Happy Boy wrote:The pictures of the nozzle guide vanes posted, was that the result of a direct encounter with a dense volcanic plume? Do you know how long the particular engine was exposed to volcanic ash and what the approximate density of the ash concentration was?
Thanks
Nobody knows the density, but it looks like that was about 30 minutes in the ash cloud.
That is one of the engines from the June 1982 BA Flight 9 incident. While they were gliding through the ash cloud for about 30 minutes, if you examine the time line it was only about 3 minutes from the first on-board indications of problems to complete engine failure. In other words, this damage occurred in about 2-3 minutes.
The ash cloud could not be seen, as this occurred at night, but nether was it dense enough to show up on the airplane's weather radar. Could it have been seen in daylight? Who knows - but quite likely not. I've spoken with a pilot I know who had an inadvertent encounter with Mt. St. Helens ash - he never saw it, but it "sandblasted" the windows on the airplane and removed most of the paint, all of which had to be replaced. It doesn't have to be thick enough to be seen to be dangerous.
Also keep in mind that the image shown is of the engine AFTER shock-cooling broke off enough of the ash for the engine to re-start. In other words there used to be even more shit stuck to that engine.
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So, um, what's the situation in Europe regarding this? I keep hearing there are problems, but of course the US media declines to be specific.
(Admittedly, for those living North America the Gulf of Mexico oil eruption is more of a focus than an Icelandic volcanic eruption, but I was just curious.)
A life is like a garden. Perfect moments can be had, but not preserved, except in memory.Leonard Nimoy.
Now I did a job. I got nothing but trouble since I did it, not to mention more than a few unkind words as regard to my character so let me make this abundantly clear. I do the job. And then I get paid.- Malcolm Reynolds, Captain of Serenity, which sums up my feelings regarding the lawsuit discussed here.
If a free society cannot help the many who are poor, it cannot save the few who are rich. - John F. Kennedy
Silly Broomie. Check the Met Office VAAC site and NATS air control. Cloud is quite dense and being detected over the Atlantic and France, Spain and Italy.
Ah, but that doesn't tell me if the airlines are being sensible and staying on the ground or being silly and flying through ground glass, does it? The weather is one thing, what people do about it is another.
A life is like a garden. Perfect moments can be had, but not preserved, except in memory.Leonard Nimoy.
Now I did a job. I got nothing but trouble since I did it, not to mention more than a few unkind words as regard to my character so let me make this abundantly clear. I do the job. And then I get paid.- Malcolm Reynolds, Captain of Serenity, which sums up my feelings regarding the lawsuit discussed here.
If a free society cannot help the many who are poor, it cannot save the few who are rich. - John F. Kennedy
For anyone who is interested - points which sparked my interest from the European Geosciences Union special session on the eruption.
*One of the airlines, though the airline name was confidential, is in talks with one of the big names from ash remote sensing, whose name escapes me for the moment, to develop and fit infrared sensors to the nose cones of their fleet in order to get in-situ readings of ash clouds in suspension to actually give the pilot a way to respond to ash in realtime, rather than waiting for someone like VAAC to be told an eruption is happening and run their model.
*One of the big things they were stressing about the VAAC maps at the conference was that the models were absolutely fine, but relied on having accurate knowledge of the eruption rate, mass emissions, plume height and particle size distribution, all of which are very tricky to get without actually being on station to conduct extensive measurements. Garbage in, garbage out, etc. This is not to say that they were rubbishing the science or the VAAC, but they were obviously saying that there remain a lot of unknowns, and particularly, that things could be worse than predicted depending on the quality of the initial data (although equally, could be better).
*The General Electric recommended safe level of ash in suspension for flying was mysteriously raised by a factor of 20 two days before the ban was lifted over UK airspace after the first eruption. However, interestingly, it only takes one or two large ash aggregates (300 um) per cubic metre to go from the GE initial safe level to the new value, and more interestingly, there are a couple of reports from the people who had the NERC flight out that they thought they had found a few large ash aggregates in deposits in the UK, which stands in contrast to the conventional wisdom which says they should be removed nearer to the vent. I don't know the intricacies of the VAAC model, but I doubt it considers factors such as ash aggregation, cementing and armouring in its calculations either, as these are pretty much unknowns even in eruption plume models as far as I know.
*I was talking to some of the ash dudes from LMU, Munich, and they were saying that they were very keen to get their hands on a jet engine to try and break it, so were desperately trying to email every airline company they could think of. This could be very interesting, as Munich have this huge frickin' fragmentation bomb which lets them take a rock up to molten temperatures under high pressure, then drop to atmospheric, intiating fragmentation. They can synthesise most of the other ash types as well, including phreatomagmatic ash. Would be very interesting to see what you actually need to do to an engine and for how long to really fuck it over.
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Evil Brit Conspiracy: Token Moose Obsessed Kebab Munching Semi Geordie
I'm sorry, as an ignorant, ugly American, what do you mean? I hear that the volcano that blew lately was the 'little brother' of a pair, one that blows first, then then big one within a year after. So the big one is going off?
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KlavoHunter wrote:I'm sorry, as an ignorant, ugly American, what do you mean? I hear that the volcano that blew lately was the 'little brother' of a pair, one that blows first, then then big one within a year after. So the big one is going off?
No, there is no actual evidence at all that Kafla is any danger of going off at the moment. Due to the fact that the two have gone off in tandem previously, they aren't ruling out the possibility in the future, but there is no evidence for the moment.
"...a fountain of mirth, issuing forth from the penis of a cupid..." ~ Dalton / Winner of the 'Frank Hipper Most Horrific Drag EVAR' award - 2004 / The artist formerly known as The_Lumberjack.
Evil Brit Conspiracy: Token Moose Obsessed Kebab Munching Semi Geordie
KlavoHunter wrote:I'm sorry, as an ignorant, ugly American, what do you mean? I hear that the volcano that blew lately was the 'little brother' of a pair, one that blows first, then then big one within a year after. So the big one is going off?
Eyjafjalayokull has been erupting intermittently for two months. Every once in a while a BIG plume of ash goes off, and UK airports shut down. This is expected to go on for a few years.
When the 'big one' goes off you'll know it, it will be the lead story on the news.
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