As a follow up to our 4/19 story about ash cloud modeling:
Ash cloud models – overrated? A word on Post Normal Science by Dr. Jerome Ravetz
I offer below a compendium of articles from Benny’ Pieser’s CCNET and GWPF of the UK
Above:
The Met Office has been blamed for triggering the “unnecessary” six-day closure of British airspace which has cost airlines, passengers and the economy more than £1.5 billion.–The Telegraph 19 April, 2010
…
Global airlines have lost about $1.7bn of revenue as a result of the disruptions caused by the Icelandic volcanic eruption, a body has said. Giovanni Bisignani, chief executive of IATA, criticised governments for the haste with which they closed airspace, and called on them to provide compensation to the airlines. “Airspace was being closed based on theoretical models, not on facts. Test flights by our members showed that the models were wrong.” —BBC, 21 April 2010
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We are becoming a risk-averse society and that is dangerous. You cannot run a national economy on the precautionary principle; indeed, the sound position is to embrace as much risk as possible. Societies that embrace risk, such as the United States and recently the UK, tend to thrive, while those that seek to minimise risk, such as Britain during the 1970s, tend to wither. Financial capital is now fleeing Britain, heading to the Far East. A long queue of companies is chasing the money, including our own Prudential, which is floating a business on the Chinese stock market. The true venturers are over there, not in Britain. —The Times, 21 April 2010
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Rational decisions have to be taken on the basis of some empirical understanding of the risks involved, and on the balance between risk and reward (or the cost of avoiding risk). Exposing the nonsense and muddle of the so-called precautionary principle is an essential part of the GWPF’s declared mission ‘to bring reason, integrity and balance to a climate debate that has become seriously unbalanced, irrationally alarmist, and all too often depressingly intolerant’. If the argument now raging over the policy response to the volcanic ash clouds assists in achieving this, it will demonstrate that ash clouds, too, have a silver lining. —The Global Warming Policy Foundation, 20 April 2010
Keith Minto (20:02:40) :
You provided a link to the professional bed-wetters at Volvo explaining why jet engines can’t fly through ash clouds.
Empirical evidence that says otherwise was provided at UK John (12:30:39), more than 7 hours before you posted, referring to practical experience of aircraft ops during the Mt St Helens eruption.
Does NOBODY read what’s been posted to the thread already?
Consider also that sulphur simply may not be that big a problem because the engines are constantly exposed to sulphur anyway; the jet fuel contains up to 3000 ppm(m) of it.
http://www.easa.europa.eu/ws_prod/r/doc/research/EASA_SULPHUR_Project_11-01-2010.pdf
Bernd Felche (21:28:41)
My summary of a Professional Pilots web site that I use is that, yes, there is controversy and as I said before, if visual flight rules are enabled and volcanic ash is not visible to the eye, then the aircraft will fly but damage will accumulate in the engines and sensors and shorten their life. This reduced operational life of an aircraft will vary with the ash intensity and flight duration. So each aircraft will differ in its operational life and who will determine that damage on that craft?. Will each aircraft be stripped down to check for damage? of course not, only the scheduled maintenance period check will apply.
Would you like to roll the dice with an aircraft effected like this on your next flight?
One pilot expressed his frustration well ……
The problem is real. Yes, I know volcanoes erupt all over the world. I know that there are sand storms in the Desert and dust in the air. I know intrepid pilots fly around erupting volcanoes. I know that some European airports remained open. The problem however is that this particular dust from this particular volcano thanks to this particular weather system stuck itself in large quantities over Britain, and it has the capacity to bugger up very expensive jet engines that are not quickly replaceable by the manufacturers. I know you paid your Twenty quid to get to Paris, but I am not going to risk wrecking Ten million dollars worth of engines to get you there today.
The “real world” runs off all kinds of computer models. Whatever electronic device you are reading this on was designed using computer models.
Closing airspace was a prudent decision in a day and age where we are virtually strip searched on flights to the US in the 1 in a hunderd million chance somebody will bring onboard something which could blow up the airplane, and be competent enough to do it.
I expect airlines to have insurance for stuff like this. If not, it is the same stupidity which led them to not have decent locks on cockpit doors.
Anyone suggesting we should trust in the airlines for safety has been asleep for the past 10 years. I suspect though that left to it’s own devices even they would have suspended travel. They are just looking for a handout, and the gullible public may even swallow it.
Bernd Felsche (21:28:41) :
Keith Minto (20:02:40) :
You provided a link to the professional bed-wetters at Volvo explaining why jet engines can’t fly through ash clouds.
Empirical evidence that says otherwise was provided at UK John (12:30:39), more than 7 hours before you posted, referring to practical experience of aircraft ops during the Mt St Helens eruption.
Does NOBODY read what’s been posted to the thread already?
Apparently you don’t if you think jet engines can operate in ash clouds.
At Mt St Helens a 727 and a DC-8 encountered ash clouds, both airplanes experienced damage to their windshields and other systems, but both managed to land safely. A BA 747 over Indonesia encountered ash at 36,000′ and lost all engines, it was able to relight 3 of the engines at ~12,000′ after a fairly rapid descent. It was able to land at Jakarta with no visibility through the windshield, no landing lights and a malfunctioning pitot static system! All the engines were replaced plus the fuel tanks and other systems. Shortly thereafter a Singapore Airlines 747 lost its engines at altitude and ended up landing with two engines. A 747 lost all engines due to a Mt Redoubt eruption with similar results, they managed to restart the engines with one minute to spare!
The airline with the most experience of volcano ash is Alaska Airlines, as a result of their experience their planes never take off, fly or land in ash. If Alaska Airlines can’t stay at least 35 miles away from ash, it doesn’t fly. And if it’s nighttime and pilots can’t see or if the airline isn’t sure of the actual winds aloft, it won’t operate.
ok so there was ash. then, where did it go? the airspace here (switzerland) was closed but no has whatsoever has deposited on the ground. none. and even a tiny amount of dust shows very well when it concentrates on a flat surface.
the ash concentration was grossly overestimated and the reaction was nonsensical.
simply, aeronautic regulators, which are the worst type of bureaucracies, cannot stand the thought of heavy pieces of metal suspended in the sky. these things are a constant threat to their career and must be grounded as much as possible. a continuous attempt, through stricter and costier regulations, is under way to eliminate this liability. ash cloud was just another excuse to accelerate the process.
the final goal is to reach the objective of zero risk in aviation, which can be achieved only with zero flying.
airlines are the ones who have everything to lose, and have the instruments and competence to deal with things like vulcanic eruption. no airline wants to ruin massively expensive engines, let alone lose aircrafts, passengers and crews. in italy airspace was closed even for piston driven light aviation, which is ridicolous and shows that the problem is not the risk of flight, but the lazy, useless auronautic agencies bureaucrats, bent on reaching retirement age with the least amount of work and responsibility.
Mark C (11:34:25) : 1) Operationally useful ash observations amount to diddly squat. Lack of a signature on satellite is not evidence of absence. Damaging ash concentrations are entirely possible at levels well below what can be seen on satellite.
The ICAO manual for dealing with volcanic ash is on the internet. It states:
“Moreover, the first two or three days following an explosive eruption are especially critical because high concentrations of ash comprising particles up to ~10 μm diameter could be encountered at cruise levels some considerable distance from the volcano. Beyond three days, it is assumed that if the ash is still visible by eye or from satellite data, it still presents a hazard to aircraft.”
Therefore if it is not visible by eye or on satellite the ICAO recommendations are that it is not a danger. And they should know. They wrote the manual. The ash cloud was visible over the North of Scotland. That should have been the only part of British airspace which aircraft were dissuaded from using.
UK airspace was closed without good reason. European airspace was closed without good reason. Britain’s best equipped aircraft for detecting these things (BAe-146 G-LUXE) was undergoing maintenance so we were relying on a Dornier Do228. When it first went out it couldn’t find the ash cloud as it wasn’t where the Met Office said it should be.
Models are useful tools but they can only ever stand a chance of being accurate if there is plenty of real world data being constantly fed into them. This data is what has been lacking, making the Met Office projections get less accurate as the days passed. These were passed on to the CAA who appear to not have known what to do.
The ICAO has been running exercises in dealing with volcanic ash, one as recently as March this year. The procedure for dealing with volcanic eruptions is an exclusion zone around the volcano 120km in radius (or centred 60km downwind). As the ash cloud extends beyond the exclusion zone it is for airlines and air traffic controllers to work together to make sure they don’t fly through it or above it. You can fly below it though. But all that requires observations as well as models. The various European met offices were seemingly ill-prepared for getting up in aircraft and finding the cloud.
We pay for a computer model to predict when you can fly. That computer model should make the best estimate, with a level of certainty, and then be compared with known events. If the models prediction is shown to be seriously out it should be ignored. The argument that they would be blamed if they said you could fly is irrelevant – the reason why that is an issue is presumably because they have oversold their accuracy to get funding. The model should give the most accurate prediction it can, but a disclaimer should give the degree of certainty of the predictions. If you are scared of being sued for a plane going down, don’t make models predicting when people can fly. It almost seems like governments just allocate funding, and have no mechanism for checking fitness for purpose. Considering the importance of the decision, have they shown accuracy at predicting the ash outside of european airspace? Were they unusually inaccurate this time? If they can’t answer that question then they haven’t been doing their job.
Keith Minto
What does it have to do with the pilot if the engine is worth 10 million dollars?He doesn’t pay for it,he doesn’t lose any pay either,when stranded.
As an aside I am wondering if the windmills all over Europe had an effect on where the ash went?They do disrupt wind patterns.
Looks like the Met Office’s computer not only generates carbon dioxide it also makes volcanic ash. It’s becoming self fulfilling.
Anthony I couldn’t agree more with your view of theoretical models versus observation and proper analysis. For models to be valuable they have to be properly validated and predictive: something the Met Office and the like seem unable to do or grasp the significance of. When did you last see a really predictive climate model!
Tony Berry
I agree with Anthony and Phil in this case.
re Anthony: The insurance companies run the show and do everything possible to reduce risk to 0%. Decisions made flow from that or else we can’t buy insurance. Therefore agencies have an overwhelming incentive to take no risks. This scenario will only worsen if post-normal science gets in on the act.
re Phil: Pilots can no longer fly around stuff on their own. The skies are so bloody crowded that meandering about avoided risks will likely result in traffic chaos and plane parts falling from the sky, let alone body parts.
stevengoddard (10:11:42) : The Met Office is in a no-win situation, and chose “better safe than sorry.”
Under that excuse we had better Stop all CO2 Emmissions today just in case the AGW crowd are right.
Flawed Science is Flawed Science.
Come on Steve they had no emperical data whatsoever and no intention of getting any. The airlines had to force their hands.
Tony (19:56:18) : can you provide the evidence that the UK flew test flights please?
stevengoddard (22:31:11) said:
I think you are vastly overstating the case. At most they (the various chips) were designed with the aid of a bunch of simulation, both functional and timing, and maybe there was a process simulation.
However, these simulations are vastly simpler than those to do with the atmosphere. They are mostly event driven and do not have to solve enormous 3D fluid dynamics problems.
Pamela Gray (06:39:23) :
re Phil: Pilots can no longer fly around stuff on their own. The skies are so bloody crowded that meandering about avoided risks will likely result in traffic chaos and plane parts falling from the sky, let alone body parts.
Pilots have autonomy in the case of an emergency, if a plane flies into an ash plume the procedure is to shut the engines down to idle and make a descending 180º turn (and other associated actions). Of course also get on the horn and declare an emergency to Control, who will clear airspace for you and also reroute other traffic where necessary.
Eyjafjallajökull flight cancellations: How the right decision is being made to look wrong
http://scienceblogs.com/eruptions/2010/04/eyjafjallajokull_flight_cancel.php
To fly or not and how close can you be.
Here is a paper that I think demonstrates the difficulty for the aircraft operators and air controllers.
http://www.alpa.org/portals/alpa/volcanicash/03_NASADC8AshDamage.pdf
Tony (19:56:18) :
Err, guys. You’ve fallen for the oldest MSM trick in the book. It is not a 1.7b loss. How can it be when they were previously reporting a 128m loss/day. The newspaper says “Global airlines have lost about $1.7bn of revenue”. Revenue is ticket sales. That does not account for fuel, maintenance and other direct costs associated with flying a plane. For example, Ryanair doesn’t even pay its First Officers a penny if they don’t fly. Using knowledge of my airline’s costs I would guestimate that the actual loss was about 400m.
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It would be interesting, to gain some perepective, to compare those 400m with the annual package of just the top 5 executives in each and all of the affected companies combined.
Steve Goddard (11:27:17) :
“What kind of GPU Acceleration was SUNY using in the early 2000s? Before CUDA in 2006, everything was slow, low precision and lacking in scatter capability. Both ATI and Nvidia were calculating intrinsics using lookup tables until, a couple of years ago. You couldn’t do IEEE32 math prior to that.”
Actually at that time Compaq/HP was working on a clustered workstation product with an FPGA base board which extracted data out of the GPU. They were using a combination of pre-CUDA code (yes it was difficult, but it was possible – see a number of papers at Eurographics 2002), and the compositing network on the cluster to do the simulation.
At that time, yours truly felt much like a man baying in the wilderness when talking about GPGPU to anyone. It’s much different today.
I suspect that the real reasoning behind the UK government’s change of mind was the fact that the press was carrying stories of German aircraft overflying Britain (which were seen by many people) whilst all our planes were still grounded. Politicians couldn’t pretend any longer that all was exactly as they spun it and simply had to react. Our current government is enormously risk-averse and Brown is renowned as a ditherer, so it’s no surprise either that nothing very direct was done to investigate the problem through observation in the interim between the eruption and the resumption of flights. Walsh’s decision to send 24 (so I believe) aircraft to Britain and demand landing inside British airspace also must have had a huge influence on decision-making. Watching those flights shifting themselves around Britain before they finally came in certainly suggested that some serious arm-twisting was going on.
Richard Sharpe (08:04:40) said:
As someone who has been involved in the development of 3D chemically reactive fluid dynamics models of various processes used in the Semiconductor industry (SiGe deposition, HfO2 ALD, Si nanocrystal growth, Ion implantation, Reactive Ion Etching, PVD, etc…) I would beg to differ. Sure, the atmosphere is much more complicated than the few liters of highly controlled reaction volume modeled in a typical semiconductor industry equipment simulation (usually limited to the laminar flow regime). However, that just frees us to include significantly more microscopic detail in our models (larger reaction mechanisms, use of ab-initio methods, Quantum chemistry, micro-loading effects, etc…). It also means our simulations are significantly more accurate and useful!
Model complexity for any sufficiently complex system is usually governed more by the computational capabilities of the model developer than the complexity of the system being modeled. In other words, the models include limiting assumptions, which are chosen so as to make the problem solvable with the available computational resources. Since the companies doing this kind of work have names like Intel and IBM and they work in collaboration with the National Labs in several countries, the available computational resources are significant.
The Sun (not a paper I’d normally recommend or even link to) is running this story of possible ash problems with a civil passenger flight, with an audio recording of the pilot’s comms with the ground:
http://www.thesun.co.uk/sol/homepage/news/2942884/UK-flight-is-aborted-after-pilot-smells-volcanic-ash.html
SemiChemE (14:45:08) said:
Thanks for enlightening me. After I wrote that I also figured that there would have to be a thermal simulation of the chip as well to get some idea of the heat dissipation to be expected and look at optimizing it for better thermal characteristics.
Gareth (01:47:17) : “Moreover, the first two or three days following an explosive eruption are especially critical because high concentrations of ash comprising particles up to ~10 μm diameter could be encountered at cruise levels some considerable distance from the volcano. Beyond three days, it is assumed that if the ash is still visible by eye or from satellite data, it still presents a hazard to aircraft.”
It seems like from the rest of the posting that Gareth thinks that 2-3 days after the eruption started that everything was good as long as the plume could not be seen visually. That’s a logical reading and conclusion, but based on a mis-interpretation. That timing is for each discrete piece of the plume. So, if one short eruption sends a plume downwind, then after 3 days if you can’t see it the assumption is that the particles have all fallen out or diffused so much as to not be a hazard.
That was not the case in this event. Almost-continuous explosions kept feeding fresh material into European airspace that was always less than 3 days old. If they hadn’t abandoned ICAO rules then the waiting period after the last plume was visible overhead would have been at least another day to allow fallout and dispersion.
Cool — so let’s put them in charge of future Icelandic-ash-related flight no-go zones.
I doubt that they’d have issued such wide-area shut-downs, nor issued them so far in advance of ash’s reaching certain areas, based on their 35-mile rule.
Interviews with Alaska Airlines ash experts and pilots, and extracts from their pilot’s and scheduler’s manuals, should be sought as part of any follow-up inquiry or policy-making decision in Europe.