Ash clouds threaten air traffic

[BreezyDC]

Search of previous incidents with volcanic ash cloud addressed by NTSB reveals only one since 1962 (based on searches for volcanic and for ash). Looks like KLM should be dusting off the procedures they put in place after this event.

NTSB Identification: ANC90FA020 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X29893&key=1) .
The docket is stored on NTSB microfiche number 41866.
Scheduled 14 CFR KLM ROYAL DUTCH AIRLINES
Accident occurred Friday, December 15, 1989 in ANCHORAGE, AK
Probable Cause Approval Date: 6/30/1992
Aircraft: BOEING 747-400, registration: PHBFC
Injuries: 245 Uninjured.BFR TKOF, CREW OF KLM FLT 867 ADZD OF VOLCANIC ERUPTION ABT 100 MI SW OF DESTN. EN ROUTE, FLT ADZD OF ANOTHER ERUPTION. FOR ARR, FLT CLRD TO DSCND FM FL390 AT PLT'S DISCRETION; VCTR GIVEN TO AVOID LAST KNOWN AREA OF ASH CLD. DRG DSCNT THRU FL260, FLT ENCTRD ASH CLD; ASH/SMOKE ENTERED COCKPIT/CABIN. CREW DONNED O2 MASKS; USED MAX PWR TO CLB. 1 MIN LTR, ALL ENGS LOST PWR (TO 28%-30% RPM); THERE WAS ELEC PWR INTRPN, LOSS OF AIRSPD INDCN, FIRE WARNING ALARM FOR FWD CARGO AREA. AFTER 8-9 ATMTS & DSCNT TO 13,300', ALL ENGS RESTARTED & FLT CONTD TO SAFE LDNG. DMG FND ON EXTERNAL SFCS OF ACFT & IN HI PRES TURBINES OF ALL ENGS. BOEING OMB #747-B2-4, ADZD TO AVOID VOLCANIC ACTIVITY; BUT IF ENCTRD, RETARDING THRUST TO IDLE WLD RDC BLDUP IN ENG & IMPROVE STALL MARGIN. ATC RADAR COULD ONLY DETECT VOLCANIC ASH FOR 5-10 MIN AFTER ERUPTION; ACFT RADAR NOT DESIGNED TO DETECT ASH. ASH CLD FCST TO MOV NNE AT 60 KTS; REVIEW OF SATELLITE DATA SHOWED IT ACTUALLY MOVED AT ABT 120 KTS. KLM HAD NO PROC FOR 747 ENCTR WITH ASH CLD & NO ADNL INSTRNS WERE GIVEN TO KLM CREWS.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
INADVERTENT ENCOUNTER WITH VOLCANIC ASH CLOUD, WHICH RESULTED IN DAMAGE FROM FOREIGN MATERIAL (FOREIGN OBJECT) AND SUBSEQUENT COMPRESSOR STALLING OF ALL ENGINES. A FACTOR RELATED TO THE ACCIDENT WAS: THE LACK OF AVAILABLE INFORMATION ABOUT THE ASH CLOUD TO ALL PERSONNEL INVOLVED.

[carmel]

I've heard a lot of talk about the decision of the airlines to start flying again, but what about the role of the aircraft insurers in this scenario?

I would've thought that they would be wary of covering aircraft that will be flying into ash clouds, or maybe they would increase their premiums?

[ZQA297/30]

We are not totally without information on plume penetration. A very special NASA DC-8 documented ash levels, sizes, and gas concentrations and the details are all there for those who have the time to read it.Here (http://www.nasa.gov/centers/dryden/pdf/88751main_H-2511.pdf)
I quote from the report on the inadvertent ash incident with the NASA DC-8, a fully instrumented airborne science research test bed.

More than 100 commercial aircraft have unexpectedly encountered volcanic ash in flight and at
airports in the past 20 years. Eight of these encounters caused varying degrees of in-flight loss of jet
engine power (ref. 1)
and
Reference 5 explains
that a range of damage may occur to aircraft that fly through an eruption cloud depending on the
concentration of volcanic ash and gas aerosols in the cloud, the length of time the aircraft actually spends
in the cloud, and the actions taken by the pilots to exit the cloud

The airplane was re-engined with four CFM56-2 engines prior to delivery
to NASA.

[teifiboy]

Compared with this time yesterday, the live webcam Eyjafjallajökull frá Hvolsvelli (http://eldgos.mila.is/eyjafjallajokull-fra-thorolfsfelli/) suggests a considerable weakening of the plume

[TiiberiusKirk]

@carmel
I expect that the insurance companies don't really have much of a say.
It would be impossible for them to examine and risk-assess each and every flight every day and in all conditions, so the only practical way would be for them to cover all flights 'provided they are being operated "in accordance the regulations in force".

It's very unlikely that they have any form of veto.

If heavens forbid something went wrong they might try to recover losses from the authorities _if_ they could prove they were negligent in setting the regulations.

[EvilDoctorK]

Looks pretty tame this morning from this angle too - Picasa Web Albums - eyjafjallajokull_... - Eyjafjallajok... (http://picasaweb.google.com/102175391233488315229/EyjafjallajokullVolcano20thOfApril2010#5462093623990149826) (as it did last night ... which seems to run against the NATS statements, but presumably they know better)

[pax britanica]

Well presumeably all S UK airspace is not closed having just watched a KL 747 sail majestically along headed for AMS . Is it just certain levels or just departures? Or are we letting the cloggies do a bit of guinea pig work for us ?
As its track will take it right over London I am sure a lot of people will wonder whats going on

PB

[Young Paul]

Danny: Report from 2000 - The "Diffuse" plume. How diffuse? What concentration? You are saying that we shouldn't resume flying because of the unscientific analysis of a few odd commercial flights. You are saying we should stop flying because of the unscientific wording of a single military report!

I am not saying that because you can't see it, it is safe. What I am saying is that without proper research, which is doable, we might just as well all give up and go home now. The "safe" solution is not to fly at all. The gungho solution is to say we can't see anything, or well, it's a bit grey, but hey, it's okay. Probably. The scientific solution, the sapient solution, is to properly analyse and manage the risk. It is only in the last 24 hours that Europe has come close to doing that, but even then as far as I can tell, it's not based on proper research, but on setting aside former assumptions about risk.

[ZQA297/30]

Young Paul
check page 10 of the NASA report, there are 2 graphs, one for SO2 concentration, airborne Fourier transform infrared spectrometer , one for Aerosol data; airborne Langley condensation nuclei counter, 12 nm–1 micron.

[Whippersnapper]

So, the KLM flew at 40,000', above the ash cloud, so their only exposure was in the climb and descent. BA spent a total of 2h45min airborne instaed of their planned 4h, and spent it at varying levels, so only a matter of minutes at the intermediate altitudes that have the highest risk. That invalidates their "tests".

No-one on here supports the apparent lack of investigation into the problem, and no-one wants the restrictions to last longer than needed. However, the continuing view from some that no engine failures means it is safe to resume normal ops is astonishing - given that the company test flights were a con trick, and that numerous military engines have been wrecked, it points to a complete cowboy attitude. Anyone supporting an immediate return to flying should have their licence permanently revoked - you're wanting to play Russian Roulette with hundreds of lives.

The simple fact is that there is not enough data to make an objective assessment whether it is safe or unsafe, and it is that research that is needed, not a resumption to ops because patience has worn out or economics are deemed more important.

[peter we]

I expect that the insurance companies don't really have much of a say.
It would be impossible for them to examine and risk-assess each and every flight every day and in all conditions, so the only practical way would be for them to cover all flights 'provided they are being operated "in accordance the regulations in force".

It's very unlikely that they have any form of veto.

If heavens forbid something went wrong they might try to recover losses from the authorities _if_ they could prove they were negligent in setting the regulations.

Insurance companies do not have to provide cover. They asses the risk and provide cover with an automatic 10% profit. Engine and aircraft manufactures state that no volcanic dust is acceptable, so as standard no insurance company will cover flying through dust.

So its not so much a veto as an aircraft is uninsurable until its been completely inspected and repaired - probably after EVERY flight. And its not just the engines, volcanic dust screws electronics as well.

Insurance companies cannot blame authorities for opening or closing the airspace, its the airlines who would be ignoring the manufactures guidelines and the airlines a who will bear the cost if they deliberately ignored them.

[Mountee]

Interesting after BA made a lot of noise about the lack of ANY effects of the flights through the ash they've grounded their fleet, probably a good reason:confused:

[Jonty]

On plane finder this morning Amsterdam is very busy with aircraft. So is northern France and traffic is transiting the French side of the channel at altitudes down to 20,000ft.

These areas are right in the red zone according to the latest Vaac maps, ash down to surface level. So why are these aircraft not falling out of the sky? Could it be that someone has made a huge mistake, just because "that's what the book said"?

Someone needs to have their balls felt for this, and not in a good way.

[jcjeant]

Hi,

BBC News - European airports start to reopen for flights (http://news.bbc.co.uk/2/hi/europe/8631238.stm)

But British Airways says it has cancelled all short-haul flights, after the UK air traffic control body, Nats, warned of more volcanic ash.

A US official said on Monday a Nato F-16 fighter jet had suffered engine damage after flying through the volcanic ash cloud.

EU Trade Commissioner Karel De Gucht said the bloc's economy would suffer badly if the disruption continued for a long time.
"What makes me a little bit afraid is that there is no timer on this volcano," he told news agency Reuters.


there is no timer on this volcano :)

[The SSK]

Translation: "the cost of the shutdown has now exceeded the cost of a downed aircraft so its time to get back to work - at least until the first one comes down".

INTEL101: Where you live (Charlotte NC it says here), do they trade off safety against financial considerations? If so, commiserations. We don't do that in Europe.

[ZQA297/30]

What I find curious is that not one of the many that have flown through "the zone" seem to have published borescope results, or oil spectronalysis results, both of which are eminently do-able.
Will the CAA require aircraft that have traversed the suspect zone perform hidden damage checks as they would, for instance, in a heavy landing incident?
What are the implications of unnoticed/unreported encounters, and the IFSD rate especially for ETOPS?

[Smoketrails]

Jonty

...long term mate, think long term!

[gassy 02 heavy]

All these comments about aircraft not falling out of the sky, do none of you consider the long term prospects, just becuase it is not having an effect today does not mean that long term exposure will not have effects in weeks/months.

[atco-matic]

BASED ON THE VAAC ADVISORY TIMED 0000Z APRIL 20TH THE SCOTTISH
FIR/UIR OUTSIDE OF THE CONTAMINATED AREA WILL OPEN AT 0600Z APRIL
20TH. THE LONDON FIR/UIR REMAINS ZERO RATED BELOW FL200 UNTIL
FURTHER NOTICE.

So thats why you can see panes above FL200 over England.

[markhooper]

As we all know, contrary to what they say on the news, the airspace isn't 'closed'. Just that IFR clearances aren't being given in affected areas.

As it's VMC pretty well all over Europe I would imagine the Air Taxi operators and Biz jets that aren't stuck on the ground in Class A airspace should be doing good business. But I'm not hearing that is the case. Why is that?

[tocamak]

UK plc starting to look a bit daft now

Given that using the ash cloud overlay on the radarvituel picture on what basis has the rest of Europe allowed flying to continue. Is the ash density much less (all the way across the N sea!)?

[discus2]

An ATR42 equipped with special probes took off on Monday from Toulouse-Francazal towards Montpellier to take air samples.
More flights scheduled on Tuesday further north.
A second aircraft, a Falcon 20 is due to conduct more tests.
Aircraft equipped by SAFIRE and the CNRS ( FRench national research and science center)
Reacting to national critics, according to scientists, such experiments usually take 6 months preparation and quote:
"We are not a quick response team, usually such experiments are prepared 6 months in advance".

We might know what 's up there ! ( finally...):confused:

[ZQA297/30]

Of the over 100 historical ash encounters only 8 involved immediate engine malfunctions. Just 8%! and that involved some pretty heavy ash.
Statistically there are not going to be that many aircraft "dropping like flies".
On the other hand there seems to be some evidence that hot section deterioration can be the result of "invisible" dust. Therein lies the proverbial rub. The implication is that there might be some compromised turbines that could fail catastrophically at a later date,100 hrs, 500 hrs, who knows?

[mary meagher]

Breezy DC quotes the KLM encounter with ash in 1989 near Anchorage.

On entering cloud, ash/smoke entered cabin. Crew used MAXIMUM POWER TO CLIMB. One minute later all engines lost power.

Boeing recommends DESCENDING 180 degree turn, as maximum power climb seems to provoke failure.....

[Bruce Wayne]

do none of you consider the long term prospects, just becuase it is not having an effect today does not mean that long term exposure will not have effects in weeks/months.


Do you not consider how an aircraft engine is maintained ?

routine oil analysis..
routine borescope inspections..
LLP limits..
hot section intervals..
engine trend monitoring...
egt reports..

etc etc

[kinsman]

With 20 or so volcanoes active at any one time, ash clouds like this must occur all round the world especially in the area of the ring of fire. Yet in all my years flying round the world I have never seen such an over reaction. I am all for safety first but I can't help thinking this is becoming a face saving exercise by those who have made this incredible decision to close the airspace.

What I really don't understand is why manufacturers and those who are making the decisions are not pouring money and time in to getting some solid scientific data on the effect of this type of ash on the aircraft. Get some test aircraft up there instead of leaving it to the airlines.

The long term impact on the economy is going to be huge if this goes on much longer and not just for the airlines! Time the Governments got of their arses and started to get some facts instead of relying on poor science, nobody knows how this cloud will effect aircraft it appears.

They keep trotting out the same stories including the BA flight that hit the plume of a volcano some years ago but fail to mention the ash cloud they flew into was very close to the volcano and the ash was altogether different and more dense.

So my message to those in charge is get your fingers out and go get some facts instead of speculation based on poor science or worse no science. :mad:

[bbrown1664]

Statement on Icelandic volcanic eruption: Tuesday April 20, 0900

The situation regarding the volcanic eruption in Iceland remains dynamic and the latest information from the Met Office shows that the situation today will continue to be variable.
Based on the latest Met Office information, part of Scottish airspace including Aberdeen, Inverness and Edinburgh airports will continue to be available from 1300-1900 today, and also south to Newcastle Airport. Restrictions will remain in place over the rest of UK airspace below 20,000ft.
Overnight the CAA, in line with new guidance from the International Civil Aviation Organisation (ICAO) decided flights above the ash cloud will be permitted in the UK; between 1300-1900 this will enable aircraft movements above 20,000ft in UK airspace.
We will continue to monitor Met Office information and the situation is likely to change during the course of the day. We will make a further statement at approximately 1500.
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 working closely with Government, airports and airlines, and airframe and aero engine manufacturers to get a better understanding of the effects of the ash cloud and to seek solutions.

[kinsman]

And another thing aircraft are flying all over the UK without problems outside controlled airspace including gas turbine powered aircraft again without problems! :ugh:

[Whippersnapper]

Some people just do not listen, do they?

The vulcanologists have clearly stated that this eruption is unusual in the content of its ash and the dispersal pattern. Several aircraft have suffered clearly photographed damage that allowed the engines to run, but would have resulted in failure after cumulative exposure.

Whatever is happening in continental Europe is not necessarily appropriate for the UK - look at the dispersal pattern and you'll see the plume comes down straight over the UK before it starts to spread east and west, becoming vastly thinner in the process of that divergence - it would be reasonable to assume from that map, if it's sufficiently accurate, that the ash is far denser over the UK than over continental Europe.

How many airlines will boroscope all of their engines after each flight, or even each night? It's not likely to be the first day of operation that will see problems, but later in the week if there is a big threat. Those of you claiming that the lack of engine failures this morning are showing a complete lack of technical understanding of the issue. The experts are unanimously stating there is a risk - it is only the airline managers and the uninformed media and public crying foul.

There seems to have been very little co-ordination or political will to get on top of the situation to determine definitively if ops are safe, but in the lack of that determination, the restrictions are not unreasonable.

[ZQA297/30]

Bruce Wayne
Not sure that everyone does oil analysis, particularly for S, which was the only abnormal in the NASA incident.
How often are "routine" borescope checks done?
The recorded engine parameters used for ECM showed no abnormalities in the NASA incident. Surprisingly even during the event nothing abnormal showed on cockpit instrumentation. They operated for a further 68 hrs before damage was noticed.

[mixture]

adirondack (and other spotters),

please refer to Jetdriver's (PPRuNe Mod) post, #1754 on page 88 and stop clogging up the thread with virtual radar extracts etc.

The thread is already 90 odd pages long.....it's about time we started seeing some self-moderation and only posting if you've got something useful to say. :ugh:

[kinsman]

Whippersnapper

Yes people do listen, this eruption is unusual but examples of the same type of ash has been produced by other volcanos in recent times. The restrictions over Europe are very unreasonable considering the evidence. I do not have the details of the damage to the fighters or what density of cloud they flew through. However, several airlines have flown aircraft in the cloud without damage so we need hard data not speculation.

I see a lot of talk from the Met office and government departments but not much action.

[bbrown1664]

The problem is the airspace below 20,000ft.

British carriers cant get to 20,000 without being below it first, everyone else is overflying above that level!

[scr1]

not much open overflights allowed

INV have been asked about possiably taking transatlantic diverts:eek::eek:

Statement on Icelandic volcanic eruption: Tuesday April 20, 0900

The situation regarding the volcanic eruption in Iceland remains dynamic and the latest information from the Met Office shows that the situation today will continue to be variable.
Based on the latest Met Office information, part of Scottish airspace including Aberdeen, Inverness and Edinburgh airports will continue to be available from 1300-1900 today, and also south to Newcastle Airport. Restrictions will remain in place over the rest of UK airspace below 20,000ft.
Overnight the CAA, in line with new guidance from the International Civil Aviation Organisation (ICAO) decided flights above the ash cloud will be permitted in the UK; between 1300-1900 this will enable aircraft movements above 20,000ft in UK airspace.
We will continue to monitor Met Office information and the situation is likely to change during the course of the day. We will make a further statement at approximately 1500.
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 working closely with Government, airports and airlines, and airframe and aero engine manufacturers to get a better understanding of the effects of the ash cloud and to seek solutions.

[kinsman]

NATS are responding to information given by the Met office and god knows who else but they cannot make a decision regarding the safety of the airspace but only react to the information they are given and at the moment that information may be floored. NATS is as much at the mercy of these people as the rest of us!

[tcmel]

Notam B0798/10 Has Been Published Stating That Aircraft May
Overflycontaminated Areas Within Uk Airspace From 0300z 20th
April Subjectto The Conditions Stated In The Notam.
.
Based On The Vaac Advisory Timed 0000z April 20th The Scottish
Fir/uir Outside Of The Contaminated Area Will Open At 0600z April
20th. The London Fir/uir Remains Zero Rated Below Fl200 Until
Further Notice.
.
Caution, Current Forecasts Indicate That The Situation Is
Changing Through The Day And Diversion Airfields May Be A
Significant Distance From The Original Destination
.
Flights Intending To Operate In The London And Scottish Uir's
Abovefl200 That Are Still Caught In Zero Rates Should Contact
Ukfmp To Be Excluded
.
Ukfmp ++441489588150

[Bruce Wayne]

ZQA297/30,

A LOT of operators do engine oil analysis, its a very cheap way of monitoring the condition of a very expensive engine. I have paid 180 bucks for an oil analysis.

Borescope inspections are routine, any maintenance facility will have a 4 grand Olympus borescope, again its a very cheap way of inspecting an expensive engine can be done on wing if need be and allows a visual without having to break the sections open with the time involved in the shop and often if you break a section open then you may have to perform an expensive and unneeded overhaul on disks and blades in that section.

It's understandable that perhaps non-aviation, non-pilots may have concerns through lack of knowledge, but for commercial pilots to have so little knowledge of how aircraft and their engines work and are maintained would be surprising.

Yet comparatively, is anyone that concerned about an aircraft that has been stored in a region less than 200 miles from a coastal area ?

Corrosion to blades (exacerbated by marine moisture) and disks is equally damaging (in different ways) to blades and disks, often the damage is enough to leave an engine subject to overhaul if a chemical bath and test cell run shows the damage more than superficial.

[stalling attitude]

What frustrates me at the moment is how we as pilots are supposed to be the experts in our field i.e flying aircraft and jump down anyones throat on here who dares suggest otherwise and yet many on here feel that it is ok to question the competence of the experts in other fields such as Met and Nats. I am no expert on volcanic eruptions and so am more than happy to listen to those who are and are basing their decisions on the best available data and models.

[call100]

Latest from NATS conference call..............

The current position is:

· The volcano is still erupting with plume up to 10000 to 15000 feet as advised by Iceland Met;
· Ash concentrations over 20000 feet are “dissipating” but “maintaining a significant risk over most of Europe”;
· UK position is “variable” but no current plans to open any more airspace other than Scotland FIR. However on current predictions by 1300 local today Inverness, Edinburgh, Aberdeen and Newcastle should remain open but Glasgow, Prestwick and Prestwick may fall in contaminated area and fall out of the able to fly zone;
· At 1200 today decisions to be taken on the status of the component parts of UK airspace for the period from 1800 to 2400 – this will be issued on NOTAM;
· There are ongoing discussions between NATS and CAA as to some agreement on flying over / around cloud contamination using “hot spots” and “caution zones” but no agreement reached so far. NATS say they are pressing for a change of policy from CAA;
· Wind direction is expected to change by the end of the week turning to a west / south westerly direction;
· The issue of VFR was raised with comments re aircraft flying VFR below 21000 feet to Frankfurt;
· Met office plane will be flying from 1230 local around the UK to gather data on actual ash concentrations / contamination.

[Flyt3est]

Bruce,

I'd question the validity of Spectrometric Oil Analysis in this case, since the affected areas we are talking about on the engines aren't part of the wet system. Also Borescopes are not the be all and end all.. far from it. Yes you can check parts of the combustion chamber, and you can also check the first few compressor stages and one maybe two stages of the turbine if you are lucky, but the checks are a long way from being comprehensive.

FT

[OutsideCAS]

so, once again - why do the UK CAA not borescope the a/c of operators that have been regularily flying over the duration of the ban ?? as Bruce states, relatively cheap and should yield a conclusive answer as to whether any damage occurs over a sustained period or whether it is perfectly safe ?

[HEATHROW DIRECTOR]

<<why do the UK CAA not borescope the a/c of operators that have been regularily flying over the duration of the ban ??>>

Which opereators, please? Today is the first time I have seen an overflight since last Thursday, at that one seemd to be all alone in southern UK airspace. There have been some low-level light aircraft and business jets but I'd hardly call them regular...

[coool guy]

Whippersnapper,
Most of Europe appears to have taken the bit and started flying tentatively at least, are you saying they are all reckless fools? You have now backpeddled and tried to justify closure by claiming the cloud is worse over the UK even though it is clearly shown pretty much everywhere. At this rate you will still be sticking to your guns when the dust is falling on your head alone! I admire your tenacity but not your logic or common sense.

[tocamak]

Given the likelihood that LHR will be closed for most of the day at least I am surprised that BA (KLM, LH etc) who conducted test flights have not been even more forceful with their comments. Surely by now they would have been in a position to state exactly what they found on post-flight inspection rather than the rather vague "all was normal during the flight".

[Nemrytter]

Hello JetII

[Squawk_ident]

The only good news is about the weather. No clouds, blue sky, Cavok etc on most part of Europe. Important because it seems that the German airpace (and some others also) is closed for... IFR flights. Consequently only VFR for takeoff and landing. Just imagine what the situation would be if it was fog or pouring rain. The French are closed up to FL205 but we have our corridors to allow aircraft inside!

[OutsideCAS]

Heathrow Director,

Iceland volcano ash cloud flight risk 'blown out of proportion' airline claims | Metro.co.uk (http://www.metro.co.uk/news/822250-iceland-volcano-ash-cloud-flight-risk-blown-out-of-proportion-airline-claims)

well, for starters these guys seem to have been fairly regular - maybe not as the normal airline's on a normal day but surely a step in the right direction with regard to borescope inspection ??

[TRC]

I'd question the validity of Spectrometric Oil Analysis in this case, since the affected areas we are talking about on the engines aren't part of the wet system


There is probably a chance of contaminated air getting into the oil system via balancing air for the labyrinth seals.

PWC recommend an oil change in the event of flight through volcanic ash.

[Bruce Wayne]

I'd question the validity of Spectrometric Oil Analysis in this case, since the affected areas we are talking about on the engines aren't part of the wet system. Also Borescopes are not the be all and end all.. far from it. Yes you can check parts of the combustion chamber, and you can also check the forst few compressor stages and one maybe two stages of the turbine if you are lucky, but the checks are a long way from being comprehensive


Fly3est,

I didn't say Oil analysis would be in this case.

No, 'scopes are not the be all and end all, i didn't say they were either.

And it depends on the engine type what you can inspect, on the engines i have owned (all off wing from 737) have been able to inspect all the LPC, all the HPC and the T1 blades and disks. I have about 40 scope video on my shelf behind me, some of those engines I have owned some I have not.

As I said, what they enable is an understanding of what is going on, or rather, what has gone on in the engine without having to break it open and subject yourself to unnecessary maintence.

In the case of contaminant ingestion in this case, we know that damage can occur from the combustion chamber backwards and with the T1 operating higher than the material limits, as such a scope of the T section will provide an indicator of any damage due to contaminant ingestion.

I would rather scope an engine than not.

[Airclues]

The 'ash cloud' charts produced by the Met Office are computer predictions of where the ash might be, taking into account the wind at various levels. As is stated below the maps, they do not indicate the concentration (if any) of the ash.

Should we stop calling it an ash cloud and now call it an 'area of computer predicted possibility'?

[kinsman]

Right I have counted to ten!

Given the circumstances it was probably prudent to take drastic action last week but given the nature of the problem several things should by now have happened and have not.

Those making the decisions should have instigated a comprehensive flight test program in collaboration with the engine and airframe manufacturers. Had they done so we would now have some solid data on which to base the decisions being made. However, none of this has happened or at least only to a very limited degree and it has fallen to a few airlines to put aircraft up, at their own expense, to see what effects the ash cloud actually has, apparently only to have their findings largely ignored.

Military fighter engines are very different animals to civilian engines and may be more susceptible to such damage. The point is we need data and we need to start getting it now as this volcano is not going away anytime soon it would appear and even if the weather pattern moves the cloud away we a very likely to be back in this position within a few weeks.

Doing nothing and closing airspace as a precaution is not not an option, we face an economic catastrophe and not just in the airline world. If this ash cloud is dangerous fair enough but we need data and we need it now. What we don't need is a devastated economy based on assumptions and poor or no science!

[Jonty]

Spot on!

EU and national government have been too slow to act on this.

[Bruce Wayne]

so, once again - why do the UK CAA not borescope the a/c of operators that have been regularily flying over the duration of the ban ?? as Bruce states, relatively cheap and should yield a conclusive answer as to whether any damage occurs over a sustained period or whether it is perfectly safe ?


Becuase the CAA has no authority to do so on foreign registered aircraft overflying UK airspace.

Then, the CAA doesnt have the equipment or the capacity to do so.

Then, Ok they scope the engine, then what ?

It's the A&P that signs it off, he's regulated by the authority, but it's his a$$ that he signing off on a Form 1. :}

[ZQA297/30]

Bruce,
I think you are missing my point.
I set up spectro analysis on a small fleet of DC-6Bs way back in 1974, and it was so effective that we could tell who had been using fast idle on #4 to boost cabin ground cooling.(High Si)
Thing is, it is not normal to check for Sulphur which is not an expected wear product. This was the clue for NASA.

How frequent are scheduled Borescope checks? What is the interval?
I am aware of blade contamination from sulphur products in fuel (and additives eg water methanol in turbo-props) We used to walnut shell blast compressors for salt air contamination. Volcanic ash was not among the contaminants we used to to deal with. What are the procedures?

[SILENT_BADGER]

It certainly seems to me that not enough data gathering is going on. The handful of planes going up through the levels and hanging around for an hour or so trying to make a point didn't really prove much because they couldn't measure what level of ash they actually encountered.

The NASA document on their accidental ash encounter was a real eye opener on the insidious danger posed by the cumulative effect of diffuse ash. Certainly scared me.

Ideally we'd have got all the military/scientific aircraft available worldwide flying round and round for as long as possible over the last week then getting their engines boroscoped/stripped down in an effort to quantify things. Until we're able to say something like x g/m3 = y safe hrs between boroscope inspections then we're stuck I'd guess.

Without this aren't we looking at a future of trying to operate long term with long periods of lockdown followed by massive repatriation efforts. Would the public adjust to that, going on holiday thinking they had a 50/50 chance of getting home on time?

Unless we put this volcano out of course. I saw this cartoon once and all they needed was a really big bucket of water.

[OutsideCAS]

Bruce,

Only scope UK operators ?

Maybe the CAA obtain the services of an engineer with a borescope and expertise in analysis of the engine core ?

Then, assess the results and come to a conclusion - maybe publish the results for all to see ?


I'm no expert but it seems logical to me, purely to gain an insight of some sorts if nothing else.

I really can't see the objection to an investigation of the exposed airframes and engines in order to clear this whole sorry mess up and all being well get things flying as normal.

[Flyt3est]

Bruce I would rather scope an engine than not

I agree 100%, I am just raising a question as to whether a borescope inspection is sufficient to clear a passenger carrying flight following events, the effects of which are relatively poorly understood. I am thinking a comprehensive test flight through the anticipated environments, followed by a thorough engine inspection upon which less intrusive maintenance operations / inspections may be based, might be a more robust solution to an otherwise much speculated issue?

I am coming from a point of view of getting aircraft flying whilst mitigating as much risk as possible in the interests of safety, as opposed to "I have seen tons of aircraft on an internet screen so it must be alright" - Not that I am suggesting that's your point of view, I understand we are both batting off the same crease. :ok:

FT

[kinsman]

ZQA297/30

Good questions! I know the engines are scoped on major checks but not on daily or weekly checks. This would need to change whilst this cloud is affecting airspace. I have no doubt we would need to carry out a range of checks on the engines and pitot static systems post flight as long as the aircraft are operating in the area of the ash cloud.

Again these are procedures I hope someone is working on now. I believe the BA aircraft will have been subjected to a wide range of inspections as it is no coincidence the aircraft flew to Cardiff, as this is a heavy maintenance base for BA.

I suspect the authorities have had a full report from BA but I doubt BA will publish this to the public other than making vague statements for very obvious liability reasons.

[mickjoebill]

Diamond Airborne Sensing : A Diamond aircraft delivers volcanic ash cloud measurement data (http://www.diamond-sensing.com/news_detail1+M5edeec65255.html)

"Since Saturday, a Diamond HK36 MPP (Multi Purpose Platform), operating at MetAir, the Swiss airborne measurement company, is providing the only specific measurement data from the ash cloud of volcano Eyjafjallajökull.

...The results clearly show that the ash particle concentration is remarkably high and noticeably decreases visibility. Additionally, the ash cloud loses altitude very quickly. At the beginning of the measurement flights the cloud was at an altitude of 5000 meters but only nine hours later it had descended to just 2000 meters....

.....are able to fly in the heavy aerosol particle concentration due to being equipped with a special air filter."

Video of the flight here.
Schweizer Fernsehen: SF Videoportal - Tagesschau - Flug in Aschewolke (http://videoportal.sf.tv/video?id=3297749b-2bb3-4a28-8a9d-48aad952e879)
The HK36 MPP is a single engine internal combustion engine aircraft.


Mickjoebill

[ianmt36]

Could somebody explain why VFR and IFR are treated differently?
If this is about ash density VFR / IFR seems to be irrelevant and a VFR flight will be just as safe / dangerous as an IFR flight in the same density

or is it just simpler to control ifr traffic ?

[Bruce Wayne]

ZQA297/30,

I think we are aiming for the same target, but from different angles.

In terms of scheduled borescope inspection, thats up to the operator, on how they want to monitor the condition of their engines. As I am sure you are aware an engine in the shop is not only costly in terms of maintenance but also in terms of down time, unless of course you have a spare engine you can spin on wing in the interim, then of course if you have multiples then what about spare engine quantities and that is a lot of money to tie up and of course your spare engine is calendaring out while its on a stand, unless it is subject to a an approved storage program.

The upshot is that, as I am sure you are aware, an operator wants to preserve its engines.

An operator i used to work for, it was a sackable offence to go over 95% The types we operated would get off at 92% MTOW, hot and high at our shortest runway limits. Anything above that was toasting the engines and burning dollar bills.



Volcanic ash was not among the contaminants we used to to deal with. What are the procedures?


What are the concentration levels ?

Like I said, we seem to be on the same target but from different angles.

[Whippersnapper]

Whippersnapper,
Most of Europe appears to have taken the bit and started flying tentatively at least, are you saying they are all reckless fools? You have now backpeddled and tried to justify closure by claiming the cloud is worse over the UK even though it is clearly shown pretty much everywhere. At this rate you will still be sticking to your guns when the dust is falling on your head alone! I admire your tenacity but not your logic or common sense.Tentative flights are fine, if frequent inspections are made, but a return to full scale ops is reckless.

The problems in continental Europe will be less than in the UK for the reason I clearly explained - the plume passes over the UK in a narrow corridor before spreading east and west as it reaches the Channel, diffusing as it spreads. If you cannot grasp that, I pity you.

At no point have I back pedalled - you are claiming a false victory because you, like many others, can't understand the logic of the argument. I have maintained throughout that we simply don't know whether the ash levels are safe or not because too little research has been available. The evidence seems to support the view that it is unsafe, but those supporting a return to normal ops are keener to show traits of machismo than prudence or intelligence.

The severity of the implications of this risk demand that it be treated with the utmost seriousness and caution. It is one thing for an aircraft to have failures of all engines, but it is quite another to have dozens of simultaneous emergencies, with the ATC and airport saturation which would occur. Just imagine two or more aircraft needing to make glide or partial power approaches to the same airport at the same time, and other aircraft with damaged engines having to hold or divert for them. Do you really want to risk being a part of that?

As I said before, I really don't know whether it's safe or not, and nor does anyone on here, but I'll hedge my bets with the cautious side, especially since they're the ones with the evidence to back them up. the old mantra of "if there's doubt" seems to be being wilfully ignored by many so called "professionals", adding weight to the companies' positions when they try to force us all to fly in unsafe circumstances and strengthening the management position of money over safety.

[OutsideCAS]

IFALPA spokesman Gideon Ewers just seen on BBC News stating similar thoughts with regard to inspection on aircraft exposed to low levels of particulate and stating that it is better to be on "the safe side" with regard to flying under the current circumstances.

comments/thoughts ? personally, seemed logical to me.

[ChalfontFlyer]

Understand from a source in BA that at least 6 long haul fleet flights are now en-route for LHR hoping to make it in time for this evening's 'window' as per the earlier NATS press release.

[Martin2116]

Everywhere in N Europe they are now flying (flightradar24.com). But over England a big empty space. What an absolute nonsense: nobody here wants to take responsibility for the decision, nothing to do with the technicalities of ash concentrations: look at the maps from VAAC/Met Office. Its just indecision, pure and simple.

[pete999]

Interesting, balanced article:

The Great Debate UK Debate Archive Impact of the volcano disruption on the airlines | The Great Debate | (http://blogs.reuters.com/great-debate-uk/2010/04/20/impact-of-the-volcano-disruption-on-the-airline-industry/)

[13Alpha]

Everywhere in N Europe they are now flying (flightradar24.com). But over England a big empty space. What an absolute nonsense: nobody here wants to take responsibility for the decision, nothing to do with the technicalities of ash concentrations: look at the maps from VAAC/Met Office. Its just indecision, pure and simple.


Au contraire. A decision was made - just one you don't agree with.

Scottish airspace has been opened - was that the result of indecision as well ?

13Alpha

[Re-Heat]

Everywhere in N Europe they are now flying (flightradar24.com). But over England a big empty space. What an absolute nonsense: nobody here wants to take responsibility for the decision, nothing to do with the technicalities of ash concentrations: look at the maps from VAAC/Met Office. Its just indecision, pure and simple.
Being the closest island from Iceland in the direction in which the wind is prevailing, it's not a big surprise that we get the worst of it.

Maybe its the days of not having a clue when i will fly again that's pickled my brain. But how can we have a Scottish FIR open the most Northern airspace that is first to be impacted but no other airspace opened. Is our data so accurate that we can open a airfield in the north such as Newcastle at 13:00 but not Manchester, Leeds, Doncaster? Come on.
Why don't you just look at the Met Office charts and think about it logically?

[TRC]

I am neither for nor against an immediate return to normal operations, so I don't want any flaming from the two opposite sides of this debate.

I find it interesting that there has been so much emphasis on the so-called 'test flights' by KLM, BA, etc., but hardly a mention of the flights by G-CALM and the Swiss DA42 quoted a few posts ago.

Both of these well equipped aircraft found significant contamination in the air at various levels from 5000m down.

Why has there been so little mention of these findings?

[dougie247]

Source at NATS on BBC:

"Flights in the south of the UK are unlikely to resume on Tuesday."

BBC News - Some UK flights resume after volcanic ash disruption (http://news.bbc.co.uk/1/hi/uk/8631326.stm)

[tocamak]

Everywhere in N Europe they are now flying

Largely true but of course a rather general remark which ignores Poland, Denmark and Norway

From the BBC website (so caveat about accuracy):-

EUROPEAN AIRSPACE 0900
BELGIUM - Airspace open: Some planes landing, flights to depart from 1200 GMT
UK - Airspace open over Scotland and Northern Ireland. Limited airspace over north of England. London airports remain closed
FRANCE - Plans to re-open airports progressively on Tuesday
GERMANY - Airspace closed, with some exceptions, until at 1200 GMT on Tuesday. Lufthansa planning to operate 200 flights
IRELAND - Airspace closed until 1200 GMT on Tuesday
ITALY - Airspace open
NETHERLANDS - Airspace open. Passenger flights arriving and departing in Amsterdam
SPAIN - Airspace open; 17 airports operating
SWEDEN - Airspace open
SWITZERLAND - Airspace open
DENMARK - Airspace closed
NORWAY - Airspace closed
POLAND - Airspace closed

[belowradar]

I am surprised that it is NATS who decide, why can't Airlines and Aircraft manufacturers decide based on engineering knowledge and experience of previous and data from current eruptions.

If not an over reaction then why is NO IFR flight allowed in UK ? Piston aircraft are not having problems ??

[eagle21]

SPAIN - Airspace open; 17 airports operating


Not correct , all airports are now open to traffic.

www.aena.es

[judge11]

Of course this is political. The decision to close UK airspace will have been taken at the highest level of government. NATS has been presented as the front for the imposition of these restrictions and it, and the Met Office (they of the 'barbecue summer' computer prediction models) can conveniently take the justified ire of the public and the airline industry.

The real decision makers ie government will happily hide behind NATS and Met office to avoid the embarassment that the initial decision to close airspace was taken without an iota (or micron) of empirical data.:ugh:

[flying brain]

Engine inspections carried out on the Airbus A380 and A340-600 sent up yesterday to assess the effects of the volcanic ash cloud did not uncover any problems.

Airbus used two previously-scheduled development test flights to fly into the ash cloud to monitor engine performance and to assess any potential damage caused by ash particles.

"The post-flight inspection showed no irregularities. We have passed the information to the engine manufacturers and the airworthiness authorities and it will be the role of the authorities to make a decision based on that," says an Airbus spokesman.

A380 MSN004, powered by Engine Alliance GP7200 engines, landed back in Toulouse at 18:00 local time yesterday after a 3hr 55min flight. A340-600 MSN360, powered by Rolls-Royce Trent 500s, landed at 19.40 after flying for five hours.

The A380 operated within French airspace, while the A340-600 operated in French and German airspace.

Airbus' spokesman says that during the test flight the two aircraft "would have visited altitudes that airlines would normally visit".

Source: Air Transport Intelligence

[Denti]

I do think the current flight operation in parts of europe is more than questionable. For example in germany you have to fly VFR until you are out of the restricted area which is GND to FL 195. Now all the airlines are flying VFR without any training to do so (yes, everyone started out flying VFR, however for many that is more than 20 years ago), questionable documentation and in parts of germany IMC conditions.

Safety first? Yes, of course, as long as it doesn't have an impact on the bottom line, lets hope we will be spared a bigger incident or accident.

[B777FD]

OK, from nats.co.uk:

Overnight the CAA, in line with new guidance from the International Civil Aviation Organisation (ICAO) decided flights above the ash cloud will be permitted in the UK; between 1300-1900 this will enable aircraft movements above 20,000ft in UK airspace.

That explains it!

[mixture]

Safety first? Yes, of course, as long as it doesn't have an impact on the bottom line,

Huh ? Your statement doesn't make sense. How can you say "yes" to safety and then immediately say "as long as it has no impact on bottom line". You are contradicting yourself.

Commercial pressures must never impact on safety. :ugh:

[cats_five]

And another thing aircraft are flying all over the UK without problems outside controlled airspace including gas turbine powered aircraft again without problems! :ugh:

Apparently without problems now. Maybe with problems in the future.

[neila83]

Is not not sensible really that in the UK we wait until the wind changes, at which time we can be sure the ash has cleared? Frankly I really don't like the idea of someone being on an ETOPS mission, an engine cutting out, and then spending however many hours looking out the window at that one remaining engine, crossing your fingers aware that it has been operating in and out of ash for several days. Isn't the whole point of ETOPS to remove any possible non-independent sources of failure? I don't see how engines operating in these conditions can be ETOPS certifiable, are they going to be doing full detailed inspections after every flight? If they're running normal schedules, impossible surely? I don't know, maybe the engineers can help here.

And a few more days shut down (wind changes fri/sat) is probably a lot cheaper than a fleet of wrecked planes. I actually think this is pretty much what will happen, the UK will stay shut, unless the volcano actually remains far less active, the airlines are somewhat less suicidal than some on here appear to be. Note BA appear to be accepting operations may not commence today without protest.

And please can people use a bit of nuance and try to understand the perfectly logical basis behind the UK being shut while other areas are open, it's not that difficult, but some are determined to ignore any evidence that doesn't support their position:
a) the UK is nearer Iceland than Continental Europe is
b) prevailing winds have been driving the ash cloud west when it gets to the north sea, so the densest part travels straight over SE England, avoiding the continent.
Is that so hard?

[Matt101]

Just as a point of order.

The material being ejected from this volcano is not in someway completely different to other volcanoes as some have said. Most rhyolitic rock is about 70% silica - and that is believed to damage aircraft engines. The rest is commonly mixtures of quartz, feldspar, biotite and hornblende along with some other minerals I have clearly forgotten. But the crux is the the SiO2.

If you read the contributions from volcanologists on this thread or indeed if you do some research yourself, or have a basic understanding of eruptions, what they are saying is that this is a specific type of eruption. One which involves water/steam (phreatic eruptions/phreatomagmatic eruptions respectively). This is because the Volcano sits beneath a large Glacier.

The rapid thermal contraction which occurs in these instances produces an explosive eruption, which in turn produces particles of ash in sizes from clay to sand which can be thrown high into the atmosphere and in this case inconveniently into a jet stream bound for Northern Europe.

Please desist with the "but this is magical ash" comments. It is not accurate.

Moreover this is not the first explosive eruption to have occurred.

[SussexDon]

The Green Party is loving all this. I run a small aircraft leasing company, and am expecting airlines not to pay us this month, what about all the ancilliary businesses that rely on aviation from taxi drivers to fruit importers.
I am sure this is all nonsense. I cant see how engines cut out because of this, no one is saying fly through the plume of the volcano, we are 800 miles away! What I can see is engines going to shop visits sooner than before, but if this crazyness does not stop soon there will be no aviation industry in Europe. Most people asked "would you fly at the moment" say "no"
BBC - Have Your Say: Would you fly? (http://www.bbc.co.uk/blogs/haveyoursay/2010/04/would_you_fly.html)
so suggest all of you say you would be prepared to fly (that is of course if you are so willing) otherwise the media will be reporting that the majority of people dont want to fly and the politicians wont step in.

[DCS99]

Worth a read

"Mystic Met closed Europe with computer model - And not much data"

Mystic Met closed Europe with computer model ? The Register (http://www.theregister.co.uk/2010/04/20/mystic_met_volcano_model/)

I worked with the son of Barry T-F, (FE on BA009) so I know a little about volcanic ash, but I can't really knock El Register's critique of what's been happening.

At least we are starting to see Departures from ZRH now...

[Faire d'income]

I used satire to highlight the idiocy of the 'tests' being conducted but that seems to be unacceptable here. I'll put it another way. Non-test pilots using no scientific equipment randomly flying hither and tither is about as useful as throwing paper airplanes around and drawing sweeping conclusions from their journeys.

Quack medicine has its place, but not in aviation.

[orionsbelt]

1 What is the ICAO standard for Ash emissions - how many ppm etc

2 If there is an ICAO Ash standard why is it not applied to the whole world.

3 Based on that supposed standard why are flights in South East Asia permitted within 2000 km of Jakarta, while they are not permitted in the UK/EU etc.
( Just Goggle Earth and look at Indonesia )

4Can the Met Office / CAA publish data for the total areas of the no fly zone to justify the decisions.

Sorry if these points have already covered but my flight this evening to collect my wife has been cancelled.

***

[BoughtTheFarm]

It's clear from the posts here and the generally available information that there's no firm and conclusive position on this issue. Of course safety first. Of course, consideration to the economic impact downstream. But, this issue may be a 'first', but there are warnings that it may not be over and could resurrect itself in the coming days weeks and months. In the unthinkable position of airspace being closed down like this going forward for a number of times of equal or greater length, then there needs to be a Plan B.

Whilst I accept the modelling of the MO and the response by NATS and Eurocontrol I'm still a little bothered by the lack of empirical evidence. The BA flight spent much of its time above FL200 so I'm not sure how valuable that 'test' was. Right now we have clear skies (forgive the pun) and for me at any rate a need to perform some flight tests up to FL200 across the whole of UK airspace and indeed the same in mainland Europe and start getting empirical evidence of what the true impact of this is on airframes and engines. Not to solve the problem today as such but to gain the much needed instrumentation to plan for if this happens again.

Apart from people stuck out of position (not to mention a/c) we need to consider medical supplies, transplants and vital product import / export via cargo flights. None of these can take priority over air safety, but I'm yet to be conviced we have conducted here in the UK or across Europe the definitive due diligence to fully understand the impact to this at an engineering level. Without that, and the feedback from a/c and aero engine manufacturers we will still be, to some extent, guessing on the impact. Air safety needs more than this. These are unusual times and we therefore need unusual solutions and I think a more diligent set of airborn tests are needed. The MO can tell us what they predict is going on up there. NATS can take the correct route of caution, BUT, if much of this is hidden behind lack of empirical facts then whilst the current issue may resolve itself through a meteorogical change later this week (and I do hope so), we currently have the window of opportunity to conduct much more stringent and in depth testing of cause and effect. And yes, this means being airborn in one way or another. I'd like to see more effort put into this to equip us with a better engineering perspective than we currently have. Right now, it appears there are differing lines of action and behaviour across Europe and we need a consensus with the fact to support it. Until we have them and the chance to debate them, any repeat of this may leave us no further forward with only a repeat of the same. We cannot afford to have that - on any level. FL200 or otherwise.

[stagger]

Frankly I really don't like the idea of someone being on an ETOPS mission, an engine cutting out, and then spending however many hours looking out the window at that one remaining engine, crossing your fingers aware that it has been operating in and out of ash for several days. Isn't the whole point of ETOPS to remove any possible non-independent sources of failure? I don't see how engines operating in these conditions can be ETOPS certifiable, are they going to be doing full detailed inspections after every flight? If they're running normal schedules, impossible surely? I don't know, maybe the engineers can help here.

Indeed! This is exactly the point I was trying to make earlier.

ETOPS certification depends on a documented IFSD rate of less than 0.02 per 1,000 hours. But this exceptional level of reliability was not achieved with engines that were operated in areas of significant volcanic ash exposure for a period of several days or weeks.

The issue I was trying to get at (and that neila83 has explained) is not whether the ash causes immediate IFSDs - but whether engines operated in this environment have an IFSD rate > 0.02 per 1000 in the coming months.

[EPPO]

There are a number of active volcanoes right now over the world, yet it looks like there are no flying restrictions in Ecuador and Colombia, other than the advisory of avoiding immediate vicinity of the volcanoes.

Current Volcanic Ash Advisories - Washington VAAC - Satellite Services Division / Office of Satellite Data Processing and Distribution (http://www.ssd.noaa.gov/VAAC/messages.html)

From these reports, it's clear that satellites can do a good job on detecting ash concentration. Why are they resorting to computer simulations then?

[800m RVR]

Maybe they do have some good data now....

https://www.cfmu.eurocontrol.int/PUBPORTAL/gateway/spec/PORTAL.14.0.0.P.254.53/_res/2004_0600UTC_Volcan_FIRs.pdf

But if this is accurate begs the question why UK airspace is not open for business...

[Man-on-the-fence]

The issue I was trying to get at (and that neila83 has explained) is not whether the ash causes immediate IFSDs - but whether engines operated in this environment have an IFSD rate > 0.02 per 1000 in the coming months.Your point is valid however the point becomes moot when you end up with a fleet of aircraft parked with perfect engines because the airline has gone out of business.

As with all things in life there is a balance to be struck, those who take a position at the extremes of both sides are possibly being either too cautious or too reckless.

[kinsman]

Cats Five

There will be no damage to these aircraft and history will prove it but sadly not until irreparable damage has been done to the economy. Just been listening to Radio 2 and a professor of geology who was having his moment of fame! Even he admitted they just don't know!

So lets get the information Airbus clearly don't see a problem in the short term and if more inspections are required and ultimately long term engine life is reduced I am sure that will be acceptable to the airlines given the current level of costs of not flying.

This is nothing new this happens around the world all the time without this over reaction.

[wxjedi]

Heres the latest

http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271763280.png

Get me home!!!!!!!

Tom

[cats_five]

There will be no damage to these aircraft
<snip>

References? Sources? So far as I can tell no-one actually knows what the answer to this is so stating it as a fact is sticking your neck out - a long way.

[Roy Kemp]

As I see it the data required for a decision is:
1) The concentration of ash in the air at different locations and altitudes.
2) The allowable concentration for safe flight.

The first can be gathered by data collecting flights which appears to be being done.

For the second, is it practicable to run a test bed engine (on the ground) and feed known concentrations of ash through it to determine this limit?

What do you think ?

[kinsman]

BoughtTheFarm

The problem is the MET office do not have the equipment to accurately model the movement of content/density of the ash and cannot predict it's effects on aircraft systems which is why we need to get more test aircraft up there.

Someone mentioned that a some measurements had been made and we were not referring to the fact they found dangerous levels of ash at some levels. The question is dangerous to what? What are they basing this assertion on? The aircraft making the measurements returned safely. Was it inspected? Did it suffer damage? Apparently not.

Data, hard data not hysterics and over reaction!

[iwantmyhols]

roy that sounds far too much like a real scientific exp that could give out useful data!- much better to just send planes up willy nilly with no data instruments and bring back down safely to prove all is ok. Then we can open up safe paths through ash- that change hourly so that pilots and passangers can all go on mystery flights taking off with no idea exactly where they will land if the parting of the ash moves abit. So much data recording time to planned sets of exps has been lost already.

[kinsman]

Cats Five

My data is my own aircraft which I have been flying since Thursday which has been inspected.

35 years and 20,000 hours flying round the world where these events are common!

[fireflybob]

From today's Daily Telegraph (in fact the paper headline is "Met Office got it wrong over ban on flights")

Volcanic ash cloud: Met Office blamed for unnecessary six-day closure (http://www.telegraph.co.uk/news/7608722/Volcanic-ash-cloud-Met-Office-blamed-for-unnecessary-six-day-closure.html)

[Mariner9]

From Lloyds List:

Jet fuel trade invokes force majeure
Martyn Wingrove - Tuesday 20 April 2010
TRADERS of jet fuel have called force majeure on deliveries to the UK on long range product tankers because of the cancellation of flights, writes Martyn Wingrove .
The UK is one of the largest hubs for jet fuel in Europe and deliveries through at least five ports in southern England and Wales will be affected, as product is usually immediately piped to airports to supply aircraft.
One London shipbroker said product tankers would be unable to discharge cargoes at Avonmouth, Fawley, Thames terminals, Milford Haven and Immingham, so suppliers have called force majeure on deliveries.
“Tanks are full in airports and everything is stacking up. There is no where to put the jet fuel so it will have to remain in the tankers. Ships with jet fuel on board will have to sit there on demurrage or owners will renegotiate some sort of storage rate,” a London broker said.
Another broker said the impact on deliveries would be temporary: “Once the ash cloud disappears, demand will catch up. But if it goes on for weeks, then we will see more floating storage of jet fuel.”
Brokers expect jet fuel deliveries to Le Havre, Copenhagen and ports in the Amsterdam-Rotterdam- Antwerp area will also be affected if flights from nearby airports also remain affected by the volcanic ash cloud.
Since all north European flights were banned, jet fuel consumption has dropped by 1m barrels per day, or about a fifth of global consumption. European stocks have risen by 5m barrels.

[iwantmyhols]

kinsman - how many flying miles did nasa have before they tried to use a D- rings beyond there certified test temp. limits. Equip comes with limits for reasons. If no limits have been established then it should only be used within the routine levels used in testing. Thus, if now required, new limits should be sought, by means test experiments- as is the case for SiO2 levels of safety in the ash. It will take time yes- but for facts on safety rather than deductions - that is what is required. You may be completly correct and it may be totaly safe to fly in the ash now - but that at the moment that can only be assumed and is not proven.

[Nemrytter]

Hello JetII

[MineDog]

How can we state that flying VFR (in Germany below F200) can be the safest option you can think of? Esp. since part of Germany is cloudy right now with a BKN layer below well below 5000' (giving HAM as a example). And what is gonna happen @ night in this case. Will we consider it to be the safest option to fly night VFR up to F200? I frankly do not understand this VFR up to F200 thing, especially since it has been confirmed much of the ash is invisible to the naked eye... Can someone comment on this one?

[BoughtTheFarm]

Well that makes 10 inbound to LHR from the US. Can't wait to see if more are on their way. I wonder what consideration exist if they do arrive about passing through FL200 into LHR? And if you can have 10 descents through FL200 why not have climbs out to FL200+++? Don't want to end up focussing on this all day, but at least it's tangible data in real time (at least if the feed is accurate). Anyone know crew on these inbounds?

[Wildfire101]

:confused:
I read a lot of hysteria about the volcanic activity and it's outfall - this Forum is generally matter of fact and logical - suit me! with the odd spattering of trolls - where hasn't.

The current situation seems to have caught the airborne fraternity off guard - primarily due to the distinct lack of applicable information!

Met office can tell what's floating around in the atmosphere - debates on the accuracy are just that! we've had very little reason to delve deeper and pick out individual substances.
The engine and frame manufacturers have limited info on damage limitations and mitigations to counter adverse impact.
Operators are working to the letter supplied by the manufacturers.

Ok! my point is that we (Goverment, Military & Commercial Carriers) need to use this period of 'low activity' to collect info on the respective ash concentrations and compound effect on airframes.
The current activity is relatively minor, however has had a profound effect on our ability to maintain air travel around and to & from the UK, if as the volcanologists predict 'prolonged activity may set off Katla' this would effectively stut down operations from the UK for months and years, as opposed to days.

In collecting samples, and determining damage, would it not be possible to utilise a platform with two turbine engines and two Internal Combustion engines - the level of damage to the turbines could be monitored after each flight and then set updated maintenance levels for flying in a similar environment. The two Internal combustion engines with decent air filters would ensure that the airframe could maintain flight throughout the assessment.

Thanks!

[eagle21]

Maybe they do have some good data now....

https://www.cfmu.eurocontrol.int/PUB...olcan_FIRs.pdf

But if this is accurate begs the question why UK airspace is not open for business...


I agree rather strange. It seems that in the UK nobody is willing to take responsability for allowing flights. If the airspace is not openned soon they will start looking like clowns.

In most cases the most simplistic approach is the best one, but NATS(goverment,...) are just trying to stay legal. Common sense must prevail. Who cares about long term damage to engines now, if we don't start flying soon there will not be airlines. Let's save the industry and then worry about long term implications.

The response from the UK is arriving late, far too late...

[22 Degree Halo]

Rumours, stress rumours, about Flybe BE128 flight from GLA to BHD "may have suffered damage". I know no more. Anyone? Bull**** gossiping or .... ?

EDIT: LINK (http://volcanicdisruption.webs.com/apps/blog/show/3512455-latest-update-12-30pm-20-04-2010)

[MineDog]

ASH LAYER on arriving aircraft into AMS (arkefly from Antalya) this morning causing big concern. After inspection the ship has been released back to service. How long does it take to do a boroscopic I wonder?

[Bruce Wayne]

The MET office, like every other meteorological institute has access to data that can provide the ash density with an accuracy of around +-30%. The ash extent/movement can be mapped to within 6km at worst and 500m at best.

I was, however, unaware that the MET office was supposed to predict the effects of ash upon aircraft.


Simonpro,

As you are well aware, no one has suggested that the MET office should provide predictions as to the effects of ash on aircraft. indeed, we are well aware of what the effects are and how those effects occur in large concentration.

if the MET office can provide ash density figures with an accuracy of +/-30% from 6km to 500m over specific airways and and specific levels, why has that not been done and the information disseminated to NATS in order that ASHTAM's can be issued and airways and flight levels opened to IFR traffic?

toodle back to the Global Warming Thread and continue to praise Jones and the CRU for manipulating climate change data. :ok:

[BDiONU]

NATS can take the correct route of caution,
I will reiterate from previous posts because the message doesn't appear to be getting through.
NATS is an ANSP (Air Navigation Service Provider), one of 56 throughout Europe, note the words Service Provider. All ANSPs provide a service in accordance with the licence issued by its respective government (in addition to the rules, regulations and laws they're also required to obey). The decision by European ANSPs to close airspace is directly in compliance with the requirements of their licence. Some European governments have gone further than simply close controlled airspace and have allowed no flying at all. In the UK NATS mandate to close airspace only covers controlled airspace and the UK Government has not chosen to go down the path of closing all airspace, hence you have seen aircraft flying VFR outside of CAS.

In the UK the airspace regulator is SRG (Safety Regulation Group) of the CAA (Civil Aviation Authority), a department of the Department of Transport. Why HM Government and the D of T have been silent and are chosing to hide behind NATS skirts I have no idea but NATS spokesmen are only talking heads. NATS does not enact policy, it complies with it.

BD

[BDiONU]

if the MET office can provide ash density figures with an accuracy of +/-30% from 6km to 500m over specific airways and and specific levels, why has that not been done and the information disseminated to NATS in order that ASHTAM's can be issued and airways and flight levels opened to IFR traffic?
What are the density figures which it's safe to fly through? I can tell you the answer, none are defined. The rules are no flying through ash contaminated airspace, very woolly but with no possibility of misinterpretation. Hence the call for some standards to be defined, cause we have none.

BD

[ChalfontFlyer]

Bought the Farm : "Well that makes 10 inbound to LHR from the US. Can't wait to see if more are on their way".

A further 8 BA flights are en-route to LHR, predominatly from the east e.g. BKK, BAH, AUH, DEL, BOM, NRT, PEK plus GRU in Brazil.

Let's hope they all make it!

Added: now hearing they may have to be diverted - to where?

[iwantmyhols]

yep my moneys on madrid and I would also think that they knew that's where they may end up. Because at the same time we are sending consulate staff to set up centers for travelers there- Also Ryan air are going to get all stuck in canaries to mardid (as long as travelers agree all responisblity to get home from there is their own)

[ChalfontFlyer]

Stalling altitude: "gotta be Madrid".

I think BA Ops Team would much prefer Scottish airport(s) but if they are not available then AMS could be the fall back...obviously much closer to UK than MAD.

[BoughtTheFarm]

BA website still shows LHR as destination. I'd like to think that an alt has been decided if applicable or is a 'window of opportunity' planned to be open in this FIR later today for sure? Nothing like making things up as you go - dynamically speaking...

[MAN777]

Dumping a dozen very full B747 flights anywhere outside the UK at the moment would be madness, Every effort to get them this side of the channel must be made. Maybe BA coming over as a "Gang" is meant to put more pressure on whoever it is thats running this mess.

[airseb]

diverting to spain where coincindentally (???) a few royal navy ships are due to arrive soon. not an extremely bad option, if uk airspace has to close again.

[Type1106]

I've followed this thread closely and I don't think I have seen this paper referred to - if it has been then my apologies, but from some of the wild statements posted here then many others have not read it either!

The link is at Flight Safety Digest 1993 | Flight Safety Foundation (http://flightsafety.org/archives-and-resources/publications/flight-safety-digest/flight-safety-digest-1993) Click on May1993

Does anyone have knowledge of any later papers following this one?

[cabot]

My money is on EDI given that GLA is closed.Outlook looks better on the east coast and transport links.Landing 10 744's in mainland europe and would give BA a major headache and massive additional costs.Anyone have any ideas as to the timings of these aircraft ?

[Bruce Wayne]

What are the density figures which it's safe to fly through? I can tell you the answer, none are defined. The rules are no flying through ash contaminated airspace, very woolly but with no possibility of misinterpretation. Hence the call for some standards to be defined, cause we have none.



Exactly!

However, there will always be contaminants in the atmosphere, which includes volcanic ash. Volcanic activity in the past has seen volcanic ash tracked to circle the globe up to three times and remain in the atmosphere for years.

Do you subscribe that we dont fly if there is any contaminants in the atmoshpere ?

What about aircraft that have been stored within 200nm of marine air, which corrodes blades and disks, which is equally damaging to engines (in different ways)?

Operators monitor engine conditions routinely as its a very inexpensive way of managing a very expensive piece of equipment.


The rules are no flying through ash contaminated airspace


So you are saying that the BA flight to Cardiff and other VFR operations which have occured since last week have been conducted outside of regulations ?

Can you please post the regulation and under which regulatory body this citation pertains to which should therefore stipulate the conentrations at which airspace would therefore be 'contaminated', how that airsapce is defined .. is it a FIR or an airway ... and who would therefore determine the contamination levels and by what method. thx.

[neil_2008]

This is a total mess, how can we have NATS taking advice from the Met Office producing charts like these:
http://www.metoffice.gov.uk/aviation...1271763280.png (http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271763280.png)

And EuroControl taking advice from whoever else producing charts like this.
https://www.cfmu.eurocontrol.int/PUB...olcan_FIRs.pdf

I fully understand the safety calls and am not disputing it, but one would have hoped in todays age in that some kind of co-ordination between air traffic services could come up with what at least looks like a common approach. How can we have a position on one side of the channel shich is so vastly different to that in continental Europe? And Im not talking about the fact that the ash could exist either side Im referring to the fact that one thinks it is there and poses a major risk and one does not.

We now have relatively busy airspace on one side of the channel and nothing much flying here at all.

I await the NATS announcement with interest at 15:00.

[airseb]

alot of people are asking about this vfr ifr thing. i'm not working for the german regulatory. but it seems like good sense that visual conditions (Visual Flight Rules), i e out of the clouds and 1000 feet (or whatever) separation from those clouds, be applied. I wouldn't like to run into a little nimbostratus knowing that it might or might not contain VA. better to stay out and away from it. I'm not saying it's unsafer but VA is one thing (I guess you might be able to see a big concentration) but VA + water might be another thing completely.
please, no nonsense about flying vfr as in following rivers and country roads to known landmarks before looking at the airport's wind sock!

[ElyFlyer]

Taken from the BBC

Ferry companies operating out of Dover will be allowed to take 10% more passengers on their larger ships (http://news.bbc.co.uk/1/hi/england/kent/8630702.stm) to help ease the current transport crisis.
According to David Osler, reporter for Lloyd's List, this suspends "whole chunks of the Safety of Life at Sea Convention, introduced after the Titanic disaster of 1912".

The irony of at all! One rule for one form of transport another for a different one:ugh:

[BDiONU]

Do you subscribe that we dont fly if there is any contaminants in the atmoshpere ?
Of course not but thats not the legal position in Northern Europe currently. We need an effective compromise but our leaders have failed to provide this within the contingency legislation for volcanic ash events in Northern Europe.

So you are saying that the BA flight to Cardiff and other VFR operations which have occured since last week have been conducted outside of regulations ?
As I've said previously you are allowed to fly VFR outside CAS in the UK. There was undoubtedly special dispensation for wee willie walsh's publicity stunt.
Can you please post the regulation and under which regulatory body this citation pertains to which should therefore stipulate the conentrations at which airspace would therefore be 'contaminated',
As I said previously the 'ban' is a blanket ban and I cannot post chapter and verse as the rules and regulations are not public domain.
how that airsapce is defined .. is it a FIR or an airway ...
Airspace is airspace, some is controlled and some not :)
and who would therefore determine the contamination levels and by what method.
As I previously said we have no defined standard and we have no method by which any concentrations could be measured. This is all stuff which should have been done as a contingency measure but wasn't. Possibly because this volcanic event is unprecedented and our great leaders never considered the risk high enough to spend the cash. One can only hope that they will do so as a matter of urgency.

BD

[howiehowie93]

Greetings,

is it possible for someone to post the eurocontrol picture as following the link requires a secure log in.

regards
Howie (stuck in Azerbaijan ):*

[ianmt36]

airseb

I agree - i posted earlier asking why the different rules for vfr / ifr (n.b. not vmc imc) - the ash density will be the same regardless of the rules.

Also as others have pointed out the lower level of atc control for vfr has to be less safe

[CaptSeeAreEmm]

Anyone know what excuse the French and Dutch have used to open Paris and Amsterdam - they seem to quite busy now. But they are still well within the VAAC ash cloud predicted area.

[neil_2008]

http://www.eurocontrol.int/corporate/gallery/content/public/news/AirAsh%20Concentration%20Chart_200410_1200UTC.pdf

[molluscan]

There is a common theme developing on this thread and outside - the lack of scientific information on the CONCENTRATION of ash

The Met office has obviously reacted to this by publishing this update at 12:36 titled "Science underpins ash cloud advice".
Met Office: Icelandic volcano eruption (http://www.metoffice.gov.uk/corporate/pressoffice/2010/volcano.html)

Here is my comment emailed to their pressoffice

"I am increasingly concerned about postings on your website have a bias against aviation and contain 'bad science'
I refer to the article titled above Last updated: 1231 BST on Tuesday, 20 April 2010
Clearly this is in response to critiscms but it does not answer the key questions:

the first is for the Met Office
1) what are the actual and forecast concentrations of ash at different location and altitudes (g/m3) and other data such as particle size distribution and composition.

the second is for the aviation industry and regulators
2) what is a safe concentration
there is no doubt there is a concentration which is damgaging but equally there will be a level where the risk of damage is statistically insignificant (not zero)

All the information at present states whether ash is present or not but gives no information on concentrations.
This has caused the present problem because ICAO have not defined an acceptable concentration for IFR flight
It is bad science to refer to absence of ash or zero concentration. This is a physical and mathematical impossibility.
Every aircraft flies in the presence of ash on every flight. The concentration may be below the limit of detection of the sensor but it is not zero.
The limit of detection needs to be stated.

The bias is in referring to damage to F16 aircraft while not referring to the very large number of General Aviation flights that have taken place over the past few days without any known damage and at various altitudes and some with turbine engines. Neither is a Met Office matter.

Lets have figures and proper scientific reporting please."

[eagle21]

Well I think the Eurocontrol image speaks for itself, what excuses do they need if their own tests show no problems at all on the aircraft performance, their airspace and (the UK's) is clear on the Eurocontrol charts, and they will just revise their mainteinance schedule in future to keep an close eye on any long term damage to their aircraft.

Is NATS where authorised by someone ( nobody really know who is in charge here...) to use the same chart as the Eurocontrol use, the UK airspace would be open right now. It is a matter of politics now. Eventually Mr Brown will do something about it (2 days late) and be hail as a hero....

[howiehowie93]

Thanks Neil

I can see the conflicting info now.

regards
Howie

[Nemrytter]

Hello JetII

[Stoic]

Anyone know what excuse the French and Dutch have used to open Paris and Amsterdam - they seem to quite busy now. But they are still well within the VAAC ash cloud predicted area.The French and Dutch probably declared the contamination de minimis and used their common sense!

[Drink Up Thee Cider]

Rumours, stress rumours, about Flybe BE128 flight from GLA to BHD "may have suffered damage". I know no more. Anyone? Bull**** gossiping or .... ?


Total and utter cobblers. Saw the aircraft myself. I know we like a good rumour here, but posting scurrilous bull**** like this is beyond childish and puts all of us at risk. :ugh:

[Back at NH]

I cannot post chapter and verse as the rules and regulations are not public domain.

Regulations not published??

EUR Doc 019
INTERNATIONAL CIVIL AVIATION ORGANIZATION
VOLCANIC ASH CONTINGENCY PLAN
EUR REGION
Second Edition
September 2009

Explains the process nicely :ok:

[Air.Farce.1]

British Airways said it had scrapped plans to operate some long-haul flights from Heathrow airport. The airline said: "Despite the fact that airspace over most European countries is open, UK airspace remains effectively closed. We deeply regret the great inconvenience caused to our customers as a result of Nats' decision to close UK airspace over the last six days."

A bit rich coming from BA considering they, along with other major carriers own part of NATS

[Defruiter]

Statement on Icelandic volcanic eruption: Tuesday April 20, 1500 The situation regarding the volcanic eruption in Iceland remains dynamic and the latest information from the Met Office shows that the situation will continue to be variable. Based on the latest Met Office information, part of Scottish and Northern Irish airspace including Aberdeen, Inverness and Edinburgh airports will continue to be available from 1900 today to 0100 tomorrow, Wednesday 21 April, and also south to Newcastle Airport. Glasgow and Teesside airports will additionally become available in this time period. Restrictions will remain in place over the rest of UK airspace below 20,000ft. Flights above the ash cloud are now permitted in the UK; between 1900 today and 0100 tomorrow, this will enable aircraft movements above 20,000ft in UK airspace. We will continue to monitor Met Office information and the situation is likely to change during the course of the day. We will make a further statement at approximately 2100 today. 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 working closely with Government, airports and airlines, and airframe and aero engine manufacturers to get a better understanding of the effects of the ash cloud and to seek solutions.

[aguadalte]

Buckster (http://www.pprune.org/members/252087-buckster)



how much pressure will pilots be under now ? assuming they have final say on safety ? is it still ok these days for a pilot to say no - that route at that time is unsafe ?


Companies are not allowed to decide for themselves if a flight can or can not be done in closed airspace. Its up to the national authorities to define which parts of their own airspaces are closed for flights.

I think that each country should define the portions of national airspace that can be used for a certain period of time and Eurocontrol should gather that information and define routes (like NAT organized tracks) to be used for (lets say) a 6 hour period of time. Companies should organize themselves to bring their passengers to (open) aerodromes closer, as much as possible, of their passenger destinations. (This could be a great test to Star Alliance, One World and others, to coordinate efforts in a crisis like this one).
Indeed, this is a great opportunity for the airlines to join efforts and to talk about cooperation issues, because this is only the very first one, of future world crises.
EU should lead and learn from its ineptness and lack of preparation, for catastrophes like this. Almost a week without any idea how to deal with this drama is not a good "business card" for the European Union. Paranoia is the enemy of common sense and all that the "authorities" have done so far, was to take flight safety to its "zero risk detent". Flight safety however, is the compromise of taking an operation under acceptable risk levels. The no fly decision leaves us without risks but, without operations also...:sad:

[eagle21]

Statement on Icelandic volcanic eruption: Tuesday April 20, 1500
The situation regarding the volcanic eruption in Iceland remains dynamic and the latest information from the Met Office shows that the situation will continue to be variable.

Based on the latest Met Office information, part of Scottish and Northern Irish airspace including Aberdeen, Inverness and Edinburgh airports will continue to be available from 1900 today to 0100 tomorrow, Wednesday 21 April, and also south to Newcastle Airport. Glasgow and Teesside airports will additionally become available in this time period. Restrictions will remain in place over the rest of UK airspace below 20,000ft.

Flights above the ash cloud are now permitted in the UK; between 1900 today and 0100 tomorrow, this will enable aircraft movements above 20,000ft in UK airspace.

We will continue to monitor Met Office information and the situation is likely to change during the course of the day. We will make a further statement at approximately 2100 today.

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 working closely with Government, airports and airlines, and airframe and aero engine manufacturers to get a better understanding of the effects of the ash cloud and to seek solutions



Nats have been adding the highlighted line above since last night's update. Things will change very soon, I think

[mixture]

I cannot post chapter and verse as the rules and regulations are not public domain.
Regulations not published??

EUR Doc 019
INTERNATIONAL CIVIL AVIATION ORGANIZATION
VOLCANIC ASH CONTINGENCY PLAN
EUR REGION
Second Edition
September 2009


Downloadable here, no login required :
www.paris.icao.int (http://www.paris.icao.int/documents_open/show_file.php?id=274)

[Phil Rigg]

The disparity between the two published ash cloud charts from the UK Met Office & Eurocontrol combined with NATS's and Eurocontrol's respective differing interpretations of flying in what essentially amounts to the same contaminated air warrants causing this entire event to descend into a monumental farce.

If NATS's so called "zero tolerance" interpretation of the ICAO regulations regarding flying in volcanic ash is correct then I trust they are taking down the registration details of all aircraft currently being flown within the contmainated area over mainland Europe prior to issuing future bans on them ever entering UK Airspace.

After all we wouldn't want these entirely unsafe aircraft to enter UK airspace risking multiple engine failures and randomly descending onto the heads of the very unsuspecting citizens which they are currently going to such extreme lengths to protect!

[FoxRomeo]

While surfing the web I found this piece of information:

Rheinisches Institut für Umweltforschung - EURAD-Projekt (http://www.eurad.uni-koeln.de)

Shows some neat films and predictions at various altitudes.

Regards,
FR

[ManofMan]

All of the inbound BA longhauls will be going to BCN and MAD, no plans to go to Scotland.

[ba038]

Diedtrying

The reason why they are flying in over UK airspace is because they are above the altitude in which ash clouds are this allows them to avoid the ash clouds to some extent.

However most UK mainland airports are closed because the climb to that altitude would encounter in going through the ash clouds hence this factor is the most dangerous.

[Bruce Wayne]

Simonpro,


Because until yesterday morning the ash was covering most of Europe. I don't know about the UK but at least where I am they did open the airways in regions that were unaffected by ash, this is still the case today. Altitudes in which no ash has been found are open. Altitudes where ash is still present are not open. It's quite simple.


Was it? is that why the UK airspace is closed because they have found ash contaminant in the atmosphere?

Is it that simple ?

The aircraft that have been operating VFR don't seem to have encountered it to a level that has been detrimental to flight.

If the UK airspace has been closed due to contaminants, at what concentration are those levels and where and at what levels ?

Please, do tell.. the UK avaition industry would appreciate you imparting that knowledge, perhaps NATS too.

If NATS has decided to close everything regardless of this information then that is their concern. I have no idea why they would do that.

Are the MET office using some s**tty model, that doesnt seem to gel with what the rest of the EU airspace models are and what the actual facts are ?

... kind of like that whole manipulation of data, AGW, Bullcr@P model to support global warming thing that harks back to CRU/Jones "hide the decline" thing ?

Is our industry in the UK facing yet another kick in the cajones becuase the MET office is relying on B/S models that are not fit for purpose ?

Or the failure of our politicians to deal with a situation with a foot in reality.. hmm.. rather like doubling APD due to global warming.. only to tell us that the money from APD is being used to prop up the banks ??

Perhaps you'd care to stick to discussing this matter rather than attempting to discredit me.


That exactly what I am doing, you dont need any help on being discredited, you continue to do a fine job of that yourself on the Global Warming thread.

That fact is Simonpro, our politicians are useless, they stand around politiking, instead of dealing with a situation and indeed "fiddle* while rome burns" and fail to gather factual data, or even any data, meanwhile, everybody else picks up the pieces and foots the bill.

If I pay for a dog, I don't expect to bark myself.



*Not just their expenses

[ManofMan]

The reason why they are flying in over UK airspace is because they are above the altitude in which ash clouds are this allows them to avoid the ash clouds to some extent.

Yeah thats all well and good, until they have a engine our or a de-pressurisation then have to decend into the ash concentration !!!

[RoyHudd]

Idiotic comment manofman.

[condorbaaz]

Guys,
The Statistically Safe concentration needs to be determined with specifics to Particle size and composition.

The particle size would be easy: similar to suspended dust and smoke found often over Africa/ Asia.

The composition would be trickier esp regarding quality of toxins and effect on breathing.

However, considering that even with deposits on cars etc, there are no widespread issues of running eyes, short breath etc,

It may be prudent to assume that the flight is possible in the plume.

Also it is one thing to fly into the cloud when released because concentrations are high, the time bound dissipation will always reduce the threat.

[Airclues]

I'm 25 miles from LHR and looking out of the window at the perfect visibility. Whatever the arguments about long term engine damage, there is no way that an aircraft would be in any danger approaching LHR today.
If the CAA (or NATS) force the BA inbound aircraft to divert to another airport within the Met Office 'guess-map', then somebody needs to question their judgement.

[ManofMan]

I'm 25 miles from LHR and looking out of the window at the perfect visibility. Whatever the arguements about long term engine damage, there is no way that an aircraft would be in any danger approaching LHR today.
If the CAA (or NATS) force the BA inbound aircraft to divert to another airport within the Met Office 'guess-map', then somebody needs to question their judgement.

I think you will find that they already have been forced, MAD, BCN and NCE.

[diesel862]

Dear All

My two cents, which map is correct?, the CFMU issued at 1200UTC or the Met Office Sig Wx chart issued via Jeppesen at 1230UTC showing two completely different ash cloud concentrations.

How can anyone make a correct decision with such a vast difference in the charts?

Vince

[mangid]

Bruce Wayne asked
Was it? is that why the UK airspace is closed because they have found ash contaminant in the atmosphere?

Is it that simple ?

The aircraft that have been operating VFR don't seem to have encountered it to a level that has been detrimental to flight.

If the UK airspace has been closed due to contaminants, at what concentration are those levels and where and at what levels ?

Please, do tell.. the UK avaition industry would appreciate you imparting that knowledge, perhaps NATS too.

The first 12 minutes or so of Bang Goes The Theory (http://www.bbc.co.uk/iplayer/episode/b00s61dk/b00s61b9/Bang_Goes_the_Theory_Series_2_Episode_5/) are about the impact of the volcano of flights. There's a bit on the plane they kitted out to do the measurements, and a comment about how the levels in the cloud are really quite high.

[Bruce Wayne]

Yeah thats all well and good, until they have a engine our or a de-pressurisation then have to decend into the ash concentration !!!




and over what level of concentration would it be problem ? you can give it in ppm or gm/3 i dont mind...

so an engine out automatically means an aircraft cant maintain altitude?

better get on and revise those ETOPS regs !!

and an emergency descent isnt going to be a push the nose over and descend at flight thrust.. VmoMmo will be behind you.

yes in an explosive decompression (which are rare events) the objective is to get to a lower altitude, but you cant do that if you are over mountains.. the ground tends to get in the way.

also, we are not talking about prolonged flight over ash concentration of whatever level, and if an explosive deco happens at altitude you dont have long to get on supplimental O2 before its game over anyway.

if on a twin jet you loose both engines going over an ash concentration it's all rather moot as you are in a very expensive and heavy glider anyway.

[Whippersnapper]

How do you know that, Airclues? The Finnish F18s and (Belgian?) F16s were flying in similarly clear conditions when their engines were damaged. This is the problem - it's not just flying through visible ash that can wreck the engines, and we don't know what the safe limit of contamination is and we have no way to monitor the actual contamination levels - we're blind on both counts.

As I and others have repeated, the damage is cumulative. I don't expect to see any engine failures today, but I am concerned that multiple failures may occur in the coming days or weeks.

People are being blinded by machismo and economics.

[Stoic]

My two cents, which map is correct?, the CFMU issued at 1200UTC or the Met Office Sig Wx chart issued via Jeppesen at 1230UTC showing two completely different ash cloud concentrations.At what concentration is ash in the atmosphere an ash cloud?

[Riding Air]

Just a point of fact that NATs are basing their decisions on information provided to them by the Met Office.

Have we all forgotten that this was the organisation that forecast a "barbecue summer" for 2009 and that the winter of 2009/2010 would be one of the "warmest on record"!

Wasn't there a recent forum stating "The Met Office - not fit for purpose", perhaps somebody from Nats should be questioning their relationship with the Met Office.

Jon

[Whippersnapper]

Manofman, the reason your point is off kilter is that if an aircraft has a decompression or loses an engine, it will be making a landing at the nearest suitable airport anyway. The rate of accumulation of engine deposits is unlikely to further affect that flight, and the aircraft will be undergoing repair for the failed system so boroscoping the engines won't be much of a hardship. Normal ops planned in a significantly contaminated environment are different because they will have vastly greater exposure and the aircraft will be expected to continue in service.

[theron]

Not sure if this has been posted already (too many posts to go through) but i felt it was relevant.

BBC News - Test shows how volcanic ash impacts a jet engine (http://news.bbc.co.uk/2/hi/science/nature/8632572.stm?ls) <--- video, 3mins 8secs.

feel free to discredit it and/or ridicule me. :}

best regards from a klm passenger stranded in lima who is trying to get to the uk before work on friday)

[gemini76]

The document referred to in posts #1908 and #1914 infers that everyone has done, and continue to do , exactly that stated in the Plan. Rather comforting. I wish I had read it before reading some of the rubbish posted here.
Somewhat ironic that ICAO have used KATLA as an example in their Notams and Sigmets though.....................................................: eek:

[ChalfontFlyer]

Statement on Icelandic volcanic eruption: Tuesday April 20, 1500

The situation regarding the volcanic eruption in Iceland remains dynamic and the latest information from the Met Office shows that the situation will continue to be variable.
Based on the latest Met Office information, part of Scottish and Northern Irish airspace including Aberdeen, Inverness and Edinburgh airports will continue to be available from 1900 today to 0100 tomorrow, Wednesday 21 April, and also south to Newcastle Airport. Glasgow and Teesside airports will additionally become available in this time period. Restrictions will remain in place over the rest of UK airspace below 20,000ft.
Flights above the ash cloud are now permitted in the UK; between 1900 today and 0100 tomorrow, this will enable aircraft movements above 20,000ft in UK airspace.
We will continue to monitor Met Office information and the situation is likely to change during the course of the day. We will make a further statement at approximately 2100 today.
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 working closely with Government, airports and airlines, and airframe and aero engine manufacturers to get a better understanding of the effects of the ash cloud and to seek solutions. ENDS.

Therefore, as it would seem from this statement that GLA, EDI & NCL are all to remain open why should the current 22 BA inbounds have to divert as far south as Spain this evening as was posted earlier? Surely they will be spread across these 3 airports.

[Finn47]

As far as the Finnish F-18 Hornet engines are concerned, no actual damage has been proven yet - only particle concentrations spotted. The engine(s) have been dismantled and sent to Patria Aerospace who are examining them at the moment. Results can not be expected until a couple of days later. Finnish Air Force press release in English here:

Puolustusvoimat - Frsvarsmakten - The Finnish Defence Forces (http://www.ilmavoimat.fi/index_en.php?id=1152)

Notice the careful wordings: "may cause" significant damage, etc.

[Postman Plod]

Riding Air, I think you'll find the Met Office forecasts are verified by what has been physically observed across the whole of Europe. Take your crosshairs off the Met Office, and find someone else to blame.

I think you'll also find its not the Met Office telling planes not to fly, its NATS / CAA, and they're basing their advice on ICAO guidance, and guidance from aircraft and engine manufacturers.

and I think you'll find the "Not Fit for Purpose" thread actually turned out to be fairly pro-Met Office (once the misinformation / scepticism was taken care of)

There is an AWFUL lot of rubbish / misinformation flying around in the press and on here, from supposidly educated parties. You'd think they had their own agenda or something, and were looking for a scapegoat...

[pete999]

"The output from the Met Office volcanic ash dispersion model has been compared with our neighbouring VAACs in Canada and France since the beginning of this incident and the results are consistent."

and

"The Met Office is the north-west European Volcanic Ash Advisory Centre with responsibility for issuing the Volcanic Ash Advisories for volcanoes erupting in this area in line with internationally agreed standards and processes. This means the Met Office’s role is to support NATS, CAA and other aviation authorities decision-making"

Maybe these standards and practises should change in the future, but that is how they are now.


"It is for the aviation industry and regulator to set thresholds for safe ash ingestion. Currently, world-wide advice from ICAO is based on engine and airframe manufacturers stating a zero tolerance to ash ingestion. This means that aircraft should not be exposed to any volcanic ash."

Nobody blames the ICAO so far. Looking at their website, they in fact seem quite pleased that everyone is following their guidelines.


On a separate note, I think the Eurocontrol area is different because the EU leaned on them to introduce a third "safer" zone. Not saying this is the wrong thing to do, but it is the reason I believe why their interpretation of the data look different.

[Bruce Wayne]

If one more person mentions long term engine damage i will track you down and bludgeon you with my wireless mouse..

its like talking about long term damage to shoe leather or the tread on your car tyres.

blades are replaced when they meet the time and cyc limits defined as an LLP (Life Limited Part) they are also inspected at intervals as well as trend monitoring, if there is any question as to the longevity they are replaced prior to LLP limits, Also with AD's and SB's they are often overhauled or replaced if they don't meet limits prior to intervals anyway.


As for flight into an ash plume, that will also warrant a bludgeon with a mouse, the plume is what is vented from this volcano.. 500 or a 1,000 miles away we're talking airborne contaminants.

[Capot]

Regardless of the rights and wrongs of the airspace restrictions, I remain very puzzled by the legal process which appears to be operating in the UK and, for that matter, Europe.

NATS is a privately-owned ATM service provider. It is regulated by the CAA to ensure that it operates safely, in accordance with UK legislation etc etc.

NATS is not itself a regulator, and has no powers or indeed expertise to regulate. We can all laugh at a pig-ignorant Harriet Harman announcing that NATS is the UK's civil aviation safety regulator, but the fact is they are not and we should all be getting quite concerned about who is calling the shots.

Not least because when the aircraft start flying, closely followed by the lawsuits for unnecessary total closures when a more thoughtful response might have saved everone a lot of trouble and money, the lawyers will need a target.

Who will it be? The CAA is taking no apparent role in all this, so they can only be accused of standing well away from any decision making. Nothing new there.

The Met Office? Well, no, they are only advising on where the cloud is, not the engineering safety of aircraft operations in it.

Gordon Brown? Nice idea, but he'll plead that it was NATS/CAA/EASA/Eurocontrol/The Conservatives/etc etc etc, "I was only taking the expert's advice."

So who is actually preventing aircraft from flying? We know how it's being done, in controlled airspace, and that NATS are doing that. But is the decision to do it taken solely by NATS on its own authority, with or without consultation with others? If so they are on very shaky ground indeed.

I sense some very lucrative lawsuits looming although not by me, regrettably. But who is responsible, the final decision-maker, the person whose desk says "the buck stops here", who gets sued?

[bubblesuk]

If one more person mentions long term engine damage i will track you down and bludgeon you with my wireless mouse..

its like talking about long term damage to shoe leather or the tread on your car tyres.

blades are replaced when they meet the time and cyc limits defined as an LLP (Life Limited Part) they are also inspected at intervals as well as trend monitoring, if there is any question as to the longevity they are replaced prior to LLP limits, Also with AD's and SB's they are often overhauled or replaced if they don't meet limits prior to intervals anyway.


As for flight into an ash plume, that will also warrant a bludgeon with a mouse, the plume is what is vented from this volcano.. 500 or a 1,000 miles away we're talking airborne contaminants.


But wouldnt flying through this ash etc cause engine damage and reduce those cycles? and also increase the frequancy of inspections? I'm only asking out of interest before you kill me to death!

[DjerbaDevil]

VAAC=Volcano Ash Advisory Centres (please note the plural), there are nine of these centres around the world. See URL:
http://www.metoffice.gov.uk/aviation/vaac/ (mhtml:{25171FF0-2B93-487E-847D-B68C941D8898}mid://00001518/!x-usc:http://www.metoffice.gov.uk/aviation/vaac/)

London VAAC is the smallest of all, only looking after the British Isles and Iceland and is part of the Met Office. Toulouse VAAC looks to be the largest, covering all of continental Europe, Russia, Africa and east to India and most of China.

Assuming they are all coordinated, particularly Toulouse and London VAACs, do they all have the same standards and predict concentration danger levels of VA to aircraft in the same way? From previous posts it would appear that Washington and possibly Montreal VAAC have different standards for measureing the concentration levels of VA and where these relate to be dangerous to aircraft.

According to a press article today (El Pais, Madrid, page 5) VAAC London pass data on the VA concentrations to Eurocontrol and base their predictions on a mathematical formula. Eurocontrol in turn submit the data to the 27 individual State Aviation Authorities, who take individual decisions concerning their own air spaces. The mathematical formula for preparing the data for the predictions is theoretical and has never been tested in real live experiments.........

In the meantime the authorities are thankful to the commercial airlines that have flown aircraft through the VA clouds for their input, as this will help them to determine whether their theoretical mathematical formula could be improved to provide more acurate prediction data....

With the cost of government, local, national and European to the tax payer, Europeans would expect that both VAAC in London and Toulouse would have been provided with sufficient funds to be able to conduct scientifically proved methods to predict the VA clouds and concentrations that would be dangerous to aircraft. The fact that the predictions are based on merely tentative theoretical mathematical formulas is a shameful situation and more so, as it could spell the ruin of many companies, airlines and many many others...

And NOW is the moment to conduct such experiments to find a scientifically based method for predicting the danger levels of concentration of VA cloud to aircraft.

Not in the budget.....never mind, let the politicians in all European countries pay for it, since it's their fault it wasn't done before....

[paidworker]

The CEO of Citi-jet released a press statement saying he believes British Airways took "undue risks in conducting test flights " , he also claims to have knowledge that "the aircraft involved in those tests were damaged" . He goes on to say that it appears safety authorities are being pressured by commercial interests. Source : RTE Ireland news at one.

[Whippersnapper]

If one more person mentions long term engine damage i will track you down and bludgeon you with my wireless mouse..

its like talking about long term damage to shoe leather or the tread on your car tyres.

blades are replaced when they meet the time and cyc limits defined as an LLP (Life Limited Part) they are also inspected at intervals as well as trend monitoring, if there is any question as to the longevity they are replaced prior to LLP limits, Also with AD's and SB's they are often overhauled or replaced if they don't meet limits prior to intervals anyway.

No, it's not like that at all. Just like with shoes, you expect engines to wear out from normal use, but no-one knows how accelerated any wear may be, if there is any increase at all, with varying levels of ash contamination. To use your analogy, it's like expecting a normal pair of shoes to stand up to walking across a rough lava field - they just won't last as long, but you can't predict how quickly they'll wear out.

What is certain is that the ash will build deposits that do more than just cause wear - they will cause hot spots and thermal stresses or melting of components as well as affect the internal thermodynamics of the engines. How rapidly these deposits form is unknown. What level of deposit is safe is unknown. How big these deposits can grow before detaching is unknown. the level of damage caused by deposits breaking off is unknown... Therein lies the problem; there are too many unknowns to determine if flying through this amount of predicted contamination is safe.

[JimmyTAP]

I thought this might be interesting. The previously grounded BAe146-301 from FAAM is currently airborne over Scotland at FL260. Let's hope it provides more answers.

http://www.faam.ac.uk/index.php/position

[peter we]

At what concentration is ash in the atmosphere an ash cloud?

Someone posted that it was measured at over 2000ppm. The NASA aircraft that was damaged, flew through 600ppm I believe.

Correct me if I'm wrong, but if a an engine is producing 10,000lb of thrust, it would be consuming 0.01lb of dust per second ppm. Or 36lb per hour (16.36Kg).

600ppm would mean 9816kg per hour passing - and melting - through the engine.

[Basil]

so an engine out automatically means an aircraft cant maintain altitude?
That is correct. (If the aircraft is already cruising at its best level)

[Dusty_B]

For everyone who is disgusted that the Met Office are using "theoretical mathematical models" to FORECAST the ash movement... wtf do you think they use for all their other FORECASTS? Little pixies? Oracles? You've got to start from something, and microscopic radioactive particles seams like a good enough starting point for me - seeing as it's only been running for a week.

[BoughtTheFarm]

Dusty B - Agree. But that is also why we need the physical empirical evidence to go with it. Now (and for the last 5 days) we've had the chance. May be too late to enact a solution based on the 2 observations - theory vs actual. But, it will bode well for the future if this scenario arises again. Sorry to bang on, but we need the evidence eventually and the level of 'test flights' thus far and how they've been executed does not appear to show the needed due diligence.

[Postman Plod]

Funnily enough, the model is being verified by observed data...

And of course aircraft are transitting UK airspace - its open above FL200!

BoughtTheFarm, you're right - test flights need to be instrumented and done properly, covering the whole range of flight levels across all areas, rather than just a jolly around the eastern Atlantic at FL whatever which proves nothing. Even then, If you go fishing (test flight) you might not catch a fish (ash) , but it does not mean there are no fish (ash) in the sea. (air)

[timmcat]

With the greatest respect guys, and I know it's not really 'any of my business' but the mods have repeatedly asked for the 'spotteresque' posts to be kept out of here. Can see their point, it clutters up interesting debate and they are working overtime keeping the thread tidy.

I'll shut up myself now.

[License to Fly]

Just heard that the BA longhaul planes on the way to LHR have been told they are not landing there today ...

[steamchicken]

Unfortunately, it just seems that there is a sort of subculture of (usually) right-wing people in the UK who are obsessed with the idea that the Met Office is plotting against them. This thread has now reached the point where the same people who were yelling that Gordon Brown was at fault for closing the airspace and it wasn't really a problem - no link or citation has yet been produced to support the idea that it was Brown's decision rather than CAA, NATS, or VAAC - are now yelling that Brown should really intervene and have it reopened rather than "hiding behind NATS".

And, apparently, a volcano going off in Iceland is Harriet Harman's fault. Frankly, you could cry.

Also, with regard to the link to The Register: when I was a tech journalist (like Andrew Orlowski) we had a saying that if it was on the BBC it was probably out of date, if it was on ZDNet it might be right, if it was in Wired it was probably right but overhyped, and if it was in the Reg there was no way of telling whether it was right, wrong, or pure pub drivel. I am not aware that the former fanzine editor has any competence to say anything at all intelligent about modelling ash dispersal, and it would vastly improve his product if he were to shut up more often.

[DjerbaDevil]

Dusty B:

Fair enough to use mathematical models for forecasting weather patterns and cloud movements. This is quite scientific and has years of proven ground.....BUT to use theoretical mathematical formulas that have never been tested to predict the levels of concentration of the volcanic ash that is dangerous to aircraft would appear to me to be verging on irresponsability.

On the other hand, one has to say in their favour, that if they are not provided with electric screwdrivers, then they are doing a very good job using a hammer for the screws......

[BDiONU]

NATS is a privately-owned ATM service provider. It is regulated by the CAA to ensure that it operates safely, in accordance with UK legislation etc etc.

NATS is not itself a regulator, and has no powers or indeed expertise to regulate. <snip> So who is actually preventing aircraft from flying? We know how it's being done, in controlled airspace, and that NATS are doing that. But is the decision to do it taken solely by NATS on its own authority, with or without consultation with others? If so they are on very shaky ground indeed.
NATS operate with a licence from HMG, and all other European ANSPs operate similarly with a licence from the state. NATS must operate within the terms of it's licence and all of the other rules, regulations and laws applicable to an ANSP. The 'law' governing flights in ash conditions is the ICAO document referenced in previous posts. Who exactly could be sued and for what reason? Who has done something wrong or likely to bring harm to others?

BD

[Airclues]

Wippersnapper

I don't expect to see any engine failures today, but I am concerned that multiple failures may occur in the coming days or weeks.


So let me get this right. There is absolutely no danger in the BA aircraft approaching LHR in this lovely weather, but they are being refused permission because NATS is concerned about the long term damage to their engines. Is this correct?

[acad_l]

Correct me if I'm wrong, but if a an engine is producing 10,000lb of thrust, it would be consuming 0.01lb of dust per second ppm. Or 36lb per hour (16.36Kg).

600ppm would mean 9816kg per hour passing - and melting - through the engine.

Very wrong. You need to calculate the air flow through the engine. Nothing to do with thrust.

An example. Which I based upon figures from the Canadian VAAC, which seems to use a distinctly better model than the British one, with results divided in low, medium and high concentrations. Low goes from 10 to 100 micrograms per cubic meter of air. If you consider a plane flying at 180 m/s, an engine with a capture area of 3 square m, and a concentration corresponding to the upper limit of the "low" concentration, over ten minutes (an estimate of the time to cross a lower level cloud, after takeoff or before landing), you absorb roughly 0.3 grams of ash per engine.

[pete999]

@DjerbaDevil

There are a couple of points where you misunderstand:

1. The VAACS model is not predicting concentration. It explicitly stated in the earlier graphs (although appears to have stopped doing so) that density of the "cloud" is unknown. This is not to excuse the process, but merely to state a fact. Maybe the ICAO should alter their process to not consider such models where concentration is unknown, but the VAACS model is officially approved by the ICAO.

2. The VAACS model does not try to suggest at which concentration of ash engines might be damaged. That is for the engine manufacturers to decide. Since they do not know, they recommend concentrations of zero.

[lamina]

It looks like common sence is about to prevail. The Met Office model is about to be given the heave ho.

[Beausoleil]

I don't know if the link was posted yet, I've not been following the thread assiduously, but here is the NASA technical report. I hope it is helpful. It seems to me to conclude that flying through a diffuse cloud can cause hard to see damage that nonetheless has a major impact on engine lifetime and hence safety.

http://www.alpa.org/portals/alpa/volcanicash/03_NASADC8AshDamage.pdf

SUMMARY

In the early morning hours of February 28, 2000, the National Aeronautics and Space Administration (NASA) DC-8 Airborne Sciences research airplane inadvertently flew through a diffuse plume of volcanic ash from the Mt. Hekla volcano. There were no indications to the flight crew, but sensitive onboard instruments detected the 35-hr-old ash plume. Upon landing there was no visible damage to the airplane or engine first-stage fan blades; later borescope inspection of the engines revealed clogged turbine cooling air passages. The engines were removed and overhauled at a cost of $3.2 million. Satellite data analysis of the volcanic ash plume trajectory indicated the ash plume had been transported further north than predicted by atmospheric effects. Analysis of the ash particles collected in cabin air heat exchanger filters showed strong evidence of volcanic ash, most of which may have been ice-coated (and therefore less damaging to the airplane) at the time of the encounter. Engine operating temperatures at the time of the encounter were sufficiently high to cause melting and fusing of ash on and inside high-pressure turbine blade cooling passages. There was no evidence of engine damage in the engine trending results, but some of the turbine blades had been operating partially uncooled and may have had a remaining lifetime of as little as 100 hr. There are currently no fully reliable methods available to flight crews to detect the presence of a diffuse, yet potentially damaging volcanic ash cloud.

[peter we]

Very wrong. You need to calculate the air flow through the engine. Nothing to do with thrust.

An example. Which I based upon figures from the Canadian VAAC, which seems to use a distinctly better model than the British one, with results divided in low, medium and high concentrations. Low goes from 10 to 100 micrograms per cubic meter of air. If you consider a plane flying at 180 m/s, an engine with a capture area of 3 square m, and a concentration corresponding to the upper limit of the "low" concentration, over ten minutes (an estimate of the time to cross a lower level cloud, after takeoff or before landing), you absorb roughly 0.3 grams of ash per engine.

Ok.

So (180m/s x 3m) *10microgram=5400microgram/second.

5400microgram * 10*60= 3.24grams in 10 minutes.

At a higher concentration (still low) of 100 micrograms per cubic meter of air it would be 32.4g per engine per transit through the layer.

This is assuming 10 minutes transit, I believe the cloud is now down to FL10 and below isn't it?

[peter we]

"It looks like common sence is about to prevail. The Met Office model is about to be given the heave ho."

So we are going to use common sense for future weather predictions as well are we?

200 years of science, some of the most powerful computers in the world and all we needed was common sense instead.

[Stoic]

Quote:
At what concentration is ash in the atmosphere an ash cloud?
Someone posted that it was measured at over 2000ppm. The NASA aircraft that was damaged, flew through 600ppm I believe. I have just been giving the NASA DC8 report a once over. There is no statement of the ash cloud's particulate parts per million during the 7 minute encounter but there are two graphs, 7a and 7b, of what happened. 7a shows the sulphur dioxide concentration against time which peaks at about 800,000 parts per trillion by volume. 7b shows the aerosol number density against time which peaks at about 28,000 per cubic centimeter. Can anybody explain how these figures translate to the concentration of particulates in parts per million (physics a bit rusty!).

One bit of good news for the brave souls flying the test flights is the following quote from page 13 of the NASA DC8 report:


There is no evidence of significant engine performance change following the ash encounter. In fact, there does appear to be a slight drop in cruise EGT. This is
consistent with experience that says that a very mild ash encounter cleans and polishes the compressor blades, slightly increasing their efficiency.

Sounds like an on-the-wing de-coke!:)

[acad_l]

So (180m/s x 3m) *10microgram=5400microgram/second.

5400microgram * 10*60= 3.24grams in 10 minutes.

At a higher concentration (still low) of 100 micrograms per cubic meter of air it would be 32.4g per engine per transit through the layer.

This is assuming 10 minutes transit, I believe the cloud is now down to FL10 and below isn't it?


Right. I made an algebraic error. 32 g is it.

You can easily adapt to different times and conditions.

[Capot]

The 'law' governing flights in ash conditions is the ICAO document referenced in previous posts. Who exactly could be sued and for what reason?

Well, yes and no. ICAO EUR Doc 019, if that is what you are referring to, comprises guidance and recommendations for various bodies to follow if a volcano blows in the N Atlantic area, but is a very long way from being law in England and Wales or anywhere else in the UK.

Any other ICAO document would have a similar status.

IF the person or organisation who decided on the airspace restrictions got it wrong, or was not even empowered to do that in law even though he/she/it obviously can in practice, repeat IF, then that's where the airline lawyers will aim.

Reason? Don't be naive; money, and lots of it, in compensation at taxpayer expense.

[fireflybob]

From a political perspective this is all further proof that the lunatics are running the asylum.

Management is doing "things right", leadership is doing the "right thing".

If we had leaders with any backbone they would have the moral courage to open the airspace, albeit with some restrictions. Having those BA aircraft diverting away from LHR is utter nonsense.

[Jig Peter]

David Learmount, on Flightglobal (q.v.) rightly says that "the" problem is twofold:
1) A volcano in Iceland is erupting vioently
2) A very stable High-pressure system is unusually far North and directing the plume south-eastwards.
#2 is unusual for this time of year.
This is an unprecedented situation, which is why none of the "risk assessment" or researchers have predicted it (for all their Ph(u)Ds from Llaregub U).
Because of the above, engine manufacturers have not spent time and money collecting samlpes of volcanic ash to throw at engines on test-beds (And probably won't in the future, for cost/benefit reasons, which is sensible).

OK, it causes chaos and hardship for passengers (and airlines), which insurance companies will no doubt still be disputing in years to come.
The situation will ease when the weather pattern changes - maybe a Low will send the stuff from this and any bigger bang northwards, over the Pole and into Nothern Canada or even Alaska - then what will Sarah Palin say ???


N.B. Tongue ever so slightly in cheek at times ...

[Clandestino]

2. Empirical evidence for density that is dangerous to an engine.

Number 2 is the responsibility of engine manufacturers. Maybe the industry will fund such research now for the future.

Oh, but airline industry is conducting such a research on an Europeanwide basis right now. If things go pear shaped, at least historical LIDAR, wx baloons and research aircraft data will show what was the concentration that stopped the fun. If not we'll know what's the safe level.

I did participate in a "test" flight today, albeit on the fringes of the VA propagation forecast (as forecast by the Met Office, not Eurocontrol) and therefore I would be only too happy to wake up and discover that Finnish Hornet story was hoax, that data from Friday's met flight in UK are secret to hide the fact that closing the aerospace was overreaction and that avoiding VA by using Mk1 eyeball guarantees long and happy engine life.

What are my chances of waking up fat, dumb and happy?

Poor to nil, I'd estimate.

[rayand]

Just been trying to get a feeling for "parts per million" as this is discussed a lot on this thread - and what is apparently being measured.

1 part per million - by weight, what is it?

Well, the weight of the atmosphere causes pressure, and sea level pressure is about 1,000hPa = 100,000N/m2 so that means about 10tons of air above each square metre. (That makes sense because 1m3 of dry air weighs about 1.2kg at sea level, so without allowing for declining pressure, thats 8,000m - so if the air spreads up to 20-30km before "fading out" that makes sense). Thats 10million tons above each square kilometre.

The weight of air above the UK, surface area, 250,000km2 must therefore be 10million times 0.25million tons = 2.5 trillion tons. (2.5 thousand billion tons)

So, if the ash were 1 part per million, and were spread uniformly throughout the air above the UK, the ash in the UK air would weigh 2.5 million tons.


Similarly the whole of Europe is 10million km2, 40X UK so there is about 100trillion tons of air above Europe. 1ppm would be 100 million tons.

Some other points:

1 ton per second of ash generation means a million tons every 12 days

The first three days of the eruption on 14 April 2010 at Eyjafjallajökull (http://www.pprune.org/wiki/Eyjafjallaj%C3%B6kull). generated about 750 tonnes / second on average - so thats about 200 million tons errupted in total so far

If spread uniformly over (just) europe that would be 2ppm

Obviously its not spread uniformly, has also spread over the atlantic and russia.

Can anybody provide a number for the mass of air passing through a typical (e.g. A320) jet engine per hour of flight?

[Jetex_Jim]

If we had leaders with any backbone they would have the moral courage to open the airspace, albeit with some restrictions. Having those BA aircraft diverting away from LHR is utter nonsense.

If anything is a display of backbone it's the fact that in the UK the restrictions still stand while the rest of Europe is out flying. I should say that somebody IS demonstrating moral courage, and a proper respect for safety.

[Tyres O'Flaherty]

From a Volcanologists blog, a ray of hope maybe ?


Less ash, more lava: Eyjafjallajökull changing its style? The Volcanism Blog (http://volcanism.wordpress.com/2010/04/20/less-ash-more-lava-eyjafjallajokull-changing-its-style/)

[Optimistic-aviator]

Or the opposite view is saving face and trying not to get sued! My guess is we will be flying by Friday or Saturday, until the wind changes that is and then we will either have a different kind of ash or we will be using option 2 or 3 of the EASA plan. We are currently on option 1 according to the information being published by my company. So I am hopeful we will see sense returning to the situation shortly.

[GOLF_BRAVO_ZULU]

BBC News - Ash ban to remain for most of UK (http://news.bbc.co.uk/1/hi/uk/8632930.stm)
Nats has allowed for "overflights" - flights that pass over UK airspace at an altitude above 20,000 feet - allowing for many flights between Europe and the Middle East and North America.

Leaving aside the arguments about wise caution/over caution, what do we think the plans are for a decompression descent? OK, not probable but caution is still caution.

[MPN11]

@ Tyres ... valuable input. There was always the hope that the eruption process would change; perhaps this is the "end of the beginning"?

@ Spotters various ... thank you for your inputs gleaned from the spotters websites. :ugh:

[rgsaero]

Having read every page of this thread over the last six days (up to page 99 which is when I started typing this offering) it is clear that there is a wide variety of argument and counter argument, much of it centering around conjecture.

Having been trained in the industry as an engineer 50 years ago! (though I never "practised) and as a PPL of 20 years, from what I can deduce there are some things we know, some we don't know and some which we ought to know for future episodes of a similar nature.
In summary I think these include -

What we know -
1 A volcano erupted and due to the high inflow of glacial meltwater it's output consisted of high level of fine particulate ash which is relatively unusual.

2 An unseasonal slow moving high over the UK caused a southerly flow which caused the plume to move south before splitting and moving both east and west. This dispersal pattern is generated by computer models rather than direct empirical observation.

3 Volcanic ash (VA) with high levels of silica CAN cause severe problems both short and longer term to jet engines, both immediately suppressing combustion and damaging turbine blades.

4 An ICAO "directive" or advisory, issued after a major emergency in 1982 laid down "rules" to be followed in the event of VA clouds impinging on airspace.

5 The subsequent shutdown of UK and European airspace has caused economic damage to the industry, other industries, national economies and considerable discomfort and worse to large numbers of passengers.

6 A small number - very limited - of "research flights" have launched in the later stages of this situation and the results, if clear, have not been widely published.

7 Airframe, engine manufacturers, operators and national and international regulators have failed to undertake or insist upon research which would increase knowledge on which to base actions regarding such situations.

What we don't know -
1 The degree of accuracy of the models and therefore the actual dispersal of dust, either laterally or vertically, and there is little information as to the vertical thickness of layers.

2 Precise data about particulate size, or chemical composition once the dust has reached altitude, and even if we did -

3 There appear to be few if any advisories from engine manufacturers as to the chemical composition of dust, the particulate size, or the density of cloud (ie likely throughput) which engines can "tolerate" without damage, or continue to operate in while maintaining power while suffering damage.

There are many, many more knowns and unknowns but these seem to be the key ones.

Therefore given that the regulators and "safety authorities" do not know what's going on, or what is a safe situation in the first place it is entirely predictable that they will take the NIL RISK route, assuming the worst case scenario and avoiding it by putting aircraft on the ground.

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.

Until that happens I suspect that the authorities will insist that we sit this out until it goes away…..

[Airclues]

BA124 nearly made it to LHR but is presently turning back to AMS (now looks like Brussels)

This is not a spotters post. I'm wondering why it is safe to land at Brussels but it's not safe to land at Heathrow? The weather is the same at both, and they are both in the Met Office 'ash cloud'.

[OpenCirrus619]

After reading much of this thread, along with some other research, I can only conclude that it's going to be difficult to define a "safe" concentration.

Any outpourings from a volcano, encountered by a turbine powered aircraft, are likely to pose some sort of long term risk.

From: http://www.caa.co.uk/docs/375/fsd_may93_p1-9.pdf..these gases may remain suspended in the stratosphere for years after the solid rock particles have settled. The sulfur dioxide in the clouds absorbs water vapor and is converted into droplets of sulfuric acid.

From: http://www.nasa.gov/centers/dryden/pdf/88751main_H-2511.pdfThere was no evidence of engine damage in the engine trending results, but some of the turbine blades had been operating partially uncooled and may have had a remaining lifetime of as little as 100 hr.(Interesting photos on page 1).

Sounds like flying in any aeroplane that has ever been flown through volcanic ash and/or gas is going to be less safe than one that has not.

I realise that most things in life involve risk assessments - I'm just glad I'm not the one with the responsibility of making the decisions here. I think it may be a little unfair to be slating people for taking the safe(r) route of maintaining the airspace suspensions.

Just my point of view.

OC619

[Phil Rigg]

This is beginning to look like the blind leading the blind leading the blind.

If you study the six-hourly actual/predicted 'ash cloud' source map data from the London VAAC that is being published by the Met Office and allegedly being used by NATS to make its UK Controlled Airspace open/closed decisions, you can see from the predicted data yesterday exactly why they chose to open the Scottish FIR and nearby regions, albeit temporarily, today. However, the maps are all clearly marked "ASH CONCENTRATIONS UNKNOWN".

If the ash concentrations are unknown then how is it possible to define the edge of the contaminated area where presumably the ash concentration has supposedly fallen to some identifiably small but as stated "UNKNOWN" level in the first place? What is that level and how does the VAAC even know where to draw the line?

Further, this apparently unknown concentration region of ash extends throughout most of Europe where flying has been permitted today.

NATS is clearly basing its fly/no fly decisions precisely on these maps and the livelihoods of large numbers of people around the world are being substantially impacted by this extremely ill-defined and completely misleading information.

Someone needs to be brave enough to step up and stop this madness. Everyone is hiding behind data produced by a group of well-meaning technical staff at the London VAAC but not being prepared to make a common sense decision as the stakes of making that call are astronomically high if wrong!

It does appear that the Europeans have been prepared to stick their necks out well before our politicians/bureaucrats have.

[BDiONU]

Well, yes and no. ICAO EUR Doc 019, if that is what you are referring to, comprises guidance and recommendations for various bodies to follow if a volcano blows in the N Atlantic area, but is a very long way from being law in England and Wales or anywhere else in the UK
Is UK signed up to ICAO? Yes. Is part of NATS licence to comply with ICAO etc? Yes.
IF the person or organisation who decided on the airspace restrictions got it wrong, or was not even empowered to do that in law even though he/she/it obviously can in practice, repeat IF, then that's where the airline lawyers will aim..
Very big if and given that NATS has complied precisely within the terms and conditions of it's licence they're squeaky clean (and I do believe I've said this previously).
Reason? Don't be naive; money, and lots of it, in compensation at taxpayer expense.
Compensation for what, following the guidance and recommendations of one of the governing bodies for Aviation? I would very firmly put the boot on the other foot and state that NATS should be prosecuted if it had FAILED to follow the ICAO guidance and recommendations.

BD

[paddymcc]

Those BA planes could be getting re-routed to Shannon Ireland. Some info here from the irish aviation authority:

Irish Aviation Authority - UPDATE ON AIRSPACE RESTRICTIONS (http://www.iaa.ie/index.jsp?p=93&n=96&a=874)

Looks like im going to be stuck in Paris until the end of the week.

[tempesta]

there are too many unprofessional people out there. Nobody knows how to deal with a crisis and everybody just act to protect themself, not in the name of the safety of flight, but in the name of the "law" wich is far away from the environment we're all working in. no common sense:=:confused:

[80/-]

I'm wondering why it is safe to land at Amsterdam but it's not safe to land at Heathrow? The weather is the same at both, and they are both in the Met Office 'ash cloud'.

Perception of and attitudes to risk management I guess. What I still don't understand is why flights were allowed into Luton this afternoon, but none were allowed into LHR.

Anyone know why the flights from Canada to Luton were cleared through closed airspace ?

80/-

[alwaysmovin]

Colleague heard from a Klm pilot on his freq that KLM policy is that they are only allowed fly IFR in VMC conditions ??????..... seeing as they were the ones shouting about how safe it was to fly......why this policy????

[lomapaseo]

Some points

The air we fly through normally is not always clean and often contains ppm of volcanic residue. Thi sis known by the large high altitude world wide operators who have to maintain planes and restore ash errosion and contamination (windows, leading edges, engine bleed and oil systems etc.

Through the collective data of the OEMs all operator warnings are in place relative to what is very bad and can lead to completely disabling an aircraft and the onset of the symptoms that forewarn this (see your FCOMs). In bertween this and quite, common in major erruptions, Mt Redobt,, St Helens, Pinatuba etc. are events where the engine or aircraft has to be taken out of service at high cost in order to return it to an airworthiness standard.

To both the aviation safety professionals as well as the operators this can be described as a Red (do not fly zone), Yellow (you may have imapct on your operation) and Green (normal wear and tear).

It was always the objective that the volcanolgists and meteorolgists would model the Red zone and Yellow zones make up in PPM and content and advise the operators where they would be at any given time so that safe and effective fleet management could take place. Obviously this did not happen in an organized way. We all share the responsibility for this in not anticpating this and for me this is especially troubling since I bear a large respionsibility in this.

Now we have the operators themselves absorbing the task by flying test flights to at the same time accepting some risk of increased maintenance costs should they encounter Yellow zones for any length of time. Always the intent is to err on the side of safety so do expect some diversions, and Air-turn-backs. Eventually the forecasters will better be able to antcipate these zones and the operations will be able to operate on schedule.

In is in the interests of all aviation interests to devise means to best meet the challenges including supporting both long terms research as well as short term management of risks.

[ed1016nw]

With regard to all the comments re the safety of airspace to the south of the British isles has it not occured to the posters that the same islands are upstream and in a far more concentrated ash stream than the southern european countries and therefore the continued closure makes sense. Why be the guinea pigs with potentially the most damaging results.

[Mr Angry from Purley]

DHL are operating a lot of flights into BRU tonight iso LEJ/EMA. Only problem they are all manned by crews who have been stuck down route since last week and all the replacements are in the UK / LEJ.
Makes me so angry I could throw the phone down :\

[holyflyer]

MPN11 - easy now I'd say most on here have multiple windows open at the moment.

My real concern is that if the BA's don't divert into 'open' UK airports the media is going to have a field day regarding the decision to launch, the decision to refuse descent, landing clearance etc etc etc. Yes, I know there may be constraint issues in terms of the number of stands at Newcastle or Aberdeen that can take a 747-400/777 etc. But the media won't see that.

[Magellan]

And so the Public Relations war gets underway: "heroic" British Airways versus NATS (Govt) et al.

It's no accident that all major news channels are now running headline stories about BA's "determination" to bring 26 flights into the UK tonight. Including Heathrow and Gatwick. The story is being orchestrated direct from BA's Press Office.

Presumably it will be good for BA's business to be seen as the equivalent of an embargo buster. But what kind of signal is that as to the relevance / influence or otherwise of all the agencies and authorities so far involved?

[bubblesuk]

A BA source is now saying that they are not engaged in a act of defience and the 26 flights will not be landing in the UK tonight.

[CDG1]

Update on activity

Eruption in Eyjafjallajökull, Iceland

Current events

Deflation - 20 April 2010 13:30

Latest available results from GPS stations around Eyjafjallajökull showed deflation associated with the eruption. This suggested that the volume of eruptive material which has been ejected already, relieves pressure off the volcano.
No movements associated with the Katla volcano are presently observed.
Sound blasts - 20 April 2010 12:30

Heavy sound blasts have been heard and found near Eyjafjallajökull, especially south and east of the mountain, and more clearly after wind speeds became lower.
The viscosity of the magma from Eyjafjallajökull is higher than on Fimmvörðuháls. This enhances the explosive sound effect. Shock- and soundwaves are carried long distances.

Articles < Seismicity < Icelandic Meteorological office (http://en.vedur.is/earthquakes-and-volcanism/articles/nr/1884)

Latest advisory image

http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271763280.png

[SlingsbyT61]

May be of interest to some of you that Heathrow Special are now issuing SVFR clearances for transit of the London CTR for 'normal' (non-emergency) aircraft again for the first time since this all started.

Hope this of interest to someone.

[763 jock]

Chronus, there will be no money left to invest in anything. This total farce will finish us all off.

[holyflyer]

Radio Teelevis Eireann: Shannon Airport has said it is preparing for up to 11 British Airways flights arriving from the United States between 7pm and 9pm tonight.

[Airways B]

I suggest anyone who doubts the presence of the ash in the air goes to their local flying club or training organisation and looks at the piston engined aircraft that have, thankfully for the health of the club, still been regularly flying over the last 5 days in 20K plus visibilities at low level...

Unusual grey propwash shaped streaks and swirls are visible on leading edges and black propellors are grey. Fortunately these aircraft are cutting through the air at not much more than 100 knots and everythings at not much higher than ambient temperature. Air filters designed to cope with dusty grass runways are not presented with a problem.

[Airclues]

I'm sure that many of us are presently watching those aircraft holding over the IOM and Liverpool trying to get to LHR (even the anti-spotters are secretly doing it). The commanders of those aircraft all feel that it is safe to land at LHR. Could somebody please explain why it is safe for these aircraft to land at other airports within the 'ash cloud' but not at LHR? Is the ash thicker at LHR than it is at BRU?

[763 jock]

Meanwhile, the BA YYC-LHR flight is almost directly overhead a CAVOK LHR on a diversion to god knows where. Is anyone seriously suggesting that landing in Ostend or Brussels is so much safer than landing at LHR?:ugh:

[Airbubba]

Could somebody please explain why it is safe for these aircraft to land at other airports within the 'ash cloud' but not at LHR? Is the ash thicker at LHR than it is at BRU?

I dunno but BA 038 just touched down in AMS and it appears that BA 206 and BA 9120 just made the turn toward SNN. BA 084 and and BA 284 are holding on either side of Eire.

Meanwhile, looks like the LH and KL flights to the U.S. have resumed...

[eagle21]

I am sure there will be a few red faces in the near future in the UK aviation panorama for the decission made these days (or lack of). The press need to be made aware that the UK are using a different forecast to everyone else's this is why there are no flights in the UK. It has nothing to do with scientific measurements...

What would have happenned if 24 BA planes had landed at LHR without clearance??? Well you will never find out but if they had done it the restrictions would have been lifted much faster.

[neil_2008]

Transport sec and Chair of CAA making statement along the lines that airspace will be reopened from 22:00. Also 'The Met Office confirms that the current indicated no-fly zones do not currently cover the UK'.

Lets hope we can get something down tonight out of the BA 26.

[Phalconphixer]

Quick question...

This is getting very political; a battle of wits between BA and NATS/CAA/HMG despite what BA say.

Have been watching BA084 at FL340 in orbit over the Irish sea/IOM for the best part of an hour...whilst others arriving from the USA are heading for Shannon.

Could it be that BA084 is being used by the company as a 'fuel emergency' trial aircraft to force the issue and request a straight in to LHR or MAN?

pp

[biddedout]

Watching those BA aorcraft probing the UK FIR with nothing else in the sky reminded me of the opening graphics on Dads Army.

[Airbubba]

BAW084 seems not to be giving up, maybe getting some practise hand-flying the hold

I don't think you can practice hand flying in RVSM airspace these days...:cool:

At least three B744 Speedbirds still in holding, are they waiting for some announcement about opening EGLL? Is someone about to make a decision on opening UK airspace?

[neil_2008]

...Adonis says the BA flights can land, WW must have applied some pressure tonight.

All airports can reopen.

[BoughtTheFarm]

Apparently it has been reported just now on BBC News 24 that LHR will receive BA flights from 2100z tonight. Anyone?

[eagle21]

It took two Cobra meetings to achieve this. Now they will start looking into responsabilities...

Well done for BA, at last some good publicity :-)

[TissieSaffie]

Breaking News on Sky News.

CAA alllows all British Airports to phased reopen from 10pm tonight.

[lexoncd]

I think its a case of showing aircraft flying round uk airspace then diverting to most other european Countries surrounding the UK to show the public what BA and others would like to do. No argument about continued flying in ash but one off positioning flights in cavok?> make no mistake the Government can't move the thousands of passengers stuck throughout the world....

[DangerousDriver]

BBC News:
BREAKING NEWS:The Civil Aviation Authority [not heard much of them during this] will phase out UK airspace restrictions from 2200 BST

[judge11]

yes indeed, it's a miracle. Five minutes ago it was dangerous and now its safe. This decision should have been made last week. A complete farce:confused:

[judge11]

I still don't believe it was NATS call; look further up the food chain.

[Homer_J]

theres another ash cloud heading our way....

gordon Nropwn "saftey is paramount"

all airports colsed till tomorrow....

and then....

a cobra meeting with the airline bosses....


Its all fine, you can all go flying. we still know no more about ash densities or AC engine tolerances, but its political suicide now so you can all go flying.

Its either safe or not.

If they were saying it was unsafe today, do we really want to go flying tomorrow just because Gordon Brown is down in the polls and WW is loosing money.

[Ceannairceach]

I really don't a few things about where we stand now.

Firstly, the decision to impose zero flow rates was not NATS' alone. It'd be foolish to use the ANSP as a scapegoat.

Secondly, the ash situation is no better in many ways than it was last Friday, yet now the Government, facing an election and some pretty strong pressure from BA et al, decide it's fine to fly now, but not then.

Not rocket science really.

[tocamak]

This will of course be most welcome news for all those experts who say that the airspace should never have been shut. Standby for the pious glee of those who never will be in a position to have to make such decisions but nevertheless try to talk as if they knew the answer all along.

[loubylou]

Nice disclaimer from the CAA that airlines will need to conduct their own assessments whether to fly.
And about time they did step up to the plate - NATS are merely a service provider - The CAA are the regulatory body and should've been prominent from the beginning

louby

[mseyfang]

Risk assessment with this is exceedingly difficult because of the lack of concrete information. However, using some arbitrary numbers and a bit of probability theory suggests that the closure isn't the overreaction some believe it to be.

If one assumes that the probability of a serious incident from an ash encounter under these conditions is one in a million; i.e. the probability of an individual flight making it to its destination is 999,999/1,000,000, then you can compute the likelihood of an incident over a given number of flights. You actually compute the odds of having no accident then subtract, but it yields the correct result.

Using this method, while admittedly arbitrary, does yield some interesting results. Over the span of only 25,000 flights, the chances of an incident are around 2.5%. For 50,000, it's 4.9%. Whatever number you use, it is clear that the risk is not negligible. Here, I've assumed that a given flight is 99.9999% likely to fly without having an incident. The numbers get a lot grimmer using lesser figures.

I think what this exercise does do is to demonstrate the difference in perspective between those in government, who have to look at the overall picture, and the individual pilots here who would launch under these conditions. Individually, the risk is seemingly small. However, cumulatively, a somewhat different picture emerges. This result is not entirely dissimilar to the "tragedy of the commons" problem in economics.

[Homer_J]

Does anyone else think its a bit too much of a coincidence that the airspace opens just as 14 BA longhual AC arrive in european airspace with not a lot of holding fuel, and with WW in a meeting with Cobra?

[EGLD]

This will of course be most welcome news for all those experts who say that the airspace should never have been shut. Standby for the pious glee of those who never will be in a position to have to make such decisions but nevertheless try to talk as if they knew the answer all along.

In the absence of meteorological changes to the weather forecast altering the decision to keep UK airspace shut again tonight, why wouldn't people come to the conclusion that this has been a ridiculous overreaction now they've changed their minds?

[Ceannairceach]

How easy it is for you all to shout about over-cautiousness when, thanks to the regulations, there hasn't been a single incident. Well apart from D-CALM running away from some pretty bad stuff during one of it's flights...but that seems to get handily ignored here.

Perhaps those cocksure ladies and gentlemen amongst you, the armchair pilots and decision makers, would be rather more reluctant to scream for heads to roll if, heaven forfend, something came down in an unrestricted, ash-filled airspace, as a result of commercial pressure exerted on non-commercial organisations more interested in safety then profit.

To be honest, it's a little sickening how so many can claim to know so much about such a complex and oft-changing situation. We're clearly blessed with unparalleled levels of aviation expertise. Lucky us.

[RoyHudd]

Adonis (government) and Hutton (CAA/government). live on Sky and BBC. Squirming Liars, attempting to protect their faulty decisions, with the absolute safety mantra.

They and their cohorts deserve to pay a one-way visit to the volcano!

[Ceannairceach]

What precisely was the CAA's motive for this supposed over-cautiousness?

[PhilW1981]

This was a test flight conducted by easyjet.

Finally common sense prevails and a huge amount of spin from Adonis there. Also interesting that the 6pm VAAS forecast from the met office hasn't materialised.

[EGLD]

What precisely was the CAA's motive for this supposed over-cautiousness?

Do they need a motive?

[teifiboy]

Rather than wait for the weather to shift the volcanic ash, the UK government has simply shifted the goalposts regarding the UK policy on volcanic ash operations.

[Magellan]

@bubbles #1920:
A BA source is now saying that they are not engaged in a act of defience and the 26 flights will not be landing in the UK tonight.

Thanks bubbles re mine at #1919 but BA certainly did orchestrate this to exert pressure and its denial is meaningless. LHR was showing all the US, Canada and Mexico City flights on its arrivals board almost from the get-go, not so much an information exercise for the benefit of a general audience as BA's clear signalling of intention to politicos and the rest.

It does seem we're now into 'posture politics' whereby BA can claim it did nothing other than "assist the decision making process" whilst the, er, decision makers can say something along the lines of, well, hey, as soon as we heard the volcano was *really* calming down, then that's why we lifted the restrictions.

Unfortunately, neither of the above addresses the fundamental issue here.

[Ceannairceach]

I just think the anti-NATS and anti-CAA storm is ludicrous. Because surely the only motive the CAA have, or should have, is ensuring safe flight.

Personally I'd rather be regulated by over-caution than cowboy when so many lives are at stake.

Wouldn't you?

Oh and for the person crying wolf about the non appearance of the latest met chart...

http://www.metoffice.gov.uk/aviation/vaac/data/VAG_1271785386.png

[763 jock]

Every single aspect of the way that NATS/DfT/Met Office have conducted themselves from day one should be the subject of a public enquiry. It was completely ridiculous to close the whole UK FIR last Thursday when the offending ash was north of Scotland. They used a sledgehammer to crack the nut and it has taken them nearly a week to admit it.