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.
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wobble (08:50:58) :
Not sure how many times I am going to have to repeat this:
Hey Skipper (08:55:29) :
The aviation authorities make their decisions based on current conditions, regulations and standards.
The fact that some people don’t like those conditions, regulations and standards doesn’t really make a lot of difference, does it?
http://www.guardian.co.uk/world/blog/2010/apr/25/volcano-stranded
Well, I’ll start with your implication that flights originating in the US wouldn’t have the range to divert to the west if they ran into ash conditions they believed were dangerous.
Next is your implication that flights couldn’t have been limited to daytime VMC.
Also, the fact that you didn’t answer my most recent question. I’ll repeat it.
wobble (10:37:32) :
It is not the job of the CAA to control automobile traffic.
You are missing the point about diversion. One plane can divert and do frequently. The problem is allowing hundreds of airliners in the air which may all have to divert.
It is 7,000 km from Denver to London. The flight is a 767 which has maximum range of a little over 9,000 km on fully loaded fuel tanks. That is not enough range to get back, particularly fighting the wind flying west.
5th INTERNATIONAL WORKSHOP ON VOLCANIC ASH Santiago, Chile 22-26 March 2010.
Convened by the World Meteorological Organization
In collaboration with the International Civil Aviation Organization
http://www2.icao.int/en/anb/met-aim/met/iavwopsg/Lists/Workshops/DispForm.aspx?ID=3
P.10: Quote:
‘…Referring to the need to have established alert thresholds, Airbus was then asked what is the safe particle size and concentration of ash that is sustainable by aircraft. Similarly, the same question relating to Sulphurous gas was also asked. Airbus could not provide an answer to either question because this information is not readily available. Airbus highlighted that flight in volcanic ash laden atmosphere is not part of the environmental specifications to which aircraft and engines are built.
However, an action item was taken by Airbus to write to the engine manufacturers asking if an answer is available. Airbus will respond to IATA…’
If aircraft manufacturer doesn’t know – then who may do so?
BTW.
http://www.boeing.com/commercial/aeromagazine/aero_09/index.html
See Volcanic Ash Avoidance..
‘…Boeing has always advocated that flight crews avoid volcanic ash clouds or exit them immediately if an encounter occurs…’
Perhaps someone needed to keep the airlines in check?
– Pip
stevengoddard:
As an aviator, I have some serious objections to just about everything you have said on this thread.
I don’t know which 767 variant you are on, but I would bet it is an ER version, which has a range from 10,400 to 12,200 km.
You simply do not understand the diversion problem
No, of course it doesn’t have enough fuel to fly to LHR, fly an approach and missed approach and return all the way back across the Atlantic, but that cannot possibly be the situation.
The ash cloud’s density must be inversely proportional to its diffusion.
If the cloud is dense, it must be localized. The resulting problem is nothing more than a typical problem which ATC and pilots must be prepared for everyday; contrary to your assertion, sometimes lots of airplanes have to divert. (For example, see the video someone above linked showing how that works when a localized meteorological phenomena closes an airfield.)
All those airplanes, just as with your DIA – LHR flight, had enough fuel to fly hundreds of miles beyond their destination, and still arrive with required fuel reserves. In Europe, that puts the number of available airfields somewhere in the high scads.
To be further contradictory, the arrival rate at LHR is (guessing here) about sixty per hour. So the diversion problem at LHR can never amount to hundreds of airliners, because to reach that number requires including aircraft en-route or that haven’t even taken off. The en route aircraft have much more fuel, and, therefore, options, because they haven’t used the portion of fuel required to get to the descent point, plus descent, approach, missed approach and climbout, and fuel burn to the alternate.
Obviously, the aircraft still on the ground simply don’t count, so don’t count them.
On the other hand, if the ash cloud is widespread, it cannot be dense enough to present an air safety issue, particularly at the low thrust settings used during descent.
So, either the ash cloud is in principle no different a problem than, say a runway closure due to snow, or it is no problem at all.
True as far as that goes. However, the aviation authorities did not, in fact, make their decisions based upon current conditions, but rather forecasts that were, to put it as kindly as possible, spectacularly wrong.
In so doing, they deprived themselves of invaluable meteorological data. Ash goes where the wind takes it. So, if you want to know where the ash is going, you have to have a good idea of the winds aloft.
As it happens, our flight plans generally have very good wind predictions, because the forecast models are continually modified by real-time data.
The airplane I fly continually calculates the wind. Because the GPS velocity error is essentially zero, that means the wind calculation is accurate to within a degree and a knot. Most transoceanic airplanes have CPDLC (controller to pilot data link communication). My airplane frequently uses satcom to automatically transmit all kinds of information, including wind velocity.
That means that our weather department has a very good idea of winds at cruise altitudes, which, depending on traffic and weight, which typically ranges from 29,000 to 36,000.
So, shutting off all the airspace, based upon a hysterical reaction, helped ensure that a forecast that was pretty lame to begin with got essentially no real time data with which help put things less wrong.
—-
At the volcano they do, but until there is light-speed volcanic ash, not everywhere.
Here is how it would have gone, without pig-ignorant bureaucrats abetted by indefensible Met Office forecasts:
Volcano pops off. Two-hundred mile surface to infinity no-fly zone established around volcano. En route aircraft re-route if able, or divert. For all aircraft that have not yet passed Iceland eastbound, any number of Canadian and even US airfields are well within range.
NB: the number of aircraft in question amounts to those going between Europe and SEA, and maybe SFO, LAX and DIA. Number of aircraft en route? Don’t know for sure, but 10 from those airports isn’t a bad guess.
Airline dispatchers fuel subsequent aircraft to take account of the airspace restriction, plus the possible movement of the cloud based on current winds during the time from takeoff to landing.
Controllers get pilot reports, which, in combination with updated wind profiles, are used to plot actual ash location and movement. (Initial uncertainty might restrict operations in the area to day VMC.)
That, in turn, might increase required fuel reserves. If so, that might cancel some flights, or require payload penalties, or change in equipment.
Continue to update ash cloud location based upon PIREPS and winds, remembering that ash sufficiently diffuse to be invisible presents absolutely no hazard to flight.
That is how it worked when Redoubt popped. An eruption closed airspace that included Anchorage. Wait for a bit to see where the ash goes, then re-open ANC if there was no visible ash-fall headed towards the airport. Airlines would then launch, or not, based upon their own operational decisions.
And that volcano was only 90 miles away, not 800-ish.
BTW, how bad does a forecast have to be before it is no longer defensible?
wobble (08:39:24) :
u.k.(us) (16:53:17) :
It was fun, but, “a little knowledge can be dangerous”.
Are you criticizing Steven Goddard for refusing take the advice of experienced aviators and tweak his argument to make it more reasonable?
===========
First, as you know, i wasn’t criticizing Steven.
Second, whats with the fixation about increased highway deaths? Do you propose all travel is done by air, to save lives? What about trains?
The “advice of experienced aviators”, doesn’t mean much when the populace has ceded decision making to Government Bureaucrats.
Hey Skipper (14:21:13) :
767 range is listed on wikipedia from 9,400 to 12,200 km. LAX-LHR is 9,000 km.
LHR isn’t the only airport in Europe. Suppose the average long haul flight is 8 hours. One third of the long haul arrivals are in the air at any time. There are probably hundreds of long haul flights on their way to Europe every night.
Hey Skipper (14:21:13) :
…….”That is how it worked when Redoubt popped. An eruption closed airspace that included Anchorage. Wait for a bit to see where the ash goes, then re-open ANC if there was no visible ash-fall headed towards the airport. Airlines would then launch, or not, based upon their own operational decisions.”
And that volcano was only 90 miles away, not 800-ish.
===================
Apples and oranges.
The airspace over Europe has 100 if not 1000 times more traffic than Anchorage.
Steven,
You do realize that all London area airports can close at any time, right? You realize that all inbound aircraft would need to be diverted, right?
It’s sad that you make sophomoric comments instead of answering a difficult question.
Now, are you claiming that the CAA grounded planes without any input from the Met Office?
If not, then what input did CAA receive from the Met Office?
stevengoddard:
I don’t know how that number is calculated. If it is flame-out on touchdown — which makes it a useless number — then the 9400 km variant isn’t on the LAX – LHR route.
If it is a useful number, then 9400 km range means that is the farthest it can fly and have an operationally useful fuel reserve remaining.
Either way, it doesn’t matter. No airplane is dispatching from anywhere without the ability to make a detour en route. An unpredicted squall line of thunderstorms can arise just as quickly as a volcano, and across a much greater area.
As you said above, that volcano can erupt in a blink of an eye. May I presume you are never flying to Europe again?
Like I said above, area and density are inversely related.
There is simply no way an ash cloud from a volcano 800 miles away can, without substantial warning, shut down all the airports in Europe at once.
If winds aloft are strong enough to move the cloud quickly, then it isn’t dispersed, therefore any closures would be localized.
On the other hand, if the winds aren’t strong — as in this case — then the cloud can’t move very fast, which means there is far more time for ash to fall out of the sky, which means airports won’t get closed.
So, yes there are hundreds of long haul flights on their way to Europe every day.
On average, though, half of them are less than halfway there.
Adding to the stupidity of this is history. Eyjafjallajökull had no more than a third the ejecta of Mt St Helens, and it was less explosive.
When was the last time a volcano of that size caused anything like a significant ash fall 800 miles away?
I’ll bet “never” is the right answer. Mt St Helens ash fall was zero further than 450 miles from the mountain.
So to bureaucratic pusillanimity* and a Met Office forecast that would finish second to throwing darts blind, we can add bottomless ignorance of history.
Every one of those stranded passengers, everyone who had important travel plans, should be focusing red hot hate beams at the EU, CAA, and the Met Office.
Without whose contribution, none of that public “service” would have been possible.
——-
* one word that says it all: timid, timorous, cowardly, fearful, faint-hearted, lily-livered, spineless, craven, shrinking, chicken, gutless, wimpy, wimpish, sissy, yellow, yellow-bellied.
Canceling flights causes increased highway travel which causes increased deaths. This fact is independent of the dynamic that occurs with train travel. This concept really isn’t that difficult.
Yeah.
wobble (17:08:04) :
I’ll post it again for you – for about the fifth time:
The question comes down to whether the met office’s predictions caused the uk authorities to stop air flights – and where the models appropriate for making that judgement. According to the telegraph the maps produced by the met office were very different to the ones produced by the sensors on the ground – hence the UK had 100% shutdown whereas most of Europe had partial shutdown. This piece appears to suggest that it is wrong to question the models because lives are at stake. As an engineer I cannot accept that. The job of the computer models are to inform the decision makers. If the models are wrong they serve no purpose and ground measurements need to be increased until the models agree with the ground measurements and add extra detail.
By defending the models you are in effect cutting the crucial feedback step which would make the models fit for purpose. The model makers have to be taken to task for making incorrect predictions. They then must update the models where possible. At the moment they appear to be allowed to check their own homework. That has to stop if they are to be used for public policy.
Computer models we rely on are built up over decades with every error sent back to the developpers, quality assurance mechanisms set in place – and most of them are deterministic. A computer model of a new device would fail if any state in the system was incorrect after running a lot of code, the models would be fixed. Computer models are only as good as their quality assurance. The met office has to demonstrate that their quality assurance was up to the job. Talking about issues of planes falling out of the sky is a separate question.
By all means, post it as many times as you’d like.
But answer the question.
Are you claiming that the CAA grounded planes without any input from the Met Office?
Anthony, I apologize for assuming you wrote the article defending the UK’s Met office from a position of ignorance of aircraft operations.
stevengoddard, thankyou for pointing out my error.
FLIGHT PLANNING MORE
Steven, please read my point that flight planning takes into account availability of diversion airports. (I mentioned a flight diverted to Greenland, but that was due to a bomb scare (specifically, it landed at Soendre Stroemfjord which is a historic diversion/refuelling airport but somewhat sensitive to weather so cannot be planned on if forecast is not good).) Note that there is an airport in the Azores, available for at least emergencies such as the A330 whose flight crew did not catch that they had a fuel leak early enough to turn back. (Yes the Azores are well south but flights from the east coast of NA. See http://gc.kls2.com/cgi-bin/gc?PATH=kmco-lfpg&RANGE=&PATH-COLOR=red&PATH-UNITS=mi&PATH-MINIMUM=&SPEED-GROUND=&SPEED-UNITS=kts&RANGE-STYLE=best&RANGE-COLOR=navy&MAP-STYLE= or
http://www.gcmap.com/mapui?PATH=kmco-lpaz&RANGE=&PATH-COLOR=red&PATH-UNITS=mi&PATH-MINIMUM=&SPEED-GROUND=&SPEED-UNITS=kts&RANGE-STYLE=best&RANGE-COLOR=navy&MAP-STYLE=
and zoom out to see where the Azores are. (Those routes are Orlando Fl to Santa Maria in the Azores to Paris deGaulle which is in northern Europe), chosen to show where the Azores are whereas normally flights would be non-stop, and choosing Florida to show an east coast departure point as I and “Hey Skipper” point out. Anyone can look up the non-stop route and try airports further to the east and south of , which flights from the eastern US commonly go to (into Germany for example, from the east coast and places like Atlanta) – note where the greatest population is in the US thus the greatest demand for flights to Europe.
SOP on oceanic/remote flights is to monitor fuel against flight plan as the flight progresses – especially easy to do as the flight plan includes way points with fuel expected to remain at each of them.
stevengoddard, the reason the article is useless (your term) is that your premise is false – that airline flights always do not have enough fuel to divert. It has been pointed out that flight planning is supposed to take into account conditions – over the pole they even have to watch fuel temperature which can go below accepted limit on long flights when temperatures are quite low. So whether or not airspace was closed the flight would have to be planned for current risk – that is SOP and regulation. Yes, there is risk that an airline will not do the right thing – which was the case of the A330 that diverted to the Azores, and the case of a South Pacific airline that was veering into the USSR, and some cases of poor oceanic flight planning that came close to running out of fuel. That’s the nature of choosing your service provider, expecting competence. (E.G: Think about what is different for this flight if anything. (If going into a new area, study more and ask for advice – going deep into middle Africa, for example, don’t depend on navaids being on the air as scheduled – carry ample fuel to go to another country. Electromagnetic storms might affect communications. Etc.) Triple check and make conscious decisions (at top of descent, or “oceanic gateway”, or point-of-no-return if the flight has one, for example.
MISCELLANEOUS
Meanwhile, other comments that need review are:
– stevegoddard, reread this thread to see what people are saying about routings that will take you over Iceland, I don’t read anyone halfways credible saying that flights would never go over Iceland, but credible people are saying that is not the only possible way to get to Europe especially from the east coast of the US (which BTW you can fly to from the west coast). The whole question of whether or not flights go directly over Iceland is irrelevant – obviously some do, but the ash isn’t just over Iceland.
– I demand proof of the claim that AF447 did not have enough fuel to divert. Note the length of its non-stop flight, much of the latter part of it near land – when it crashed it had should have had enough fuel to divert. Many flights threaded through typical tropical storms in the same area that night, perhaps taking risk no one should not have, it is likely the AF447 crew got caught in one of those tall moist ones typical of that area and the airplane and crew did not cope well with it.
– people, the cabin display is not used by the pilots, as has been pointed out – thus does not have the safety rigor of flight deck systems, but is probably supplied with position data from those systems thus should be accurate as long as it is correctly displaying the data. Which BTW is not necessarily from GPS though that is increasingly common (the traditional system being Inertial measurement), sometimes blended so each sensor source helps the other and errors are more likely to be caught.
Dr. Roy Spencer will be interviewed tonight (Mon.) on Coast-to-Coast from 10pm to 2am Pacific time.
Keith Sketchley (11:40:09) :
Try diverting dozens or hundreds of long haul flights at the same time. with most airports in Europe shut down.
Let me know how that works out for you.
“stevengoddard (05:01:20) :
Keith Sketchley (11:40:09) :
Try diverting dozens or hundreds of long haul flights at the same time. with most airports in Europe shut down.
Let me know how that works out for you.”
Steven, you are obscuring your main point by making incorrect exagerated statements in areas where you have less expertise.
The airports were shut for departures . I realize from a passenger’s perspective this means that they are shut down. However, the airport itself and its staff would still be there and available for arrivals especially those in emergency. Moreover, it is not uncommon in an emergency (and I have done this myself) to contact the managers of an airport and have it (re)opened outside its normal hours.
There are NOT hundreds of flights to divert; there would only be those beyond their normal point of return that would continue that would probably be well less than a hundred. And all those airports open (although without departures) and other traffic would have had NO problems in accommodating the flights. There are also military and industry airfields which were open and perfectly capable of accepting wide-body aircraft.
Ian W (05:42:38) :
Most of the airports in Northern Europe including most in the UK and France were shut down last week because it was deemed that it was not safe (under existing standards) to fly through the ash cloud.
The fact that you think they would have allowed people to land doesn’t do any good if there is considered to be no safe approach to the airport.
The point isn’t whether or not some of the planes might have been able to find a place to land safely. The point is that under existing regulations, the CAA had no choice but to shut down the airspace.
WHO ACTUALLY CLOSED UK AIRSPACE?
– I urge separation of the issue of forecasting location and amount of ash, and measuring it, from determination of acceptable threshold for airplane operation.
– The Met Office routinely provides forecast for water and in the air and how it moves (to spell it out, that’s clouds, precipitation, and storms. The Met Office runs the UK’s ash advisory service.
– But I expect the operational safety authority, the CAA, to set the threshold used to make the decision to close airspace. (Richard Briscoe is in effect saying that.) They are the authority on technical operation of airplanes.
– A Telegraph article of April 21 indicates it was the airspace control organization NATS, which has delegated authority from the CAA, who chose the initial threshold.
– (NATS also controls the eastern mid-north Atlantic oceanic area, delegated from a group of countries probably via ICAO. That might be relevant to flights from the US east coast, whereas the true-north Atlantic that flights from the west coast of NA go through is controlled by centres in Iceland and Greenland, under the same delegation. The Western mid-north Atlantic oceanic area is controlled by Nav Canada. Lower altitudes, such as below 19500 feet, and areas near coastlines including islands north of Iceland, may be handled by local control centres. To my limited knowledge they cooperate well.)
– Talk of “models” is confusing. Measurement feedback should be included, as it eventually was to some degree according to the Guardian’s article on deciding to relax the threshold. The output routine of the model could include threshold simply to generate useful plots for decision makers – apparently it did. However the threshold should have come from the airspace control authority.
– People say the Met Office’s initial forecast of location of ash was pessimistic, but that is variable with winds and how quickly it falls – at one point it was showing up off the east coast of NA, though it may not be difficult to find some ash in the air so that is another reason why having a realistic threshold is so important.
– The Guardian article on deciding to relax the threshold says the CAA made the relaxation decision and UK transport secretary Lord Adonis depended on them.
– Note too that the CAA of the state of registry of the airplane has some authority over operation of it, though I don’t understand how state of registry and area of operation differences are decided in a technical case like ash (rather than rules to keep airplanes apart which must be followed by everyone in the airspace) and the UK case is further compounded by the pan-European airworthiness regulatory authority for the technical capability of airplanes.
That is unreasonable.
Ash cannot move both far and wide enough to shut down most, or even a few, airports in Europe within the en route time of even long haul flights. There have been many volcanic eruptions in recent history, has even one of them created such an outcome?
That ash fall forecasts proved so laughably wrong is one thing.
The imposed policy is something else altogether. By mandating what amounts to a zero-tolerance policy for ash, then there is no way of saying how far from the volcano was far enough.
There was never a time when there wasn’t a safe approach to virtually all of the airports in Europe during the entire shutdown.
At all times, flight through whatever ash was present would have produced no safety impact whatsoever.
It might have increased maintenance costs for the airlines down the road, but that is another matter altogether.