Overview

The Aero L-39 Albatros is a high-performance, jet trainer aircraft developed in Czechoslovakia during the 1960s to replace the L-29 Delfín. It was the first turbofan trainer produced, and was later updated as the L-59 Super Albatros. The design is still produced in an evolved state as the L-159, while more than 2,800 L-39s still serve with over 30 air forces around the world. The Albatros is versatile, seeing duty in light attack missions as well as basic and advanced pilot training, and is the most widely-used jet trainer in the world.

The L-39 first flew on November 4, 1968, and was employed as the basic jet trainer for the Soviet Union, Czechoslovakia, and the rest of the Warsaw Pact nations from 1971 onward. The L-59, originally designated the L-39MS, a minor update to the design, remained in production until 1999.

L-39 versions

L-39X	Prototypes
L-39C	Standard production version
L-39V	Single-seat for target tug KT-04
L-39ZO	A four pylon light attack variant with an enhanced wing structure
L-39ZA	A significant enhancement of the L-39 ZO, employing sturdier landing gear, a higher payload and notably the GsH-23L - 23 Millimeter twin barrelled cannon suspended under the pilots compartment supporting 150 round magazine within the airframe
L-39Z/ART	Thai version with Elbit avionics
L-39MS	Original Czech Air Force name of L-59
L-139	Updated L-39C with Western avionics and Garrett TFE731 engine. First flown 1993, prototype only

L-39 External Dimensions

Wing span	31 ft (9.46 m)
Length	39 ft 10 in (12.13 m)
Height	15 ft 8 in (4.77 m)

L-39 Weights and Loadings

Basic empty weight	7,496 — 7,892 lb (3,400 — 3,580 kg)
Max ramp weight	12,500 lb (5,670 kg)
Internal fuel capacity	2,314 lb (1050 kg)
Total fuel capacity	3,360 lb (1,542 kg)

L-39 Performance

Max level speed	466 miles/h (750 km/h, or 450 KTAS)
Never-exceed speed (sea level)	565.5 miles/h (910 km/h, or 491 KTAS)
Max rate of climb (approx.)	4,130 ft/min (21 m/s)
Service ceiling (approx.)	36,000 ft (11,000 m)
Max range (with drop tanks)	840 miles (1,350 km)
Max endurance (with drop tanks)	2 hr 45 min
Take-off run (sea level)	1,770 ft (540 m)
Landing run (sea level, 50 % fuel)	1,800 ft (550 m)
Stalling speed (landing flaps, 50 % fuel)	98.2 miles/h (158 km/hr, or 85 KTAS)

L-39 Engine (AI-25)

Type	AI-25 TL twin-shaft turbofan engine
Bypass ratio	1.98
Maximum static thrust	16.87 kN
Specific fuel consumption	56.9 kg/hr/kN
Air flow	103.1 lb/s (46.75 kg/s)
Overall Pressure Ratio	9.5