 In 1928 he graduated from the "Kriegsakademie" (War Academy) first in his class and in April Jeschonnek worked for Inspectorate 1 (L), the aerial warfare branch of the Ministry of the Reichswehr ("Reichswehrministerium") under the command of Hellmuth Felmy from 1929.The department was covertly responsible for the building of military aircraft prohibited by the Treaty of Versailles.Jeschonnek was one of 300 aviators, including 168 officers, who formed part of the embryonic air staff on 1 November 1930.