Letter: Right ash

"Now and Then" (18 May) reports that it was exactly 30 years since Mount St Helens volcano erupted "creating an ash cloud 2,500 miles long and 1,000 miles wide". Did we not have aeroplanes in the 1980s? Or do we now have the "wrong kind of ash" for air travel?

By The Newsroom

Published 19th May 2010, 23:03 BST