Many highly interdependent disciplines are concerned with the system noise assessment of small propeller aircraft concepts, including aircraft, propeller, engine design and acoustic modelling, flight trajectories calculation, noise propagation and ground effect modelling. There are no state-of-the-art simulation processes in Europe which account for all the aforementioned disciplines, as efforts heretofore have been focused on large transport aircraft concepts. This paper presents the development of such a simulation process at the German Aerospace Center (DLR). The simulation process inputs top-level aircraft design requirements, producing a valid CS-23 conceptual propeller aircraft design. It then calculates realistic flight paths for departure and approach for the conceptual aircraft and simulates noise immissions at user-specified locations. The immissions assessment would then guide design modifications, low-noise flight trajectory generation and novel aircraft design. A Reims-Cessna F406 is considered as the reference aircraft and is used to obtain the first results from the simulation process. The results are compared with measurements from a flight test campaign using the same aircraft. Important effects observed in the results and in the immissions assessments are also presented in this paper. Furthermore, the capabilities of the simulation chain will be demonstrated with sensitivity studies that show the effects of modifying operational procedures on ground noise immissions.