johnbr
2nd Lieutenant
Jack's concept was actually designed around a proposed liquid-cooled 24-cylinder H-block engine, Pratt & Whitney's X-1800. When the engine builder gave up on that design, however, Northrop was forced to adapt the airframe's design to accommodate a very different engine shape, the air-cooled Pratt R-2800 radial engine, which was embedded in the fuselage right behind the cockpit. The engine drove two contra-rotating pusher props, and excessive flexing of the drive shafts caused additional problems.
The first of the two prototypes was destroyed while doing a high-speed taxi test on Muroc's lakebed, when the left tire disintegrated and the plane went out of control. The second prototype, 42-38353 and the aircraft shown here, took over testing. A number of design changes were made to try to improve the stability, including the addition of the upper vertical and the installation of an innovative flaperon system that was pneumatically actuated (by a system of bellows powered by air from the venturiis on the wingtips). First flight of 42-38353 was on March 23, 1944, but was very short, since the pilot experienced problems in pitch control, with the aircraft acting extremely nose-heavy. There were other problems, as well, including excessive fuel consumption and an inability to fly anywhere near the top speeds that the engineers expected.
To investigate the causes of these issues, NACA was asked to test the aircraft in their giant wind tunnel at Moffatt Field. However, higher priority projects pushed the XP-56's schedule to the right, so some additional tests were flown at Muroc. The handling qualities problems continued, and further testing was not deemed safe. The wind tunnel testing was delayed another year, and by this time the war was over and the age of jet aircraft was dawning. Ultimately, the Air Corps gave up and cancelled the program. The sole surviving XP-56 is stored awaiting restoration at the National Air and Space Museum. Vintage Air: Black Bullet
The first of the two prototypes was destroyed while doing a high-speed taxi test on Muroc's lakebed, when the left tire disintegrated and the plane went out of control. The second prototype, 42-38353 and the aircraft shown here, took over testing. A number of design changes were made to try to improve the stability, including the addition of the upper vertical and the installation of an innovative flaperon system that was pneumatically actuated (by a system of bellows powered by air from the venturiis on the wingtips). First flight of 42-38353 was on March 23, 1944, but was very short, since the pilot experienced problems in pitch control, with the aircraft acting extremely nose-heavy. There were other problems, as well, including excessive fuel consumption and an inability to fly anywhere near the top speeds that the engineers expected.
To investigate the causes of these issues, NACA was asked to test the aircraft in their giant wind tunnel at Moffatt Field. However, higher priority projects pushed the XP-56's schedule to the right, so some additional tests were flown at Muroc. The handling qualities problems continued, and further testing was not deemed safe. The wind tunnel testing was delayed another year, and by this time the war was over and the age of jet aircraft was dawning. Ultimately, the Air Corps gave up and cancelled the program. The sole surviving XP-56 is stored awaiting restoration at the National Air and Space Museum. Vintage Air: Black Bullet
Attachments
Last edited:
