Dewoitine D.21

The Dewoitine D.21 was a French single‑engine fighter that emerged in the early 1920s as a development of the earlier D.12 series. Designed by Emile Dewoitine for the French Air Force, the aircraft first flew in 1923 and quickly attracted interest from several foreign services, most notably the Polish, Yugoslav and Chilean air forces. Constructed of a mixed metal‑wood frame with fabric covering, the D.21 featured a low‑wing cantilever monoplane layout, an enclosed cockpit, and a fixed‑gear undercarriage. Powered by a 450 hp Hispano‑Suiza V‑12 engine, it could reach a top speed of about 250 km/h (155 mph) and was armed with two synchronized Vickers machine guns. Its slim, aerodynamically clean design gave superior climb performance compared to many biplanes of the era, marking a shift toward modern monoplanes. Although only a few dozen were built, the D.21 demonstrated the viability of all‑metal construction and high‑speed monoplanes, influencing later Dewoitine models such as the D.500 series and contributing to the broader transition in military aviation from biplanes to sleek, faster monoplanes in the interwar period. In Poland the D.21 served with the 2nd Air Regiment until 1929, providing valuable pilot training and proving the durability of its airframe under demanding conditions.