Volcanic ash stops flights

Frame Dragger

Thanks Andre, ViewsofMars... I didn't realize that this wasn't very common knowledge re: prop vs. jet engines. *shrug*

ViewsofMars

""

Andre, you aren't a pilot are you? A simple yes or no will do. Honestly, I've known a few pilots. They wouldn't risk their life or passengers if there was risk. Have you read any articles where airline pilots are protesting the closure of air space in Europe? I haven't.

""

*Shrug* all you want FrameDragger! I said airline pilots!

Andre

I used to be pilot but it's not a simple yes-no at all.

Obviously there is a lowest concentration at which harm is negliglible and concentrations at which major damage is inevitable. For instance, how many times have aircraft landed in dusty hazy conditions near big cities and that is clearly visible?

So it's rather impossible to say something useful here, but just suppose for arguing that the actual concentration is only 5% or 10% or 30% of the damage threshold in the regions where it counts, why the fuss then?

It's just that these things have probably never been tested because it used to be a non factor in the past, so probably nobody has a clue what the best decision is.

Frame Dragger

I can't speak for Andre, but I'm no pilot, yet I know that volcanic ash is TRICKY. I've been trying to find a citation online, but I recall a NatGeo or Discovery program which described a plane that had flown into volcanic ash. The pilots had no CLUE what was happening, other than intermittant engine failure. They finally figured out that it was the ash vitrifying in the engines, but only once they landed. The pilots were simply bright and lucky enough to realize that they couldn't fly at their normal cruising altitude.

To be blunt, what information do you expect? It takes tiime for the glass to form, it's almost impossible to detect, and then BOOM, your engine can fail. Ascent and Descent are relatively brief compared to the time spend at altitude, and no one is willing to take that kind of risk. You don't crash test passenger jets in volcanic ash, and isolating the effect to a particular period of ascent or descent is pointless outside of a lab.

You don't fly air-breathing engines in ash, period.

@ViewsofMars: *shrug*
@Andre: Sorry if I stepped on your toes with this simul-post. I'll delete it if you prefer.

lisab

Haven't heard of protests, but the pilots who made these test flights must not have felt they were in danger, otherwise they would not have flown. The test flights, btw, apparently showed no ill effects from the concentrations of ash through which they flew (which I presume were quite low).

I think it's a good bet that there is a concentration of ash which is safe to fly through; what that level is isn't known. Which raises the question: is there a way to measure concentration of airborne ash? Because before we can determine what level is safe to fly through, we need a way to measure it.

ViewsofMars

""

Duh, FrameDragger! You don't fly airplane(s) into air space that has volcanic ash. You can locate that information in several articles via link that I have provided on this page and the previous one.
---
""

Hi lisab. :) Since pilots are inside the plane, I doubt there would be volcanic ash in the air they breathe. Volcanic ash clogs up the engine of a plane. Perhaps a very short span of time in air space with ash might not cause a plane's engine to die. Of course, measuring what level is safe could result in the pilot's death. Of course, they would have to get an *ok* by the control center of an airport and present the route. Has that happened yet?

Quite frankly, I haven't located the instrument used for measuring in air space the amount of volcanic ash. Perhaps, we should go digging for that information. I'm sure it's out there in cyberspace.
---

""

FrameDragger, I'm a serious contender with a gentle manner. And I don't mind you
rolling on the floor laughing. Also, as you can see, I like to condense cyberspace and free it up for others. I personally think a person should enjoy particpating in discussions. I may not always agree with everything someone has to say, but I do appreciate knowing that people are having a wee bit of fun.

Frame Dragger

Sure, you could probably do these tests at JPL...I believe they had a setup to test the effect of static discharge caused by particulate matter.

The problem is: Volcanic ash is not homogenous, and just hasn't been well studied. It takes some time for glass to choke an engine, and frankly... who will take that risk with a full cabin? There is the issue I raised earlier as well, which is that there could be cumulative damage.

I would also add that pilots do things such as fly into Hurricanes, not because they feel they are in no danger, but for the same reasons they fly into Anti Aircraft Fire. They have to: it's a job they love, and there is no other way right now (that people are willing to pay for). I doubt those same pilots would do this with a 747 and a full crew-cabin.

Finally, what is a safe concentration? You could determine an average, and still run into a sticky patch, which probably means that you and all souls will be lost. Airplanes just don't have much of a fail-safe at high altitudes if the engines are glassed.

@ViewsofMars: "Duh"? I don't know if you're angry or amused, but you're absolutely making me laugh in real life (with, not at). Maybe a bit of a softer touch would be helpful however? Everyone doesn't feel as rough-and-tumble online as I do.

Borek

http://en.wikipedia.org/wiki/British_Airways_Flight_9

Frame Dragger

Borek you wigged genius, THANK you!

lisab

Yes, good points. I would expect the ash concentration to vary some, but I wonder how much the ash itself varies? Are some types of ash more likely to glassify than others? I really don't know.

Galteeth

Is this eruption likely to have any short term effects on the climate?

Frame Dragger

The answer is "yes". Some ash is organic or composed of non-silicates, but a LOT of it is very fine pumice, which vitrifies like *snaps fingers*. There is also glass ALREADY suspended in the ash, which rapidly melt and then fuse, forming nucelation sites for more growth.

This might be useful: http://volcanoes.usgs.gov/ash/properties.html

Frame Dragger

The ash is unlikely to have much of an effect, but if this volcano released a lot of SOx, then it could have an effect for 2 or 3 years.

tomkeus

I'm really getting tired of people quoting BA Flight 9. It went into ash plume 150km downwind of the volcano. I don't see that this case is any argument to close down airspace 2000 or 3000km away from the Iceland.

Even after that, Indonesian authorities have closed down just the area adjacent to the volcano. They didn't proceed and shut down entire South East Asia.

I mean, we had large eruptions, even larger recently but not one caused shutdown on such large scale as in Europe. This is plain and simple irrational paranoia.

For example, engine flameouts did occur while flying through heavy rains. Does this mean we have to ground all air traffic if we have some rain sipping somewhere?

ViewsofMars

""

Frame Dragger, do you have a link (url) to substantiate your claim?

""

Frame Dragger, do you have a link (url) to substantiate your claim?

""

Frame Dragger, do you have a link (url) to substantiate your claim?

FrameDragger, I'm strickly asking for references for my own on-line library collection. (Please note that I have on the last two previous pages to this topic provided links (url's).) Thanks in advance for your help FrameDragger.

Frame Dragger

Please don't take this the wrong way, but this is something you can do with google and search terms such as "hurricane flight plane" or "composition volcanic ash". From there, you whittle down the info to something more specific, such as: "Volcanic ash troposphere remain" or "concentrations". Here is a simple search: "Composition volcanic ash"... and look at what it yields: http://www.google.com/search?hl=en&rlz=1T4DKUS_enUS306US306&q=composition+volcanic+ash&aq=f&a qi=g-m1&aql=&oq=&gs_rfai=

When it comes to something like QM or Relativity, I can understand wanting citations, but in this case it's probably good to do independant research, if for no better reason than having that skill at hand.

@tomkeus: Good luck selling that to your insurance company and investors if you own an airline.

mheslep

I was generally aware of these penalties, and they suggest to me a reason for temporarily raising the ticket prices to pay for more fuel and for reducing the number of flights. It doesn't explain to me, by itself, why the airspace should be completely shut down.