Between 15 April and 21 April 2010, Europe experienced an unprecedented closure of its airspace, with over 100,000 flights cancelled, and an estimated 10 million passengers affected over a period of seven days. Airlines based in Northern Europe had all of their aircraft grounded as a result of airport closures, and overall, the European airline industry had 75% of its operations closed at the peak of the ash plume. It was catastrophic.

Three days into the crisis, as European airspace remained closed, several of the major carriers protested that national civil aviation authorities and Eurocontrol were acting too cautiously in maintaining the flight ban. Several airlines conducted their own test flights in the last two days of the crisis, including Air France- KLM and Lufthansa, and found the atmosphere to be clear.

Since the volcanic ash crisis, Airbus and Nicarnica Aviation have been developing technology for the fitting of sensors to aircraft for the detection and the measurement of the density of ash clouds, so that pilots can avoid them. In an extraordinary experiment conducted on 13 November 2013, a tonne of volcanic ash, collected and dried from the 2010 Eyjafjallajokul eruption by the Institute of Earth Sciences in Iceland, was flown to Toulouse, then carried in an A400M Airbus aircraft and released at between 9,000-11,000 feet over the Bay of Biscay, to simulate conditions consistent with the volcanic ash cloud in 2010. easyJet then flew an Airbus A340-300 fitted with Airborne Volcanic Object Identifier and Detector (AVOID) sensors developed by Nicarnica Aviation towards the ash cloud, and successfully identified the ash from distances of 60 km, as well as accurately measuring its concentration. The tonne of volcanic ash released was apparently measured at 2.8km in diameter and was visible to the naked eye, but quickly dissipated, becoming difficult to identify. Aircraft fitted with AVOID sensors would be able to feed back information to the ground in any future volcanic ash eruption, giving real time data to enable an accurate picture of the location and size of ash clouds to be built up, as well as their density, which would inform decisions on the ground as to whether airspace needs to be closed.

easyJet is planning to fit several of its aircraft with AVOID sensors by the end of 2014, so that if, and when, the Icelandic volcanoes erupt again, they will be able to argue coherently with national civil aviation authorities in the EU that it is not necessary to impose a blanket no-flight ban and shut down large areas of European airspace.