Martin XB-16

The Martin XB-16, company designation Model 145, was a projected heavy bomber designed in the United States during the 1930s.

Design and development
The XB-16 was designed to meet the United States Army Air Corps (USAAC) request for a bomber that could carry 2,500 lb of bombs 5000 mi.

The XB-16 (Model 145A) was to use four Allison V-1710 liquid-cooled reciprocating V-engines; contemporary American aircraft used air-cooled radial engines.

In 1935, Martin revised the XB-16 design as the Model 145B. The wingspan was increased from 140 ft to 173 ft, and a set of V-1710 engines added to the trailing edge. This version had a wingspan 20% greater than that of the B-29 Superfortress, the first operational bomber that would fill the role intended for the XB-16.

The XB-16 was canceled for essentially the same reason that the Boeing XB-15 project was, as it was not fast enough to meet the requirements set by the Army. Since both were canceled around the same time, Martin did not have time to produce an XB-16.