Emissions from aircraft have adverse effects on air quality in and around airports and can contribute to public health concerns within neighboring communities. Routine air quality monitoring at airports generally focus on regulated air pollutants. However, recent work has shown that aircraft exhaust emissions are a major source of UFP (<0.1μm) in and around airports. This is creating significant concern as the health and environmental impact of UFP is currently insufficiently understood. AVIATOR (Assessing aViation emission Impact on local Air quality at airports: TOwards Regulation) is a European proposal which will adopt a multi-level measurement, modelling and assessment approach to develop an improved description and quantification of the relevant aircraft engine emissions, and their impact on air quality under different climatic conditions. Engine generated particulate matter (PM) and gaseous emissions in test-cell and on-wing from an in-service aircraft will be measured to determine pollutant plume evolution from the engine and APU exhaust. This will provide an enhanced understanding of emitted pollutants, and the scalability between the regulatory test-cell and real-world environments. ... mehrSpecific attention will be focused on non-volatile PM and volatile PM (down to <10 nm), and volatile PM gaseous precursors. AVIATOR will develop and deploy across multiple airports, a proof-of-concept low-cost sensor network for the monitoring of ultra-fine particles (UFP), total PM and gaseous species such as NOx and SOx, across airport and surrounding communities. Transport of emissions from aircraft engines and APU will be monitored in this complex environment through high-fidelity and sensor measurements. Measurement campaigns will be complemented by high-fidelity modelling of aircraft exhaust dynamics, and microphysical and chemical processes within the plume. Inter-connected process models will be applied and new validated parameterisations of the critical processes determined. AVIATOR will develop improved guidance on measuring and modelling the impact of aircraft emissions with specific reference to UFP.