Dornier 228 has been up to sample the air at various levels, The expert quoted "there's a lot of muck up there " and " Not a place for big jets" paraphrased.
Nuff said, went up, inspected, deemed not safe.
Update. ROBDEAN below found the link thanks,
to quote
A high-tech plane with sensors calibrated to find volcanic ash has landed after finding 'a lot of muck' in UK airspace.
Aeronautical engineer Dr Guy Gratton of Airborne Atmospheric Measurements, said he would advise against flying passenger jets in those conditions.
Source: BBC News.
Last edited by dope05; 16th Apr 2010 at 22:41.