 The production aircraft were powered by an 825 hp (615 kW) Pratt & Whitney R-1535-94 fourteen-cylinder, twin-row, air-cooled engine driving a three-blade propeller.Armament consisted of two 0.30-caliber (7.62 mm) machine guns, one fixed gun in the right side of the fuselage forward of the pilot and a flexible gun in the rear cockpit.The aircraft had a bomb displacement swing located on the centerline of the fuselage for a 500-lb (227-kg) bomb or a 45-U.S.-gallon (170-liter) fuel tank.