The eruption of Icelandâs Eyjafjallajkull volcano in 2010 clearly demonstrated the vulnerability of aviation to volcanic eruptions that occur in or near to high density airspace. More than 100,000 commercial flights were cancelled during the volcanoâs eruptive phase and over $5 billion1 in global GDP was lost due to what eventually became the largest shut-down of European air traffic since World War II. IATA estimated that its airlines alone lost $1.7 billion due to this single volcanic event.