Register to reply

Volcanic ash stops flights

by wolram
Tags: flights, stops, volcanic
Share this thread:
ViewsofMars
#91
Apr18-10, 01:35 PM
P: 463
"
Quote Quote by Frame Dragger View Post
You don't fly air-breathing engines in ash, period.

@ViewsofMars: *shrug*
"

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.
---
"
Quote Quote by lisab View Post
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.
"

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.
---

"
Quote Quote by Frame Dragger View Post
@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.
"

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
#92
Apr18-10, 01:37 PM
P: 1,540
Quote Quote by lisab View Post
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.
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
#93
Apr18-10, 01:42 PM
Admin
Borek's Avatar
P: 23,523
Quote Quote by Frame Dragger View Post
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.
http://en.wikipedia.org/wiki/British_Airways_Flight_9
Frame Dragger
#94
Apr18-10, 01:45 PM
P: 1,540
Borek you wigged genius, THANK you!
lisab
#95
Apr18-10, 01:52 PM
Mentor
lisab's Avatar
P: 2,984
Quote Quote by Frame Dragger View Post
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.
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
#96
Apr18-10, 02:09 PM
P: 320
Is this eruption likely to have any short term effects on the climate?
Frame Dragger
#97
Apr18-10, 02:10 PM
P: 1,540
Quote Quote by lisab View Post
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.
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
#98
Apr18-10, 02:11 PM
P: 1,540
Quote Quote by Galteeth View Post
Is this eruption likely to have any short term effects on the climate?
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
#99
Apr18-10, 02:12 PM
P: 79
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
#100
Apr18-10, 02:19 PM
P: 463
"
Quote Quote by Frame Dragger View Post
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.
"

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

"
Quote Quote by Frame Dragger View Post
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.
"

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

"
Quote Quote by Frame Dragger View Post
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.
"

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
#101
Apr18-10, 04:50 PM
P: 1,540
Quote Quote by ViewsofMars View Post
""

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.
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
#102
Apr18-10, 05:08 PM
PF Gold
P: 3,097
Quote Quote by Andre View Post
About aircraft range and altitude. Maybe this link helps a bit, especially this sixth graph.

Notice that a fuel flow of 540 lbs/hr generates a max range speed of 200 knots true airspeed (KTAS) at sea level and 440 KTAS at 45,000 feet. Notice also that the sea level curve is much steeper, so flying faster than best range is at a greater penalty than at high altitude.

Also I expect this graph to be based on air density only since -as said- the temperature and related mach number play a big role for engine performance/efficiency and these are not linear in that altutide range due to the tropopause.

The exact numbers are not very relevant but it gives an impression of the rate of changes in range versus altitude.
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.
ViewsofMars
#103
Apr18-10, 05:16 PM
P: 463
Quote Quote by Frame Dragger View Post
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=
Why would I use Google? I am a science researcher. I go to either peer-reviewed articles or use U.S. Government-Science website for scientific information, or a scientist's website, etc. By the way, I already had reviewed http://volcanoes.usgs.gov/ash/properties.html
I was basically asking you for a website to confirm your comments. Please don't through it back on me. Why? Because it is insulting. I'm especially still waiting on your comment, "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." That isn't a scientific statement.
tomkeus
#104
Apr18-10, 05:21 PM
P: 79
Quote Quote by Frame Dragger View Post
@tomkeus: Good luck selling that to your insurance company and investors if you own an airline.
You don't have to sell anything. Just wait for a few more days for losses to accumulate and they will be begging you get those planes airborne.
sophiecentaur
#105
Apr18-10, 05:22 PM
Sci Advisor
Thanks
PF Gold
sophiecentaur's Avatar
P: 12,117
Quote Quote by Andre View Post
About aircraft range and altitude. Maybe this link helps a bit, especially this sixth graph.



Notice that a fuel flow of 540 lbs/hr generates a max range speed of 200 knots true airspeed (KTAS) at sea level and 440 KTAS at 45,000 feet. Notice also that the sea level curve is much steeper, so flying faster than best range is at a greater penalty than at high altitude.

Also I expect this graph to be based on air density only since -as said- the temperature and related mach number play a big role for engine performance/efficiency and these are not linear in that altutide range due to the tropopause.

The exact numbers are not very relevant but it gives an impression of the rate of changes in range versus altitude.
Thanks for the info on those graphs Andre. Looking at the minima on those two red curves it seems to me that the 'fuel consumption' (mpg, in motorcar terms, ignoring winds) at 45k is about twice that at sea level. (i.e. same fuel flow at just over twice the air speed) Presumably it wouldn't be quite so bad at 10k as at ground level. That would imply that the cost of flying low would only be about twice that of flying at normal altitudes. Sounds a lot more attractive than spending hundreds of pounds on hire cars, extended stays in hotels and missed business deals.

So why aren't they considering at least some flights (high priority, perhaps) at lower, safe, altitudes? Is it just an admin (ATC) problem?

I feel that this thread should be split into two - one to deal with the safety issue and the other to discuss possible (non-hazardous) solutions.
Frame Dragger
#106
Apr18-10, 05:26 PM
P: 1,540
Quote Quote by ViewsofMars View Post
I was basically asking you for a website to confirm your comments. Please don't through it back on me. Why? Because it is insulting.
It is responding with the understanding that you were being rude, and patronizing, and apparantly unwilling to perform your own research to confirm a statement. In short, returning your "offer" is no more insulting than it was for you to make the request in the first place. You were hardly being subtle, polite, or reasonable. I on the other hand, gave you the benefit of the doubt, a mistake I won't make twice. As for you being a "science researcher", that statement alone gives away a great deal about what you are, and are not. If you have a further issue, feel free to continue, but my new policy on PF is to disengage and report now. Keep that in mind.
Frame Dragger
#107
Apr18-10, 05:28 PM
P: 1,540
Quote Quote by tomkeus View Post
You don't have to sell anything. Just wait for a few more days for losses to accumulate and they will be begging you get those planes airborne.
No, they won't. Those losses won't be fatal for a business, but a crash that could be blamed on negligence (can you IMAGINE the civil trials alone?!) could absolutely ruin an airline. A plane that crashes now is immediately going to do ENORMOUS damage to a company's public image, and as Pan AM could have told you, that matters when you're trying to convince people to fly in your aluminum and composite cigar with wings.

EDIT: On the bright side, we just wait those few days and see who is correct. No need for speculation when time will answer this.
ViewsofMars
#108
Apr18-10, 05:35 PM
P: 463
Quote Quote by Frame Dragger View Post
It is responding with the understanding that you were being rude, and patronizing, and apparantly unwilling to perform your own research to confirm a statement.
Frame Dragger, that is your opinion.


Quote Quote by Frame Dragger View Post
In short, returning your "offer" is no more insulting than it was for you to make the request in the first place. You were hardly being subtle, polite, or reasonable. I on the other hand, gave you the benefit of the doubt, a mistake I won't make twice. As for you being a "science researcher", that statement alone gives away a great deal about what you are, and are not. If you have a further issue, feel free to continue, but my new policy on PF is to disengage and report now. Keep that in mind.
Frame Dragger, that again is your opinion. I think you are skating around to basically avoid answering that last question of mine to you! Which is absolutely not a scientific answer. Retraction from you is never an option as I can see. Furthermore, the language you have used isn't scientific by any means.


Register to reply

Related Discussions
Static Helicopter Flights Introductory Physics Homework 2
Full body scans for US bound flights General Discussion 224
Anyone knows a good website providing low price flights? General Discussion 14
Earth rotation and long flights General Physics 7