Stearman Aircraft Inc. was founded in 1926 by Lloyd Stearman in Venice, CA where he built the first Stearman biplanes, the C-1, C-2 and the C-3. Stearman had been in California for one year when his Wichita friends raised $80,000 to move back to Kansas and establish his company there. In 1929, Stearman Aircraft became part of a large holding company, the United Aircraft and Transport Corp. (UATC), of which Boeing was the major stock holder. Stearman continued to build mail planes and other types of conventional biplanes. Sales of Stearman's C-3R Business Speedsters helped the company weather the Depression. In 1931 Lloyd Stearman left the company to follow other interests in the aviation field, but the company retained his name. In 1933, Stearman Aircraft designed and built the Model 70, the prototype of the Kaydet Trainers (1934-1944) sold by the thousands during WWII. In 1934 federal legislation mandated that UATC be divided into several different companies, and Stearman Aircraft became a wholly owned subsidiary of the Boeing Company.

The Model 80 was a two-seat primary trainer variant of the Model 4 Speedmail from 1933 with dual controls. The Model 81 was a variant of the Model 80 with a cockpit canopy and larger fuel tanks.