Within the project of MAHEPA (Modular Approach to Hybrid Electric Propulsion System), a 1: 5 scaled model of the Hy4 will be presented at the Aero 2019 in Friedrichshafen. The Aero is one of the largest international trade fairs for general aviation. “With more than 600 exhibitors from 35 nations, 33,000 visitors and 600 journalists from all over the world, AERO Friedrichshafen is the world’s most important annual gathering place for the community”. (Source: Aero). The model of the Hy4 will be exhibited in Hall A7 on the E-Flight Expo. The development engineers of the Hy4 address the questions of the public and show the advantages of hydrogen fuel cell technology as main propulsion for aircraft.