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Ash clouds threaten air traffic

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Ash clouds threaten air traffic

Old 21st Apr 2010, 02:44
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Hi,

Reducing the threat to aviation from airborne volcanic ash

From belgian newspaper "Libre Belgique" (20/04/2010)

It is beautiful, the birds sing. The quiet fills the skies above Europe hardly touched by the hubbub of this world: the planes can fly? The answers vary with particular airlines, testing support, requesting the reopening of the skies they get little by little.

But the debate rages about many unknowns. "States are working to get quantitative and qualitative observations about pollution and determine a degree of dangerousness is acceptable, says Mr Peter calmly Ghyoot Secretary General of the Belgian Cockpit Association. It is extremely difficult to determine because at the global level today, when there is presence of volcanic dust, air traffic is banned: it is the rule. In fact, there are no standards on the number of grams of ash per m3 air. It does not exist. And even if we knew a number concentrations in the air, it changes all the time. "

Alain Bernard, he rejoices in good volcanologist from the Free University of Brussels, to see the volcanic particles reach our region, is not optimistic: "The rules or criteria to tell the airlines," you can fly because the organic particles are below a certain threshold, it does not. It quoted figures, but we could not verify. Aeronautics grumbles because the aircraft can not fly, but at the same time, we never really tested what degree of problem with a dilute cloud of ash. There was absolutely no objective criteria to say "Here, the concentrations are such a level and you can fly. "There are research aircraft that made the tests, but nothing can make, because we did not test the tolerance of prolonged engine aircraft vis-à-vis volcanic ash. "

For his part, Gerald Ernst, a volcanologist at the University of Ghent, enraged. There are about ten years, he had already warned against this kind of phenomenon and its impact on air traffic. Specialist physical dispersion of explosive eruptions and volcanic ash, he helped set up an alert system in Iceland, but his research, like that of his colleagues, suffered a setback due to lack of resources and interest. He points the finger when the unpreparedness about this event: "We did not models that take into account the reality of the eruption. This model has been developed for the Chernobyl disaster and it does not consider the dynamics characteristic of the explosion. An eruption is not Chernobyl and the cloud is not dispersed passively by wind. And there is another aspect not taken into account: it's like a rash happens near a glacier, he yal'interaction between lava and ice, and it explodes. Very fine particles then form aggregates, pellets of ash and ice. These flakes falling so quickly. A good Part of gases and ash are discharged early, causing damage mainly in Iceland. But the problem is that the ice clouds the satellite and it causes uncertainty about the amount of aggregate, gas and ash that contains cloud "

And Gerald Ernst to suggest a quack occurred ten years ago with the current forecasting system: "In 2000, there was an explosion in Iceland. A cloud moved over the north. A research aircraft from NASA to then walked around 1 800 km north. According to the simulation made at the time, it should not be a cloud of ash. They are still spent in the middle and it cost four to five billion dollars repair the aircraft. It shows that the model was not developed and they use the same model today. There should have been laboratory experiments to calibrate the instruments. It has not been done: no funding. "

No doubt the magnitude of the economic mess will soon present standards and research on the subject.

Last edited by jcjeant; 21st Apr 2010 at 03:06.
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Old 21st Apr 2010, 02:45
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Speaking as a pure amateur

I think the debate has polarized around caution vs poor interpretation of the information. However please bear with me. I fly more than 250K miles both as a revenue and non-rev passenger each year.

I think there is a clear case here for one thing - MORE RESEARCH. My argument is that judging from the data from D-CMET the concentrations of ash vary widely even at the predicted levels. Therefore it would be safe to conclude that the mathematical models combined with met info are not sufficient to make cast iron decisions. Reading through this thread the vast majority of people agree. Neither do I think the decisions left to the Pilots alone is a safe decision - they are not being provided with enough tools to make the "right" decision. Despite a significant amount of data that points to the damage that can be done, the impact of lesser concentrations of ash remain hard to comprehend. The hard data tends to deal with the catastrophic type situations (BA009, NASA's DC8 and the F/A18s).

We also know that we are dealing with the shades of grey. Personally I would feel a lot better if there were better ways to continue to measure the particulate concentration at the different flight levels, with the goal of creating/establishing some safe corridors and flight profiles on a real time basis. We have seen from the Germans that these concentrations of ash are not consistent at particular flight levels therefore to continue flying constant flight levels may be (I stress maybe) creating opportunities for ash encounters. However I don't see that the type of different flight profiles flown by D-CMET other than the one time event are being encouraged. This to me is where the authorities who have the resources should be deploying aircraft equipped with the type of equipment on D-CALM and D-CMET that can measure the particulate.

If for no other reason than this is a unique opportunity to create a lab to examine the situation for future occurrences - we should be encouraging science to get involved in this situation.

With that said - may I just hope that we can get a degree of qualification rather than conjecture into this process. My one nagging fear is that we are creating a situation of reducing life of an aircraft's engines that will result in premature failure - long after the equipment has lived its primary life in a well cared for home and gone to that lesser grade second cousin three times removed that you don't want to acknowledge and the EC occasionally blacklists.

Cheers
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Old 21st Apr 2010, 02:59
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I just want to say as an ATCO..respect to those pilots who have flown today...basically through the unknown....no matter what all the 'experts' say...nobody knows what could happen and still you went to work! Have to say even on the ground it felt a bit strange.... esp giving pilots VFR clearance and then IFR passing fl200...later Fl250 (in Germany)....so respect and well done!! Not sure I would have been so brave!!
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Old 21st Apr 2010, 03:23
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I just want to say as an ATCO..respect to those pilots who have flown today...basically through the unknown....no matter what all the 'experts' say...nobody knows what could happen and still you went to work! Have to say even on the ground it felt a bit strange.... esp giving pilots VFR clearance and then IFR passing fl200...later Fl250 (in Germany)....so respect and well done!! Not sure I would have been so brave!!
The pilots operate with at least some knowledge of the risks involved. The same is not true for any passengers they carry, who simply trust pilots and the airline operator to maintain the highest level of safety. And unfortunately, as long as there is ash in the air, the usual highest level of safety is not being maintained, although the revenue stream of airlines is being maintained. Recent events have shown that there is no danger that cannot be ignored if there's enough money at stake.

Fortunately nature has cooperated slightly and the ash concentrations seem to be diminishing. Hopefully nobody will be killed by airline greed on this pass, but only time will tell.
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Old 21st Apr 2010, 04:19
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And unfortunately, as long as there is ash in the air, the usual highest level of safety is not being maintained, although the revenue stream of airlines is being maintained.
Well, you can also say that the highest level of safety is not being maintained as long as there are planes in the air.

Apart from safety and the revenue stream, the needs of passengers are important too. Thousands of pax are having their business and vacations ruined, and lifetime wasted.

Let's see, a life expectancy of 80 years means 30000 days. If a pax gets delayed by 3 days, he has lost 1/10000th of his lifetime. Sure, some will enjoy the unplanned extra vacation, but I am pretty sure that for the majority of passengers, this is wasted time coupled with extra expenses which will make their life worse in the future. So for every 10000 delayed passengers, one life is practically lost by such a delay (and we are not even talking about actual health damage due to stress, lack of medication etc.).

If flying through ash means bringing pax to their destinations 3 days earlier, it pays off even if one plane in 10000 crashes because of a higher danger level.
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Old 21st Apr 2010, 04:28
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Well, you can also say that the highest level of safety is not being maintained as long as there are planes in the air.
But there's a difference here: the general risks of aviation are well understood and quantified, whereas the risks of volcanic ash are not. It's clear that volcanic ash is a bad thing, but the maximum allowable ash concentration for a given level of safety is unknown. In aviation, if you don't know, you don't go, which is what has made air travel so safe. In this case, that general guideline is being ignored, for the sake of money.

If flying through ash means bringing pax to their destinations 3 days earlier, it pays off even if one plane in 10000 crashes because of a higher danger level.
You realize that one in ten thousand means a dozen or so crashes per week, with more than a thousand people dead, right?
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Old 21st Apr 2010, 04:48
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In aviation, if you don't know, you don't go, which is what has made air travel so safe.
I disagree, that has never been the approach in aviation. What has been the approach is a graduated approach to risk, not a risk free environment. It is abundantly clear that the ash cloud is not having the expected effect on high-bypass ratio turbofan engines. If you want sound data on what is an acceptable level of ash and what it's long term effects are you will not get them from mathematical modelling, you will only get them from empirical evidence, and that means going out there and flying. The airframe and engine manufacturers can only gather so much information and experience from predictions and test flying. The rest does, and has to, come from airlines flying and reporting back their findings. It has always been the way, and it will always be the way, simply because an exhaustive program of testing by manufacturers whould be prohibitively lengthy.
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Old 21st Apr 2010, 05:53
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@Seat 32F

Also, the normal rules for safety for dealing with engine failures are designed around the assumption that most engine failure scenarios are independent - designers go to great efforts to make the two (or more) engines on a multiengine plane as independent from each other as they can. And operational and maintenance procedures exist to try to eliminate any remaining "common causes" (things like dont change two at the same time, in case the same maintenance error affects both, and so on).

Now, if a plane fly through a dangerous level of ash, that condition applies to all engines, and all may fail (or be affected) equally. So the aircraft may not have the option for a flight at a lower altitude; it may become a rather large, and not very efficient, glider. Which is not a good outcome, from a continuation of flight perspective.
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Old 21st Apr 2010, 06:00
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Hello JetII

Last edited by Nemrytter; 30th Oct 2017 at 16:15.
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Old 21st Apr 2010, 06:02
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Hi,

Hand Solo

you will only get them from empirical evidence, and that means going out there and flying. The airframe and engine manufacturers can only gather so much information and experience from predictions and test flying
Test flying .. with passengers ?
Methink actually with your theory .. passengers are "beta testers" and so must be paid instead paying for fly
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Old 21st Apr 2010, 07:18
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I think you misunderstand. Test flying is done by the manufacturers, without passengers. The vast majority of their in-service data comes from the airlines. The manufacturers simply do not have the time to put a million hours on an engine before making a decision.
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Old 21st Apr 2010, 07:19
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Latest CAA press release is interesting, and worth the read.

The Civil Aviation Authority (CAA), the UK’s independent specialist regulator with oversight of aviation safety, today issues new guidance on the use of airspace. This is issued in conjunction with the Irish Aviation Authority (IAA) and covers the Anglo Irish Functional Airspace Block (FAB).

The new guidance allows a phased reintroduction from 2200 tonight of much of the airspace which is currently closed due to the volcanic ash plume over the UK. There will continue to be some ‘no fly zones’ where concentrations of ash are at levels unsafe for flights to take place, but very much smaller than the present restrictions. Furthermore, the Met Office advise that the ‘no fly zones’ do not currently cover the UK.

“Making sure that air travellers can fly safely is the CAA’s overriding priority.

“The CAA has drawn together many of the world’s top aviation engineers and experts to find a way to tackle this immense challenge, unknown in the UK and Europe in living memory. Current international procedures recommend avoiding volcano ash at all times. In this case owing to the magnitude of the ash cloud, its position over Europe and the static weather conditions most of the EU airspace had to close and aircraft could not be physically routed around the problem area as there was no space to do so. We had to ensure, in a situation without precedent, that decisions made were based on a thorough gathering of data and analysis by experts. This evidence based approach helped to validate a new standard that is now being adopted across Europe.

“The major barrier to resuming flight has been understanding tolerance levels of aircraft to ash. Manufacturers have now agreed increased tolerance levels in low ash density areas.”

Our way forward is based on international data and evidence from previous volcanic ash incidents, new data collected from test flights and additional analysis from manufacturers over the past few days. It is a conservative model allowing a significant buffer on top of the level the experts feel may pose a risk.

In addition, the CAA’s Revised Airspace Guidance requires airlines to:
· conduct their own risk assessment and develop operational procedures to address any remaining risks;
· put in place an intensive maintenance ash damage inspection before and after each flight; and
· report any ash related incidents to a reporting scheme run by the CAA.

The CAA will also continue to monitor the situation with tests both in the air and on the ground.
Link to the article:
CAA Press Release
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Old 21st Apr 2010, 07:33
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In addition, the CAA’s Revised Airspace Guidance requires airlines to:
· conduct their own risk assessment and develop operational procedures to address any remaining risks;
· put in place an intensive maintenance ash damage inspection before and after each flight; and
· report any ash related incidents to a reporting scheme run by the CAA.
Basically, fly at your own risk - if you think its safe, go ahead.

We will have the answer to the question of the economic cut off point of flying through dust. Using real aircraft and real passengers.. I wonder how many passengers are going to voluntarily take part once the desperate have been repatriated.
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Old 21st Apr 2010, 07:36
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CAA & Research

So the CAA seems to agree that more research is needed! It, and the other regulators worldwide are only about 28 years too late to have avoided massive cost and inconvenience to Britain and the rest of Europe.

At post No 1970, before anyone "reopened" our airspace I wrote -

"Far more important than what is happening at the moment is what WILL happen in the coming months. The industry must undertake detailed research to find out what its equipment will "tolerate", while national and international authorities MUST put in place systems to ensure that any computer models of future events can be checked in detail by actual sampling to ensure that a vital industry is operated on the basis of knowledge rather than computer guesstimation.

Had such work been done on a regular basis since 1982, we would have 28 years worth of useful information instead of very little."

I wonder when they will start or have they? That's where the industry has to put the pressure now.

Given that the CAA is one of the few, if not the only "safety regulator" tasked by Government with making a profit - yes, 6% on turnover - surely it should be putting in place a PROPER system, and b****y fast, not least because the next door volcano could go off at any minute!
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Old 21st Apr 2010, 07:46
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"Thomas Cook TCX952P registration G-JMCF (Boeing 757-28A) just made a u-turn to Manchester, it was out over the North Sea off Nofolk/Suffolk, it reported to London and Manchester Control it had an engine bleed problem after an 'intense smell of volcanic ash in the cabin during the climb between FL160 and FL200."

More details at:
http://www.airnavsystems.com/forum/index.php?topic=4703.540


Just noticed this! True or just ?
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Old 21st Apr 2010, 07:47
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The new guidance allows a phased reintroduction from 2200 tonight of much of the airspace which is currently closed due to the volcanic ash plume over the UK. There will continue to be some ‘no fly zones’ where concentrations of ash are at levels unsafe for flights to take place, but very much smaller than the present restrictions. Furthermore, the Met Office advise that the ‘no fly zones’ do not currently cover the UK.
ReHeat

But that is the real question we can all see the billowing solid black clouds at the point of the eruption and no one would want to touch that.

But 2 Km, 20 km, 200km, 2000 km ??? downwind? at what point downwind does dispersion make a serious threat to life and limb become minimal to no threat?

Pace
I'll assume that you've not read anything on here at all as to the effect of silica in the engines of the Finnish F18s, NASA's DC8 in an earlier eruption, the air samples taken by Cranfield, the muck picked up by the Scottish heli crew, and the new evidence that World Airways picked up engine deposits on a short hop to Maastricht today...?

Reheat
Obviously The CAA have not either?

Pace
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Old 21st Apr 2010, 07:48
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Indeed I-FORD. So, are all those who were in favour of grounding aviation till the last ppm of ash was out of the sky refusing to fly today?
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Old 21st Apr 2010, 07:49
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flying has always had an eleement of risk. and the person who has the final say is the captain.

what I would like someone to do is use some, yet to be made, gadget to tell the pilot about the healthiness of the air being sucked into the engine. sensing the particulate matter and displaying in EZ to understand terms/images if one should continue or turn around.

a parakeet in the coal mine for jet engines.
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Old 21st Apr 2010, 07:50
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Let's rename the CAA Pontius Pilate shall we? They (and the Irish authorities) can have this year's Buck Passing award.

A I
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Old 21st Apr 2010, 08:14
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Ella:
I am more than happy to take to the skies with passengers on board, and would have done so from day one
So you actually knew from day one that there was no risk. On what was this based.
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