In the years following the Western Front, there was a distinct lack of unity within the civil aviation industry due to the recruitment of people with various backgrounds; this was a common situation in times of emergency when personnel were recruited hastily and in high quantities. To standardize backgrounds, many centers were created to train aeronautic personnel. Airfield commanders were trained in Orly while technical staff for air navigation were trained in Le Bourget. Wireless operators and radio technicians were also trained in Orly, although under the Department of Telecommunications and Signaling, which was not connected directly to the world of aviation. Technical managers were mostly trained in engineering schools, including "Arts et Métiers" and the National School of Meteorology ("École nationale de la météorologie"). Designers were trained by the "École spéciale des travaux aéronautiques" while aircrew were trained by other public or private institutions. ENAC's mission was to unify the training of all aviation personnel.