The North American XB-28 (NA-63) Dragon was a proposed high-altitude follow-on to the B-25 Mitchell twin-engined medium bomber. Three prototypes were ordered on February 13, 1940.
The XB-28 aircraft was generally similar to the B-25 in overall configuration, but had a single vertical tail rather than two. It had appreciably more power than the B-25, being powered by a pair of turbosupercharged Pratt & Whitney R-2800 engines It carried a crew of five in a pressurized cabin and could carry up to 4000 pounds of bombs. The defensive armament consisted of remotely-controlled upper, lower, and tail turrets, each of which contained two 0.50-inch guns. The guns were aimed by gunners inside the fuselage who operated periscopic sights in stations behind the pilots' seats.
The XB-28 flew for the first time on April 26, 1942. The serial was 40-3056. The second prototype was completed as the XB-28A reconnaissance version with R-2800-27s. The serial was 40-3058.
Although the high-altitude performance of the XB-28 greatly exceeded that of the B-25, most medium bombing during the war was done from relatively low altitudes, and it was decided not to interrupt Mitchell production for an untried type, and the XB-28 project was cancelled after only two examples were built.
A third XB-28 prototype was also ordered (bearing the serial number 40-3057), but was canceled before it could be built (the serial 40-3057 was later re-used for the sole Grumman XP-50 prototype.
Engines: Two Pratt & Whitney R-2800-11 air-cooled radial engines, rated at 2000 hp for takeoff and 1840 hp at 25,000 feet. Performance: Maximum speed 372 mph at 25,000 feet. Cruising speed 255 mph. Service ceiling 34,600 feet. An altitude of 10,000 feet could be attained in 9 minutes. Range was 2040 miles with a load of 6000 pounds of bombs. Weights: 25,575 pounds empty, 35,740 pounds gross, 37,200 pounds maximum. Dimensions: wingspan 72 feet 7 inches, length 56 feet 5 inches, height 22 feet, wing area 676 square feet.