Douglas B-18 Bolo

The Douglas B-18 Bolo was an American twin-engined medium bomber that served with the United States Army Air Corps and the Royal Canadian Air Force, which called it the Digby, in the late 1930s and early 1940s. The Douglas Aircraft Company developed it from the DC-2 airliner as a replacement for the Martin B-10, and the initial contract called for 133 aircraft using Wright R-1820 radial engines. By 1940 standards it was slow, with inadequate defensive armament and a small bomb load, and by 1942 surviving aircraft were relegated to antisubmarine, training and transport duties. A B-18 was one of the first Army Air Forces aircraft to sink a German U-boat, U-654, on 22 August 1942.