Northrop XP-56 Black Bullet Pursuit Fighter Prototype
The Northrop XP-56 Black Bullet was another U.S. Army Air Corps proposal to research the benefits of pusher-propeller design - this time within a flying wing arrangement.
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The XP-56 "Black Bullet" was a "pursuit fighter" designed by the Northrop Corporation to a United States Army Air Corps (USAAC) proposal known as the "R-40C". The compact fighter became yet another advanced World War 2-era fighter entry for the Americans and focused on a flying wing concept mated to a "pusher-type" propulsion configuration. The pusher arrangement was in contrast to the widely accepted "puller-type" arrangements found on many conventional piston-powered aircraft of the period. The proposal (and subsequent flyable aircraft) sought to define inherent benefits (if any) in the pusher-type configuration. Unfortunately for the Black Bullet, very little value was revealed and the aircraft was never adopted for serial production.
The XP-56 was fitted with large-area wings, cranked downwards at their outboard sections, and attached to a rather stubby fuselage. Aspiration for the the engine was through intakes integrated directly into the mainplane leading edges to feed the engine buried in the aft section of the fuselage. A sole vertical fin was seated over the rear of the aircraft and there was also a ventral protrusion. The cockpit was mounted at front which gave the pilot a commanding view over the nose with his view to the rear obstructed by the raised fuselage spine. A tricycle undercarriage (wholly retractable) rounded out the list of modern design features.
Power was derived from a single Pratt & Whitney R-2800-29 engine developing 2,000 horsepower and driving a three-bladed propeller unit.
Proposed armament was 2 x 20mm cannons coupled with 4 x 0.50 caliber heavy machine guns, presumably all mounted in the nose or wings or spread across both.
The Black Bullet was initially flown in prototype form on September 23, 1943 though this aircraft was eventually lost during a high-speed ground run exercise that same year. A second prototype followed on March 23, 1944 and incorporated some improvements to the original design including a yaw control system and a larger-area vertical stabilizer. This example underwent a battery of tests only to finally reveal that the aircraft offered no real performance benefits in its unique design and layout when compared to conventionally arranged prop-driven fighters. Additionally, advanced being made in bringing jet-powered fighters along helped to doom such programs.
As such, the XP-56 program was limited to just the two prototype examples, the second ending her days as a museum piece. All development ended on the XP-56 in January of 1946.
As completed, the XP-56 held dimensions that included a length of 27.5 feet, a wingspan of 42.5 feet, and a height of 11 feet. Its empty weight was 8,700lb against a Maximum Take-Off Weight (MTOW) of 12,145lb. Performance specifications with the PW engine in place included a maximum speed of 465 miles per hour, a range out to 660 miles, a service ceiling up to 33,000 feet, and a rate-of-climb of 3,125 feet-per-minute.