Standard basic trainer for Soviet Union, Czechoslovakia and export. Originally designated L-39, but renamed L-39C when later variants appeared. Two pylons under wing. Approximately 2,260 built.[28]L
L-39ZA
Significantly upgraded L-39ZO for armed training and light attack, employing sturdier landing gear, a higher payload (total 1,290 kg (2,844 lb))[21] and notably provision for a GSh-23L 23-millimeter twin-barreled cannon attached in a conformal pod under the pilots' compartment, having a 150-round magazine within the airframe. Outer pylons wired to carry K-13 or R-60air-to-air missiles. Two prototypes, with first flying on 29 September 1976. 208 aircraft delivered.[80]