The aircraft-mounted passive infrared volcanic ash detector system called Avoid that is being tested by EasyJet and Airbus was developed some years ago by the Climate and Atmosphere Department of the Norwegian Institute for Air Research, but no-one took up the idea until now.
Dr Fred Prata of the institute says that being able to "see" the ash is the key to being able to navigate through it safely, because it is not distributed uniformly throughout the block of airspace downwind of the volcano that is producing it.
Prata explains: "I think it needs to be stressed that volcanic ash never fills the skies and there are always routes around the hazard. This is what happens in most parts of the world now, especially, Alaska, Japan and Indonesia, where airlines make quite large, costly diversions to avoid ash clouds forecast by models and observed from satellites. With Avoid fitted these diversions would be shorter, and more direct routes could be found."