Slashdot Mirror
Was Flight Ban Over Ash an Overreaction?
HaymarketRiot writes "Richard Branson has claimed that the flight ban, due to the eruption of the volcano Eyjafjallajokull, was an overreaction on the part of the authorities. Britain's government has even called for the airlines to be compensated. This does look like a perfect excuse for already greedy airlines to try and get more money ... any experts care to comment on the effect of volcanic ash on planes?"
Basically, the jet's internals are hot enough to melt rock back into glass... So after a couple of passes through ash clouds, you have a thin layer of glass covering all the internal turbine blades. Which completely destroys the engine, and is extremely hard to repair without completely replacing the blades.
So, basically, what I've been told is that, yes, flying a jet through a volcanic ash cloud is a good recipe for completely destroying the engines, such that they need to be rebuilt, within two or three passes through the ash. It sounds plausible, and I've not yet heard anyone who actually does aircraft maintenance or anything like that suggest that it's harmless.
My blog: http://www.seebs.net/log/ --- My iPhone/iPad app: http://www.seebs.net/seebsfrac/
The summary is wrong. It is the founder of Virgin Atlantic that wants compensation, not the government. Has anyone ever heard of a government wanting to dish out compensation?
Better known as 318230.
Don't know if you put any stock in what an aircraft manufacturer might say on the subject, but...
http://www.boeing.com/commercial/aeromagazine/aero_09/volcanic_story.html
Summary: If you find yourself flying into an ash cloud, turn around immediately.
So, yeah, maybe Branson wants a check, but flying into ash clouds is a very bad idea. And they don't show up on weather radar.
Why yes, I AM a rocket scientist!
I dunno. KLM Flight 867 lost all four engines after flying into Mt. Redoubt's ash plume, back in 1989. I was in Fairbanks at the time, and many people I know where stranded, trying to get home for Christmas vacation.
Ash is not good for jet engines. Period.
Microsoft is to software what Budweiser is to beer.
I know almost all regulations are written in blood. If the wind decides to shift and a plane goes down that's unacceptable.
Erik Klemetti's Eruptions blog has a recent post called Eyjafjallajökull flight cancellations: How the right decision is being made to look wrong defending the decision to cancel, with much discussion in the comments section. (IMO, that blog's recent series of posts on the Iceland situation has been the best place to read about the eruption.)
That's a really telling translation. It appears as if the Google translator is trying to decipher the sentence in a way that assumes Finnish word suffixes are directly mapped to English prepositions. It saw the "sta" at the end of "perunajauhomaista" and assumed it means "from", and properly translated "perunajauho" as potato flour... Of course, the word is a form of "perunajauhomainen" which is an adjective that basically means "resembling potato flour" that was being used to describe the volcanic "ash dust".
Shutting down most of Europe's airspace was entirely the right decision. All it would take is one flight through an unexpected dust cloud to produce a near-disaster, if not a crash. That's happened at least five times in the past. Read Boeing's advisory on volcanic ash.
Read Branson's autobiography? Several times in his life, he's been involved in adventure vacations that left someone else dead. This is not someone you want making risk management decisions for others.
The big problem now is that the airlines are botching the logistics of getting people back where they're supposed to be. There are people being told they can't get a flight until mid-May, because they booked a flight using frequent-flyer miles or via some discount deal that has a low priority. They can't get the airline on the phone, and they get hit with heavy roaming charges while on hold. This is really tough on people in transit running out of money.
I would like to add that on the near accidents mentioned above the damage to the aircraft was also VERY extensive. The BA flight needed 4 new engines (around U$ 14 million EACH), new windows (more expensive than you would think), new pitot and static ports (and an overhaul of tubing and sensors) and a paintjob (big surface, costs quite a bit) as well as a thorough overhaul of pretty much everything.
Even if no one dies it is still extremely expensive to fly accidentally into an ash cloud.
I really don't think this was an overreaction. Safety must be paramount, and if only one or two aircraft had gone down due to ash that would have seriously impacted the publics faith in the airline industry and their view of safety. That would have been a lot more expensive in the long run, and the airline industry has spend decades building an image of themselves as super safety minded.
And just for the record, I'm an ex-commercial pilot. From Iceland. I've flown smaller aircraft around volcanic eruptions and had great fun.
The cooling system used in gas turbines (jet engines) is very sophisticated and necessary to keep the superalloy blades from creeping too fast. The system consists of bypass air channeled through the blades and exhausted through tiny perforations, creating a layer of cooler air between the blade and the hot flow from the combustor. Furthermore there are two ceramic layers on the outside of the blade. One to prevent oxidation. One to slow heat transfer (insulate). As has been mentioned in other articles, the cooling pores could get clogged by the ash. I also suspect the coating might fail if impacted by ash. If the coating fails or otherwise reacts with the ash, then you can definitely have a problem.
If the blades get just a few tens of degrees hotter, they will surely fail. There's not a lot of margin for error with jet engines. Through good design and manufacturing control, we've managed to make gas turbines extremely reliable, but ash is not a design condition at all. It's abrasive, might react with the coating, and might accumulate on the blades, changing both their mass and aerodynamics.
"There are some people that if they don't know, you can't tell them." ~ Louis Armstrong
That's an apple-oranges comparison. The video shows a GE-Honda HF120 turbine, a 2,000 lb two-stage, two-compressor turbofan designed for the light jet market. A very different design from...
Commercial airline engines are rated from 14,000 (old-school Boeing 737) to over 100,000 (Boeing 777) pounds.
Aside from that, the difference in scale of a fine volcanic ash particle compared with a grain of sand determines the melt rate. Volcanic ash passing through a turbine is essentially a fluid, one that melts at around 1000 C. Aggregate sand (in the video) melt between 1500-1700 C.
Turbofan combustion chambers burn at between 1500-2000 C. Grains of sand are too thick to melt, given the airflow rate through an engine (250-1400 mph.)
O lord, bless this thy holy hand grenade, that with it thou mayest blow thine enemies to tiny bits, in thy mercy.
That's the problem, I'm not from a major European country. I'm Norwegian. Norway took the correct measures to stave off any negative effects (according to the OECD). Jobs, banks and housing markets remained stable. We have 2.6% unemployment.
While there might be more to the story than simply having regulated our banking industry we did very well during this recession. It doesn't hurt that we're the world's 3rd largest exporter of oil, or that we have no national debt, and put our oil revenue in a huge sovereign fund invested abroad. We base our welfare state on taxes, not on oil revenue.
Part of the reason our banks were already regulated was the fact that during the 1980s Norway had its own bank crisis and housing market crash. The government had to take control of the collapsed banks and rebuild them. Since then our banks have been strictly regulated and the housing market stable.
The UK was badly hit by the recession obviously, but Germany has been out of recession for a long time now. Germany is the major nation in Europe. I believe France technically came out of recession too. Spain, Portugal and Greece are not large countries. I doubt you can find a European country that experienced the recession on the scale of the US.
I can provide a source too if you like: http://seattletimes.nwsource.com/html/nationworld/2009217763_norway14.html
Dude, maybe you should just stop thinking, because thinking doesn't work very well for you. I mean, 10-20 percent? You are basically saying that you don't have any hard data and just pulling some number out of your arse, then adding that the figure might be twice as high.
Well, I've got news for you. In 2008 the unemployment rate in France was at 7.9%. Now the unemployment rate in France is 9.7%, which is exactly the same rate as in the USA.
Judging from your other postings here you are just a selfish prick who has missed his flight and had to stay in Frankfurt/Main. Dude, as someone who lives in Frankfurt, I can only say that I am very glad that you finally went back from whence you came. It is people like you who give Americans a bad name.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
So that's an easy one: no, it wasn't.