With the major goal of climate-neutral flying, we are conducting research on potentials and synergies through highly integrated aircraft development in numerous sub-projects at TU Braunschweig, University of Stuttgart, LUH Hannover and DLR Göttingen/Braunschweig in the new transregio SynTrac collaborative research centre. We use interactions of the disciplines aerodynamics, acoustics, flight physics, structural mechanics and thermodynamics through a multidisciplinary, cross-system view of the aircraft development process to develop future highly efficient aircraft through innovative approaches.