From Dutch aviation newspaper http://www.luchtvaartnieuws.nl/nl-NL/Article.cms/Airlines/Test_easyJet_met_kunstmatige_aswolk
English translation :
LONDON - EasyJet in August is a test with Airbus to see if new technology (to detect ash clouds) works. This EasyJet announced thursday.
Airbus has, with the Norwegian company Nicarnica Aviation, infra-red technology developed what pilots and air traffic control should warn about ash particles in the air. Hundred kilometers away.
Airbus and EasyJet had wanted to introduce the technology in 2012 but that did not work. The three partners are now hoping the system is ready end of 2013. The equipment can potentially avoid a repeat of the chaos in the airspace of April 2010 at the hands of the eruption of the Icelandic volcano Eyjafjallajökull.ash particles
The test is planned for august, first an Airbus aircraft climbs to an altitude of 30,000 feet (more than nine kilometers) where a ton of ash particles will be released into the atmosphere to mimic an ash cloud - the particles are actually from the Eyjafjallajökull.
Thereafter, an Airbus A319 of EasyJet, with only a cockpit crew, flying towards the ash cloud to test the new equipment and then, if the plan works, to fly around it. A location for the test has not yet been determined, they are searching for a quiet area, possibly over France. According to Airbus. The amount of ash that is used is so small that it will bring no harm to the ordinary traffic.
Currently there is no good radar technology that can detect ash clouds. Pilots can't see the cloud, unless they fly near the volcano.
Volcanologists think the next thirty to forty years the volcanic activity in Iceland will increase. Two volcanoes would be on the verge of erupting.