The L-39 Albatros was developed in Czechoslovakia in the 1960s as a new jet trainer to replace the L-29 Delfin. Seven prototypes were built, with the first prototype conducting its maiden flight in November 1968. Initial flight testing went well and showed the airplane had good handling qualities. The L-39 was powered by a Soviet AI-25TL engine and featured a tandem cockpit layout like other jet trainers of the time. It would go on to become one of the most produced jet trainers worldwide.