The Curtiss-Wright Model 21 (also known as the Curtiss-Wright Model 21 Demonstrator, the Curtiss-Wright CW-21 Interceptor, the Curtiss-Wright CW-21 Demon) was an American fighter-interceptor developed by the St. Louis Airplane Division of Curtiss-Wright Corporation during the 1930s. In 1938, George A. Page, head of the Saint Louis Airplane Division of Curtiss-Wright, decided to develop a fighter aircraft based on Carl W. Scott's two seater Model 19. Page's concept was a lightweight fighter interceptor with as high a rate of climb as possible in order to allow bomber formations to be attacked with minimal warning. If faced with fighter opposition, it was intended not to dogfight, but to use its superior climb rate to escape. While this was a direct contradiction to the United States Army Air Corps′ requirements for fighters (which stressed low-level performance), this did not concern Page, since the new fighter was intended for export. Detailed design of the new fighter, the Model 21, or CW-21, was carried out by a team led by chief engineer Willis Wells. It was a single-seat, all-metal cantilever low-wing monoplane with retractable tailwheel landing gear, where the mainwheels retracted rearwards into fairings under the wing. The fuselage was a semi-monocoque structure that tapered sharply behind the pilot's cockpit. It was powered by a 1,000 hp (750 kW) Wright R-1820-G5 nine-cylinder air-cooled radial engine. It was designed to carry various combinations of two .30 in (7.62 mm) or .50 in (12.7 mm) machine guns, mounted in the nose and synchronized to fire through the propeller, while no armor or fuel tank protection was fitted in order to save weight and hence improve performance. The prototype first flew on 22 September 1938, carrying the civil experimental registration NX19431. Although the CW-21 was not commissioned by the U.S. military, it was test flown at Wright Field in Dayton, Ohio. The Army Air Corps immediately rejected the aircraft, with one officer commenting that it took a genius to land it. Variants Model 21 Interceptor. One prototype built in 1938 (c/n 21-1 / NX19431). Three production units and a total of 27 sets of components shipped to the Republic of China to be assembled by CAMCO. Easily identifiable by the Seversky P-35 type of main undercarriage fairings; 31 built (unknown number assembled and flown). Model 21A Interceptor. Proposed design to use the Allison V-1710; not built. Model 21B (Specifications below) Interceptor. A total of 24 built for the Netherlands East Indies, easily identifiable by the inward retracting main landing gear, that eliminated the need for the undercarriage fairings notable on the Model 21. For details of operational history, click here.
