Envisaged originally as a high-altitude version of the B-25 Mitchell, the North American NA-63 (XB-28) emerged finally as an almost entirely different aircraft. With single vertical tail surfaces and a circular-section fuselage with a pressure cabin for the five-man crew, the XB-28 was powered by two 1491kW Pratt & Whitney R-2800 radials and bomb bay capacity was 1814kg. Dorsal, ventral and tail turrets, each containing two 12.7mm machine-guns, were remotely controlled from the cockpit; three similar forward-firing weapons were also fitted. Of three prototypes ordered in February 1940, the first flew in April 1942, the second was cancelled and the third, with a reconnaissance camera installation, crashed during the test programme. Although the XB-28 achieved a maximum speed of 599km/h at 7620m and could carry a 272kg bomb load for 3283km, production orders were not placed.

3-View

A three-view drawing (700 x 1053)