Jimmy Doolittle and the Army Air Service’s Engineering Division

Doolittle joined the Army Air Service’s Engineering Division at McCook Field near Dayton, Ohio, as a test pilot in 1924. Doolittle (front row, third from left) and his fellow test pilots, including T-2 pilot John A. Macready (back row, third from left), flew experimental aircraft to evaluate high-altitude and high-speed flight and new equipment, such as the engine turbosupercharger and variable-pitch propeller.