On Wednesday, 14 April 2010, Eyjafjall erupted on Iceland and gave Europe quite a lesson. No volcanic eruption has ever prevented air traffic before for so long and so extensively. In addition to thousands of daily internal European flights, it also grounded most long-haul flights.
Volcanic ash clouds are extremely dangerous to aircraft. That’s why every means is employed to avoid flying into an ash cloud. Ash clouds spread far and wide and can easily result in flight activity being restricted over a large area encompassing many countries.