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-   -   Ash clouds threaten air traffic (https://www.pprune.org/rumours-news/412103-ash-clouds-threaten-air-traffic.html)

Airclues 18th April 2010 23:25

BeechNut


Has anybody bothered to study the similarities between the eruption of Mt St Helens in 1980 in N.America? Google isn't turning much up on the subject
Although the visible plume was well defined, the ash from Mt St Helens reached the US east coast in three days and spread around the world in fifteen days. There are plenty of referenced to this, such as Keep Your Eye On Mt. St. Helens' Ash, Alaska Science Forum
At the time, maps were available showing the location of the visible plume, and we planned around this area.

In 1991, the ash from Mt Pinatubo extended around the globe, and is often credited with reducing world temperatures. Once again, aircraft were warned of the location of the visible plume, and avoided it. There were some spectacular sunsets that year.

When Mt Redoubt erupted in 1989/90, we continued operating into Anchorage (daylight only), visually avoiding the plume. This often meant a longer route in, due to the closeness of Mt Redoubt to Anchorage.

If there are any engineers who were around at the time then perhaps they could comment as to whether there was any damage to the aircraft during these times.

Perhaps it's time for the engine manufacturers to determine if there is a safe level of ash. Do we know how the present level compares with past eruptions?

Dave

lomapaseo 18th April 2010 23:27

Predicted IFSD rates are not expected to rise because of ash ingestion as it would only be an minute contribution among all the various causes.

Futhermore ETOPS is predicated on independendant en-route failures and not on common cause which affects more than twin engine aircraft.

The safety related effects of ash are developed in minutes and immediately obvious (cabin lights go out etc.). The longer term effects are discernible over many flights as deteoration of performance and addressed by maintainence between flights.

I can't understand why posters are making this doom and gloom stuff up rather than leaving it to operators and OEMs to sort out.

paidworker 18th April 2010 23:29

"A spokesman for KLM said: 'We have not found anything unusual and no irregularities, which indicates the atmosphere is clean and safe to fly.' " That seems very broad.

I spoke to a Parachute Pilot in Ireland today who said that whilst they flew there was a visible layer of ash and also a strong sulphur smell in the air. Its a small operation and they were able to file VFR as it was truely VFR conditions. He said you could see nothing from the ground but once you got up to 9000ft it was very obvious as was the smell. The skydivers reported being able to smell and feel it in freefall.

Im wondering what happens if only a handful of airspaces open up , does it
signifigantly alter the picture. The cost to us in business terms is terrible and soon our own company has no choice but to lay people off as already things were so tight with the non volcano recession.

The logic in the points being made is that Tin may not start falling out of the sky if it encounters ash straight away and this seems plausible but I have a very bad feeling for the economy and aviation sector if for example flights stop and start based on local conditions and wear becomes a factor. I suspect that when flights start a lot more inspection procedures will become the norm increasing costs to pacify a public who have been led to believe that aviation is very dangerous so long as there is " ash " in the air. It is kind of obvious too as there is " dithering " over what is a safe level.

I suspect also a large problem now will be a legal one with insurance companies looking to cover there rear , engine manufacturers looking to cover their rears etc. I hope I am wrong but suspect and fear this is going to get messy with nobody wanting to take responsibility for saying it is " safe ". Meanwhile the non commercial tests being conducted by G- CALM continue to point out that they do not feel its safe.

Somebody posted Continental had suspended all Northern European flights until the end of the month, I cant find that anywhere on their website.

spaceman18 18th April 2010 23:38

TCX have aan A330 coming full of pax from Cancun into Alicante tomorrow.

paidworker 18th April 2010 23:44

South and Central Spain are not closed , never have been to my (local) knowledge.

spaceman18 18th April 2010 23:49

Obviously.

The plane is full of english passengers, which will then be brought back to the UK by land/sea etc.

stagger 18th April 2010 23:51


Originally Posted by lomapaseo (Post 5643829)
Predicted IFSD rates are not expected to rise because of ash ingestion as it would only be an minute contribution among all the various causes.

They may not be expected to rise - but aren't ETOPS certifications based on documented actual IFSD rates achieved by certain operators under standard conditions? It remains to be seen whether rates will change after fleets have spent a week or two operating in the ash environment.


Originally Posted by lomapaseo (Post 5643829)
Futhermore ETOPS is predicated on independendant en-route failures and not on common cause which affects more than twin engine aircraft.

Indeed - but the point I was trying to make was that if operating engines in an ash environment for a period of weeks compromises future reliability - then the probability of two independent en-route failures during future ETOPS is increased.

Let me put it this way - this summer you have an IFSD during ETOPS. How comfortable will you be with the fact that your one remaining engine spent a week or two operating in an ash environment?

Sunfish 19th April 2010 00:00

I am staring at a GE First stage turbine blade as I write this. It has dozens of holes in it that channel cooling air through it. The holes are about .25 mm or less in diameter. They are also angled and profiled.

This blade operates in a gas stream that is around 300C hotter than its melting point.

If the cooling system fails due to clogging with molten ash, damage will be immediate, severe and very very expensive.

Please understand that the airlines are currently between a rock and a hard place until they can satisfy themselves that they can fly without wrecking their very expensive equipment.

They can fly, earn revenue, then bust the equipment and lose revenue as well as suffer repair expense, or they can lose revenue until it is determined that there is no hazard, or that the risk is manageable.

At present no one to my knowledge knows enough to satisfy themselves that the risk is manageable. Failure to manage that risk could involve loss of life or grounding a large chunk of the fleet in the coming weeks/months due to lack of engines.

tcmel 19th April 2010 00:01

New map up
 
http://
http://www.metoffice.gov.uk/aviation...1271634757.png

Looks like all new cloud caps out at FL200....?
Definitely looks "friendlier" than previous forecasts..

AEST 19th April 2010 00:18


I am staring at a GE First stage turbine blade as I write this.
Good to hear from someone that is not a meteorologist or vulcanologist (or politician) on the possible effects. For once some relatively sane observations between the "Don't fly it's risky" and the "To hell with it, let's go" :ok:

My only point so far is that the decision should be left to those best able to make them:
1. Airlines
2. Insurance firms
3. Pilots (w butt at risk)
4. PAX (idem)

Having zee Govt making the calls means vanilla for all, wether you like it or not.:ugh:

bugdriver 19th April 2010 00:19

Well said Sunfish

EGCC4284 19th April 2010 00:19

Watch Air Traffic - LIVE! - We said cash, not ash!

Aeroflot AFL315 is flying from Moscow to JFK via PORTO Portugal right now

Hows that for a re route

Landroger 19th April 2010 00:44

As a very small example of the thought process that is probably now evident in the minds of 'the authorities', the Blackwall Tunnel (A102M) in East London is, I think, instructive.

At one time, a couple of years ago, the two Lanes of traffic through the northbound 'old bore' were supplemented during the morning rush hours by one lane of the southbound 'new bore'. Diverting gates and lane closure lights emphasised local custom and it was a system that worked pretty well, allowing almost half as much traffic again, to flow through the tunnel. Once the peak morning period was over, the lights changed and the southbound bore reverted to two lane for the rest of the day.

For a reason best known to himself, but most Londoners suspect it was part of his agenda to shutdown private traffic in London entirely, Ken Livingstone - the Mayor - suddenly stopped the morning contraflow scheme. It was said that this was 'for safety reasons'. Now most Londoners had been completely unaware of frequent - or indeed any contraflow related accidents. This added 40 minutes to the average transit through the tunnel, making it about an hour and a quarter or more, to travel a couple of miles and cross the river Thames.

When Boris Johnson was elected mayor, he commissioned a review of the Blackwall tunnel situation and found, to no-ones great surprise, that the effects on accidents was negligable, but the effect on congestion was unacceptable. So he ordered that the contraflow scheme be reinstated.

However ........... the HSE said, 'oh wait, if we start the contraflow and there is an accident after all this time not doing it, then it will be our fault. So we cannot agree to opening it.' And there it rests, a perfectly good system for reducing congestion cannot be used because, basically, nobody wants to take the responsibility for saying it can.

As I said, a bit off thread, but you can probably see where I was going with it.

Roger.

Gulfcapt 19th April 2010 00:48

Jetstream forecast
 
Here's a forecast summary for the week coming up. Interestingly, this article states most of the ash is 10000 feet and below. Maybe more ash over UK/Germany midweek but in a narrower band. Southwesterly to kick in late week and take the ash away from Europe.

A respite until the next northwesterly flow sets in?

AccuWeather.com - Weather News | Ash Plume to Shift Farther South through Europe

Best,
Jim

LoboTx 19th April 2010 01:02

Strange
 
"Over in the US, Continental have announced today that they don't expect to resume flights to Europe this month!"
I heard that this afternoon on FoxNews, found it rather odd. What do they think they know that we don't - hiring psychics now ?

"It must be getting serious, the yanks are even covering it on the TV now."
Believe it or not, some of us here in the colonieshave been following it from the get-go, but more as a curiousity of nature. :}

mocoman 19th April 2010 01:05

Landroger...

nail...head...hit...

Good analogy.

RobertS975 19th April 2010 01:34

The entire situation has been receiving quite a bit of attention over here in the States. There are plenty of pax stranded in North America as well.

tcmel 19th April 2010 02:13

new NATS release
 
NO change on restrictions - still 7pm. First time they hadn't extended it....

Conditions around the movement of the layers of the volcanic ash cloud over the UK remain dynamic. NATS is maintaining close dialogue with the Met Office and with the UK's safety regulator, the CAA, in respect of the international civil aviation policy we follow in applying restrictions to use of airspace. We are currently awaiting CAA guidance

lomapaseo 19th April 2010 02:41


At present no one to my knowledge knows enough to satisfy themselves that the risk is manageable. Failure to manage that risk could involve loss of life or grounding a large chunk of the fleet in the coming weeks/months due to lack of engines.
Of course we do, it just takes a little time and data to sort it out to the satisfaction of the operators and the authorities.

The risk managers define the data necessary and the authorities examine the numbers to ensure that they do not appreciably increase risk compared to the normal base risk that is carried in day to day operations. No doubt it may take some extra precautions for the time period that the risk of encounter is raised (operation downstream of an eruption) as well as increased maintainence actions between flights.

Bobbsy 19th April 2010 03:26

Let me start by saying that I'm SLF, not a pilot and I'm also not a geologist. However, I have a friend who IS a geologist and one that specialises in volcanoes. A couple of us asked her about why THIS eruption is causing such a problem and also about the prospects for the future. Her reply might be of interest here:


To answer your question, It ALL depends on the type of magma that is erupting - how viscous it is and how much there is going to be erupted. The volcano /could/ - it has before - erupt for up to two years or more. If the magma is basaltic then yes, pretty much as soon as it runs out of water it will go from phreatoplinian style (phreato indicating the presence of water, plinian being the eruption type - see pic below - it's v. recent) back to the effusive Hawaiian lava fountain type that was happening last month - it's a bit like pouring water on a chip pan fire (which I can tell you from seeing this done in controlled conditions is a /most/ impressive fireball). Samples collected last month and analysed suggested that the lava being erupted was a alkali-olivine basalt, with a silica content
of about 47% (silica being the thing that makes a lava all sticky and gooey and therefore more difficult for gas to escape). So it was all fairly fluid and gas trapped in the lava could easily escape. So far as that goes it would cause relatively few problems once the glacier had melted (10-15% of this has already gone according to my sources.)

However, the ice isn't really a massive problem in the long term especially if the lava IS still the same composition because once the ice has gone the eruption will settle down - locally however it could (and has) caused MASSIVE damage from jokulhlaup (meltwater floods). Roads, infrastructure, and farmlands have all been destroyed but so far there have been no fatalities as people had been evacuated from hazardous areas. Iceland being prepared for these eventualities.

It is currently erupting from a series of vents along a 2 km long north-south oriented fissure, with meltwater flowing down northern slopes of the volcano, but also to the south. The eruption has been fairly steady throughout this phase and will continue to be so for days at the least. Chemical analyses of the ash samples from this phase of the eruption however reveal fluorine rich intermediate eruptive products with silica contents of 58% (a more sticky magma than that erupting earlier) so it has evolved from the initial lava producing phase of the eruptive activity possibly by crystal fractionation in the magma chamber.

The eruption at Eyjafjallajokull is however still going strong with frequent regular cycles of steaming and phreatomagmatic explosions. The Icelandic Met Office is heading up to the volcano to conduct a survey of the crater area to find out (1) what it looks like and (2) how much new water (i.e., ice) is there available for the erupting magma. More water is likely to mean more explosive eruptions in this phreatoplinian style - however, like I mentioned earlier, the bulk andesitic composition of the ash implies it might have a decent ability to produce explosive eruptions without a lot of extra water (but it helps). You can see a great sequence of images from the eruption on this video (although the music might not be the most fitting). It shows the "puffing" nature of the eruption, which might imply periods of melt water getting into the conduit and flashing to steam (very loosely like a geyser behaves). The Icelandic Met Office has excellent information on the ash and the flooding, which has been somewhat forgotten in the news. There has been extensive flooding around the volcano due to the melting ice.

SO FAR there is little or no evidence that Eyjafjallajokull erupting is affecting her big sister Katla (who can cause far bigger eruptions) and is likewise sitting under an ice cap.
Eyjafjallajokull could keep erupting like this for months. It may not. It depends on many factors. We just have to wait and see (and pray Katla doesn't get set off - she is overdue for an eruption)

The weather patterns certainly aren't helping either so it really is a combination of things.
I haven't bothered recreating the links she posted, mainly because they're ones I've already seen in PPRuNe.

However, what seems to come out of this is that the particular combination of Magma erupting under a glacier is why this is creating "the wrong type of ash" and causing the problems we are seeing. My friend's post also explains why it it misleading to assume that, because a previous volcano did or didn't cause problems, there is a precedent in this case. This eruption is a particular combination of circumstances--I quite like the analogy to pouring water on a chip pan fire--and I, for one, am happy to leave the decision about when it is safe to fly to the experts.

Hope this is of use.

Bob

Al Fakhem 19th April 2010 03:35

Total lack of scientific approach
 
The closing down of European air space and airports is a dreadful knee-jerk reaction brought upon us all by politicians. There is no proper collection and processing of scientific data to support the measures.

Are air samples collected from the allegedly contaminated FLs at hourly (or, at least, regular) intervals? Obviously not, or we would have this data being released on an ongoing basis.

The people inflicting this chaos on us are, in fact, flying blind with all instruments turned off. Dreadful, absolutely dreadful.

Sunfish 19th April 2010 04:11

Fakem:


Total lack of scientific approach
The closing down of European air space and airports is a dreadful knee-jerk reaction brought upon us all by politicians. There is no proper collection and processing of scientific data to support the measures.

Are air samples collected from the allegedly contaminated FLs at hourly (or, at least, regular) intervals? Obviously not, or we would have this data being released on an ongoing basis.

The people inflicting this chaos on us are, in fact, flying blind with all instruments turned off. Dreadful, absolutely dreadful.
1. The precautionary principle applies, especially to things that might involve life. The Volcanic Ash is regarded as dangerous to aircraft UNTIL it is proved scientifically that the risk is insignificant NOT the other way around as you suggest.

2. Politicians do not shoot from the hipthey make decisions on the basis of ADVICE they receive from public servants. I would imagine that public servants, mindful of the precautionary principle, asked for scientific advice on the level of risk, and failing receiving a ringing endorsement from the appropriate engineers and scientists for opening the skies, they applied the precautionary principle themselves.

To put it another way:

I know your holiday plans are in tatters. There is nothing anyone can do about it until the evidence is in that indicates it's safe to fly.

cam_snapper 19th April 2010 04:22

Avoid the ash at different FLs?
 
Hi all,

Massively interesting reading your thoughts on all this. Quite a range of opinions, but all well-informed, which makes a nice change from the front pages of the tabloid at least!

My question that I haven't really heard is this: the ash is mostly at quite high altitude, right? Couldn't the airlines therefore simply fly beneath it? I do realise that because of the increased density at lower FLs this would require greater fuel to generate greater thrust to overcome resistance, and would therefore be more expensive... but would it be prohibitive? Would the ATCs be set up to deal with this?

Apologies if this is a stupid question, or well answered elsewhere.

Cheers all.

Pom Pax 19th April 2010 04:22

Eurocrats?
 
Thai announced a sensible solution yesterday extra daily flights to Rome & making Madrid a daily service.
However almost at once had to can the idea.
Quote
"Due to uncontrolled situation change at Rome and Madrid airports, the planned TEMPORARY additional flights have been put on hold until further notice."
Who threw a spanner in the works.?

tocamak 19th April 2010 04:23


There is nothing anyone can do about it until the evidence is in that indicates it's safe to fly.
But unfortunately what will happen is a fudge whereby flying will start without either the cloud dispersing or any scientific evidence to show that the ban was sensible in the first place.

CokeZero 19th April 2010 04:43

Another thought for you....

If you intentionally go flying through this ash cloud on a revenue flight and something happens (major or minor) who is to blame for it?

Answer: The Captain.

The Captain at the end of the day takes fully "legal" responsibility for his aircraft and in a court of law he would be fined/imprisonment/loss of job.

We have no legal protection if we knowingly fly through a known ash cloud cloud. It's not the company that would get fined (hmm they would be liable as well - probably).

Food for thought - Is it worth the risk?

anartificialhorizon 19th April 2010 04:49

50% ban lifted? (whatever that means....)
 
Just reported.

Eurocontrol lifts aviation ban; 50% of flights to resume | The National Business Review - New Zealand - business, markets, finance, politics, property, technology and more

Cacophonix 19th April 2010 05:07


What do you want to compare? The colour? Well, yes.
And maybe the size.
Ultimately it is the composition of the volcanic ash that is of real importance to the question of flying in the presence of ash clouds. To be more specific it is the amount of silica in the ash that might ingested and remelted in an aircraft engine that is of key significance.

The colour of the plume gives some clues to this key question but is of itself not very revealing.

Volcanic Ash, What it can do and how to minimize damage

NOAA Economics of Volcanic Ash & Dust Storm Data and Products | Commerce & Transportation | Extreme Events

tocamak 19th April 2010 05:10


We have no legal protection if we knowingly fly through a known ash cloud cloud
I don't think anyone will suggest knowingly flying through a known ash cloud. If flying is allowed then it will be with the approval of the regulatory bodies acting on advice from whatever source they deem fit. Clearly they are trying to avoid such a scenario as you suggest as they in the first place stopped all the flying.

galaxy flyer 19th April 2010 05:23

Cam Snapper

Actually, at the beginning it was at high levels, but over the first few days, it settled to below FL 350. It further settled to Earth and showed up as dust over England. So, the problem was at lower levels, climb and initial cruise. Final cruise levels for short haul.

GF

Al Fakhem 19th April 2010 05:35

Sunfish: my holiday plans are not affected.

However, if the politicians have - as you suggest - scientifically significant data showing the ash concentration at various FLs across Europe, why do we not know about it?

All else is a knee-jerk reaction to a perceived threat. The correct measure is to ascertain whether the perception is backed up by hard facts. That is not being done anywhere in Europe - except through private initiative.

That air space might be initially closed while we are waiting for results from statistically sound sampling is OK. However, I repeat, there is NO sampling going on that we know about.

luoto 19th April 2010 05:35

The Finnish aviation authority Avia is opening the airports of Tampere-Pirkkala and Turku for a period of six hours today, Monday. In addition, the airspace above Southern Finland was opened from the early hours of Monday.

FlyingVisit 19th April 2010 05:49

The volcano pulsates the ash to different heights. So in answer to your question: no.

Besides, what goes up must come down. Gravity and all that.

Thirdly, planes must keep to a flight path - they don't keep ducking and diving. The ash cloud is irregular.

TiiberiusKirk 19th April 2010 05:49

Ratio Changing
 
Well is seems the the Dollar : Danger ratio is changing.

The airlines seem to be applying pressure in two directions.
Test flights by LH, KLM & BA to show the bureaucrats it's safe.
Presence onboard of BA and KLM chief execs to convince the public it will be safe for them to fly too.

Interesting to see what the US will do when the ash reaches them this evening, will they close down, limit/reroute or just carry on as normal...

noelbaba 19th April 2010 05:50

Ash cloud hits Turkey, Istanbul's airports stay open *updates*
 
tourismandaviation.com

Massive ash clouds from a volcanic eruption in Iceland have reached Turkey, forcing the shutdown of airspace over three provinces in the country's north, the air authority says.

"The volcanic ash clouds have begun affecting the airspace of our country," the Directorate of Civil Aviation Ali Arıduru said in a statement on monday. Airspace at an altitude between 20,000 and 35,000 feet over the Black Sea provinces of Zonguldak, Sinop and Samsun will be closed till noon wenzday, it said.

For the time being the ash will not likely to affect airspace over Istanbul, Turkey's largest city and the hub of its domestic and international air traffic, and it will stay open without restrictions, directorate head Ali Ariduru told Anatolia news agency.

Europe-wide air turmoil caused by the ash cloud has stranded thousands of foreign tourists in Turkey, a major holiday destination for Europeans, and thousands more have been unable to arrive for scheduled vacations.

On the country's Mediterranean coast, hotels offered extended stays for stranded holiday-makers, with hoteliers, tour operators and airlines jointly picking up the tab, Sururi Corabatir, head of the Mediterranean Hoteliers Union, said in remarks published on Saturday.

Hotels in Istanbul struggled to meet the increased demand for rooms, media reports said, adding that unused compounds at the city's main airport were opened to stranded passengers who were given also blankets and food.

aeroDellboy 19th April 2010 06:14


Thai announced a sensible solution yesterday extra daily flights to Rome & making Madrid a daily service.
However almost at once had to can the idea.
Quote
"Due to uncontrolled situation change at Rome and Madrid airports, the planned TEMPORARY additional flights have been put on hold until further notice."
Who threw a spanner in the works.?
I think the problem is that Rome and Madrid can't cope with more people, I know someone stuck in Rome who has accommodation until Wednesday, then no guarantees. Until the UK Government announce measures to get people out, then it is pointless bringing more people into areas where they can't get out of.

dirtyrat 19th April 2010 06:27

Ash forecast change
 
Do I notice that the forecast for the ash area from a couple of days ago covered a much much larger area of Europe than the actual ash map now issued 1 hour ago.

After airlines are calling for the ban to be lifted, I wonder if the economic implications of closed airspace has 'shrunk' the ash cloud?

Maybe I've over analysed it.;)

Superpilot 19th April 2010 06:30

If flights do not resume right now (and yes there will be the inevitible long term damage to some aircraft engines) and this continues for the next month, Western society as we know it and a lot of the third world which depends on it is going down the pan. What's worse? Having a few lost engines or saving the livlihoods of millions. Difficult question as usual, needs someone with more than just an interest in aviation safety to answer.

helldog 19th April 2010 06:37

Yeah. Al Fakhem is right. Once the call to shut all airspace came more should have been done. I would have thought the country's brightest minds would be mobilised. I would expect scientists out with hand vacs colecting settled ash. RAF Tornados up testing the air. I would have expected met balloons going up like a swarm of bees. So far...... A dornier 228 buzzing around and the initiative of a couple of airline bosses.

brooksjg 19th April 2010 06:41

...or maybe the Knee-jerk reflexes have finally exhausted themselves?
...or maybe enough real data has been collected to give the 'authorities' sufficient confidence to offer risk-based advice rahter than 'CYA and let someone else make the first move' stuff seen so far.

Still don't see much more CONCERTED ACTION to collect more data about the EXTENT and PARTICLE DENSITIES of the ash cloud. This was mentioned several times yesterday. Point to point flights by single aircraft are (usually) more to do with PR than serious scientific data collection. At least UK sems to have had TWO science-based flights - 'Swindon-based' NERC plane (flying from ??) and Cranfield. We should have AT LEAST five aircraft, doing several flights a day EACH on different tracks with different planned ash exposure, if there was any proper programme to collect data about the changing position and height of various components of the ash cloud AND the longer-term effect on turbines.


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