The North American XB-28 (NA-63) Dragon was an aircraft proposed by North American Aviation to fill a strong need in the United States Army Air Corps for a high-altitude medium bomber. It never entered into production, with only two prototypes being built.
|North American XB-28 with engines running.|
|Role||High-altitude medium bomber|
|Manufacturer||North American Aviation|
|First flight||26 April 1942|
|Primary user||U.S. Army Air Force|
|Developed from||B-25 Mitchell|
The order for a high-altitude medium bomber was put out on 13 February 1940; the XB-28 first flew on 26 April 1942. The XB-28 was based on North American Aviation's highly successful B-25 Mitchell, but as it evolved it became a completely new design, much more reminiscent of the Martin B-26 Marauder. The overall configuration of the B-25 and XB-28 were fairly similar; the most important distinction was that the twin tail of the B-25 was changed to a single tail on the XB-28. It was among the first combat aircraft with a pressurized cabin.
The XB-28 proved an excellent design, with significantly better performance than that of the B-25, but it was never put into production. High-altitude bombing was hampered significantly by factors such as clouds and wind, which were frequent occurrences in the Pacific. At the same time, medium bombers were becoming much more able at lower altitudes. The gains in aircraft performance that came with high-altitude flight were not considered sufficient to justify switching from low-altitude bombing.
Even though the Army Air Forces rejected the XB-28 as a bomber, they ordered another prototype. Designated XB-28A, it was meant to explore the possibility of use as a reconnaissance aircraft. The XB-28A crashed into the Pacific Ocean off Southern California after the crew bailed out on 4 August 1943.
Data from 
Aircraft of comparable role, configuration and era
The Bristol Type 163 Buckingham was a British Second World War medium bomber for the Royal Air Force (RAF). Overtaken by events, it was built in small numbers, and was used primarily for transport and liaison duties.Henschel Hs 130
The Henschel Hs 130 was a German high-altitude reconnaissance and bomber aircraft developed in World War II. It suffered from various mechanical faults and was never used operationally, only existing as prototype airframes.Junkers Ju 388
The Junkers Ju 388 Störtebeker is a World War II German Luftwaffe multi-role aircraft based on the Ju 88 airframe by way of the Ju 188. It differed from its predecessors in being intended for high altitude operation, with design features such as a pressurized cockpit for its crew. The Ju 388 was introduced very late in the war, and production problems along with the deteriorating war conditions meant that few were built.Martin XB-27
The Martin XB-27 (Martin Model 182) was an aircraft proposed by the Glenn L. Martin Company to fill a strong need in the United States Army Air Corps for a high-altitude medium bomber. Its design was based approximately on that of Martin's own B-26 Marauder. The XB-27 remained on paper, and no prototypes were built.North American B-25 Mitchell
The North American B-25 Mitchell is a medium bomber that was introduced in 1941 and named in honor of Major General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served in every theater of World War II, and after the war ended, many remained in service, operating across four decades. Produced in numerous variants, nearly 10,000 B-25s were built. These included a few limited models such as the F-10 reconnaissance aircraft, the AT-24 crew trainers, and the United States Marine Corps' PBJ-1 patrol bomber.Tachikawa Ki-74
The Tachikawa Ki-74 was a Japanese experimental long-range reconnaissance bomber of World War II. A twin-engine, mid-wing monoplane, it was developed for the Imperial Japanese Army Air Service but never deployed in combat. The Ki-74 was designed for high altitude operation with a pressurized cabin for its crew.