In September 2024, Turbotech, Safran and Air Liquide completed ground demonstration testing of a hydrogen-fuelled gas turbine aeroengine based on an ultra-efficient regenerative cycle and fed from a liquid hydrogen tank. This demonstration followed a first test phase in January 2024 using hydrogen fuel stored in gaseous form in order to perform an initial characterisation of the engine. In this second test phase, the engine was coupled to a cryogenic liquid storage system developed by Air Liquide to demonstrate the end-to-end integration of a propulsion system replicating all functions on a complete aircraft.

“This is a major step forward in the transition to fully decarbonised aircraft propulsion, which will be ready to fly as soon as the world mass-produces green hydrogen,” states Turbotech CEO Damien Fauvet. “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.”

“This second stage marks the successful culmination of the project,” adds Pierre-Alain Lambert, VP hydrogen programmes, 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. For Safran, it rounds out the range of small-scale, agile exploratory projects we've been conducting, which are particularly valuable for addressing specific challenges in hydrogen propulsion for commercial aviation.”

Xavier Traversac, VP Air Liquide's advanced technologies, comments: “Decarbonisation calls for close collaboration between the various industry players. We're proud to be involved in this project as a recognised 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.”

Turbotech, Elixir Aviation, Safran, Air Liquide and Daher formed the BeautHyFuel joint research project in June 2022. The aim of this project is to design and ground test a hydrogen propulsion system rated for light aviation and develop a methodology so it can be certified for retrofit. BeautHyFuel benefits from the unique combination of Turbotech's ultra-efficient light turbine technologies, Safran's expertise as an aeroengine manufacturer and fuel system designer, Air Liquide's cryogenic hydrogen storage technologies for aerospace propulsion, Elixir's role as a manufacturer of innovative light planes and Daher's experience in aircraft development, certification, production and maintenance.

The BeautHyFuel project is supported by the French government through DGAC within the framework of the country's post-pandemic stimulus programme. It complements other initiatives by Safran to reduce the greenhouse gas emissions of air transport.