This thesis examines the impact of the flight tax on the amount of passengers at Amsterdam Schiphol Airport. The flight tax was a Dutch ecotax, started in 2008 to discourage air traveling in order to release pressure on the environment, to make the environment more sustainable in the future. In this paper, a panel study is executed under five major European airports to obtain the real impact of the flight tax. GDP functions as a controlling variable. The outcome of the analysis should provide information to be able to assess whether the flight tax is a legitimate fiscal instrument