The L-39 series of trainer and light attack aircraft was designed and produced by Aero Vodochody in the Czech Republic, this company producing some 10,000 jet trainers for the world’s markets over the years.

The CA-31 was one of a series of projects designed by the Commonwealth Aircraft Corporation to meet a requirement of the RAAF for a supersonic trainer and light attack aircraft, being designed to facilitate pilots proceeding from the Macchi MB-326H to the GAMD Dassault Mirage IIIO, being expected to be