Division near Dresden. Sperrle travelled to Lipetsk in the Soviet Union at this time, where the Germans maintained a secret air base and founded the Lipetsk fighter-pilot school. Sperrle purportedly visited the United Kingdom to observe Royal Air Force exercises. At Lipetsk, Hugo Sperrle and Kurt Student acted as senior directors which trained some 240 German pilots between 1924 and 1932. The air staff remained small, but Sperrle's contingent were present in the 4,000 officers retained in the military. In 1927 Sperrle, at the rank of Major, replaced Wilberg as head of the air staff at the Waffenamt an Truppenamt (Weapons and Troop Office). Sperrle was selected for his expertise in technical matters; he was seen as highly qualified staff officer with combat experience in commanding the flying units of the 7th army during the war. On 1 February 1929 Sperrle was replaced with Hellmuth Felmy. Sperrle's departure came as he was pressing for an autonomous aviation authority. Felmy persisted, and on 1 October 1929, the Inspektion der Waffenschulen und der Luftwaffe came into existence under the command of Major General Hilmar von Mittelberger—it was the first use of the term "Luftwaffe". By 1 November 1930, the embryonic air headquarters could count 168 aviation officers including Sperrle. Sperrle was promoted to Oberstleutnant (lieutenant colonel) in 1931 while commanding the 3rd battalion, 14th Infantry Regiment from 1929 to 1933. Sperrle ended his army career in command of the 8th Infantry Regiment, from 1 October 1933 to 1 April 1934. At the rank of Oberst (colonel), Sperrle was given command of the headquarters of the First Air Division (Fliegerdivision 1). Sperrle was given responsibility for coordinating army support aviation. Sperrle's official title was Kommandeur der Heeresflieger (Commander of Army Flyers). After Adolf Hitler and the Nazi Party seized power, Hermann Göring created and Reich Air Ministry. Göring handed most of the squadrons in existence to Sperrle because of his command experiences. Sperrle was involved in the difficulties in German aircraft procurement. Four months after assuming command, Sperrle was rigorously critical of the Dornier Do 11 and Dornier Do 13 in a conference on 18 July 1934. Five months later, with development failing, Sperrle met with Wolfram Freiherr von Richthofen, head of aircraft development and Luftkreis IV commander Alfred Keller, a wartime bomber pilot. It was decided Junkers Ju 52 production would be a stopgap, while the Dornier Do 23 reached units in