The Lipetsk fighter-pilot school, also known as WIWUPAL from its German codename Wissenschaftliche Versuchs- und Personalausbildungsstation "Scientific Experimental and Personnel Training Station", was a secret training school for fighter pilots operated by the German Reichswehr at Lipetsk, Soviet Union, because Germany was prohibited by the Treaty of Versailles from operating an air force and sought alternative means to continue training and development for the future Luftwaffe. Wikipedia