Design work for the Martin "Mars", the largest active-duty flying boat the world would ever see, started in 1935. After reviewing proposals submitted by Consolidated, Boeing, Vought-Sikorsky and Martin, Martin received a contract for a long-range patrol bomber designated the XPB2M-1 "Mars" on 23 August 1938. The patrol bomber's keel was laid on 22 August 1940, and the aircraft, known affectionately as the "Old Lady" was rolled from its hangar on 27 September 1941...