The "refutation" and "lack of re-refutation" have no more status than the original rumor. For hobbyists, this might be enough. For many professional purposes, it does not suffice.

PBL

It looks from the synoptics as if there may be a drift towards the west of the UK by 25th.

Earthquake action continues
 

Earthquake activity both at Eyjafjallajokull (many) and again two at Katla (the most recent occurring in the last 4 hours, while not very big at 0.4 on the Richter scale, was deep at 13.7km which is concerning).

Also just found out that the last time Eyjafjallajokull erupted it lasted for 14 months.... so this could be a long thread. :{

- GY

What a very strange thing to come out with. You could use the same logic with Concord; it had a perfect safety record, until it didn't.

Maybe its becuase aircraft have always avoided flying through dust, certainly when they do, in certain concentrations its got very very expensive and dangerous. And VA is not the same from all eruptions, some, like this, are far more damaging.

Yet more earthquake activity at Katla
 

Another quake directly under Katla of 0.9 magnitude at a shallower depth 4.8km.

A bunch under Eyjafjallajokull.

-GY

Flight safety risk analysis does not work with extremely rare consequences.

What is done is to review much more common outcomes which fortunately for the passenger and crew are measurable degradation in safety (all nicely tided up in the definitions under 25.1309 and the Industry wide CAAM report published by the FAA.

Therfore even sucessful outcomes (the plane landed safely and the passengers changed their underwear) become part of the data. And nobody takes credit for events where nothing happened in millions and millions of hours but instead simply looks at the statistical probability that "any" degradation of safety (according to measured definitions) may happen that contains Volcanic Ash as an ingredient.

I keep saying that the volcanic conditions that we speak of today "will" result in some measurable degradation of safety but no more than the typical risk that we operate within everyday for all other causes (risk is never zero but it is managed within acceptable limits)

Most readers have no idea of what risk is allowed to underly each and every flight and the variable contributions of the causal factors versus time. Just because you identify a newly recognized causal factor "du jour" doesn't mean that you have to manage it to zero to justify to keep flying.

How much damage has this one actually done ? So far no one seems to have any confirmed damage.

Or do you mean that the response to the ash cloud was far more damaging (to the tune of a couple of billion) ?

an F-18's engine is like a ramjet when compared to todays hi-bypass engines; no wonder it picked up a load of VA!

Precisely ! The F18s would have been manoeuvring at high speed, high thrust, with no engine bleed worth speaking of, and probably at medium/low level. Under these circumstances they would have almost inevitably been damaged by ash ingestion.
Your average high-bypass commercial turbofan, on the other hand, operates at lower speed and relatively constant thrust, with air bleed. Our manuals tell us that in the event of an ash encounter we reduce speed and increase air bleed (and get the hell out of there).
The British government and authorities at the time of the original ash closure also mentioned an RAF Typhoon that had allegedly been damaged by ash. No doubt that was also manoeuvring at high thrust, low level, which bears no resemblance to the civil jet environment.

Seismic activity has increased in the last few hours
 

Frequent but weak tremors in the area around our beloved Volcano in the last few hours, extending also to the proximity of Katla. Hopefully I am just over reacting and it does not mean anything at all.
The increase in seismic activity is objectively a fact in the last few hours but it seems normal activity intensity-wise, the location instead is a bit more worrying as epicentres seem to be moving towards Katla crater, but it could mean nothing, hopefully:uhoh::uhoh:

This looks to be an official note on the incident - I think someone already posted it ealier:

CEN10RA135 Note the date of the incident - it's pre iceland VA.

I doubt there have been two uncontained failures like this on the same type in less than three months (or rather, if there had I think it would have been bigger news and we'd know).

PBL: From this incident note and your professional contacts you may be able to confirm the details and tie in the photos - in which case the date and location rules out VA.

This may be as close as the rest of us amateurs get to an official statement (reported statement form Cessna): Engine Damage Not Caused by Volcanic Ash: AINonline.

Latest update from the Iceland Met Office and Institute of Earth Sciences indicates that the explosive activity has died down considerably.

Articles < Seismicity < Icelandic Meteorological office

:8:8:8

Well except take offs, up to 10 a day for some of our aircraft, and go arounds.:D

And how can you say "no doubt" at low altitude and high thrust?

Lomapaseo

This is a well written and thought ;) If you want zero risk DONT Fly.

There are far more PROVEN risky elements to flight than Ash yet ASH has cought the public imagination hyped by the media amd reacted to by a whole host of back watching Burocrats and quangos.

We have had many fatal landing and takeoff accidents in strong winds and shear conditions even within the "accepted operational levels" but do we have a long thread like this one demanding all takeoffs and landings should only be with zero wind?

Ash which has NO fatality record throughout aviation history has been hyped into a monster or bad wolf which is out to get you.

Peter We

Volcanic eruptions are nothing new. Jet aircraft 20+ years ago had hardly any sophisticated equiptment and NO fancy computer generated Ash Prediction charts.

Maybe they flew through low level ash concentrations and never knew about it. If you cannot see it it wont hurt you.

Volcanic Ash really isnt a new phenomina!

Our MEDIA HYPE driven, paranoid, liability and blame culture IS!!!

Oh well off to bed so I can dream of shooting and killing a few million birds to save us from Bird flu!

but more likely to save us from ingesting them in our jet engines a real ignored threat.

Pace

Thanks, IF! Yes, brother forget posted it earlier, along with a quote, and I missed it (the quote distracted me).

The pictures show an aircraft with a D-reg (can't see other letters), with engine, rear fuselage and tail markings identical to those on pictures on the WWW of some other Citations from Eisele Flugdienst. So I can call up the BFU, or indeed the company, and find out.

PBL

I guess that a whole lot of the 'Ash Emergency' reporting from the Meeja generally is examples of 'Never let a Few Facts get in the way of a Good Story'.

Even the Flightglobal story reporting no significant damage to the F-18 engines, with a by-line of 23/4/10 was followed the very next day in the same magazine with 'Europe's volcanic ash response: was it adequate?' which mentioned the original 'reported' F-18 damage but not, strangely enough :rolleyes: , the previous day's 'no damage' story. I haven't ploughed through the literally 100s of VA references just in Flightglobal to try to judge their attempts to balance what was published but my guess is that they were also to some degree cheerleaders on the 'High VA risk - We're all gonna die' bandwagon. Given Flightglobal's position as an industry-specialist publication and particularly its own masthead (Serious about Aviation), this is disappointing.

It would be a bit of a stretch to envisage a conspiracy in which someone hijacked the NTSB website and planted a faked-up story about the Citation CJ incident so as to place it well before VA became an issue!!!

BrookSJG

That is the sickening thing with the media they create the story they want and either ignore the facts or worse falsely make one thing appear to be another.

There are people who have had their lives ruined by the media by pretending something is true and painting a false picture to influence readers into believing it is true. Some of these people have been accused of horrendous crimes. When the courts find them not guilty that report gets a half inch column in the depths of the media report.

It is the same with this charade very damaging to aviation and made up of selective and false reporting designed to generate unfounded fear in the public.

These people including a select few in this forum should be ashamed of themselves as all they achieve is damaging an industry and peoples livelyhoods by their false representations. Worst is most dont even know what they are talking about.

Pace

Interesting to see the nature of this ash, note the chunky structure.

Eyjafjallajökull ash under a petrographic microscope in crossed-polarized light at ~40x. Image by Erik Klemetti.

http://i726.photobucket.com/albums/w...b-400x300-.jpg

Eyjafjallajökull ash under a petrographic microscope in crossed-polarized light at ~100x. Image by Erik Klemetti.


http://i726.photobucket.com/albums/w...x300-49461.jpg

Icelandic Met Office reporting marked decrease in activity:
Visibly very different!

VA forecast accuracy
 

Now that the dust has settled (at least for the moment!), has anyone seen any proper explanation (especially from the Met Office) for the overall lack of accuracy of VA Forecasting and, in particular, for the error(s) that led to the sudden and very obvious revision between 0600 and 1200 last Monday (17th May)?

Quite apart from the disruption caused by lack of inbound flights to LGW and other short-term problems, there was also a potential risk (already mentioned above) from reassignment of certain areas of the North Sea from 'white' to Black in the same revision.

Superficially, it looked like inaccuracies in weather forecasting had been allowed to 'bleed through' into the VA Forecast, with no later corrections being applied as real weather data superseded the forecasts. I have no actual evidence of this but unless something like this occurred, how could such a major restatement of the position of the ash cloud ever be required? - unless, of course, there were other problems with the model that only came to light over the weekend 15/16th May.