By Steven Goddard
As reported on WUWT, The UK Met Office is taking a lot of heat for airline financial loses, caused by no flight rules during the Icelandic volcanic eruption. Many readers have expressed their agreement with those criticisms.
I don’t agree with all of these criticisms, and here is why.
Suppose you are taking a ten hour 8:30 PM flight from Seattle to London. You pass Iceland eight hours into the flight, and ash conditions may have changed dramatically since you left. A new volcanic eruption may have occurred overnight, and your plane is almost out of fuel. No matter how accurate the circulation models are, they can not predict the behaviour of the volcano. The modelers and the people in charge of decision making have to be conservative.
Do you want to be on a plane over the frigid waters of the North Atlantic, which can’t progress forward and does not have enough fuel to turn back? I know I don’t. Erupting volcanoes can change in the blink of an eye, as people near Seattle found out at 8:32 AM on May 18, 1980. There is always going to be some risk, but this particular volcano has been spewing out a lot of ash and deserves particular caution.
Now that enough information has been gathered, the decision has been made to restore the flight schedules. It has been a very long week for travelers, but in terms of the required science and engineering – seven days isn’t very long when making life or death decisions.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Eduardo Ferreyra (10:38:06) :
Nonstop. I used to take the BA SFO -> LHR flight every few weeks, and they are equipped with a GPS TV station so you always knew exactly where you were.
The problem is that too little is known about aircraft risks due to ash. The only thing that we know is that if we fly through areas with high ash concentrations we risk extensive damage. We don’t know exactly how high these concentrations are and not what the damages will be at different concentrations. That is why airliners take puts security first and disband all flights, although the margins might be wide.
To reroute air traffic to lower altitudes where the concentrations are significantly lower is impossible in practice.
There would be completely new schedules, which means that ALL flight schedules at ALL airports would have to be recalculated. Those who have read mathematical optimization at universities know how difficult it is to create such optimal planning. Today it is mostly based on experience gained from many years of air traffic.
It is much more difficult to fly on lower altitudes since the air space consist of zones around airports where exact guidance is needed from control towers. Air routes on higher altitudes are more or less straight lines and divided in lots and lots of altitude segments, and navigation is aided by GPS.
It would concentrate too many aircraft within the same area and therefore also increase the risk of collisions.
The aircraft would consume more fuel due to a denser atmosphere and due to more complicated flights (shorter distances and fewer passengers). The current tables for calculating fuel requirements/passengers/luggage would no longer be trustworthy and they would need to take extra wide margins when taking onboard fuel, which would lessen profits. Regarding the bad economy of most airliners this would be out of the question.
To conclude, even with the super computers of today, even a temporary air traffic change would be almost impossible to do.
There is a lot of dicussion around the computer models not being skillful. This is important if the models are used for making important decisions. The problem as I see it is that most people tend to focus on the lack of ash where flights are cancelled. This is understandable, people get upset when stuck for five days, as I have been, if the models are wrong about ash that is not there.
Everyone claims that safety is more important than anything else. I think this is wrong. If safety was the most important thing when taking decisions where to fly, then the models should be forced to show that when they say there is NO ash, then there should be no ash, Think about it, if the models say that there is ash in Denmark but not in Sweden, grounding planes in Denmark is a no brainer if safety is your only concern, but to continue to fly in nearby Sweden should be a headace. How good are these models to avoid false negatives should be the most important question if safety is the major concern, but that discussion is not found anywhere.
Liar (10:38:34) :
What is different about this volcano is that it is located upwind of the world’s busiest airport, in a region where the weather and visibility is normally poor.
Billy Liar (11:02:44) :
Phil. (10:49:23) :
Hu McCulloch is right – you’re not.
http://www.nasa.gov/externalflash/Glopac/
http://www.nasa.gov/centers/dryden/research/GloPac/glopac_instruments.html
The Global Hawk can fly at altitudes up to 65,000 feet. Its range is greater than 10,000 nautical miles and its endurance is greater than 31 hours.
And it’s equipped for the job!
And it isn’t the military one used in Afghanistan. How long to take it to it’s destination and set up a search pattern to adequately cover the expected plume, and how many are you prepared to lose due to engine failure?
About 30% of predators are lost in Afghanistan due to icing issues.
Symon (10:33:47) :
Interesting statistics, thanks. I’m far more concerned about the drive to DIA than the flight itself. I rarely get there without seeing at least one serious accident on I-25, which is one of the most dangerous stretches of overcrowded, narrow highway I have ever seen.
UBS (11:19:06) :
Rubbish! Air traffic control is usually managed chaos. If everthing changes it’s still managed chaos. The risk of collisions is always the same – someone has to make a mistake for the risk to arise.
How do you think they cope when major thunderstorms occur in the summer in the continental US?
1DandyTroll (11:16:58) :
Why would the flight path be assumed to be a straight line to begin with? And is flying close to Iceland, when a volcano is actively spewing out ash, a requirement?
The shortest route between two points on the earth is a great circle, certain map projections are used for navigation because a straight line on the map is a great circle! (Gnomonic)
The transatlantic airliners could’ve gone by route of New York, Washington DC, Miami, to Ireland, Portugal, Spain, Italy, France.
From Seattle one could open up a corridor by way over Siberia to Europe as well.
All longer routes probably requiring stops.
Met Office ought to be sued back down to earth.
Yeah sued for doing their job properly which would result in shutting down all the world’s VAAC systems thereby blinding all air traffic to such events!
That’s really smart.
http://www.avweb.com/pdf/volcanic_ash_cloud_encounter_nasa_grindle.pdf
Check this out, even the path is close.
The results? impressive
Do you mean overly-conservative or appropriately conservative?
Do you think they should balance their conservation with risk management analysis frameworks?
It’s definitely wrong. If safety was more important than anything else, then we should never fly again since there are always risks involved with flying. However, the risks involved with flying are obviously acceptable given the benefits of flying.
I also need to ask about the number of deaths which resulted from the increased number of travelers that decided to drive to their destinations. It’s long been established that highway driving causes more deaths than flying. Increasing the number of highway drivers causes increased deaths. Therefore, the ground of aircraft caused deaths.
I want to know the number of deaths this has caused.
Retired Engineer (09:18:38) :
Today’s consumer is unaware or unwilling to analyze risk. …
This is exactly what I have been fighting just recently! I’m also an engineer and this is jailor who attaches the chains which anchor us to a nanny state.
The perception of a ‘safe’ world is more pervasive today than it has ever been. The outbreak of cellphone laws (which we won’t go into here) is a symptom of this. All risk has been assumed by some others: the ability to ‘insure’ practically anything has disavowed the individual of all risk, although the risk still exists.
Since the perception is one of a ‘risk free’ world, when something goes wrong it is patently obvious it *must* be someone elses fault…
One would think one would check figures before making a post like this. A number of airliners have ranges in excess of 7000 miles, sufficient to fly New York to London, circle Heathrow a few times and fly back with adequate reserves. Flying out to Iceland and turning around would have been a problem for Lindbergh in 1927 but a lot has changed since then.
Steven:
The Met office didn’t ground the flights and the “blame” (if any) needs to be on the decision makers. My criticism has been the reliance upon models instead of actual data.
I also agree it’s best to err on the side of caution.
People are amazingly unable to calculate risk in their everyday lives. How often do you see people talking on the phone or texting while driving in heavy rush-hour traffic?
Los Angeles county goes up in flames every few years and I remember watching the fires on the ground as I descended into LAX. I don’t recall any flights being grounded because of the fires but I’m sure the fires produced sufficient updraft to put lots of particulates into the air. Enough so that I had ash in my driveway 10 to 20 miles from the fires. So not all ash is equal. And the heavier most damaging components of volcanic ash will fall out of the sky much much faster than the lighter, smaller particles and water vapor from the eruptions.
And I think that is part of the problem of the MET models. They are designed to model how water vapor and gas move around the planet, not the sandy, engine destroying components of volcanic ash. They will give a good idea of where to look for them but will tell us nothing about how much is actually still left in the atmosphere.
I’ll repost something I posted yesterday:
First, it’s unlikely — I dare say impossible — that an airplane would crash from flying through light (undetectable by satellite) ash. (There have been no crashes from flying through even the heart of heavy plumes, despite some flame-outs.) The worst would have been a need for earlier maintenance on the engine. That trade-off should be the airline’s call to make.
Second, I don’t think it was necessary to prohibit flights over areas far away from the potential cloud, like Spain, at such an early date as was done. Whoever was responsible was exhibiting hall monitor behavior (jack-in-office officiousness).
Third, the real scandal was the failure to do pro-active and coordinated contingency planning, despite having a month’s advance warning. Hopefully, that planning will now occur.
Fourth, a long-range ash-cloud-monitoring drone/UAV should be designed that can fly through ash (maybe using the old V1 bladeless design) and report on its characteristics in real time, and fleets of them should be deployed in volcanic hotspots on heavily traveled airline routes. The cost/benefit ratio would be attractive, even if the project costs over 100 million $.
PS: Ash-testing drones could take off from Iceland and land downwind in Scotland, Scandinavia, SE England, Germany, etc., etc. There they’d be refueled and head back to Iceland (or wherever they were needed most). Their range wouldn’t be cut in half by a need to return to a home base, IOW.
Steven
It’s only upwind because of the positions weather systems. It actually went south south east, initially. Visibility at London airports in late april is normally very good. Visibility in artic air is very good if it isn’t snowing. The difference with this eruption is that it happened within 3000km of the nuttiest governmental regimes in the world. Europe and GB.
I don’t know if anyone will read this far… but here are the issues:
The Met Office job was to issue a SIGMET (Significant Meteorological) warning of the presence of Volcanic Ash in a defined volume of airspace moving in a defined direction. No-one has yet pointed out that if the model was inaccurate when it showed where ash should be, then it must also be inaccurate showing where airspace was ash-free; this is a far more dangerous and worrying consideration!
Normally it is the responsibility of the aircraft operator to avoid the SIGMET defined volumes that they believe would hazard their aircraft. What we saw from the EU and various countries was a assumption of the aircraft operator role by governments who put on the ground-stop and did not allow operations.
Volcanic ash rarely causes aircraft engines to fail: the aircraft has to be flown into very dense ash for a failure. However, volcanic ash does damage turbojet engines and makes them increasingly inefficient. Flying in the presence of low concentrations of volcanic ash can therefore cause the engine maintenance period to be greatly shortened and the level of maintenance to be greatly increased.: This is a significant cost to the operator. The decision to fly or not in the dispersed volcanic ash cloud is therefore a commercial/b> decision NOT a safety risk management decision.
It is the lack of clear identification of responsibility and imposition of authority – and the assumption of the role of decision maker by often inexpert governments that is upsetting the aviation industry.
Just a few other points – the minimum separation standards currently in oceanic airspace are 30 nautical miles laterally and in trail and 1000 feet vertically. That is for aircraft with navigation systems that meet the Required Navigational Performance of 4 nautical miles containment. For those with RNP of 10 nautical miles the separation is 50 nautical miles laterally and in trail.) In airspace with radar or other surveillance cover it is 5 nautical miles and 1000 feet.
I find that people that compain about air travel, airports, flight delays and airport security do not actually travel much. They also seem to use the term ‘small world’, which is a total joke if you actually have to move around it much, believe me it is actually a very big ball, in places it is over 5 movies wide.
However if the models were right in saying the air was not safe, and the air has not changed, then why is it safe now?
Why did they not simply say, “We do not know if it is safe to fly right now so we are going to check, please wait.” Then actually check the real conditions with real instruments on real planes and baloons for a day or two. Then say “OK we have checked, it looks OK, thanks for waiting” or “No, it looks bad, you need to keep waiting, we will check again tomorrow”
Honestly goes a long way with passengers.
767s have a range of 9,400 to 12,200 km. The distance from LAX to LHR is almost 9,000 km.
Not a lot of room for error.
stevengoddard (08:56:50) :
And you need to continue to be a big fan of fusion for at east another 35 years and beyond. It’s still a fairy tale. Perhaps you need to keep your feet firmly on the ground rather than walking on clouds in the sky.
Essentially all modern weather forecasting is done using computer models. Thousands of lives are saved every year because of the ability to forecast hurricane movement a few days in advance.
About 100 years ago, an unexpected storm hit the Great Plains and hundreds of school children got lost and died walking home from school. That doesn’t happen any more.
Not sure!
I have lived under where the Met office model said the ash cloud was for 6 days.
I only observed any evidence of ash on one day (the first day) when a very light dusting was on my car.
All other days the sky was remarkably clear, clearer than normal for UK, wherever I went in UK .
So the first day the model was maybe correct, but why didn’t they look out the window, and travel about a bit?
>The distance from LAX to LHR is almost 9,000 km.<
What happened to the Seattle example? And what about flights originating in New York?
And all flights could have diverted to Reykjavik if needed. That was upwind and open, right?
Billy Liar (11:29:17) : yes, but there is a difference when you have experience handling storms and know alternatives, this volcano is no such thing, it is a “first”