The Ultra High Bypass Ratio Turbofan (UHBR) has the potential to provide an important reduction in noise and burnt fuel compared to the existing subsonic engines. Unfortunately, its integration in our commercial aircraft induces some problems that have not been solved yet: between them, the increased weight of the propulsion architecture with, consequently, higher inertial and aerodynamics loads. The present work is the result of an internship at Airbus and it aims to investigate the possibility of an innovative Power Plant Structure design to make the UHBR integration easier and more efficient. The Free Size Optimization and the Topology Optimization were used for this purpose.