Sorry guys, my long winded post from last night has disappeared so I'll try to keep this one brief.
Pace and mm_flyer (I think that's your user name - your post seems to have been mislaid too) you are both correct about the nightime thing, which I missed. So perhaps the ash would have been visible during daylight but how easily discernable it would have been from cloud reamins open to question. Nonetheless, the fact remains that no other signs of an ash encounter were present. My company keeps harping on about how an actual ash encounter will show signs of abrasion on windshields, leading edges and nav light lenses, but this case proves that to not be the case. Lack of these symptoms does not mean no engine damage has occured.
Pace I can't understand how you can question the validity everything in an attempt to justify what has happened? The post strip down examination of the DC8 engiens showed ash deposits in the cooling passages. It was ash - no question. And why would you feel that the report of no other indications of an ash encounter might not be true? The report says that's what happened - why would this not be the case? I see more and more people and professionals qualifying everything to allow the possibility of things not being as they seem. Why is it so hard to see how that same logic could be applied to the new regulations?
Clandestinos link is very worrying. Test flights are finding ash out there in sufficient levels to pose the threat of damage. Why are the authorities giving the opposite impression?
I do not accept that there would be no airlines left if the regualtions were not changed. This was never going to last that long - although of course it may recur. Some may have run into trouble but most would have survived. Lets be very clear about this: This was an unprecedented occurence where high level winds were sustaining significant ash levels over most of Europe. Volcanoes have been around the whole time jet engines have been strapped to aircraft. When was the last time an ash cloud closed airspace over most of an entire continent? Just once - this last week. Yet we treat it as though the ash was with us for good. That is just not the case.
I have a major problem with amending regulations which are designed to prevent the possibility of serious damage or danger from a highly infrequent risk in order to appease business. Since when was the primary objective of safety legislation to ensure the viability of each and every company out there?
fireflybob, you bypass ratio infromation is interesting but misses the point. What you say is valid, but only for engines of the same size or thrust rating. A massive high bypass engine needs much more air than a small low bypass one. Also, it can be argued that if ash concentrations were high enough to cause damage to an engine, small or large, then the risk exists for every other engine too. It is the concentration that matters at the end of the day. I see no difference in the operation of military jets compared to civilian ones except for the possibility of different operating temperatures. Even then though, civilian engines are plenty hot enough to cause ash particles to melt.