Heads in the ash clouds

Scientists at Liverpool and Munich Ludwig Maximilian universities are getting their heads together to try and prevent another ash cloud debacle similar to the one that shut done much of Europe’s airspace in Spring 2010. 
The boffins – or volcanologists to give them their correct, rather groovy, title – say that little is currently known about the effects of volcanic ash on aircraft. Up till now, the only sure-fire way of finding out whether it will shut the engines down is to fly a plane into it and see what happens, an enterprise for which there are, understandably, very few takers.
Current guidelines on the threat of volcanic ash particles on jet engines rely on studies of the impact of sand and dust particles in road vehicle engines, which is hardly the same thing.
Quite apart from the rather different levels of acceptable risk – dropping out of the sky from 37,000ft versus spending a few hours on the side of the A5025 waiting for the breakdown man – volcanic ash is in any case chemically different. To make things even more complicated, it can also vary widely amongst volcanoes.
However, volcanologists from the university have analysed ash from nine different volcanoes to see how behaves at jet engine temperatures of 1,100-2,000 °C. The main concern is whether it melts and sticks to the inside of the turbines and it is particularly problematic if it affects the cooling system.
Liverpool University volcanologist Professor Yan Lavallée, says that progress is being made. Experiments have now developed a model to predict the melting and sticking conditions of different volcanic ash particles.
He adds: “Any robust future model to assess quantitatively the risk of volcanic ash with jet engines must be based on chemistry and melt theology,” pointing out that, given the current level of air traffic, “too much is at stake to overlook the role of volcanic ash on aviation.”