Like the Boeing XB-15, the Martin XB-16 (Martin Model 145) was designed to meet the United States Army Air Corps' request for a bomber that could carry 2,500 lb (1,100 kg) of bombs 5,000 mi (8,000 km). The XB-16 was to use four Allison V-1710 liquid-cooled inline engines; contemporary American aircraft used air-cooled radial engines. The XB-16 was cancelled for essentially the same reason the B-15 project was: it wasn't fast enough to meet the requirements set by the Army. Since both were cancelled around the same time, Martin did not have time to produce an XB-16.