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EU Conducts Test Flights To Assess Impact of Volcanic Ash On Aircraft
chrb writes "As we discussed on Friday, the eruption of Eyjafjallajökull in Iceland has led to flights being canceled across the EU. With travel chaos ensuing and the airlines losing an estimated $200 million per day, EU authorities are coming under increasing pressure to re-open the airways. Test flights conducted on Saturday were apparently successful, with no problems encountered during flight. Following the test flights, Peter Hartman, CEO of KLM, said, 'We hope to receive permission as soon as possible after that to start up our operation and to transport our passengers to their destinations.' Evidence possibly opposing this move comes from the Finnish Defense Forces, which released photos and a statement after F-18 Hornets flew through the ash cloud, saying, 'Based on the pictures, it was discovered that even short flights in ash dust may cause significant damage to an airplane's engine.' Is it safe to resume flights so soon, or should planes remain grounded until the ash cloud has dissipated?"
This links leads to a page with a video of an ambulance helicopter that was coated in a fine layer of ash in Norway today. It flew during a small windows of opportunity where the air cleared to pick up a patient in Sweden. The link is in Norwegian, but the video is, obviously, visual.
The interesting part is at ~00:30 where he shows of the ash (requires Flash): http://www.dagbladet.no/2010/04/18/nyheter/innenriks/aske/vulkan/flyforbud/11335687/
Makes me think that a large passenger jet flying long routes and sucking in a whole load of air on the trip might be at risk of engine failure as they say.
There is satellite imagery however. Both NASA and ESA traces the ash cloud based on satellite data, ESA even compiled an informative animation.
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Be yourself no matter what they say
The ash allegedly contains shards of glass, and I can see how this would cause serious problems for turbines... but I think it's obvious that just like any other phenomena of weather, the ash will be non-uniform. It makes perfect sense that one test would have completely different results from another. Thus, broadly-based testing would be necessary to derive any useful result...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Ash is abrasive. Any idiot who has washed their hands with LAVA soap can attest to that.
Q:So then, what happens when you put abrasives into parts manufactured to close tolerances?
A: Tolerances are widened.
Q: What happens when tolerances are widened on machinery that spins at high RPM?
A: Centers are lost and jitter occurs speeding disappearing tolerances and adding heavy vibration.
Q: What will that heavy vibration do Cap'n fly?
A: Titaniums can shatter, Waspalloy and Hastalloy parts will tear away from Titaniums and Aluminums, H60 coated bearings will fly as though fired from a gun.
Q: What are you really saying, fly?
A: Assume the crash position, put your chin on your taint and kiss your @ss goodbye!
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
Four engines vs. two engines doesn't really matter. Some of the most dramatic incidents of airplanes ingesting volcanic ash are 747s. Invariably, every single engine shuts down after several minutes of sucking up ash and melting it into glass. All four engines have to be restarted to recover, once the airplane descends out of the cloud and the glass has time to cool off.
Probably not. Ash has caused all engines to go out on a 747. As you say, the threat is common to all engines, whether 2,3, or 4.
The airlines have it right. All the talk has been about flights being canceled for a few days or weeks, but as far as I can tell there's no real reason the eruption couldn't continue for months, and plenty of precedent for eruptions which have. And talk about the wind shifting seems pretty much wishful thinking as well; the upper air westerlies aren't going to stop blowing eastward, nor are they likely to lose all their southward components. So a very conservative approach (no flying until the ash has dissipated) could result in most of northern Europe being a no-fly zone for months. It's probably worth the risk to find out more precisely where the conditions really are too dangerous.
And here's the gotcha, they never disclosed how close to the volcano the finn planes were.
Umm. They disclosed that they were doing training missions in northern parts of Finland while the airspace was still open to all. I'm not sure what makes this a gotcha.
It is what it is.
Do you think it is safe to say that they were about as far away as Finland is to the volcano? Say 2500km. Or do you think they said, "hey there's a volcano erupting 2500km away that we'd have to cross three sovereign nations airspace's with in our military jets (Finland doesn't belong to NATO or any common EU defense alliance), let's go fly our planes over there." Personally I would tend to believe that they flew over their own country and decided to do a 'post-mortem' on the engines when they found out how bad the ash cloud was.
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Iceland is west of Finland.
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The president-director of the KLM was on-board of one of the first test flights. So he put his money where his mouth is.
Source:http://nos.nl/artikel/151324-klm-voert-testvlucht-uit.html
Actually, the trend's the other way. Trains in Europe used to be much slower, so long trips were faster by plane. As the trains gotfaster, air travel on competing routes declined drastically.
I'll be staying home, thanks.
I still cannot find the droids I am looking for...
Actually the problem, as I understand it, is that the silica particles in the ash cloud (similar to very fine grains of sand, or glass) are melted by the heat of the engine, then then collide with the leading edge of the turbine blades and condense. This is bad for a number of reasons, firstly it expands that surface and significantly reduces the efficiency of the engine. More importantly however, it has a different coefficient of thermal expansion to the titanium blade, and very quickly it will start to crack and break away. In this process it takes small chunks of the blade with it. The process causes a lot of pitting in the leading edge of the blade.
The thermal spraying department at my work do a lot of research into repairing blades that have suffered from this problem. Most often it has been caused by planes flying through sand storms in a desert, but the effect is just the same. One of the methods of repairing the blade is to remove enough of the titanium so that you can plasma spray a ceramic in its place to make the blade the right size again.
The question is what's the history of this particular volcano
This volcano hasn't erupted in 200 years, but the last eruption lasted from December 1821 to January 1823.