Judging by the ash film that has settled on my car overnight, you would have to be a total moron to be flying even a GA aircraft in these conditions.
It might not melt the ash in a GA aircraft, but the air filter will sure be blocked. Not to mention flying with carb heat on, bypassing the filter...
Demands for scientific validation are valid, but have to be realistic - do we have the means of sampling to the extent that is required?
The scientist on the Dornier was privy to the air sample readings that he presumably took. What additional validation are the nay-sayers actually seeking from him? He was hardly reactionary.
To those who think that operating in the mild ash conditions across Europe is sensible or safe, what engineer do you think would permit the despatch of that F18s with engine conditions visibly as they were? Engineering costs would far exceed the small benefit of moving a few people around, as only 1-2 sectors would be possible before engine overhauls!
The potential effect on jobs is understandable, but I get the impression that many posters to this board are either no involved in aviation at all or have no conservatism in the area of flight safety