Hanriot HD.1 is a French single-engine fighter aircraft of mixed construction from the First World War. The prototype flight took place in June 1916, which was powered by a Le Rhône 9J rotary engine with a capacity of 110 HP. The same engine was used in serial aircraft. Originally, it was supposed to replace the Nieuport 17 aircraft, but it lost the competition with the SPAD S.7 aircraft. A small number of Hanriot HD.1 aircraft were delivered to the French Navy and the US Navy. On the other hand, it was sold on a large scale to the Belgian air force, especially to Italy, where, moreover, licensed production was launched on a very large scale. Out of approximately 1,200 aircraft of this type, Italian plants have produced as many as 831 examples! Until 1918, the Hanriot HD.1 was the main Italian aviation fighter. This fighter turned out to be highly appreciated by pilots due to the ease of piloting, great maneuverability and excellent flight parameters. Production continued until 1919. Technical data: length: 5.85m, wingspan: 8.7m, height: 2.94m, maximum speed: 184km / h, rate of climb: 6.5m / s, maximum range: 550km, maximum ceiling 6400m, armament: permanent -1-2 7.7mm Vickers machine guns.