Andrzej Jeziorski/PRAGUE

A military band played the fanfare from Jesus Christ Superstar as the L-159 - the first new Central European combat aircraft prototype since the fall of Communism - was officially rolled out at Aero Vodochody's factory near Prague, on 12 June.

The choice of music seemed odd, but then it could be said that the Czech aerospace industry really has awaited this roll-out with near-religious fervour. All the Republic's hopes for future indigenous military-aircraft production are pinned on this programme, and the manufacturer will have to export more than double the domestic requirement to break even, so marketing is critical.

The red, white and blue machine was christened the Advanced Light Combat Aircraft (ALCA). It is intended to become the mainstay of the Czech air force, which needs 72 units to fulfil close air support, tactical reconnaissance, air-defence and border-patrol duties.

As the crowd of guests gathered for a closer look at the prototype, Aero Vodochody officials could barely conceal their jubilation. That very morning, they had learned that the Government had guaranteed production funding for the Czech air force order.

Two years earlier, in April 1995, the Government had signed a development agreement committing the defence ministry to funding 25% of the estimated $50 million development programme. It also expressed an intention to buy a batch of 72 aircraft which will in future make up about three-quarters of the combat strength of the Czech air force.

The latest guarantee makes this intention look firmer, and anticipates a contract which Aero hopes will be signed later this year following the conclusion of discussions with the finance ministry, according to company chairman Jaroslav Borak. Aero says that the overall contract will be worth about $1 billion, yet with the Czech Government itself teetering on the brink - embattled prime minister Vaclav Klaus barely scraped through a recent no-confidence vote - some are asking how firm its funding guarantees can really be in these circumstances.

Borak is optimistic. "We think the political situation will not affect the contract," he says.

The news of the Government's production go-ahead was announced at the start of the roll-out ceremony by defence minister Miloslav Vyborny, for whom the L-159 is one of the key elements of an armed-forces modernisation programme which he hopes will smooth the country's entry into NATO. Substantial participation in the programme from big US and West European firms is furthermore seen as an opportunity to establish global industrial links which could prove crucial in future.

When the aircraft was unveiled, some local journalists at the ceremony were puzzled that it seemed to look no different from the L-39/L-59 jet-trainer family which has been in production since the late 1960s - especially as the first ALCA prototype is a two-seater L-159T variant.

This version is intended as a combat-capable lead-in trainer, and is expected to constitute about 10% of the initial production batch. Outwardly, the prototype's all-metal airframe certainly looks similar to that of its predecessors, but there are key differences, most of which lie under its aluminium skin.

According to Aero Vodochody's vice-president research and development, Viktor Kucera, the external differences amount to a fuselage some 0.6m longer than the earlier models, an enlarged nose to accommodate the production aircraft's Fiar Grifo-L multi-mode pulse-Doppler radar, and a redesigned wing with six hardpoints, compared with the earlier models' four. With a centreline pylon available under the fuselage, the aircraft is designed to carry up to 2,340kg of stores externally, and has an overall maximum take-off weight of 8,000kg.

Internally, the engine bay has been redesigned to accommodate the 28kN (6,300lb)-thrust AlliedSignal/ITEC F124-GA-100 turbofan engine, developed to power the Taiwanese Aerospace Industrial Development Ching-Kuo fighter. The single-seat aircraft carries 1,980litres of fuel in six fuselage and two wingtip tanks, protected by an on-board inert-gas generating system. The two-seater carries less fuel, with the rear cockpit displacing one fuselage tank.

On internal fuel only, this gives the single-seater a range of 1,570km (850nm), allowing for reserves of 10% of internal fuel. The engine should also give the L-159T - in a clean configuration with 50% fuel - double the climb rate, 25% more speed and a 30% better thrust-to-weight ratio than its L-59 predecessor, which is powered by the Slovak-built, 21.6kN Progress DV-2 engine.

The aircraft is stressed to withstand load factors from +8g to -4g, and is expected to achieve maximum level speeds of 505kt (935km/h) and a stall speed of 100kt, with a ceiling of 43,300ft (13,200m). At 5,500kg, it will require 680m to take-off to 50ft, and a 725m landing run.

The first prototype is now scheduled for its maiden flight at the end of July, and is primarily intended as a test bed for the engine. Unlike the production aircraft, it is fitted with an AlliedSignal Bendix/King avionics suite similar to that in Egyptian air force L-59s, and does not have the Fiarradar.

The first production-standard aircraft will be prototype number two, now under construction and due to be rolled out at the end of this year. This aircraft will be flown in about mid-1998, after a series of ground tests of its Boeing avionics, says Kucera. Production deliveries to the Czech air force are due to start in 1999.

The $190 million avionics contract was won by Rockwell International after a fierce struggle with Israel's Elbit, which was already providing avionics for a 36-aircraft L-39 order from Thailand (this has now grown to 40 aircraft already delivered, and a follow-on order is expected for ten more). In December 1996, Rockwell's aerospace and defence units were acquired by Boeing, and integrated into the US aerospace giant's Defence and Space Group.

The L-159 avionics programme is now being run by Boeing's Communications and Combat Systems division, which is approaching the end of ground tests on the system at its Avionics Integration Laboratory in California. Meanwhile, elements of the avionics are already being delivered to Aero, for the second prototype.

The avionics suite includes contributions from Italian, UK and US manufacturers.

The Grifo radar is linked to other avionics subsystems via a MIL-STD-1553B databus, and the pilot sees the radar image on AlliedSignal Bendix/King liquid-crystal, multi-function colour displays. The radar also provides data to the Flight Visions FV-3000 head-up display (HUD), a development of the FV-2000 installed in the L-59 with modified air-to-air gunnery and air-to-ground weapons delivery algorithms. Radar controls are integrated into the Mason Electric hands-on throttle-and-stick system.

The aircraft's threat-warning and countermeasures system includes a GEC-Marconi Sky Guardian 200 radar-warning receiver (RWR), which can detect pulse, continuous and interrupted continuous wave emissions in the E to J bands. The RWR can be used to trigger the Vinten Vicon 78 Series 455 countermeasures dispensing system to release chaff and flares, or it can warn the pilot to do so manually.


Identification friend-or-foe

The identification friend-or-foe transponder is an AlliedSignal APX-100, and the same manufacturer also provides the aircraft's air-data computer. Honeywell supplies the H-764G integrated global-positioning/ inertial-navigation system, while the autopilot and yaw damper are supplied by Lear Astronics.

Dynamic Control supplies the stores-management system - based on the design for the McDonnell Douglas F-15 - which controls the L-159's weapons.

While Aero has been vague about the aircraft's weapons, the prototype at the roll-out was displayed with an extensive selection of proposed armaments. These included the Raytheon AIM-9M Sidewinder short-range, infra-red guided air-to-air missile, the Hughes AGM-65 Maverick air-to-surface missile, and the GEC-Marconi Brimstone millimetre-wave-guided anti-tank missile.

GEC is also proposing its Thermal Imaging Airborne Laser Designator targeting pod and the Apollo electronic counter-measures pod.

Instead of having an internally mounted cannon like that of the L-39/L-59, the L-159 will be capable of carrying a Czech twin-20mm cannon pod, the Plamen. According to Kucera, this is now under development in the Czech Republic by Zbrojovka Vsetin, and is derived from the Russian GSh-23, 23mm cannon.

According to Aero chief executive Adam Stranak, the manufacturer will break even on the programme only after it has sold 230 aircraft. Export success is crucial, and the company is targeting operators of L-59 and L-39 aircraft as key potential customers, alongside any other countries looking for a cheap, capable light-attack aircraft or jet trainer which will sell at about 60-70% of the price of a British Aerospace Hawk, as Aero officials claim.

Over 2,800 L-39s have been delivered to 16 air forces since 1971, while 65 L-59s are in service with the Czech, Egyptian, Slovak and Tunisian air forces. Aero hopes that the ALCA will be a key contender to replace them.

Source: Flight International