Lipetsk fighter-pilot school
The Lipetsk fighter-pilot school (German: Kampffliegerschule Lipezk) was a secret training school for fighter pilots operated by the German Reichswehr at Lipetsk, Soviet Union, now the Lipetsk Air Base. It operated from 1926 to 1933.
Germany, prohibited by the Treaty of Versailles to operate an air force, was able to find alternative means to continue training and development for the future Luftwaffe. Apart from Lipezk, Germany also operated a tank school, the Panzerschule Kama (1926–33) and a gas warfare school, the Gas-Testgelände Tomka (1928–31) in the Soviet Union.
The Treaty of Versailles, signed on 28 June 1919, prohibited Germany from operating any form of air force after the country had lost the First World War. Initially, it also prohibited the production and import of any form of aircraft in the country. In 1922, the clause on civilian aircraft was dropped and Germany was able to produce planes again, followed in 1923 with the country regaining control of its airspace. The operation or production of aircraft for military means was however still prohibited.
The German military, the Reichswehr, was well aware of the value of air warfare and was determined not to fall too far behind in knowledge and training. For this purpose alternative means, outside Germany, were explored.
Initially, Germany was unwilling to break the Treaty of Versailles. This attitude changed however in 1923, when French and Belgian troops occupied the Ruhr area after Germany defaulted on its reparations. In light of the events of the Ruhrkampf, the German Army ordered 100 new aircraft from Fokker in the Netherlands, among them 50 newly developed Fokker D.XIIIs. Additionally, the German Navy had also ordered a small number of planes.
With the end of the Ruhrkampf in September, Germany was at a loss as how to proceed with the ordered planes which were due for delivery in 1924. At this stage, the Soviet Union was approached, and showed an interest in Germany developing aircraft in the country; the German manufacturer Junkers had already been operating a production facility for military aircraft near Moscow since 1923. 
In June 1924, retired Colonel Hermann von der Lieth-Thomsen became a permanent representative of the Reichswehr's Truppenamt, the secret General Staff of the German Army, in Moscow. At the same time, seven German instructors were sent to the Red Air Force. On 15 April 1925, Lieth-Thomsen signed a contract to establish a German fighter-pilot school at Lipetsk.
Fighter school 
Extensive works were required at Lipetsk to prepare for the German fighter-pilot school. In June 1925, the base was ready for flights to be undertaken but training of German pilots was only possible from spring 1926 onwards. The new school, up until its closure, trained 120 fighter pilots and a large number of ground personnel who, in turn, were able to be used as instructors when the new German Luftwaffe was formed in 1935. The facilities were also used to train Soviet pilots and to develop new bombing targeting methods. In an average summer, 140 German personnel were at Lipetsk, a number that was reduced to 40 in winter. Additionally, 340 Soviet personnel were employed, with an annual budget of 4 million Reichsmark.
In the early 1930s, the political situation for the flight school began to change. The Soviet Union opened itself to the West while Germany attempted a closer approach to France. Additionally, the Soviets were unhappy about the lack of development carried out at the school.
In December 1932, Germany achieved being viewed as an equal at the Geneva Conference, making the fighter school somewhat unnecessary. With the rise of the Nazis to power in January 1933, the ideological gap between fascist Germany and the communist Soviet Union became too large and the fighter school at Lipetsk was closed on 15 September 1933.
- Geheimvertrag mit der Roten Armee (German) Der Spiegel: Secret contracts with the Red Army, accessed 1 July 2011
- Lipezk. Die geheime Fliegerschule und Erprobungsstätte der Reichswehr in der Sowjetunion (German) German Federal Archives, accessed 1 July 2011
- Schulterschluss mit Moskau (German) Der Spiegel: Solidarity with Moscow, accessed 1 July 2011