Northrop XP-56 Black Bullet (MPM)

TYPE: Interceptor fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Pratt & Whitney R-2800-29 radial engine, rated at 2,000 hp

PERFORMANCE: 465 mph at 25,000 ft (estimated)

COMMENT: After the accident of the first XP-56 prototype it was decided to re-balance the second prototype and move the center of gravity forward. Other changes included a major increase in the size of the upper vertical surface, and the incorporation of a novel form of rudder control which made use of air bellows to operate wingtip split flaps for directional control. The control of the bellows was achieved by valving air to or from the bellows by means of wingtip venturis. On March 1944 the second XP-56 was flows for the first time. Nose heaviness, relative low speeds, high fuel consumption and control instability led the N.A.C.A. to test the aircraft in the wind tunnel at Moffett field. Meanwhile, some more flight test have been performed but proved not satisfactory. It was decided that further flight test were too hazardous and after the project had been inactive for more than a year the decision was taken to abandon the project (Ref.: 13).