In the research project “HyFly” (01/2018 - 03/2020), funded by the Federal Ministry of Economics and Technology (BMWi), the development of a parallel hybrid propulsion system and its integration into a regional aircraft was implemented conceptually. For ISATEC, the focus was on building systems expertise for high-performance generators and electric aircraft engines.

This project addresses a major challenge of hybrid electric propulsion systems: The propulsion components (gas turbine, gear unit, generator & motor) and the battery used for the drive concept are associated with an increased weight budget. This requires optimal tuning of the propulsion system so that it can be used expediently from an ecological as well as economic point of view. The electrical power generated in the gas turbine via a coupled reluctance motor is supplied to electric aircraft engines designed by project partner ENGIRO with a view to developing a market-driven electric aircraft engine. Battery electric support during take-off, climb and rapid load changes facilitates reducing the rated output of the gas turbine compared to conventional drives and to extend maintenance intervals. The high climb angle at take-off leads to significantly lower noise emissions compared to the reference aircraft with conventional propulsion.

This propulsion chain design can make a significant contribution to the goal regarding efficient, safe and economical systems defined in the European aviation vision “Flightpath 2050”. At the same time, it reduces pollutant and noise emissions in air traffic.