France’s top general says engine will be toughest test for FCAS

France’s Chief of the Defense Staff, General Fabien Mandon, has warned that the toughest challenge facing the Future Combat Air System (SCAF/FCAS) is the development of a new fighter engine capable of producing around 11 tonnes of thrust, a major leap ahead of current European designs. 

Speaking to French senators on November 5, 2025, Mandon suggested that France, Germany and Spain share a common vision for the next-generation air combat system, but the ability to power it will determine whether or not those ambitions can be realized. 

“The most critical part of future combat aviation today is the engine,” Mandon told senators. “To reach sufficient thrust levels, the temperatures inside the turbines must be extremely high, and there are very few materials that can withstand this.” 

From Rafale’s M88 to a 11-tonne-class engine 

Under the FCAS framework, Safran Aircraft Engines leads the engine pillar, with MTU Aero Engines as its main partner and ITP Aero representing Spain. Their joint venture EUMET, established under German law, oversees certification and production of the future power plant. 

In parallel, Safran is currently developing the M88 T-REX, an upgraded version of the Rafale engine, which was unveiled at the 2025 Paris Air Show. Designed for the Rafale F5 standard, T-REX increases thrust by about 20% while keeping the same size and modular layout. It serves as a technology bridge toward FCAS, introducing improved airflow, advanced turbine materials, and optimized thermal management. 

“We aim to bring the propulsion capacity of our engines to nine tonnes of thrust, that’s the T-REX project for the Rafale, and to reach eleven tonnes for the new generation of combat aircraft,” Mandon said. “This defines the maximum mass of the future combat aviation platform.” 

The FCAS Next Generation Fighter (NGF) will therefore require an engine producing roughly 11 tonnes of thrust for a 15-tonne-class airframe, significantly larger and more powerful than the Rafale’s 7.5-tonne M88. The NGF engine, often referred to as the New Generation Fighter Engine (NGFE), is expected to be physically larger to match the increased airframe and fuel capacity, but not disproportionately heavier. 

For comparison, Pratt & Whitney’s F135 powering the F-35 delivers about 18 tonnes of thrust with afterburner for a dry weight of roughly 2.9 tonnes, while the Safran M88 produces 7.5 tonnes for about 900 kilograms. The NGFE will likely fall between these two in scale, being heavier and higher-flow than the M88, but far lighter and more compact than the F135. Reaching that level of performance will require new thermodynamic cycles, higher turbine temperatures, and a greater mass flow, approaching that of the M53-P2 engine used on the Mirage 2000. 

“The French, German and Spanish air forces all share the same vision: a platform of around fifteen tonnes, which is what we know how to propel autonomously in Europe,” Mandon added. “We don’t need to buy an engine from the United States or elsewhere.” 

Lost know-how and industrial risk 

France launched the ADAMANT program in 2021 to accelerate research on turbine materials and multilayer coatings capable of withstanding temperatures above 2,000 Kelvin, some 250 K higher than the current M88. Safran, ONERA and the DGA are jointly leading the effort to restore Europe’s ability to design clean-sheet fighter engines after decades of incremental upgrades. 

“It’s been over forty years since we last did fundamental research on the hot section of a jet engine,” Mandon said. “The Americans have continued; we haven’t. If we don’t invest now, we won’t be able to do it later.” 

He warned that propulsion is not just a technical issue but an industrial and strategic one. “For decades, we’ve developed very few new engines,” he told senators. “That means our engineers and technicians haven’t had projects to push new materials and performance. Achieving that propulsion is essential.” 

A pacing item for the whole FCAS timeline 

Most of the turbulence surrounding FCAS has occurred openly through governance disputes and industrial negotiations about the airframe. But as General Mandon informed lawmakers, propulsion may be just as challenging as those political battles. Developing a 11-tonne-class engine is the technical test that will show if Europe’s next-generation fighter can take off. 

“If we can’t master this propulsion step, the rest of the system will never follow,” Mandon concluded. The post France’s top general says engine will be toughest test for FCAS appeared first on AeroTime.

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