In September 2024, Turbotech, Safran and Air Liquide completed ground tests of a hydrogen-fuelled gas turbine aeroengine, powered by a liquid hydrogen tank and operating on an ultra-efficient regenerative cycle. This second phase of testing followed earlier trials in January 2024, which used hydrogen fuel stored in gaseous form for initial engine characterisation.

The latest tests integrated the engine with a cryogenic liquid storage system developed by Air Liquide, replicating functions required for a complete aircraft propulsion system. The system achieved energy density comparable to conventional fuels while addressing retrofitting and certification challenges.

“This is a major step forward in the transition to fully decarbonized aircraft propulsion, which will be ready to fly as soon as the world mass-produces green hydrogen,” says Damien Fauvet, CEO of Turbotech. “The aim of this work was to achieve a similar energy density to a conventional Avgas or Jet A-1 fuel system, while taking account of the constraints associated with the retrofit, operability and certification of a cryogenic hydrogen propulsion solution. The project has been a complete and rapid success, thanks to a remarkable team effort by the aerospace majors and SMEs involved.”

The tests are part of the BeautHyFuel research project launched in 2022. Supported by the French government, the project aims to develop and certify hydrogen propulsion systems for light aviation, leveraging expertise from Turbotech, Safran, Air Liquide, Elixir Aviation and Daher.

“This second stage marks the successful culmination of the project,” says Pierre-Alain Lambert, VP Hydrogen Programs, Safran. “By coupling our technology to Air Liquide’s cryogenic storage system, which provides the energy density needed for aircraft applications, we’ve demonstrated that a complete high-tech propulsion solution with zero carbon emissions in flight is possible and that it can be directly integrated into light aircraft.”

Xavier Traversac, VP Air Liquide Advanced Technologies, adds: “Decarbonization calls for close collaboration between the various industry players. We’re proud to be involved in this project as a recognized expert in hydrogen technologies and a partner to help accelerate innovation, thanks in particular to our test facility at the Grenoble Technologies Campus. Hydrogen is one of the key elements in the energy transition and this success is another step toward low-carbon flying.”