Adaptive-Cycle Engine Eyed To Power European Future Combat Air System

The Franco-German-Spanish future fighter program may be lagging its biggest Western rivals in development, but there is one area in which the trio is looking to outdo its counterparts: the engine.

The trinational development is embracing adaptive-cycle engine architecture for the next-generation Future Combat Air System (FCAS) fighter. Despite the promise of a leap in performance, other programs—the U.S. Air Force Boeing F-47, U.S. Navy future F/A-XX and the UK-Italian-Japanese Global Combat Air Program (GCAP)—have passed on that option.

The European Military Engine Team (EUMET) joint venture of Germany’s MTU Aero Engines and France’s Safran—along with Spain’s ITP Aero, which is not part of the joint venture—offered program airframers Airbus and Dassault Aviation two engine configurations for the new fighter, which is due to enter service in the 2040s. One of their messages to airframers was: Think long-term.

• FCAS nations plan to decide on system configuration in the third quarter of 2026
• The NGF engine is to provide 30-40% more thrust than the M88 or EJ200
• AI is expected to improve sensor performance and enable pilot assistance
• Industry efforts on remote carrier development are accelerating

“This platform is a sixth-generation fighter aircraft that still needs to be able to fight in 2100, so we need to have an engine that is very capable and stretches ourselves in terms of materials, architecture and electrical power supply,” Michael Schreyögg, MTU Aero Engines chief program officer, tells Aviation Week.

With that in mind, “I pushed a lot for variable cycle,” he says. “We need to provide something which is truly state of the art; it should not just be a better M88 [from the Rafale] or an EJ200 [from the Eurofighter].”

Until now, little information had emerged about the proposed engine apart from a handful of bullet points on the EUMET website that point to a wish list of features.

The engine’s development is one of the most important programs for the three companies, Schreyögg says, since each has a 33% share of the program in development and production.

The FCAS next-generation fighter (NGF) is due to replace part of the fleet of Eurofighters flown by Germany and Spain and part of the Dassault Rafale fleet flown by France. Initial operational capability is planned for around 2040.

The engine partners are looking to have development powerplants ready in the early 2030s. More refined prototype engines are then due in the mid-2030s to support flight testing, ahead of the start of production for the aircraft’s entry into service in the early 2040s.

As with other next-generation combat aircraft projects in China, Europe and the U.S., the proposed platform is physically heavier and larger in size—up to one-third bigger than fourth-generation combat aircraft such as the Dassault Rafale, Eurofighter Typhoon, Boeing F/A-18 Super Hornet or the Chengdu J-10. All the next-generation aircraft feature extensive low-observability characteristics, including internal weapon bays, and will have much-expanded combat ranges. They are also studded with power-hungry electronics.

All that puts a premium on engines that are more powerful and thermally managed to preserve the platform’s infrared signature, while also producing much higher electrical outputs to power new radars, mission systems and—potentially—directed-energy weapons in the future.

How powerful the NGF’s engine will need to be will depend on the architecture selected for the system. That decision is due around the third quarter of 2026, say program officials. Three system configurations are in play: one that focuses on the fighter’s attributes, another that leans more on the remote-carrier capability and a third balancing the first two.

Of the sixth-generation fighter programs in development, only the European FCAS program has declared plans to use a variable-cycle engine. The architecture’s advantage is that the engine can have different modes of operation, allowing fuel-efficient cruise or high power for air combat, Schreyögg said.

GCAP engine developers Avio Aero, IHI Corp. and Rolls-Royce have opted for a simpler architecture (AW&ST May 5-18, p. 53), as has the U.S. Navy’s F/A-XX program. Uncertainty surrounds the initial engine choice for the U.S. Air Force’s baseline F-47. The platform could receive an adaptive-cycle engine in future batches.

The FCAS engine will need to deliver 30-40% more thrust than current fighter engines, according to Schreyögg, and will require a different architecture. The program, he says, also will take lessons from the U.S. Lockheed Martin F-35 Joint Strike Fighter program, whose Pratt & Whitney F135 has faced deficits in electrical power production as demand from aircraft systems has increased. “We will need to oversize the power management in order to have the margins,” Schreyögg explains.

As part of the engine development activity, the three companies have delivered all the milestones from the technology maturation phase—the so-called Phase 1B of the FCAS program—and now have a “technology suite” of about 100 ongoing programs, Schreyögg says. These are focused on advanced materials and powdered metals to support production using additive-manufacturing processes. Targets include lightweight compressor systems and durable turbines produced from ceramic matrix composites, while structural casings will be manufactured additively to secure reduced overall engine mass.

Before work begins on the adaptive-cycle powerplant, trials of some of these new technologies will be performed on a demonstrator engine, an adapted M88, with work beginning in late 2026 and running through to around 2029.

This will be something of a “Frankenstein engine,” Schreyögg says, and will test various technology projects developed by the three companies, although it is unlikely to test the variable-cycle element. That is to come in the development engines planned for the 2030s.

Testing of the demonstrator engine is part of the €4.5 billion ($5.1 billion) Phase 2 of the FCAS, due to begin in late 2026. It includes a flying demonstrator powered by a pair of M88s, a sensor testbed based on a Fokker 100 airliner and trials of remote-carrier uncrewed collaborative platforms. Program officials are exploring five classes of uncrewed adjuncts that provide mass to the force package. These will vary in size, weight and role, and whether they are expendable, attritable or deemed too costly to lose.

Progress on the development has been hampered by industrial disagreements over work allocation and other issues, causing some anxiety among program officials that the timeline for fielding the fighter may be slipping. That has injected a sense of urgency to move forward with the decision-making process.

But Brig. Gen. Philippe Koffi, the head of the FCAS program in France’s DGA materiel agency, is upbeat about the effort. Development of the demonstrators follows a two-year effort to mature technologies and architectures.

“We have built a robust and dynamic industrial ecosystem of more than 3,000 engineers and 144 companies, including major players and startups,” Koffi said at a Royal Aeronautical Society event on May 21. “This is not just about building momentum.” He added that several design reviews have been achieved, along with some “800 deliverables.”

Artificial intelligence (AI) will be one of the “main features of the platform,” he noted. Linked with the combat cloud network, AI will be essential for the “collaboration and coordination” of the uncrewed remote carriers, he said. AI also will help evolve the command-and-control of force packages, ensure dataflows to the right platforms and act as a virtual assistant, helping them command the remote carriers with “high-level orders” and enhance the capability of the sensors. Koffi even suggested AI could provide a Shazam-like capability for electronic warfare, identifying and classifying electronic signals in the same way the Shazam software identifies music.

Development of remote carriers has moved up a gear in the last 12 months. Spain’s Satnus joint venture, established to develop autonomous remote-carrier technologies for the FCAS, completed its first flight test campaign in January. Satnus’ work is focused on the algorithms and systems that will allow the Airbus- and MBDA-developed remote carriers to work with the future crewed fighter.

As part of the trials, they flew converted target drones with new communications and termination systems, and different payloads. Satnus also trialed a multiplatform simulation tool that can integrate real and simulated aircraft in the same test, paving the way for collaborative flights involving multiple converted drones.

MBDA, tasked with development of an expendable remote carrier (ERC) for the FCAS, has conducted flight trials of a testbed for remote-carrier technologies. Its Small Highly Adaptable Remote Carrier System (Sharcs), a remotely piloted jet-powered forward swept-wing fixed-landing-gear-equipped air vehicle with a composite airframe structure provided by Airbus-owned German aerospace supplier Premium Aerotec, began flight trials last summer in Germany.

Sharcs is a platform for testing various sensors, systems and associated algorithms that could be featured in ERCs. These ERCs have been designed to carry different payloads including intelligence, surveillance and reconnaissance sensors, relays, electronic-warfare systems and jammers, and will collaborate with other ERCs and weapons.

Indra, meanwhile, as the Spanish national coordinator for the FCAS, is working with Celestia TTI on satellite communications links and with a company called Idbotic on hardware encryption. Both efforts are expected to support development of the proposed combat cloud, the complex network that ties the various systems together for communications and situational awareness and for collaboration between crewed and uncrewed systems.

But while many of the disagreements among the industrial development partners have been largely resolved, tensions remain. Dassault CEO Éric Trappier has said he continues to have doubts about the future construct of the program as it moves into Phase 2, as well as the involvement of a fourth nation, Belgium, as an observer. The perennial question of whether the two European sixth-generation fighter developments, the other being GCAP, should merge is discussed regularly and subsequently dismissed by industry.

Their view is that the two aircraft need to be interoperable and capable of fighting alongside each other. Jean-Brice Dumont, the head of Air Power at Airbus Defense and Space, told France’s National Defense Commission in February the two programs must “work together on the connectivity layer,” and “develop weapons jointly.” Cooperation between the programs also could extend to the remote carrier realm, with the Trinity House defense agreement between Germany and the UK hinting of collaboration for such platforms as well.