New generation jet trainer

Alexander Mladenov attended the roll-out ceremony of the L-39NG, the first new jet trainer to be developed by Czech airframer Aero Vodochody in 20 years

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During the roll-out event, the first L-39NG, c/n 7001, was presented as a finished product with ejection seats installed, ready to launch its intense flight-test campaign within a month.
Alexander Mladenov

THE L-39NG jet trainer, rolled out at Aero Vodochody’s plant at Odolena Voda near Prague on October 12, 2018, promises to open a whole new world of options for cost-effective military pilot training. While the new-generation Albatros retains more or less the same shape as its predecessor, Aero says it is a totally different aircraft under the skin, but retains the L-39’s dependability and affordability.

The L-39NG’s unveiling happened four years after the formal go ahead of the NG programme and its maiden flight is now expected before the end of the year. Certification by the Czech military aviation authorities to European Military Airworthiness Requirements (EMAR) standards, is expected by the end of 2019.

This type certificate, according to Aero, will bring true compatibility and interoperability within EU and NATO operators, avoiding any requirement for additional certification and cross-border processes.

In addition to the first prototype, c/n 7001, shown in public during the roll-out ceremony, three more aircraft are currently in production at Aero. The second one, c/n 7002, will be used for static tests, the third, c/n 7003, is earmarked to serve as a fatigue test-bed, while the fourth machine, c/n 7004, will be the first pre-series L-39NG. Slated to take to the air in 2019, it is set to be used in the concluding part of the type’s certification programme and will then become the first customer aircraft, with its delivery tentatively slated for early 2020.

Making a new market niche

The company and its Italian-led management team maintain that the L-39NG combines affordable price, high performance and state of- the-art simulation capabilities, rendering it highly competitive on the crowded global military training aircraft market, dominated today by high-end turboprop types, mainly used for initial and basic flight training. Furthermore, the L-39NG is also being pitched as a reasonably capable machine in the advanced and lead-in fighter training roles usually the preserve of high-performance jet designs, which cost twice the L-39NG’s price. The manufacturer believes the new aircraft is on its own in this portion of the market sector with no serious competition, offering ‘zero-to-hero’ cost effective jet training options. The launch customer, scheduled to get its first two aircraft in 2020, Czech company LOM Praha, intends to use the L-39NG in this wider manner, training Czech Air Force pilots through the entire syllabus from basic to lead-in fighter phases.

Giuseppe Giordo, Aero Vodochody President and CEO, noted at the L-39NG roll-out that the new trainer defines the future of Czech aviation by taking the best from its tradition, adding modern technology, and providing the best training and light attack solution available.

According to Massimo Ghione, Chief Business Officer at the company, the new trainer is targeted at a wide range of customers and is primarily intended to compete against the Embraer EMB-314 Super Tucano and the Pilatus PC-21 turboprops. It has roughly the same acquisition price as those high-end turboprops, while the direct operating costs would be lower thanks to the very low maintenance engine. Most importantly, the jet-powered L-39NG offers much higher performance in both training and light attack roles, as it is faster and can fly higher and longer while carrying more payload than its turboprop competitors.

Ghione also added that the L-39NG has been designed from the outset as a maintenance-friendly machine. The new engine, for example, is covered by a lifetime warranty under an engine maintenance programme, offered by the manufacturer, Williams International. Known as TAP Blue, this programme covers all types of scheduled and unscheduled maintenance against a fixed price per flight hour, including repairs in case of foreign object damage. This fixed price, together with a fixed price for the airframe and systems support, could be offered as a power-by-the-hour programme for the entire life-cycle of the aircraft according to Ghione.

Another important advantage is that the L-39NG remains capable of delivering a full range of weapons and is being promoted as an affordable light combat aircraft, able to carry a war load of up to 1,600kg (3,526lb) on five hard points. There is a wide range of armament and sensor options on offer. First customer Senegal has ordered four L-39NGs in a light attack configuration featuring aircrew armour protection and countermeasures dispensers.

NG’s list of novelties

The L-39NG retains the superb handling performance and rugged design of legacy L-39s, including a sturdy and simple wide-track undercarriage. At the same time, the new-generation Albatros boasts an improved and comprehensively redesigned airframe with even better aerodynamic performance together with an easy-to-maintain and fuel-efficient engine, all-new digital avionics suite and Martin- Baker’s Mk16 zero-zero ejection seats. The aircraft has been completely redesigned, with 93% of its components, assemblies and systems being brand-new; very few legacy parts have been retained in the L-39NG’s design.

The newly-built airframe makes extensive use of composite materials and comes with a 15,000- hour total service life, enough for at least 30 years, while the engine is being offered with at least a 10,000-hour service life. Neither the new engine or avionics are controlled by the US International Traffic in Arms Regulation (ITAR) rules, so Aero will be able to offer the new trainer versions to existing customers worldwide without restrictions.

The newly-built airframe is lighter and more durable than that of the L-39C. It also comes with an all-new wing design with integral fuel tanks, the so-called wet wing, which lacks the characteristic fixed wingtip tanks used on all old versions.

Removing the wingtip tanks results in a reduction of the wing loading and contributes to an increase in roll rate.

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According to Aero’s Massimo Ghione, the company is now engaged in talks with 24 potential customers. For those who cannot afford outright purchase of the L-39NG due to budgetary reasons, the company is keen to offer various leasing solutions, including dry leasing aircraft provided by SkyTech.
Alexander Mladenov
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A look at the upgraded cockpit of the L-39CW demonstrator boasting two multifunctional displays and a HUD.
Alexander Mladenov

The fuselage has a circular cross-section, smaller in diameter than that of legacy jets because of the smaller new engine and comes with a more stepped cockpit arrangement in an effort to grant better visibility forward and downward for the pilot sitting in the rear cockpit. The fuselage structure also benefits from the use of composite materials, mainly in those areas affected by vibration, such as the air intakes, in order to extend fatigue life. The combination of the all-new wing and the extensively redesigned fuselage also creates less drag, endowing the L-39NG with better aerodynamic performance than its forbears.

The all-new wing features four pylons for carriage of external stores in addition to one more pylon under the fuselage; each is rated at 375kg (827lb). The wing pylons are wet, featuring plumbing to carry external fuel tanks.

The Williams International FJ44- 4M turbofan powering the L-39NG is a proven piece of kit used on the upgraded twin-engine Saab 105. It comes equipped with an electrical starter and provides roughly the same maximum thrust rating as that of the AI-25TL used on legacy L-39s, generating 3,600lb static thrust (16kN). The new engine, however, is lighter, and together with other design improvements (the L-39NG is about 350kg (771lb) lighter than the L-39C according to the latest data released by Aero), the fuel-efficient FJ44-4M endows the L-39NG with a higher power to- weight ratio. It also boasts a much better throttle response, with the time for transitioning from idle to maximum power setting being between three and five seconds compared to nine and 12 seconds for the rather antiquated AI-25TL.

This feature, together with the seriously improved aerodynamic performance, makes the L-39NG much more pilot-friendly than the L-39C/ZO/ZA family.

The list of other novelties featured in the L-39NG’s design includes single-point re fuelling, increased volume fuel tanks, night vision goggle (NVG)-compatible lighting in both cockpits and a single-piece canopy featuring improved bird-strike resistance for improved pilot visibility. The aircraft is also offered with a new debriefing system and a health and usage monitoring system (HUMS) like that found on high-end modern trainers.

Cost-effective avionics suite

The new modular core avionics suite for the L-39NG is supplied by US company Genesis Aero systems.

Being a non-ITAR product, the lightweight and highly capable electronic light instrumentation system (EFIS) incorporates two 152 x 203mm (6 x 8in) colour displays in each cockpit in portrait format, arranged side-by-side, while the advanced cockpit version offers three such displays. The displays are NVG compatible and the front cockpit also has a Czech-made head-up display (HUD), supplied by the Prague-based Spiel company; both cockpits feature hands of throttle and stick (HOTAS) controls. The all-new avionics suite conceived for the L-39NG also integrates a GPS module, a light attitude reference and heading system and an air data system.

The so-called Master Moding control concept allows for rapid re-configuration of the cockpit displays and other systems. It provides three master modes, navigation, air-to-air and air-to ground.

Aero owns the software code for the EFIS and can customize it according to customer requirements. For example, the company can offer the aircraft with instruments calibrated in the metric system, which would be useful for customers operating Su-27/Su-30 or MiG-29 Russian-made fighters. The basic configuration available to military customers can use unguided bombs, rockets and gun pods, and can also be made capable of firing air-to-air missiles.

According to Maco Venanzetti, vice president, L-39NG at Aero, the basic light attack sub-version will initially be cleared to use 250lb Mk81 and 500lb Mk82 free fall bombs in addition to CRV7 rockets and a twin-barrel gun pod. Such a configuration, Venanzetti maintains, meets the needs for 80% of customers. For guided weapons Aero could rely on a wide array of non-ITAR-compliant suppliers, such as Israel and Turkey, to offer a wide customisation of options for all categories of customers.

Among the advanced systems offered for the aircraft is a data link and a virtual training system from Israel’s IAI. The light attack subversion is also earmarked to be equipped with the Elbit Systems TARGO II helmet-mounted display as an option. There is also an option for fitting an electro-optical turret under the fuselage to facilitate day and night extended-range targeting and perhaps the use of guided weapons. Another option includes adding Link 16 data link and ROVER (remotely operated video enhanced receiver) terminals.

Customer base

As Aero’s Giordo told the press at the roll-out ceremony, the global market is estimated at 3,000 aircraft over the coming 10 to 15 years, and his target is to achieve between 150 and 200 L-39NG sales. As of October 2018, Giordo claimed that Aero has a backlog of 38 L-39NG orders.

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This low-cost cockpit demonstrator shows the L-39NG’s functionality offered by the multi-functional displays and the newly added HUD.
Alexander Mladenov

At first the L-39NG’s production cycle will be 20 months which is planned to reduce to 14 to 16 months. The time is dependent, however, on the engine lead time, which is 11 to 12 months.

The LOM Praha company operates a military air training centre, the Centra leteckého výcviku (CLV) at Pardubice Air Base, and this is expected to be the launch customer for the type, with four firm orders and two options; contract negotiations are on-going, and inking should take place later in the year. The first two aircraft, including the first pre-series L-39NG, c/n 7004, are tentatively slated for delivery to the CLV in the first quarter of 2020. LOM Praha’s CLV centre provides pilot training for the Czech Air Force under a contract with the country’s MoD and currently operates a fleet of seven L-39Cs.

Next in the list of customers for the new jet is Senegal, which is set to receive four L-39NGs in a light attack configuration. Two of these will be delivered in the second half of 2020, with the other two following in 2021.

Then deliveries are most likely to continue to two relatively big customers in Portugal and the USA, both of which aspire to develop provision of contracted air services.

Lisbon-based SkyTech and Phoenix, Arizona-based RSW, are said to have signed letters of intent for ten and 12 aircraft respectively, in addition to six options held by SkyTech while RSW is also going to upgrade its six existing L-39s to the new L-39CW standard.

According to Laurente Donnet, SkyTech Vice President, Business Development, who was present at the roll-out event, the binding letter of intent is going to be converted into a firm contract in the coming months. The company works to create a range of contracting models for potential customers, including offering aircraft on dry lease to interested military customers and pay-by-the-hour options.

Interim solution

Existing Albatros operators around the world are being offered an interim solution, an upgrade of their aircraft to a version identical to the L-39NG standard in terms of engine and avionics, dubbed L-39CW (when derived from the L-39C) or L-39ZW (when derived from the L-39ZA/ZO). These upgraded aircraft will be good for ten or more years of operations.

The customers could then transit to the NG at a later stage, using the existing engines and avionics reclaimed from their time-expired L-39CW/ZWs and retrofitted to newly-built airframes; this approach is being promoted as a serious cost-reducing solution for L-39NG procurement.

Ghione says that the FJ44-4M uses 20% less fuel compared to the AI-25TL. This, he avers, together with less costly engine maintenance, amounts to a saving that promises to return the customer’s investment upgrading existing L-39C/ZAs in less than six years, depending on the aircraft utilization rate.

The first light of the L-39C prototype powered by a FJ44-4M but retaining the old airframe, later on redesigned as an L-39CW, took place on September 14, 2015. The aircraft was certified by the Czech MoD’s military aviation supervisory department in March 2018, involving both the new engine and avionics installation, and it is still in active use for testing the new avionics and other systems intended for the L-39NG.

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Aero offers potential L-39CW and L-39ZW customers the option of reusing both the new FJ44-4M engine and avionics in newly manufactured L-39NG aircraft, allowing them to spread their investment in the purchase of the trainer over time.
Aero Vodochody