The prototype Stearman PT-13 Kaydet two seat biplane first flew from Wichita, Kansas in October 1934. Fitted with Lycoming R-680 radial engines, the first trainers, designated PT-13s, were delivered to the US Air Corps in mid 1936 together with more aircraft in 1937 and 1938. In 1940 demand for the trainer increased rapidly and outstripped Lycoming's capacity to supply engines. This led to the Continental engined version, the PT-17.The importance of the Stearman PT-13/PT-17 to the US war effort cannot be overemphasized. Approximately 50% of all US military pilots, who fought in WW II received their initial flight training in this sturdy aircraft. A further 10,000 RAF and Fleet Air Arm pilots used the Stearman trainer for primary training, at British Flying Training Schools throughout the U...