This report analyses the impacts of the EU ETS on the competitiveness of various types of aircraft operators by means of micro-economic analysis and by extensive short-term and long-term modelling. Because of political negotiation processes on the geographical scope of the EU ETS we analyse the impacts for two scenarios: 1. A scenario in which all emissions from flights between airports in the European Free Trade Association are covered (Stopping the Clock scenario). 2. A scenario in which all emissions from flights in the European airspace are covered (European airspace scenario). The second scope is larger, as it also includes emissions from flights between airports in Europe and airports on other continents are partly included in the EU ETS. The study shows that the EU ETS has only a small impact on competitiveness.