The signing of two critical agreements with the Czech Government in April has given Aero Vodochody the official go-ahead for the long-anticipated L-159 combat-aircraft programme.

The development agreement completed on 7 April committed the Republic's defence ministry to funding some 25% of the development costs of the programme, while the ensuing production commitment guaranteed that the Government would buy 72 aircraft for the Czech air force. With the programme now officially up and running, the manufacturer has taken advantage of the International IDET defence show, to be held in Brno from 2 to 6 May, to present its concept publicly for the first time.

The L-159 will be the first major new aircraft programme to come out of the East European republic in post-Communist years, giving a substantial boost to the country's industry and establishing valuable links with Western companies participating in the programme. For the Czech air force, it means having a home-produced -- and therefore affordable as a result of low Czech production costs - light-attack aircraft comparable with the British Aerospace Hawk and, significantly, offering compatibility with NATO standards of equipment.

The new aircraft is part of the Czech armed forces' restructuring plan, reflecting the Republic's political and economic orientation towards NATO and the European Union. The plan includes the restructuring of the air force along NATO lines, the upgrade of existing aircraft with NATO-compatible identification and communications equipment and the replacement of Soviet-built aircraft.

Aero Vodochody now anticipates that the Czech air force of the future will be based on the L-159 and a high-performance multi-role fighter "of US origin", with the L-159 forming about 75% of the air force's combat inventory.

The Czech Republic has had previous attempts to buy surplus Lockheed Martin F-16 A/Bs blocked by the US State Department which, to date, has been wary of antagonising Russia by supplying arms to former Warsaw Pact states. Recent US Department of Defense discussions with Poland suggest, however, that this attitude may be softening, (Flight International, 1-7 March).

The alternative of a $60 million upgrade, of 24 Air Force Mikoyan MiG-21 fighters, is also being pursued by the Czech defence ministry, (Flight International, 26 April-2 May) but has stirred fierce opposition from those who believe, that upgrading a platform as old as the MiG-21 is not worth the money and effort.


Whatever the final decision on the air force's supersonic platform, the L-159 will be the mainstay of Czech air power, in such roles as close air-support, tactical reconnaissance, border patrol, point air-defence and interception of low- and slow-flying targets. The aircraft will also be produced in a two-seat version for use as a lead-in trainer with operational capability and, although precise numbers have not yet been specified, it is anticipated that this variant will account for about 10% of the initial production batch.

Aerodynamically, the L-159 will be closely based on the well-established L-39/L-59 family of jet trainers, which has constituted the bulk of Aero's production output since the late 1960s. The L-39 was first flown in 1968 and some 2,900 have been produced and sold to 15 countries. The L-59, with a more powerful engine, strengthened airframe and other systems improvements, is in service with the Czech and Slovak air forces; a batch of 48 has been sold to Egypt and a further 12 are in production for Tunisia.

While Aero Vodochody does have these export orders and a further sale of 36 L-39s to Thailand - with avionics from Israel's Elbit - to its credit, the days of guaranteed business in the Warsaw Pact, which brought annual sales in the late 1980s to more than 200, are long gone. In 1992, with Eastern Europe struggling to re-orient itself to the free market, Aero Vodochody sold only six aircraft and the Aero group of companies languished in serious debt.

Although the company declines, to reveal its 1994 financial results before the release of its annual report, 1994's production figure of 51 aircraft suggests, a significant improvement in its prospects and was accompanied by a complex restructuring of the companies under Aero Holding, to settle the group's outstanding $62 million debt. Now, the go-ahead for the L-159 comes as a further fillip.

Like the earlier Albatros, the L-159 will be a conventional low-wing, single-engine, aircraft with an all-metal airframe. The nose section has been redesigned to accommodate radar and a one-man cockpit protected with composite/ceramic armour. The Albatros' rear cockpit is replaced with a new fuselage fuel-tank and avionics bay, while the rear fuselage is to be enlarged to accommodate the aircraft's AlliedSignal/ITEC F124-GA-100 turbofan engine, which was developed to power the Taiwanese AIDC Ching-Kuo fighter.

Aero has already co-operated with AlliedSignal on engines in the past, using the 18.15kN (4,200lb)-thrust Garrett TFE731-4 turbofan to power its most recent variant of the Albatros, the L-139. Now, the installation of the F124, with its maximum thrust of 28kN, gives the L-159 substantial performance advantages over its predecessor, the L-59, powered by the 21.57kN Progress DV-2 turbofan.

In a clean, two-seat, configuration with 50% internal fuel, the L-159 has double the climb rate, a 25% higher maximum level speed, a 50% higher sustained turn-load factor, a 30% better thrust-to-weight ratio and a 30% shorter take-off run than its forerunner.

The manufacturer's performance targets specify a maximum take-off weight of 8,000kg, with up to 2,340kg of external stores on six underwing hardpoints and a centreline pylon. The aircraft's maximum level speed at sea level is to be 500kt (930km/h), its ceiling 43,300ft (13,200m) and its maximum range on internal fuel, with 10% in reserve, is to be 1,570km (850nm). The structure is designed to withstand load factors from 8g to -4g.

Like the engine, the aircraft's avionics will consist of off-the-shelf equipment supplied by an established Western manufacturer - or, to be precise, by an international team, led by Rockwell International. This reflects Aero's approach to keeping the cost and development timescale to a minimum and to share the project costs with its foreign partners.

According to Aero Vodochody vice-president of research and development, Viktor Kucera, the development of the single seat version alone, will cost around CKr1.4 billion ($50 million) and the aircraft will sell for about "60% to 70% of a [British Aerospace] Hawk aircraft", probably rather more than the $6 million quoted in earlier news reports.


The avionics contract - estimated to be worth $190 million - was won by Rockwell only after a fierce, drawn-out, battle which split Aero Vodochody's management and set the company at loggerheads with its own customer, the defence ministry. The competition for this contract, boiled down to a standoff between Elbit, the participation of which, in the Thai L-39 sale had proved so decisive and which enjoyed the support of Aero Vodochody's fiery general manager Zdenek Chalupnik - and Rockwell, which made an offer found technically preferable by both the ministry and other senior Aero managers.

The dust from that particular skirmish has now settled and Rockwell won the day, bringing with it a team of companies including AlliedSignal, Dynamic Control (DCC), FIAR, Flight Visions and GEC-Marconi. Elbit, meanwhile, is to supply the avionics package for the new L-59F variant now being offered to the Royal Australian Air Force for its lead-in fighter-trainer requirement. This version of the L-59 is also powered by the F124.


Rockwell is to act as systems integrator for the L-159's avionics, with responsibility for the design, development and laboratory testing of the system. The package includes the FIAR Grifo-L multi-mode pulse-Doppler radar, providing all weather air-to-air and air-to-ground modes for target detection, designation, tracking and navigation. This is linked to the other avionics subsystems by a 1553 databus, and is controlled via the aircraft's Mason Electric hands-on- throttle-and-stick controls and the AlliedSignal multi-function colour liquid-crystal displays.

The radar provides outputs to the Flight Visions FV-3000 head-up display, which is a development of the L-59's FV-2000 and includes the same air-to-air gunnery and air-to-ground ballistic-weaponry-delivery algorithms, with minor modifications.

The aircraft features an integrated threat-warning and countermeasures system, which includes a GEC-Marconi Sky Guardian 200 radar-warning receiver (RWR) and a Vinten Vicon 78 Series 455 countermeasures dispensing system (CMDS). The RWR covers frequencies from the E to J bands, detecting pulse, continuous-wave and interrupted continuous-wave emissions. It can interface with the CMDS to dispense countermeasures automatically, or can provide the pilot with a cue to trigger countermeasures himself.

AlliedSignal provides the aircraft's APX-100 identification-friend-or -foe (IFF) transponder and its air-data computer.

For navigation, the L-159 has a Honeywell H-764G integrated global-positioning/ inertial-navigation system (GPS/INS) - a strap-down ring-laser gyro-based inertial navigation system with an embedded GPS - and radio navigation from AlliedSignal. The auto-pilot and yaw damper are from Lear Astronics.

The stores-management system (SMS) comes from DCC, and is based on the latest design for the McDonnell Douglas F-15. The SMS interfaces with and controls the L-159's weapons, which are to include gun pods, air-to-air missiles (AAMs), air-to-ground missiles, rockets and bombs. While Aero Vodochody refuses to reveal the types of weapons which will be fitted to the aircraft, it is known that they are to include the AIM-9 Sidewinder short-range infrared AAM, and the AGM-65 Maverick air-to-ground missile.

The company also hopes to add medium-range AAMs, and pods for electronic countermeasures, reconnaissance and night- navigation and targeting in future.

Kucera says that Aero is planning to begin flight testing of a two-seat prototype as early as the second half of 1996, with a second prototype -- the first single-seat L-159 - getting airborne in the first quarter of 1997. Deliveries are scheduled to begin to the Czech air force in the last quarter of 1998. Kucera stresses, however, that the Czech air force's order is far from the whole story.

"From the economic point of view, Aero has to produce more aircraft, in several versions," he says. Future versions could be equipped differently, depending on the customer's requirements.

"We hope to sell several hundred aircraft, the minimum is 200", adds Kucera. To break even on the programme, Aero needs to sell more than 150 units, including those going to the Czech air force. Its first target customers will be neighboring East European countries, to whom the company is prepared to offer industrial participation should they demand it.

Source: Flight International