johnbr
2nd Lieutenant
The XB-30 was the design submitted by Lockheed to a 1939 request from the US Army Air Forces for a very heavy bomber. Competing against Boeing, Douglas, and Consolidated, the XB-30 (Lockheed Model 51) concept was based on the L-49 Constellation airliner then on the drawing boards. The XB-30 was designed for a crew of twelve and could carry eight 2,000 pound bombs nearly 2,700 miles. This detail drawing from 1940 shows the two .50 caliber machine guns and two 20mm cannon in the XB-30's tail gunner position. Nearly 4,000 Boeing B-29 Superfortresses and 114 Consolidated B-32 Dominators were eventually built. Rather than build the XB-30, the AAF directed Lockheed to complete development of the Constellation as the C-69 transport.