class every fourth months. 47% of them graduated as pilots and went on to advanced flying training. 75% of all primary training was conducted at Randolph Field. By May 1932 the field had 251 primary trainers, most the venerable Consolidated PT-3 "Trusty", but gradually supplemented by the Consolidated PT-11D, which became the Air Corps standard in the 1930s. In 1936, the famous Stearman PT-13 Kaydet began to appear in the skies over San Antonio. Basic training followed primary, at first with Douglas BT-1s and BT-2Bs. The Seversky BT-8 was later introduced as a basic trainer, but was soon deemed too difficult to handle and was replaced by North American BT-9s in 1935. Increased flying hours for cadets and an expanded syllabus resulted in a need for auxiliary fields within a ten-mile radius of Randolph to handle the volume of takeoffs and landings, and in 1932 Randolph was encircled by seven (clockwise from west to southwest): Dodd, Cade, Davenport, Marion, C.A. Krueger, Zuehl, and Martindale. Primary training continued at Randolph until September 1939 when expansion of the Air Corps forced it to contract primary out to civilian schools, and Randolph's mission shifted to basic pilot training only. The Air Corps Act of 1926 mandated that rated pilots comprise 90% of all commissioned officers of the Air Corps. Because of this requirement, nearly all new officers of the Air Corps underwent Randolph's rigorous pilot training program and, in combination with the architectural beauty of the base, Mayor Chamber's term West Point of the Air became the unofficial nickname for Randolph Field. A 1935 Hollywood film, West Point of the Air, was filmed on location at Randolph. 1940s to 1970s In June 1941, the Air Corps became the Army Air Forces. Basic flying training at Randolph continued until March 1943, when the Army Air Forces Central Instructors School (CIS) was created. For the next two years, training instructors for ground schools, instructor pilots (including civilian contract instructors) for all three phases of flying training, and officers destined for administrative duties at air training command bases were trained by the CIS. Randolph produced 15,396 instructor graduates from this course before it moved to Waco Field in 1945. When the CIS moved to Waco Field it was replaced by the Army Air Forces pilot school, which specialized in transition training for B-29 bomber pilots, copilots and engineers. Primary pilot training returned to Randolph from Goodfellow