The authorities responsible for aviation safety in Europe were faced with a huge dilemma which was unprecedented in the form of the Eyjafjallajökull volcano in Iceland which began erupting on April 14 and prompting them to take some drastic action.

The eruption of the volcano led to the shutdown of the airspace in most of Europe stranding too many people and incurring huge losses all over. And after an airline loss that came up to $1.7 billion and people being stranded for six long days, the flight ban was lifted. But the question here is what led them to lift the ban which was imposed due to the terrifying volcanic ash.

Incidentally, the only thing that the authorities in Europe had to do was to determine the density of the contamination of the atmospheric ash which was acceptable for the engine as that level of damage was small enough for it to be acceptable and the risk of the airframe was also not too bad.

After that, they could easily clear the area for the flights to take off to those places which met the criteria.