From Fox News we have this little reminder of why planes and volcanic ash don’t mix :

BRUSSELS (AP) — A senior Western diplomat said Monday that several NATO F-16 fighters had flown through a cloud of volcanic ash and that that one had suffered engine damage.

The official, who could not be named under standing regulations, declined to provide further details on where or when the incident happened. He said only that glasslike deposits were found inside the plane’s engine after a patrol through European airspace.

But Bo Redeborn, an official of the European air traffic agency, said later that the F-16 belonged to the Belgian Air Force.

The incident highlighted the danger of flying through the ash clouds that have paralyzed civilian air traffic over much of Europe over the last five days.

So much for Willie Walsh having a Sunday day trip around the Atlantic on one of his jets and declaring it OK to fly.