At the end of World War I, the French military aviation (fr. Aéronautique Militaire) was considered one of the most powerful in Europe and had nearly 3,300 combat aircraft. In the interwar period, it maintained this position, although already in the 1930s it became clear that it required considerable changes. The Great Depression, which broke out in 1929, prevented this for many years, but in 1937 an intensive expansion of the French air force began, which in 1934 became an independent type of armed force. Until September 1939, the basic tactical unit was a squadron (French: Escadrille), and two squadrons formed the Group (French: Groupe). However, from two to several groups formed a squadron (French Escadre). After that time, the Squadrons were renamed Groupement units. There were also operational zones that were responsible for controlling the airspace over selected geographical regions of the country. It is also worth adding that, despite the usual stereotypes, both French airmen and ground staff were at least well trained. French aviation also had a relatively dense network of air bases and airports, especially in the north-eastern part of the country and in the Paris area.At the end of World War I, the French Air Force (now Fr. L'Armee de l'air) were one of the most powerful in Europe and had many very modern machines in stock. However, in the 1920s and at the beginning of the 1930s, as a result of the Great Depression of 1929, this state of affairs changed negatively. The peculiar sanitation of the French air force began in the mid-1930s, when many new constructions began to be developed and introduced into the line, such as Dewoitine D.520, Potez 630 or Liore et Olivier LeO 451. German from the same time and could undoubtedly engage in an equal fight with them. Moreover, in the period 1939-1940, France also made large orders for aircraft in the USA, which led to the fact that during the 1940 campaign, the French air force had, for example, Curtiss Hawk 75 aircraft. On May 10, 1940, L'Armee de l'air had a total of approximately 5,030 aircraft, and approximately 3,550 aircraft were fully operational. Also, the training of French pilots was not bad at all. This is perfectly evidenced by the data quoted by Karl-Heinz Friesser in his book "The Legend of the Blitzkrieg", which states that during the 1940 campaign, the French lost only 306 aircraft in the air, while knocking down as many as 733 German machines.