Diamond Aircraft has taken the leading role in a new project to explore the potential for hydrogen-electric hybrid propulsion systems in light aircraft. Through work funded by the Austrian Research Promotion Agency, the manufacturer and its partners will address use cases and technologies needed to introduce gaseous hydrogen as a fuel source for general aviation.
The Hydrogen-based Twin-engine Electrification and Digitalization Testbed (H2EDT) project consortium also includes research teams from FH Joanneum (Institute of Aviation and Electronic Engineering), the Technical University of Graz, HyCentA, and IESTA. They are developing an experimental hybrid propulsion testbed to assess the challenges of using hydrogen fuel, and this work is now based at Diamond’s headquarters at Wiener Neustadt and will continue through the rest of 2025.
The subscale testbed will be based on a design for a VTOL aircraft with up to 10 motors. Diamond said the team had first planned to model the hardware on a twin-engined general aviation aircraft, but decided that the focus should be something closer to advanced air mobility applications.
According to Diamond, the H2EDT will use a digital power management system based on a power distribution board developed by FH Joanneum, as well as a parallel hybrid architecture in which batteries or hydrogen fuel cells can both directly power any of the motors. It will leverage digital sensors and multiple power sources to automatically combine electric and hydrogen power as required.
The testing will use a digital twin combining both detailed CAD geometry and performance simulations. Data gathered will be used to test failure modes and different environmental conditions, including high altitude or high air temperatures.
In its announcement this week, Diamond also said that it is considering a possible follow-on project to evaluate the case for a hydrogen-powered version of its existing DA40 and DA42 aircraft. The H2EDT team expects to present its results in 2026.
Volocopter Merges into Diamond
Meanwhile, German eVTOL aircraft developer Volocopter is in the process of being integrated into the Diamond Aircraft Industries group. Since April 1, the company has been trading as Volocopter Technologies, after Diamond acquired its assets from an insolvency administrator on March 17.
Through the restructuring process, only 160 of Volocopter’s 500 employees have been retained by the new owners. Due to the disruption of the insolvency process, Volocopter has pushed back its target for achieving EASA type certification for its two-seat VoloCity model.