Yorkshire-based aircraft manufacturer Slingsby first flew its T7 Kirby Cadet single-seat training glider in 1935. The type was first taken on for use by the Air Training Corps during World War Two, and continued to serve post-war as the Cadet TX1. Further developments of the design were the T8 Kirby Tutor, a version with a higher-performance wing known to the ATC as the Cadet TX2, and the T31 Tandem Tutor, the first two-seat member of the line, designated as the Cadet TX3. The final examples of the TX3 model were not retired by the Air Cadets until 1985.