First time poster, long time reader here. I'm a Geologist with a life-long fascination with flight. Thought I'd post a note on the geology side after reading posts above by flying lid and carjockey.
Agree that the details matter a lot when evaluating risk. Volcanoes eject all sorts of mineral matter, not just silica, and each of these mineral types have greatly varying properties such as hardness, melting points, etc.. And in the case of jet engines I would think "size matters" could apply, although an engineer should be consulted. Even if 100% silica (volcanic glass) the size of the particles/exposure time to engine heat might dictate level of damage to an engine. Sufficent sampling should be conducted and analysis done before jumping to conclusions.
As to the history of this region's vulcanism - we do have some decent records. Based on those, if history repeats itself things could get worse, maybe much worse, before they get better ----
"..... as Science Fair noted, the Eyjafjallajokull volcano isn't necessarily the main problem. It's Katla, Iceland's noisier neighbor, that's the concern. If lava flowing from Eyjafjallajokull melts the glaciers that hold down the top of Katla, then Katla could blow its top, pumping gigantic amounts of ash into the atmosphere."

Unfortunately there seems to be correlation between the small eruptions and awakening of the big brother in the past, so cross your fingers that history doesn't repeat itself. No mention of poisonous gases in this particular article, but I've seen multiple other posts that mention deaths from gas in Britain. There's tons of data available for the Googling for those interested in more details.

Greatly enjoy reading your website - thanks. :)

It's real
 

I was a bit of a sceptic, but a German Air Force flight (GAF949 at 350 )heading east over Northern France just been told to take avoiding action to miss a reported ash cloud, about 45Deg to the right. So it must be real ?

CJ,

Totally agree with you - safety is and always should be paramount. Although with regard to damage we do have some idea from the BA009 incident of 1982 which you alluded to, namely sandblasting, turbine damage, etc.

I disagreed with your point re temperatures (as per Lompaseos post) as the temperature, and the type of ash, does have a very real effect due to the ash being able to melt and then re solidify.

I agreed with your point about sandblasting but stupidly (and rather embarrassingly) didn't think through my post before typing - my mistake, and I apologise.

It's been a very interesting day today and at the minute I'm not sure we'll be flying tomorrow yet either, but we cannot rush this. For all the stranded PAX I feel very sorry, for all the airlines losing money and handing money back, I also feel very sorry - this couldn't have come at a worse time for the industry, and I hope ALL operators survive this.

DW.

G-FBFI = G-CHAI CL601-3R Challenger 5152 OXFORD to BIGGIN

Several others into FAB 2 CHOPPERS 1 F7X (HB-JSS) +(G-SIRS)
VFR below airways

TONY

Basis for decision making
 

S76 Heavy

It isn't just a random decision

ERUPTION OF EYJAFJALLA VOLCANO IN ICELAND – ICAO SYSTEM EFFECTIVE IN ENSURING THE SAFETY OF AIR TRANSPORT ICAO News Centre

Keep an eye on Katlia, that is the real danger.
 

The Katla volcano has a reputation as one of the most dangerous volcanoes in Iceland, and it has exploded in the past just shortly after the activity of the closeby one that is causing all the mess now.
Katla has been showing signs of unrest since 1999 and geologists have concerns that it might erupt in the near future. Particularly, monitoring has been intensified following the March 2010 eruption of the volcano beneath the Eyjafjallajökull glacier. The eruption of this nearby long-dormant volcano in March and April 2010 prompted fears among some geophysicists that it might trigger an eruption at Katla.
Katlia could cause enormous disruption for very long period of times, even years. The ash cloud of today would be a joke compared to the cloud that Katlia could generate over all Europe and beyond.
Unfortunately nobody can stop this incredible force of nature.:ok:
A good reminder to us all, spoiled humans.:ugh:

S..Heavy,

Maybe the so called over reaction to the flu epidemic worked and prevented it from spreading.

If in doubt, there's no doubt.

Just because you are not involved in the debate does not mean it is not happening. I got 3 hours sleep last night because I was busy trying to provide the relevant people with high quality data regarding the ash. I've spent all day today dealing with calls and emails from scientists wanting information about how well some satellite sensors that I worked on can detect the ash. There is plenty of debate about it, and this debate will continue.

So you'd rather that the NAT etc close the stable door after the horse has bolted?
Frankly that is a reckless and dangerous attitude to take. Do you need an accident to happen just to prove that this ash is a problem?

Are we talking hours, days or weeks? No idea really.

I assume UK is particularly prone to be effected badly - in an event like this (meteo combined with the eruption) due to our relatively small size, and how close the airports are together ?

presumably in larger countries there are more possibilities to divert around ? and or divert to other airports a bit further away.

Hi res, very large image from NASA:

http://www.nasa.gov/images/content/4...o-20100615.jpg

As someone who has to sit in the ash at 36,000 feet daily my partner and children are perhaps thankful for the so called prudence and wisdom of those who have more data at their finger tips than most of us on here. If there has been an over reaction ask yourself why ? The litigious society we live in ! Imagine a flame out nowadays, everyone survives but they all sue the airline for post traumatic stress, they sue NATS in fact the passengers sue everyone they can as they now have video footage in the cabin of their trauma ?

So we all sit on the ground for 4 days, nothing happens, no one falls out of the sky that is a successful outcome surely? When you wait for a thunderstorm to pass the end of an airport does it need a jet to fall out of the sky due to a windshear encounter to justify your decision ? Nope its a duty of care that all professionals exercise when they have more data in front of them.

Do we need a jet to fall out of the sky to justify a correct decision ?

Final point, Chemist friend described the difference between volcanic dust and sand dust, sand dust is like the rock in your garden the volcanic has a rough jagged serated edge hence the windscreen damage. Discretion today is the greater part of valour.... Fly safe mon amie

Sand under microscope

Volcanic dust under microscope

Volcanic dust is vastly more abrasive than sand. It has very sharp fresh edges and can be fine enough to penetrate very deeply. It can cause severe lung damage if inhaled.

Having clarified that, I'm with those who strongly suspect a degree of over-reaction here: for instance I can't help wonder how much risk there would be heading southbound out of LGW or LHR.

I don't know that much about volcanoes, but there is very little information available to Joe Public which indicates that the ash cloud would be a danger. Yes, there's a plume around the Shetlands, but Joe Public living in London who wants to fly from Gatwick to Spain can't see how that affects him.

Presumably some people reading this thread have access to rather more information than is publicly available. If so, could they consider making it available to Joe Public, or do a better job than just saying 'When Eric Moody....'
London is 1,000 miles away from the volcano - so any ash dispersal is likely to be at a relatively steady pace dependent on the wind and presumably moderately predictable based on meteorological forecast, rather than relatively unobservable underground geological events causing the volcano to suddenly increase its activity

I can't see any national security reason as to why information on the extent of the ash or volcanic gas should not be public. Show people the scientific evidence and they'll stop saying it's an over-reaction

Updating for Paris
 

Some informations from Iceland MET office indicate that the eruption is increasing in intensity.

LFPG/LFPO/PB closed 15/2100 16/0800z.

BREST FIR/UAC closed North of 47 North. 46 and 47 N open for Eastbound. 48N and northern closed.

EHAM closed until 0800z

Regarding the doubt on the density and risk of this ash cloud. Quite possibly the only way to find out will be to fly through it.

So the question to the doubters, would you ask a crew to fly through it knowing that they may be risking a total engine loss and the possible subsequent consequences?

As one of those who has to sit in the ash cloud...or not! I'd greatly appreciate more info/debate on the risk assessment process which has led to this decision. The situation has repeatedly been described as "unprecedented". It isn't. There are active volcanoes all over the place and we work round them. What is so much worse about this one?

A massive over-reaction. I'm 25 miles from LHR and looking at a lovely clear sky. Not a particle of ash in sight. Please don't tell me that it's the invisible ones that do the most damage.

west lakes - I certainly wouldn't ask anyone to risk their life over it.

However, is there really nothing that using one or more of weather balloons, unmanned drone, or satellite that could provide information on ash density ?

Even if the investigation costs 10 million pounds per day, that's still peanuts compared to the cost to the UK economy

I agree it is prudent to close airspace to IFR high level traffic. I would be interested to see how HIA ( Highlands & Islands Airports) justify sending all staff home and closing the airports. We tried to fly our Islanders out of KOI VFR to be told no. :ugh:

"Are we talking hours, days or weeks? No idea really."

Apparently Icelandic volcanoes don't have as much gas as those in the Caribbean and other places, so it won't be years (of ash/dust thrown up).

The worry is that it will stop and start or that Katla may start up as well.

This is going to be messy...

Metcheck.com - Atlantic Jet Stream Forecast - [Updated on 15 April 2010 at 20:00] - Weather Feeds - Live Data - Long Range Weather Forecasts

My point exactly.

And as I fly hardware with spinning wings over my head, I tend not to exceed 7000 ft. So closing off the entire airspace without any concrete information about concentration levels and when they are considered to be dangerous and why, is pretty annoying.

I don't advocate finding the nearest ashcloud and drive straight through it, but after all sorts of knee jerk reactions to terrorism, illnesses and perceived threats, I am loathe to accept at face falue the simple closing of large areas of airspace "because we know it is safer".
Show me the proof, or at least show me the theory behind the caloculations. Stopping all SAR and HEMS because someone says we should not be flying to me is an overreaction when not substantiated by scientific evidence.

And what if it takes more than 4 days? What if it is 2 weeks? Are we then going to differentiate in which concentrations are safe enough to fly and which are not because the economy cannot sustain a total shutdown? What sort of evidence will we be using then?

I can understand not putting high speed IFR traffic into a risk area, but I do not believe that the entire airspace from the ground up towards the stratosphere contains enough ash to become a significant problem, and especially not in VFR/VMC conditions.

Did you actually bother looking for any information?
I'm guessing no. Otherwise you would have found this page that details the basics (very basics) of how the London VAAC operates:
Met Office: Volcanic ash detection tool
You would also have found this page, which shows the last known ash spread (top left) anf projected spread for the next few hours:
http://metoffice.com/aviation/vaac/d...1271354037.png

You'll notice that there is currently ash over London, even though the inability of our eyes to detect IR light means we can't see it.

By searching google scholar or a similar database you'd also find literally thousands of papers and articles on the subject of ash dispersion, ash detection, the effects of ash upon aircraft and countless related topics.
e.g.:
volcanic ash advisory - Google Scholar

The fact that it's on top of your island rather than on top of some godforsaken pacific island.:ok:


(edit) And for those wanting proof: The theory and calculations behind volcanic ash detection are available through google scholar, although you may need to go to a library to gain access to the actual journal articles.
The data required for detection (AVHRR) is freely available from NASA. You can download it yourself, although unless you have a fancy satellite dish you will have to put up with a day or so delay from real-time.
Then you'll have all you need to calculate the ash spread yourself.

There is certainly very rough, to the touch, brownish coloured contamination on cars in this area.

Quote from NATS

All of scandinavian airspace is closed...

My flight tomorrow to palma is delayed... =(

Not to turn this into a spotter thread but radarvirtuel is showing a lonely CL601 Challenger over the London area (G-FBFI).

I thank that is a point, so whilst some are denigrating the UK authorities, other countries are taking the same precautions. So are all these other nations wrong as well?

There may be a clue in the silence
 

S76, I disagree and I take my clue from the silence from the airlines themselves. Not a peep from Cryan or Squeezy, let alone the network airlines. They cannot be happy - expenses through the roof and refunds flowing out the door - but they aren't going to risk the reputations, their employees, or their expensive aeroplanes just because someone hasn't proved its unsafe. Fear of litigation could be part of it, but I give them credit by thinking that isn't their sole, or most important motivation. Ask BA, ask KL, ask any of the other reported 90 odd volcanic dust incidents over the last 20 years?

Better safe than sorry? You betcha.

These virtual Radar sites are only as good as info put in as G-FBFI =G-CHAI
This went to biggin hill VFR just before 1900 this eve from Oxford . possibly
its off home again.

TONY

Really? Where is that written?

I think the European aviation industry needs to come up with some drastic measures that need to be brought in during times of crisis such as this.

It's fair to say that a good 25-33% of flights from this country that are heading southbound could still take place virtually risk free at a lower level. I'm not saying my numbers are correct but an example might be: A departure out of Gatwick could trod along 100 nm south at 6000ft before being out of the risk zone and then climbing higher and proceeding normally. Clearly this means temporary changes to airspace classification across borders which would affect GA but thats a lot better than having commercial traffic at a complete standstill for a month!

Just an idea, don't shoot me down!

Sky news just showed some of the procedure if flown into a volcanic cloud (in a flight simulator).

Very informative (even for SLF like me).

And the BBC'S coverage is mostly about the live debate...

Go figure.......

As has been said multiple times, those images are available. I posted one this morning, someone else psoted one this afternoon.
After a post mentioning the BBC I just went and checked their website. They have a large satellite image of the ash as their primary image. What more do you want?

And the reason most science is not explained publically is because 99.999% of people don't care. Just about every science major project in the last 10 years will have an informative website detailing their objectives. Just about every library in every country in europe has access to scientific journals whereby anyone can see just what the scientists are doing. Again, what more do you want?

KL867
 

I've dug out the NYT article from Dec 89 KL867

This incident happened despite the KL crew knowing there was an ash-cloud in the vicinity, but There's also a mention of the BA and SQ incidents here.

Edited to Add. There is also this comment: That's how it was in 1989, thankfully we no longer leave it up to the individual airlines ...

The fact of the matter is that there is an uncertain amount of risk associated with flying through a volcanic dust cloud. Probably most aircraft would be unaffected, but there is a chance that something would happen in a small number of scenarios.
The two or three well known instances have survived by good airmanship and luck. They could very easily have gone the other way.

So who is willing to take the chance? Is it 1/10,000, is it 1/100,000? What is an "acceptable" level of risk, and who determines that.
Who would take the responsibility if the 1/100,000 chance went wrong?
In this age of litigation at the drop of a hat the legal liability would be horrendous.

No doubt this huge disruption will spur new research into the effects of volcanic dust and the forecasting of danger zones, but in the meantime we have to err on the side of caution.

@ Peter We, thank you.

Over cheshire today , looking directly upwards the blue sky had a dirty grey tinge to it, but looking either side it appeared much bluer - guess its a bit of parallax. and our cars are covered in a fine grey ash.
Frankly I'm glad my husband is not flying.:D
Not so glad to have to return to work this weekend though if it has all cleared away!;)

louby

Volcano ash vs dust up there anyway.
 

I recommend Simonpro's replies. I'm neither an atmospheric scientist, nor an engine engineer, but I think there is definitely cause to worry about flying through a spread-out dust cloud, as well as a BA9/KLM867-style eruption plume.

Any rock-like material will melt onto hot turbine parts, which are some of the hottest and most carefully-shaped surfaces that are engineered. If a random coating of volcanic glass improved jet engine performance, one would have been fitted in the factory. Piston engine/turbocharger surfaces are much cooler, and so I doubt they would suffer.

No rock ash is good, but there is a background level, definitely from meteorites and averaged volcanic emissions, and perhaps from wind-uplifted sediment, with which aircraft engines cope all the time.

Meteorite particles rain down at the rate of a few hundred thousand tons per year, over the whole earth (Access : Space Density of Dust in the Stratosphere : Nature 4838 (1962) p. 269). This gives a hard lower limit to the amount of meltable particles in the stratosphere.

Iceland currently seems to be chucking up a few tons of ash per second into the stratosphere - a rate that is about a thousand times higher than from the meteorites, and concentrated geographically (Satellites Providing Rapid Estimates Of Iceland Volcano Emissions - Science News - redOrbit).

Volcanos that went off during the last few years also contribute to the background level of stratospheric ash. I can't immediately find a number for this, but individual volcanos seem to make a factor <10 difference to lidar measurements of particle density in the stratosphere, so it's probably not hugely greater.

With a few volcanos a year throwing ash up for a few days each, and a couple of years needed for it to rain back down, that would imply something like an average of one-to-ten million tons of volcanic ash in the stratosphere at any time, likely a factor of 10 more than from meteorites, especially at aircraft heights in the lower stratosphere.

A diffuse, drifting cloud of volcanic ash from Iceland does seem to be a real risk. It is reasonable to expect levels of turbine-clogging ash over the UK to be up by a factor of at least a hundred from the background at the moment. Where a safe line can be drawn, I don't know, but Eurocontrol seems to be confident that it's below where we are now.

Let me tell how does it look from airline office:
1. We have no idea how danger it is really. All we know is similar to what Joe Public knows (like BA009 story). We are neither educated nor qualified to quantify the risk in the way like "BA009 was 100 km from volcano and it is ended up badly, so we should be ok if we are at least 200, 400 or 500 km from there".
2. We have spoken to local MET office. Actully they have no clue either. All they know is what you can read on internet. Not a big suprise, given most European countries are active volcano-free.
3. We don't want to get a bad PR from the press, who will say "airline XXX is putting revenue on top of safety and asking a clearance to resume the flights".
4. Neither we want PR like "airline XXX forced pilots to depart VFR and low level to boost the revenues".