Following its great success with the L-29 Delfin, the Aero team at Vodochody worked closely with the Soviet Union is planning the L-39 second-generation trainer, which first flew on 4 November 1968.
Entering service in 1974, the L-39 is especially noted for its robust and fuel-efficient Soviet turbofan engine. The cockpits are slightly staggered and contain zero height/150 km/h (93 mph) rocket-assisted ejection seats. Fuel is housed in five rubber cells in the fuselage and small non-jettisonable tiptanks. Double-slotted flaps are fitted, and the levered-suspension main gears are stressed for impact at high rates of descent.
By 2000, in excess of 2 800 L-39s of all versions had been built. Variants include the L-39V target tug, L-39ZA Ground-attack/reconnaissance, L-39ZO weapons trainer and L-39MS versions. This latter was developed as the L-59, a far more capable machine with a more powerful engine, strengthened airframe and upgraded avionics.
AS well as the Czech and Slovak air forces, the L-59 has also been delivered to the Egyptian and Tunisian air arms. The L-59 in turn was further developed into the even more capable L-159. This machine, flown as a single-seater from the front cockpit in the same manner as the L-39ZA, is a dedicated fighter lead-in trainer and light-attack platform. Its 28.02-kN AlliedSignal ITEC F124-GA-100 turbofan bestows a performance between 30 and 100 per cent better than that of the L-39C.
Avionics include an EFIS cockpit and HOTAS control and HUD, while the pilot sits on a zero/zero ejection seat and the aircraft carries additional internal fuel. A comprehensive weapons compatibility is included. The 72 aircraft on order for the Czech air force are set to be key warplanes within that country's inventory.