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 a United States-built interceptor fighter aircraft, developed by the St. Louis Airplane Division of Curtiss-Wright Corporation during the 1930s.
Design and development
The CW-21 was not commissioned by the U.S. military, though 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. Instead it was developed for export sales by the St. Louis
Airplane Division of Curtiss-Wright. The aircraft was a single seat, all-metal cantilever low-wing monoplane
with rearward retracting landing gear. The Model 21 was powered by a 1,000 hp (750 kW) Wright Cyclone
nine cylinder air-cooled radial Wright R-1820
The Model 21 was designed by George A. Page, Jr. based on Carl W. Scott's design of the two seater Model 19. The prototype first flew in January 1939 and bore the civil experimental registration NX19431. The prototype was designed to carry various combinations of two 0.3 or 0.5 inch (7.62 mm or 12.7 mm) machines guns, mounted in the nose and synchronized to fire through the propeller.
The first sale of the CW-21 Demon in 1939, was to the Chinese Air Force
, which received three completed examples and kits for 32 more. Assembly would be undertaken by the Central Aircraft Manufacturing Company
(CAMCO) located in Loiwing on the China-Burma border. These were armed with one 0.3 and one 0.5 inch (12.7 mm) machine guns. Three CW-21s were furnished to the Chinese as kits, assembled in Loiwing, and delivered to the 1st American Volunteer Group (Flying Tigers)
. These crashed in poor visibility on a flight from Rangoon
on 23 December 1941
In 1940, The Netherlands ordered 24 examples of a modified version designated the CW-21B (together with a number of two-seat Model 23s), for the Royal Netherlands East Indies Army Military Aviation (Militaire Luchtvaart van het Koninklijk Nederlands-Indisch Leger; ML-KNIL).
The modifications consisted of inward retracting landing gear, a semi-retractable tail wheel, two each 0.3 and 0.5 inch (7.62 and 12.7 mm) machine guns, and a slightly larger fuel tank. These changes gained an eight mph (13 km/h) speed increase at sea level.
Deliveries started in June 1940, but only 17 had been received by Vliegtuigroep IV, Afdeling 2 (No. 2 Squadron, Air Group IV; 2-VLG IV), when war with Japan began on December 8 1941. With its rudimentary pilot protection, lack of self-sealing fuel tanks and light construction, the CW-21B was not unlike the opposing Japanese planes. It had similar firepower to the Nakajima Ki-43 "Oscar", but worse than the cannon-armed Mitsubishi Zero. Its climb rate was far better than either. Squadron VLG IV claimed four aerial victories during the Netherlands East Indies campaign but the ML-KNIL was overwhelmed by the sheer number of Japanese adversaries, and all were soon lost in combat or destroyed on the ground.
- Interceptor. One prototype built in 1938 (c/n 21-1 / NX19431). Three production units : NX19441 (c/n 21-2); NX19442 (c/n 21-3); NX19443 (c/n 21-4). Twenty-seven sets of components were sent to China to be assembled by CAMCO. Easily identifiable by the Curtiss P-40 type of main undercarriage fairings.Model 21A
- Interceptor. Proposed design to utilize the Alison V-1710. Not built.Model 21B
- Interceptor. A total of 24 built for the Netherlands East Indies (c/n 2853 to 2872, NEI serials CW-344 to CW-363). It was easily identifiable by the inward retracting main landing gear that eliminated the need for the undercarriage fairings notable on the Model 21.
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