Bosch converts conventional Rotax engine to run on hydrogen
May 2, 2025
Bosch Aviation Technology has converted a 1.4 litre, four-cylinder Rotax 916 aircraft engine to run on hydrogen using existing components.
The feasibility study saw the Vienna-based Bosch subsidiary adapt a conventional BRP-Rotax powerplant for “hydrogen operation” in about four months, with all components for the hydrogen system “based on volume-production developments from Bosch”.
“In implementing the feasibility study, we were able to draw upon the proven performance of the Rotax 916 aircraft engine and combine this with our many years of experience in the hydrogen sector,” explained Bosch General Aviation Technology general manager Christian Grim. “Instead of developing an entirely new engine, we opted to modify an established engine design as we anticipate strong demand for this pioneering approach in future customer projects due to the time, cost, and operational advantages”.
The company states that the modification work – which took around four months – was able to “significantly optimise the performance of the hydrogen engine”. However, with the initial iteration delivering 115Kw of maximum power (around 2% of the thermal engine’s output), this will need to be further developed to prove operationally viable. Bosch believes this can be achieved through a “specific future development of a prototype”.
Nevertheless, Bosch Aviation Technology concluded that its future aircraft concepts could “help to reduce carbon emissions in general aviation,” combining climate-friendly technology with a growing market demand for increasing environmental awareness.
The conventional, commercially-available Rotax 916 engine is currently used in a variety of light aircraft, ultralights and homebuilds. It was first used to power the CubCrafters Carbon Cub.
