The 2010 eruption of the Eyjafjallajökull volcano in Iceland grounded flights across Europe for several weeks, stranding millions of travelers. While volcanic ash poses a serious hazard to aircraft engines, the response to this eruption revealed issues with Europe's preparedness and coordination for such an event. Specifically, the safe ash concentration levels that triggered flight bans were established without scientific basis. Additionally, individual country responses were not well integrated across Europe. Future eruptions, especially of larger volcanoes, could cause significantly longer disruptions, highlighting the need for improved volcanic risk assessment and cross-border emergency planning in Europe.