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Iceland Volcano's Ash Grounds European Air Travel
Ch_Omega writes "From the article at CBSNews: 'An ash-spewing volcano in Iceland emptied the skies of aircraft across much of northern Europe on Thursday, grounding planes on a scale unseen since the 9/11 terror attacks. British air space shut down, silencing the trans-Atlantic hub of Heathrow and stranding tens of thousands of passengers around the world. Aviation officials said it was not clear when it would be safe enough to fly again and said it was the first time in living memory that an ash cloud had brought one of the world's most congested airspaces to a standstill.'"
The BBC says "Safety group Eurocontrol said the problem could persist for 48 hours," and the Deccan Herald describes some of the effects on the ground in the volcano's home turf: "In Iceland, hundreds of people are fleeing rising floodwaters as the volcano under the glacier Eyjafjallajokull erupted yesterday again, for a second time in less than a month."
As watching endless episodes of Discovery channel would tell you ash has been responsible for plane crashes in the past. http://en.wikipedia.org/wiki/British_Airways_Flight_9
Did you even read the link you posted?, that flight never crashed, it just lost power to all 4 engines for about 15 mins, but they eventually started up again.
They closed the airports because the ash eats up jet engines, and can't easily be detected on radar. It's mostly silica and doesn't have a dielectric constant different enough from air to show up on most aircraft radar. So even if the cloud is thin enough on the ground to take off safely, you are relying on visual indications of the clouds thickening, and your visibility is poor so it's hard to see.
Any pissed off European travelers stuck in the airport reading /. may want to read KLM vs. Mt. Reboubt before hitting the friendly skies.
http://www.thenakedscientists.com/HTML/content/questions/question/2008/
The volcano is roughly 100 times as green if we're talking about CO2 emissions, and 10 times as green if we're talking about SO2. Of course, that's assuming that given
Pv = the pollution output from this volcano over two years
Pvt = total pollution output by volcanoes.
Pe = European airplane pollution
Pht = total human-sourced pollution
Pe / Pht == Pv / Pvt
And there are some gaping flaws in that logic, but the point is volcanoes are fairly inconsequential as drivers of pollution.
Well, I just had a beer with my little brother, a BA Pilot grounded here at our home in switzerland.
BA Flight 009 was special because it is the first such incident documented in a modern jet airliner. The pilots were pretty clouless when they suddenly saw funny flares through their front windows (cause by ash particles). "Somke" was reported from the cabin and after some time they piloted a very expensive glider plane (all 4 engines failed). The 747 has a glide angle of something about 1:15 which is very good for a heavy airliner. But with failing speed indicators it is quiet a challange to restart engines midair (windmill effect is used, they need to hold a certain speed before they can inject fuel and ignite it again).
I think these pilots back then did a tremendously good job if one takes into account that they had no fucking clue what was going on (today they have procedures for such situations, my brother showed me his checklist for such cases). And they had a lot of luck. The pilots lost height due to engine failure, decided to do a 180 turn and once the engines restarted (pretty low) they got into the ash cloud again and lost some engines again before they landed with reduced sight (sandpaper effect on the front window) and reduced IFR instrumentation at night.
Cheers,
-S
According to a CNN article, the prime minister of Norway is stranded as a result of the resulting travel chaos and "running the Norwegian government from the U.S. via his new iPad".
I'm looking for maps, but it doesn't seem to look that close...?
Note: rectangular maps of the world distort distances. Rectangular maps use some variant of a cylindrical projection* so as you approach the pole east-west distances appear larger than they really are.
Still it is a bloody big ash cloud (note: also because of winds it's neither circular nor centered on the source).
*The variants differ in how they deal with north/south distances. Mercator's projection (the most common afaict) modifies the north/south distances as well so local shapes are correctly represented. Peters projection modifies north/south distances in the opposite way so it preserves area but distorts local shape even more than a straight cylindrical projection does.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
An automobile's air filter will plug within minutes of being introduced to volcanic ash. Plug to the point of keeping the engine from running.
This was experienced during the Mt. Saint Helen's eruption in the United States. Stores sold out of pantyhose in very short order because people were using them to filter the ash so it wouldn't plug up the regular air filter.
Terror? More like inconvenience.
This eruption can go on for months, even years. To add insult to injury eruptions in Ejafjallajökull have historically been foreplay for eruptions in Mt. Katla which is a 100 square kilometer caldera that lies under nearby Mýrdalsjökull glacier. That eruption will be orders of magnitude bigger than this one. When Katla blows, and there is a good chance she will do so within the next two or three years or so if history is to be trusted, you can pretty much kiss air-traffic over much of Europe, or North America goodbye. Whose turn it is to not fly for a week or so at a time will depend on the wind direction and trust me, the economic damage of only being able to fly every other week for six months to a year is more than a mere "inconvenience".
Only to idiots, are orders laws.
-- Henning von Tresckow
Oh yes I am aware of all that. The glide ratio of a 747 in a clean configuration I believe is around 15:1 So at 20,000 feet will glide roughly 60 miles.
Actually a good bit less because you will need to set up your approach slow down, and drop flaps and gear to land.
I am not sure what the best glide speed of a 747 but I would guess some where around 300 mph or more.
So the pilots would have less than 10 minutes to find a safe land spot set up an approach and land.
So unless the failure was right over an airport or a handy rock hard dry lake bead you are in a world of hurt. An Airbus did do it once. They where at high altitude and had a trained sailplane pilot as the captain who just happened to know of former Air force base and managed to get it on to the run way. It was still technically a crash since the nose wheel failed but no one was hurt.
So I stand by my statment that it is just about the worst thing that could happen. Yes a massive structural failure of the lifting and or control surfaces are worse but at this point it is a case of splitting hairs.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.