Aero L-39 Albatros

The Aero L-39 Albatros is a high-performance jet trainer aircraft developed in Czechoslovakia to meet requirements for a "C-39" (C for cvičný – trainer) during the 1960s to replace the L-29 Delfín. It was the first of the second-generation jet trainers, and the first turbofan-powered trainer produced, and was later updated as the L-59 Super Albatros and as the L-139 (prototype L-39 with Garrett TFE731 engine).

A further development of the design, the L-159 ALCA, began production in 1997. To date, more than 2,800 L-39s have served with over 30 air forces around the world. The Albatros is the most widely used jet trainer in the world; in addition to performing basic and advanced pilot training, it has also flown combat missions in a light-attack role. Atypically, it has never received a NATO reporting name.

Design and development
The L-39 (under the name "Prototype X-02" – the second airframe built) first flew on 4 November 1969 and was piloted by Rudolf Duchoň, the factory's test pilot. Serial production began in 1971. The design is Czechoslovak (Czech) – the construction of Aero's chief designer Jan Vlček.

The low, slightly swept wing has a double-taper planform, 2½-deg dihedral from the roots, a relatively low aspect ratio, and 100 liter (26½ USgal) fuel tanks permanently attached to the wingtips. The trailing edge has double-slotted trailing edge flaps inboard of mass-balanced ailerons; the flaps are separated from the ailerons by small wing fences.

The tall, swept vertical tail has an inset rudder. Variable-incidence horizontal stabilizers with inset elevators are mounted at the base of the rudder and over the exhaust nozzle. Side-by-side airbrakes are located under the fuselage ahead of the wing's leading edge. Flaps, landing gear, wheel brakes and air brakes are powered by a hydraulic system. Controls are pushrod-actuated and have electrically powered servo tabs on the ailerons and rudder. Operational g-force limits at 4,200 kg (9,260 lb) are +8/-4 g.

A single turbofan engine, an Ivchenko AI-25TL (made in the Soviet Union) is embedded in the fuselage and is fed through shoulder-mounted, semi-circular air intakes (fitted with splitter plates) just behind the cockpit; the engine exhausts below the tailplane. Five rubber bag fuel tanks are located in the fuselage behind the cockpit. The main, trailing-arm landing gear legs retract inward into wing bays; the nose gear retracts forward.

A long, pointed nose made of aluminum leads back to the tandem cockpit, in which the student and instructor sit under individual canopies that are hinged on the right. The rear (instructor's) seat is raised slightly; both ejection seats are made by Aero.

The basic trainer is not armed, but has two underwing pylons for drop tanks and practice weapons. Light-attack variants have four underwing hardpoints for ground attack stores; the ZA also has an underfuselage gun pod.

This model is no longer in production, having been replaced by the L-159.

Abkhazia
In the spring of 2008, a number of Georgian drones were shot down by Abkhazian separatist forces over the Abkhazia region. The Abkhazian separatist forces claimed that one of its missile-equipped L-39s had shot down a Georgian Hermes 450 unmanned reconnaissance drone.

Azerbaijan
L-39s, along with older L-29s, were used extensively in ground attack missions by Azeri forces in the Nagorno-Karabakh War. Several were shot down by Armenian air defences.

Libya
Libya acquired some 180 L-39ZOs around 1978 which served at Sabha and Okba Ben Nafi flying schools along with Yugoslav-made G-2 Galeb for advanced jet training and Italian-made SF.260s (for primary training).

The L-39s were deployed during the Chadian-Libyan conflict, mainly to Ouadi Doum air base. During the final Chadian offensive in March 1987, the Chadians captured Ouadi Doum along with several aircraft (11 L-39s included) and Soviet SAM systems and tanks. A Chadian report to the UN, reported the aforementioned capture on 11 L-39s and the destruction (or downing) of at least four of them.

In the midst of that conflict, on April 21, 1983 three LARAF Il-76TDs and one C-130 landed at Manaus Airport, Brazil after one of the Il-76s developed some technical problems while crossing the Atlantic Ocean. The aircraft were then searched by the Brazilian authorities: instead of medical supplies – as quoted in the transport documentation – the crate of the first of 17 L-39s bound for Nicaragua together with arms and parachutes, to support the country's war against US-backed Contras were found. The cargo was impounded for some time before being returned to Libya, while the transports were permitted to return to their country.

Syria
The Syrian Arab Air Force has a number of armed L-39ZA light attack variants. In 2012, during the Syrian civil war, L-39s have been routinely deployed against rebel ground forces, a number of aircraft have been shot down by ground fire. They were used operationally during the Battle of Aleppo, striking rebel-held positions.

Insurgents captured L-39s along with their support equipment after raiding the Al-Jarrah base in February 2013, though it is uncertain if the planes are airworthy.

Civilian use
While newer versions are now replacing older L-39s in service, thousands remain in active service as trainers, and many are finding new homes with private warbird owners all over the world. This is particularly evident in the United States, where their $200,000–$300,000 price puts them in range of moderately wealthy pilots looking for a fast, agile personal jet. Their popularity led to a purely L-39 Jet class at the Reno Air Races, though it has since been expanded to include other, similar aircraft.

In September 2012 there were 255 L-39s registered with the US Federal Aviation Administration and four registered with Transport Canada. Several display teams use the L-39 such as the Patriots Jet Team (6 L-39s), the Breitling Jet Team (7 L-39s) and the Black Diamond Jet Team (5 L-39s).

There are also several L-39 available for private jet rides in Australia, Czech Republic, France, Germany, Spain and the USA. These L-39s are mostly in private hands, but some also belong to government agencies, such as those in Vyazma, Russia.

Variants

 * L-39X-01 – X-07
 * Five prototypes plus two static test airframes.


 * L-39C (C for Cvičná – training)
 * 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.


 * L-39CM (CM for Cvičná modernizovaná – modernised training)
 * Slovak upgraded C version.


 * L-39M1
 * Ukrainian upgraded C version with AI-25TLSh engines. The conversion is carried out by Odesaviaremservis and the first plane was ready in 2009. The upgrade of a further 7 L-39C's is planned.


 * L-39V (V for Vlečná – tug)
 * Single-seat target tug version for Czechoslovakia. Equipped to tow KT-04 target on 1,700 m (5,600 ft) cable. Prototype plus eight production aircraft built.


 * L-39ZO (Z for Zbraně – weapons)
 * Interim weapon trainer variant for export. Four pylons stressed for 500 kg (1,100 lb) (inboard) and 250 kg (550 lb) (outboard), with total external load of 1,150 kg (2,500 lb). First flew 25 June 1975, with initial deliveries to Iraq in 1977. 337 built.


 * 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)) 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-60 air-to-air missiles. Two prototypes, with first flying on 29 September 1976. 208 aircraft delivered.


 * L-39ZAM
 * Slovak upgraded ZA version.


 * L-39ZA/ART
 * Thai version of L-39ZA with Elbit avionics. 40 built.


 * L-39MS
 * The Aero L-39MS Super Albatros is a second generation military trainer aircraft developed from the firm's earlier L-39. Compared to its predecessor, it featured a strengthened fuselage, longer nose, a vastly updated cockpit, and a more powerful (21.6 kN (4,850 lbf)) Lotarev DV-2 engine, allowing operation at higher weights and speeds (max speed 872 km/h (542 mph)). First flight on 30 September 1986. It was later designated as the Aero L-59.


 * L-139 Albatros 2000
 * Revised version with western avionics and 17.99 kN (4,045 lbf) Garrett TFE731-4-1T engine. Single prototype built.


 * L-159
 * Further modernised advanced trainer/combat aircraft with more modern, western avionics and Honeywell F124 engine.

Operators
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Notable incidents

 * 26 September 1986 Mihai Smighelschi, a 21-year old student of the Romanian Air Force Academy, used an L-39ZA Albatros training plane to fly to Turkey and request political asylum. His aircraft was later recovered and onboard data recorders showed that he had flown no higher than 150 m above ground at 700 km/h to evade radar detection. Smighelschi had less than 100 hours at the time, including high-school glider training, and less than 3 hours on the L-39ZA. Without satellite navigation or indeed any maps, he navigated a straight line over Romania, Bulgaria and Turkey using only ground marks and the memory of a map of Europe he had access to at the Academy. He eventually landed in Kirklareli, Turkey, on a street near a group of jeeps that seemed to have American insignia, breaking the front wheel and the nose of the plane.
 * 24 January 2001 Atlas Air Founder, Chairman, and CEO Michael A. Chowdry was killed when his Czech L-39 jet trainer crashed into an open field near Watkins, Colorado, USA. Also killed was Wall Street Journal aerospace reporter Jeff Cole. Chowdry and Cole were making a planned flight from Front Range Airport.