A French government-backed initiative has demonstrated the feasibility of powering a light aircraft using a liquid hydrogen-fuelled combustion engine, with the results even showing slightly improved performance over a kerosene-burning equivalent.
Ground demonstrations under the BeautHyFuel project wrapped up in September – initial results were only disclosed on 13 January, however – having accumulated a cumulative total of 23h of run time. External temperatures during the testing in Grenoble ranged from -5°C (23°F) to 35°C.
Using a 141hp (105kW) TP-R90 regenerative turbine supplied by start-up Turbotech, the end-to-end system also featured an Air Liquide-developed cryogenic storage tank and a fuel feed and control system from Safran. Other partners in the five-strong consortium include airframers Elixir Aircraft and Daher.
“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,” says Damien Fauvet, chief executive of Turbotech.
“Overall, no difficulties were reported, engine performance was found in line with the kerosene version and the system even showed slightly improved operability in H2,” says 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,” adds Pierre-Alain Lambert, Safran’s vice-president of hydrogen programmes.
Despite the system showing “full compatibility with an aircraft integration”, Safran cautions that any qualification and certification process would “require more development and testing effort”. Project goals included the development of a methodology to enable retrofit of the powertrain.
An earlier phase of BeautHyFuel in January 2024 used gaseous rather than liquid hydrogen to perform initial characterisation of the engine at ArianeGroup’s Vernon site in France.
Research support was provided by the French government through the country’s DGAC civil aviation agency within the framework of its post-pandemic stimulus programme.
