats—the Consolidated PBY Catalina and the Martin PBM Mariner—eclipsed the comparatively few four-engine flying boats that served the Navy during the war. Those four-engine aircraft were Consolidated PB2Y Coronados. 1
In the 1930s the Navy expressed interest in four-engine, long-range patrol aircraft to support fleet operations. Prototype aircraft were ordered in 1935 and 1936, respectively the Sikorsky XPBS-1 and the Consolidated XPB2Y-1. Sikorsky—not yet developing helicopters—was a leading producer of large flying boats, while Consolidated was producing the highly successful PBY, which would serve in every theater of World War II and be produced in greater numbers than any other flying boat by any nation. Thus, both firms were well qualified in the flying boat field.