The increasing demand for efficient and environmentally sustainable flight profiles requires innovative operational concepts. Short-term trajectory adaptations, considering dynamic input variables constitute a reliable solution. According to current air traffic regulations, flight trajectories are planned ground based and submitted to Air Navigation Service Providers for an overall validation according to airspace and sector capacity constraints. This initial flight plan often relies on static atmospheric forecasts for the entire flight. Sudden changes of atmospheric parameters such as wind speed and wind direction cannot be predicted precisely and are not considered in today’s flight operations, except of severe weather phenomena. This paper investigates the benefit of en-route weather updates and subsequent short-term trajectory optimization. The resultant benefit of dynamic optimization during flight is assessed for varying shares of flights equipped with this novel capability within 1 hour of Europe’s air traffic. Therefore, fuel, engine emissions and controller task load are used as assessment indicators. 75% of the frequently optimized trajectories gained in overall fuel savings with an increased task load of 5.4%.