The overall objective of the project is to put the basis for the development, manufacturing and in-flight test of a parallel hybrid powertrain for General Aviation by the involvement of three European GA market leaders: an aircraft manufacturer (TECNAM), an aircraft engines manufacturer (ROTAX) and an electric motors manufacturer (Rolls-Royce). The H3PS project objective is to fly a GA aircraft with the parallel hybrid powertrain demonstrating the challenging advantages of the configuration but also its high scalability level. “Breakthrough” concept will be achieved by demonstrating the feasibility of a power scalability for up to 11 seats airplanes.