In order to achieve the greening of the European air transport with the deployment of low emission and low noise propulsion systems the reduction of core noise plays an important role. The ability to design low core noise aero-engines requires the development of reliable prediction tools. This development demands extensive research with dedicated experimental test cases and sophisticated numerical and analytical modelling work to broaden the physical understanding of core noise generation mechanisms.This objective is only reachable with an extensive cooperation on the European level. In this proposal “Research on Core Noise Reduction (RECORD)” the major aero-engine manufacturers of five different European countries collaborate to enable the design of low core noise aero-engines. In RECORD the fundamental understanding of core noise generation and how can it be reduced will be achieved by combining the research competence of all European experts in universities and research organizations working in this field of core noise. This concept of the RECORD project is completed by the technology development of small and medium size enterprises distributed in Europe.RECORD will promote the understanding of noise generating mechanism and its propagation taking the interaction of combustor and turbine into account. The importance of direct and indirect noise will be quantified. Through carefully designed experiments and extensive numerical calculations, the numerical methods and assumptions will be validated and extended. As a result, low-order models will provide a quick approach for the ”noise design” of combustors and subsequent turbine stages while the more time-consuming and expensive LES calculation will provide a more detailed picture of the flow physics. Finally, RECORD will develop means and methods for core noise reduction.