Contract flying schools fed the AAF prior to WWII
In about 1940, the United States was planning a buildup in Army Air Force (AAF) strength. The number of airplanes produced was to be increased to around 50,000, but the AAF's flying school in Texas could only graduate 500 pilots a year, and most of the current AAF pilots did not have enough flying hours to be instructors. To produce more pilots, the commanding general of the AAF, Henry Arnold, devised a plan for primary contract flying schools located in local communities.
Source: arkansasonline.com