FIRST will deliver key enabling technologies for combustion emission reduction by developing improved design tools and techniques for modelling and controlling fuel sprays and soot.Aviation’s environmental impact must be reduced to allow sustainable growth to benefit European industry and society. This is captured in ACARE’s 2020 goals of reducing CO2 by 50%, NOx by 80% and in SRA1/2 proposed reductions in soot and development of alternative fuels.CFD tools are essential to design combustors for emissions, soot, thermo-acoustic noise, flame stability, cooling and the outlet temperature profile. The two most significant gaps in today’s CFD capability are fuel injector spray and soot modelling.The fuel injector is critical to the design of low emission combustors. By understanding and controlling the complex physics of fuel atomisation and mixing, the emissions performance can be directly improved. CFD simulations have for many years relied upon over-simplistic definition of the fuel spray. The availability of methods developed in the automotive industry and faster computers make their application to aero-engines timely. The FIRST project will deliver a step change in the detail and accuracy of the fuel spray boundary conditions; through novel physics based modelling techniques, advanced diagnostic measurements and the derivation of sophisticated correlations.CFD computations of the combustion system also provide the information needed to allow soot emissions to be controlled and minimised. These calculations require the improved fuel spray boundary condition described but also need higher fidelity physical and chemical models describing the soot production and consumption processes. FIRST will deliver improved CFD soot models, enabling the reduction of soot in aero-engine combustors.The design of future alternative fuels will be enhanced by FIRST by performing predictions and measurements of both fuel sprays and soot across a number of alternative fuels.