The XP-56 Black Bullet never advanced passed the prototype stage. The design never achieved its design goals and the advent of the jet age pretty much relegated the aircraft to the pages of history. But what if the aircraft did achieve its designed goals and actually went into production? How would this aircraft compare to its contemporaries like the Mustang, Spitfire, or the YAK? Or how would this aircraft compare to the likes of the German Bf.109 and the Japanese Zero? We will gather as much information available and do a comparison and contrast on all of these designs to see how the P-56A would have faired against the legends of World War Two.

 

The XP-56 Black Bullet project was canceled in 1946. It was an aircraft that was very radical and unique design that brought about many challenges to Northrop and its engineers. Data gathered here was used on other projects but engine troubles, poor stall characteristics, all magnesium body, and not to forget it was a tailless design, which without computers, made it overall a difficult aircraft to handle.

The engineers at Northrop, building on data obtained from the N1M, came up with a truly unconventional aircraft design. This new aircraft was to be a tailless craft with swept back wings, with two rear facing contra-rotating propellers, powered by a single engine located behind the pilot who would sit in an unpressurized cockpit well situated forward of the craft. The design would be built around the experimental Pratt and Whitney X-1800 H-type liquid cooled engine and it was to be constructed entirely of magnesium alloy. The X-1800 allowed designers to fit the engine in any configuration. This new aircraft was designated the N2B.

Since the beginning development of the XP-56 was plagued by problems and it would continue throughout its short history. As soon as development of the XP-56 began Pratt and Whitney cancelled the X-1800 engine program, the engine that was to equip the new aircraft. As a result Northrop had to scramble to find a replacement engine. Their alternative, but less desirable choice, was the Pratt & Whitney R-2800-29 air-cooled radial engine.

Though the new engine was more powerful than the X-1800 and had a much simpler cooling system, the new radial engine had a large diameter, which meant the aircraft would have to be modified to accommodate it. The aircraft now took a more rounded stubby look, which added more weight.

The next major engineering hurdle was the welding process for welding magnesium. Magnesium is unlike most metals and when enough heat was applied this metal can ignite and burn very hot and bright. To make the aircraft lighter Magnesium was used for the construction. Magnesium is lighter then aluminum so that meant the skin could be made thicker and help distribute loads better.

In initial testing it was discovered that the aircraft tended to yaw to the left. And so the decision was made to add a dorsal fin in order to stabilize the aircraft. This combined with the larger radial engine increased the total weight of the aircraft.
Problems persisted for the XP-56. Nose heaviness made control of the aircraft difficult. Nose wheel could not leave the ground at speeds less then 160 mph, thus also increasing the amount of runway needed for lift off.

There were two variants of the 41-786 prototype fighter. The main recognizable difference between the two was an added dorsal fin. The dorsal fin was found to be needed when during early high speed taxis and low level flights reveal stability problems with the aircraft.

 

Northrop’s first attempt at a fighter design could be considered to be a dismal and complete failure. Flight tests reveal there was no significant improvement in performance over existing fighters of the day. Engineering challenges, mechanical failures, the end of the war, and the advent of the jet age help to end the quest of the unconventional high performance piston driven fighter. But not all was a complete loss as data obtained from the XP-56 program help contribute to the design of the XB-35, XB-49, and the B-2 Stealth Bomber, some 60 years later.