The Kinner Airplane & Motor Corporation had been producing radial engines since 1919 decided to enter the light aircraft market. The first design was a single-seat low-wing monoplane the Kinner Sportster K with a fixed tailwheel landing gear. Further versions followed with different engines. The strut-braced, low-wing, open cockpit, conventional gear aircraft featured folding wings.[1] In 1933, an improved version the Sportwing B-2 was introduced. An enlarged four-seat version was produced in 1935 as the Kinner Envoy. Kinner became bankrupt in 1937 and rights to the Sportster were acquired by the Timm Aircraft Company. The Sportster was also produced after the Bankruptcy by Security-National Corp as the Security S-1 Airster