In collaboration with the Technical University of Madrid (UPM), Anotec developed the MECETA model, capable of calculating the emissions generated by air traffic in Spain. Since then, this model is used to provide the Spanish government with the CO2 inventory of Aviation at national level. The model is capable of taking into account the complete mission profile (incl. en-route) and contains several improvements related to standard methods, like accounting for actual taxi times at airports, actual approach patterns (detours) and use of de-rated takeoffs.