Two-seat basic and advanced trainer designed as a modern replacement for the piston-engined trainers formerly in service with the Czech Air Force. First flown on 5 April 1959 while powered by a Bristol Siddeley Viper engine. Production aircraft, powered by one M 701C 500 turbojet engine (8.72kN) as standard, began coming off the production line in April 1963. More than 3,000 Delfins were built by the close of production; more than 2,000 were supplied to the USSR for use as trainers by the Soviet, Bulgarian, German (Democratic Republic), Hungarian and Romanian air forces. The balance were delivered to the Czech Air Force and exported to the air forces of Egypt, Indonesia, Nigeria, Syria and Uganda. The majority of those exported to Africa and the Middle East were of the L-29R light attack version, available with nose cameras and underwing stores.

Provision for a camera gun and gun sight, and either two bombs of up to 100kg, eight air-to-ground rockets or two 7.62mm machine-gun pods under the wings.