The study is based on the idea that the image of a hybrid turbine-electric system with fuel cells for a hybrid regional aircraft with a capacity of up to 80 seats and a range of up to 1,000 km will be determined by the type of energy supply (hydrocarbon or hydrogen fuel) to the gas turbine and fuel cells. As part of the work to assess the feasibility of creating a commercially attractive hybrid regional passenger propeller aircraft, various hydrogen technology-based power plant energy supply schemes are being developed and evaluated for applicability: Use of hydrocarbon fuel (kerosene) for a gas turbine engine and hydrogen for a low-temperature proton exchange fuel cell. Use of hydrogen for a gas turbine engine and fuel cells. Use of hydrocarbon fuel (kerosene) for a gas turbine engine and hydrogen production directly on board the aircraft. In this scheme, kerosene flows from the aircraft's fuel tank into a cracking reactor. The hydrogen released during the reaction then flows into a solid oxide fuel cell. At the current stage of the project, power system concepts have been developed, their applicability in a hybrid regional aircraft is being analysed, and activities are underway to select the optimal concept for supplying power to the aircraft's power plant. The results presented are based on research carried out within the framework of the EFACA project (Environmentally clean aviation for all classes of aircraft), financed by the European Commission through the program "Horizon Europe" (Grant agreement No. 101056866), included in the cluster "Climate, energy and mobility". EFACA aims to promote a greener aviation sector by developing new technologies using electric and hybrid thermoelectric power plants and new sustainable fuels to combat climate change by 2050 (www.efaca.eu).