As mentioned in the Executive Summary of the Strategic Research & Innovation Agenda, Aviation has an important role to play in reducing greenhouse gas emissions as well as noise and local air quality issues. The continuous increase of air passenger transport generates an increasing use of hydrocarbon fuel with excessive emission of CO2 and NOX (greenhouse gases, pollutants and noise). It is well known that commercial aircraft operations impact the atmosphere by the emissions of greenhouse gases and greenhouse gas precursors, and also through the formation of contrails and cirrus clouds. In 2011, during the Aerodays in Madrid, the EC launched the future of Aeronautics in the ACARE Flight Path 2050 Vision for the Aircraft report containing the ambitious goals on the environmental impact with 90% reduction in NOx emissions, 75% reduction in CO2 emissions per passenger kilometer, and the reduction of the noise in by 65%, all relative to year 2000.To achieve the ACARE Strategic Research & Innovation Agenda green aeronautics technologies will play a more and more dominant role in mastering the challenge on “Protecting the environment and the energy supply”. GRAIN2 Supported Action, based on the same collaborative and win-win spirit introduced in former EU-China GRAIN project, will provide inputs and roadmaps for the development of large scale simulation strategies for greener technologies to meet the above future requirements on emissions, fuel consumption and noise. To reach these targets, green technologies efforts will have to be collected and prospected in three major lines: Air vehicle, Air Transport System and Sustainable Energies. Three folds to be investigated as future greening technologies:1) Greening the aircraft and the aero engine2) Greening the operational environment3) Reducing the carbon foot print of aviation via sustainable alternative fuels