Volcanic ash from Eyjafjallajokull

[alisoncc]

Interesting report on an analysis of the volcanic ash emitted by Eyjafjallajokull which closed European airspace. Work undertaken by an Icelandic-Danish team.

BBC News - Volcanic ash air shutdown the 'right' decision (http://www.bbc.co.uk/news/science-environment-13161056)

Looks scientific enough to warrant acceptance. The link to the PNAS paper is of particular interest.

Characterization of Eyjafjallajökull volcanic ash particles and a protocol for rapid risk assessment (http://www.pnas.org/content/early/2011/04/22/1015053108)

On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing them to fail. Therefore, air traffic was grounded for several days.

[lomapaseo]

Looks scientific enough to warrant acceptance. The link to the PNAS paper is of particular interest.



I'm not sure that I understand to what you refer:confused:

Your links point at two articles.

The first one is a BBC summary and the part which attributes a safety assessment to a researcher is suspect. The findings themselves are accepted as factual.

The second link only seems to point to an abstract and to read further they want money.

There are two parts of this in aviation

the characterization vs time of the particulates (nice job here)

and

the management of penetration into volcanic ash by consideration of aiways, and density of particulates (poor job here)

I'll watch for a report on the later issue

[no sig]

Scientific study report published with link to PNAS...

BBC News - Volcanic ash air shutdown the 'right' decision (http://www.bbc.co.uk/news/science-environment-13161056)

Characterization of Eyjafjallajökull volcanic ash particles and a protocol for rapid risk assessment (http://www.pnas.org/content/early/2011/04/22/1015053108)

[Dani]

I'm not able to read the full scientific report, but from the abstract I read it has nothing new in it. We all know that ashes are dangerous to aviation. The question is - from which distance and in what concentration. Articles circling the world now speak of "justified closure of European airspaces", which is complete nonsense. Most of European airspace was nearly particle free and absolutely safe for aviation (let alone for breathing).

More to come...

Dani

[peter we]

Most of European airspace was nearly particle free and absolutely safe for aviation (let alone for breathing).

As the aviation industry was unable to say where it was safe and the particles were as bad as expected then its seem quite correct that the airspace was closed. Monitoring equipment is now being tested on Easyjet aircraft - so it was obviously possible before.

[Herman the Navigator]

Dani/Lomapaseo

I couldn't agree more - the whole thing hinges on the concentration/density (call it what you will) of the ash.

Saying that a report "looks scientific enough to be accepted" is either hopelessly naive or a blatant fishing mission...

I have no vested interest in all of this, but from what I've read and heard from Professor Stipp of Copenhagen University I'm quite concerned that "looking scientific enough to be accepted" was exactly the hoped for result (with new research funding to follow)... The reasons given for the importance of the research are a direct rehash of RAeS and other reports pointing out the general problems of volcanic ash (sandblasting, melting and solidifying within the engine, etc.). All of that is well known and largely irrelevant to the concentrations found in the vast majority of the closed area. Neither the Finnish F18 nor the UK Typhoon reported abrasive damage (hardly surprising) and the deposits found in the engine (because someone went looking for them) didn't lead to engine handling problems (as far as I have read)... To infer that airspace closure was justified because there was ash in the air and it has previously caused problems is the only input to the press' hype that the report has to offer (and this is unscientific speculation with no visible analysis). The question of why no one knew what safe concentrations were is conveniently sidelined by all the discussion of a report which does nothing to address this central issue.

Incidentally, the report has been produced by a team of chemists with no discernable prior knowledge of aircraft operations, atmospheric physics, meteorology,.......

What would be far more interesting would be to hear if the particle sizes which this report has undoubtedly described have any effect on the dispersion models used i.e. does the highly accurate knowledge of particle size change the predicted ash distributions/concentrations? If this was combined with well reasoned, scientific numbers for acceptable concentrations we would have a real result...

[peter we]

The question of why no one knew what safe concentrations were is conveniently sidelined by all the discussion of a report which does nothing to address this central issue.

Indeed, why did the industry fail to plan for this, given it was so widely predicted and expected and a legal requirement. You will notice that non of the company officials affected have been sued which is remarkable given their failure.

[infrequentflyer789]

Indeed, why did the industry fail to plan for this, given it was so widely predicted and expected and a legal requirement. You will notice that non of the company officials affected have been sued which is remarkable given their failure.

Surely any plan to continue airline operations through closed airspace (for whatever reason - eg 9/11 US airspace shutdown) would be illegal and threfore somewhat unwise to put on record.

Any explicit plans to lobby / pressure / bribe poliiticians to lift flight bans is probably in the same category.


Contingency planning for the displaced passengers appeared to work exactly as you'd expect, making allowance for the unprecedented number of flights affected and area of airspace closed (which seemed to be more, and for longer, than any previous volcano elsewher in the world - but that's just my impression, I don't have hard data)



Tour operators fully reponsible for accomodation and transport of pax did so where overland was feasible (in my exp) - there were huge convoys of coaches doing 1000s of miles across various bits of europe, within 48hrs (I was in one of them). Cruise ships were also chartered I recall.
Airlines that usually plan to live up to thier obligations to look after pax in the event of cancellation mostly did so through normal plans - but with efficency impacted again by the unprecedented number of flights affected
The airlines that normally plan to do as little as they can possibly get away with also seemed to follow plan (refund 99p fare and leave the pax to arrange their own way back)

[Herman the Navigator]

Quote:
Indeed, why did the industry fail to plan for this, given it was so widely predicted and expected and a legal requirement. You will notice that non of the company officials affected have been sued which is remarkable given their failure.

I was thinking much more of the aviation authorities, who I understand set policy, guidelines and rules that the airlines should follow. I'm completely unsurprised that the airlines were incredulous when the safe limit was set as zero. Let's not forget that airspace was closed all the way to the Ukraine at one point!!!

As I understand it, it was some rather ballsy decisions by the likes of Willy Walsh that broke the outrageous deadlock...

[peter we]

I was thinking much more of the aviation authorities, who I understand set policy, guidelines and rules that the airlines should follow. I'm completely unsurprised that the airlines were incredulous when the safe limit was set as zero

The standard was set by the industry and merely applied by the government bodies.

Surely any plan to continue airline operations through closed airspace (for whatever reason - eg 9/11 US airspace shutdown) would be illegal and threfore somewhat unwise to put on record.

Any explicit plans to lobby / pressure / bribe poliiticians to lift flight bans is probably in the same category.


Its the industry problem to deal with, not politicians, the world can survive without airlines for a few months, they can go bust and new ones setup. Its the airline managements responsibility to see their business is not affected, not government.

The area closed and the impact on travel would have been well know, they were doing drills for this event. When they did the BIA the financial impact would have come up in red to any airline who were doing their duty. You would expect a better response than hoping it won't happen, something along the lines of what is now happening, putting sensors on commercial aircraft that can scan up to 150km away and determine the risk precisely. A few million here and there would have saved ten times the amount - if they had done it in advance.

[sensor_validation]

Strange the BBC doesn't link to the learned report last year which was covered by BBC radio at least, and is free to download!

IMechE's latest report is 'Volcanic Ash: To fly or not to fly?' | Institution of Mechanical Engineers (http://www.imeche.org/news/archives/10-11-03/IMechE_s_latest_report_is_Volcanic_Ash_To_fly_or_not_to_fly. aspx)

apologies if posted before...

[lomapaseo]

The standard was set by the industry and merely applied by the government bodies.



Not true.

The industry simply tells the government what is known and unknown. Left to its own the industry could have developed a more reasonable balance between the two to continue operations without substantially raising the risk of a catstrophic event.

[Herman the Navigator]

Thank you! This is by far the best technical critique I've seen - and, no, I hadn't seen it before.

Interesting to note that the density difference between known flameout conditions and the final (twice revised) safety limit is a factor of 500. The level of overreaction was abundantly clear from the ash charts at the time. As soon as a non-zero limit was introduced the dangerous area shrank from effectively the whole of Europe to a couple of hundred miles downwind of the volcano.

And the aviation authorities are not the same as politicians. The airlines (from a financial POV) maybe should have been more aware of the chaos that poor rule-making would entail - but airlines do not and should not regulate themselves

[KBPsen]

Not true.
As far as I know the industry had been asked to provide input to develop more realistic limits. Apparently airlines declined to even respond to the request and manufacturers, as their customers appeared to have no interest, maintained the zero tolerance policy. So did the regulators.

It seems airlines played the game of passing the buck and regulators and manufacturers saying fine have it your way. Until the ash hit the fan and the airlines were all caught out by their own dithering. And of course blamed the regulators.

[lomapaseo]

KBPsen

As far as I know the industry had been asked to provide input to develop more realistic limits. Apparently airlines declined to even respond to the request and manufacturers, as their customers appeared to have no interest, maintained the zero tolerance policy. So did the regulators.

It seems airlines played the game of passing the buck and regulators and manufacturers saying fine have it your way. Until the ash hit the fan and the airlines were all caught out by their own dithering. And of course blamed the regulators.

a fair summary :=

If you want expert opinion than you have to remove the threat of liability. This routinely is the case where the industry acts within the existing regulations. If you ask somebody with deep pockets to work outside the regulation you get what you pay for.

I'm not sure how far or deep the questions went within the industry, but the manufacturers were certainly asked to shoulder increased risk with little to gain.

I do agree that the operators were the losers in this, but hopefully they will develop a quicker response next time now that they know that the regulators and the manufacturers are not about to accept monetary risk for the way someone operates.