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.

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.

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'?

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!

Spot on!

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

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. :}

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?

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.

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.

Bruce 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

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.

Swiss fly through the cloud above Switzerland.
 

Diamond Airborne Sensing : A Diamond aircraft delivers volcanic ash cloud measurement data

"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
The HK36 MPP is a single engine internal combustion engine aircraft.


Mickjoebill

IFR VFR
 

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 ?

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.


What are the concentration levels ?

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

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.

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.

BA on the move...at last!
 

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.

Flights all over Europe
 

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.

Interesting, balanced article:

The Great Debate UK Debate Archive Impact of the volcano disruption on the airlines | The Great Debate |

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

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.

Why don't you just look at the Met Office charts and think about it logically?

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?

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

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

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 ??

Not correct , all airports are now open to traffic.

www.aena.es

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:

ASH CLOUD: No technical problems on A380, A340 tests
 

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

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.

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!

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:

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

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?

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.

This is a disaster for everyone
 

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?
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.

"Mystic Met"
 

Worth a read

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

Mystic Met closed Europe with computer model ? The Register

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...

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.

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.

***

An empirical perspective
 

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.

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.