The Aero L-39 Albatros is a high-performance jet trainer aircraft developed in Czechoslovakia to meet requirements for a trainer aircraft during the 1960s to replace the L-29 Delfín. Designed before the Soviet armed intervention in Czechoslovakia in 1968, the Aero L-39 Albatros is now wellon the road to emulating its predecessor, the L-29 Delfin, as the standard jet trainer for Warsaw Pact (except Poland) and other airforces. Aero began with three prototypes, the middle one of which flew for the first time on 4 November 1968; the other two were subjected to structural and fatigue tests. Pilot for the first flight was Rudolf Duchon, who had also been responsible for the early test programmeof the L-29 nine years before. The powerplant selected for the L-39 is the Soviet-designed Ivchenko AI-25 turbofan, and most of the early delays in the aircraft's development are thought to be the result of problems encountered in relating this to the L-39's airframe, so ren- dering it acceptable for
licence production in Czechoslovakia. One of the chief problems seems to have been the supply of air to the engine: by late 1970, at which time five flying prototypes had been completed, modified intakes of greater length and increased area were noticed on these development aircraft. During the following year, a pre-production batch of 10 L-39s was built to the modified configuration, and series production began in late 1972. By 1979, more than 1,000 had been ordered, of which more than half had been completed. These are of three main versions. The basic L-39C, for elementary and advanced jet training, has been supplied in quantity to the Czech and Soviet air forces plus those of other Warsaw Pact nations as a successor to the L-29; it began to enter service in 1974.
When equipped for weapons training, the two-seater is known as the L-39Z. A single-seat armed variant, for use in the light close-support and ground-attack roles, is designated L-390: Iraq is known to be among the operators of this last version. Dipl.-Ing. Jan Vlcek, who led the Aero design team responsible for the L-39, has produced a physically attractive little aeroplane with a significant improvement in performance over its predecessor (Mach 0.83 top speed, compared with the L-29's Mach 0.75). Tandem seating (on zero-height ejection seats in the L39C) is retained, but naturally with the rear (instructor's) seat elevated to improve his view forward. Simultaneously, this enables the lower-placed front cockpit to slope downward towards a finely- pointed nose that reduces drag and contributes to enhanced performance.
The Czechoslovakian L-39 was built as the successor to their earlier trainer, the L-29 Delfin. Design work began in 1966, and the first prototype made its initial flight on 4 November 1968. The idea of the design was to marry an efficient, powerful turbofan engine to a sleek, streamlined fuselage, resulting in a strong, economical performer which would become the next standard jet trainer for the Warsaw Pact. Full-scale production was delayed until late 1972 due to apparent problems with the design of the air intakes, but these difficulties were overcome and the type went on to be a great success with the Soviet, Czech and East German air forces, among others.Three main variants were produced. The L-39C was built as a pure trainer and was used by numerous air forces throughout Eastern Europe beginning in 1974 and continuing through today. The armed weapons-trainer variant is called the L-39ZA, and a close-support and ground-attack version is called the L-39ZO. In addition to those mentioned above, the L-39 has been exported to numerous countries, including Afghanistan, Bulgaria, Hungary, Romania, Iraq, Libya, Estonia, and Kyrghyzstan. A modernized derivative of the Albatros, the L-59, is still being built in the Czech Republic. Another modernized, but very different version, the L-39MS, actually has much more in common with the L-59 than the L-39, despite its designation.
As of this writing, the L-39 is the most popular jet warbird in the world, with over 300 believed to be actively flying in the USA alone.
Nicknames: "L-ka" (Russian nickname)
Engine: One 3,792-lb thrust Ivchenko-Progress AI-25-TL (also built under Czech license by Motorlet).
Weight: Empty 7,340 lbs., Max Takeoff 11,618 lbs. (L-39ZO with four rocket pods)
Wing Span: 31ft. 0.5in.
Length: 40ft. 5in.
Height: 15ft. 5.5in.
Maximum Speed at 19,600 ft: 485 mph (Trainer version, clean)
Maximum Speed at Sea Level: 435 mph
Ceiling: 37,730 ft. (Trainer, clean)
Range: 528 miles with internal fuel; 995 miles with external tanks.
Armament (L-39ZO): Up to 2,425 pounds of weapons on four underwing hardpoints, including bombs, 57- or 130-mm rocket pods, gun pods, a five-camera reconnaissance pod, or two fuel drop-tanks. Centerline point carried a pod-mounted 23-mm twin-barrel GSh-23 cannon with 180 rounds.
Number Built: 2800+
Number Still Airworthy: Unknown number in military service. At least 300 flying in private ownership.