West Midlands air ambulances grounded by ash
 

BBC reports that the West Midland Air Ambulance has stopped flying due to the ash plume.

BBC News - Volcanic ash grounds West Midlands air ambulances

Volcanic ash halts air ambulances

Air ambulance services in the West Midlands region have been grounded after the Icelandic volcanic eruption.
The Warwickshire and Northamptonshire, Midlands and Derbyshire, Leicestershire and Rutland services were grounded at 1200 BST on Thursday.
Crews from the five helicopters were redeployed in rapid response cars.
West Midlands Ambulance Service said it was waiting for advice from the Civil Aviation Authority to find out when it would be safe to fly.
The Midlands Air Ambulance service, which has three helicopters, operates from RAF Cosford in Shropshire, Strensham Services on the M5 in Worcestershire and Tattenhill in Staffordshire. The Warwickshire and Northamptonshire service has a helicopter at Coventry Airport and the Derbyshire, Leicestershire and Rutland facility is based at East Midlands Airport.

Louby,

Mind I ask what part of UK you are currently at?

I myself would not want to have been doing a flying lesson today, would have been paranoid putting Carb Ice on every 5 milliseconds.

I would have thought, that with Aircraft grounded, a laser could be used to measure the dust density and give a meaningful figure to indicate whether or not it would be harmful. Assuming of course there is a known figure.

I think there is a lot of research into the subject and that is why we err on the side of caution; volcanic dust is far more dangerous than we used to assume. Its not just that an aircraft may lose all its engines in flight, but that all aircraft who fly through this !!!! may have engine damage.

Would you be happy to fly on a aircraft that has pumped tonnes of acidic and abrasive dust through its engines (and with a certain amount nicely coating every component) without being stripped down and inspected? I would not.

You cannot know what the effect will be on some engines; is it really worth flying through this and then requiring they are immediately overhauled to inspect/repair the damage - on thousands of aircraft, as an emergency procedure. How many billions would that cost and how many months disruption would it cause?

Edit:
KLM Flight 867 in 1989, Boeing 747-400 less than 6 months old -
"In this case the ash caused more than US$80 million in damage to the aircraft, but no lives were lost and no one was injured."

One of the hardest things to do, is to prove positive safety.

How do you claim credit for all the accidents that didn't happen, probably because of systems and policies implemented.

On the other hand any failure is dramatically exposed to the criticism and analysis of all and sundry, expert and simpleton alike.

Looking west after sunset - the sky was clear (ie no clouds) but there was a brownish haze along the horizon. Maybe this is as a result of looking through the upper layers of the atmosphere (looking directly up showed no haze).

Meanwhile:-
BBC News - Volcanic dust cloud suspends military training

West Coast of Scotland today - virtually no clouds and visibility unlimited ... why wouldn't you fly VFR ??

Well I hope you got outside and got them both washed then whilst he was having a doze in the sunshine.:ok:

I sympathize with the tone of posts like the ones I have excerpted below.

I do agree that it is necessary to both understand, explain and react to real or perceived aviation threats that affect us all.

It is the job of the aviation safety professionals to perform this task susch that those among us who are the better communicators can at least advise us.

The idea behind the warnings about aviation and volcanic ash were based on accumulated experience over 30 years and multiple near accidents. The general nature of the warnings were thought to be necessary on a time and knowledge based concept.

If-you-don't Know-then-don't Go

This was based on the belief that in a relatively short time period we would know enough about the make up of the ash, its altitudes and expected progression. I'm afraid that I may have had some unrealistic expectations that this knowlege would be within 24 hours of a hazardous eruption. On the other hand there could be a counter argument that the aviation community does know enough to restrict operations in certain locations for the period of time it does take for the cloud to disperse.

I'm not a vulcanologist and defer to the obvious expertise that has already demonstrated itself in this thread:ok:

There are two sides to the expected threats; rapid system deterioration significantly affecting the safe operation of a flight (including engines, airframe and avionics) and long term issues requiring significant maintainence actions. Risk assessment experts can always extrapolate the past history to determine relative risk for either of these effects. And of course apply a cost benefit regarding the maintainence vs operation costs. However, I'm sure that most of your would not support a cost benefit analysis of losing a transport aircraft.

So the question is how much is too much regarding volcanic ash?.

The experts need to know the particulate size. Smaller, (the stuff that stays at high altitudes) is worse since it's dependent on residence time withi the combustor flame. The experts also need to know the relative makeup of melting points of the particulate mater. If this can be identified and modeled within a fortnight then we might be able to make some progress to temper our reaction to the threat.

If the models are not calibrated than the shoot-from-the-hip approach might be to take an aircraft into the cloud with engines and systems running at various conditions (not all have to be at full up) and examine the results afterwards.

OK some of you wanted to debate this so I threw out the first grenade :}

Second post
 

lomapaseo

One of the more thoughtful posts I've seen in this thread. I especially like the following logic:
"So the question is how much is too much regarding volcanic ash?.The experts need to know the particulate size. Smaller, (the stuff that stays at high altitudes) is worse since it's dependent on residence time withi the combustor flame. The experts also need to know the relative makeup of melting points of the particulate mater. If this can be identified and modeled within a fortnight then we might be able to make some progress to temper our reaction to the threat."

Volcanic ejecta varies widely based on many geologic factors. Add to this the atmospheric conditions (not my field) and things get very unpredictable. Without this information one can't begin to speculate, and I would hope that it's being gathered as we speak. If not - and were I an official at a major airline - I would be buying and deploying my own test equipment tomorrow, hiring a vulcanologist or two, and engineers, costs be damned.

Based on the geologic record, this is not likely to be a short term event, although noone can say with certainty how long it may last. Just thinking of odds based on history, but volcanoes are unpredictable critters. I'd prepare for the long-haul and hope for something better, as geologic time scales run on a very different calendar. I'd also hope and pray it's big brother doesn't awaken - God help us if it does.

Regards,
LoboTx, geologist at large

I should confess at this point that job is assist companies to plan for disasters (contingency planning) so it gives me a different perspective.

When I hear people demanding that the arguments about what should be done and whether there is a scientific argument to close the airspace I am surprised. All these issues and discussion have to take place long before any event takes place. When there is a fire, do you have a debate about the merits of evacuation, the danger of smoke inhalation, and burning to death or do you evacuate? In the WTC's there was a plan of action on 9/11; some people followed it - some looked out the window rubber necking.

My point is when there is a situation, you follow the plan and discuss the issues later.

Quote:
Imagine circling over Heathrow in your para glider?

Well, I was circling over a bit of Scotland tonight in my paramotor. I got to 6700+ feet before I gave up with the motor missing due to carb ice.
Or was it perhaps dust?

Some beautiful pics from the vulcano, especially nr. 5 :ok:

Christopher Lund

My (any many other people) point is exactly about DO WE HAVE A SITUATION in the first place? And do you really have to evacuate the whole skyscraper if somebody farted in his office?

Looking NW this evening in Berkshire
 

The sky looked like this for about 20 mins, then clouded over, and then cleared with nothing visible. This might just be cirrus, but then the sun angle may have been just right at the time.

Earlier in the afternoon there was a discolouration to what looked like high thin cloud, and at this time the sun was much lower and this structure could be seen. I'm thinking this may have been the low sun angle illuminating it from below. Everything pretty much disappeared into clear sky with a little haze thereafter.
(music rights are cleared BTW)

This is 4x normal speed, so about 4minutes here showing very slow drifting of these clouds.

This view is looking North West at 18:45 today. Location is 10 miles West of LHR.

This is about an hour from sunset, so the sun is about 15deg above horizon - technically 'astronomical twilight' as that occurs when the Sun is 18 deg above the horizon.

At the 53sec mark in the film, the automatic exposure of the camera kicks in to change that.

Crikey, I don't think I'm going ga-ga.

Ashmap for the UK at 2300 tonight.
http://www.manufacturology.com/wordp...-100415-23.jpg

I think what I filmed was really ash now.

Good article here addressing the possible long-term issues.

Met Office: Icelandic volcano eruption

The eruptions seems to be getting much more violent

Breaking news: Another large flood, evacuation ordered | IceNews - Daily News

Yes of course we do. People, can even smell it in Norway and the effects of this volcano have been felt before.

Some beautiful pics from the vulcano, especially nr. 5

Christopher Lund

I think that the other volcano that erupted three weeks ago. Pretty.

Apologies if this has already been raised, but whilst half of Europe is hopping up and down at having their travel plans disrupted for just 36 hours, the last time this particular volcano erupted, in 1821, it allegedly spewed ash into the sky for two years. :eek:

Hypothetically, say this time it does the same thing - which on the face of it, would seem a reasonable possibility. What would happen if the current airspace closures were to continue for two years ?

I don't believe we have the technology to 'put out' a volcano do we ?

As a species, we excel at arrogance in the face of nature.

European Space Agency animation:

ESA Portal - Animation of the ash plume from Icelandic eruption

and picture:
http://www.esa.int/images/Meris-Icel...w-Full-res.jpg

Helsinki is also closed since 2100 GMT:
FOCUS Information Agency

Duration of the event
 

I have not seen much focus by the media on the duration of this event.

Even if it just goes on for a few weeks, the effects could be major for Northern Europe.

As has been observed, the event could last years.

What would be the effect of a long and continuous ash fallout for aviation (even at low altitudes)?

I think we're into the realms of science fiction style solutions in that scenario.

Interesting times ahead perhaps.

I have read theories on this thread that these erruptions can lead to ash clouds hanging in the air for years.

However from recent violent eruptions I am of the understanding that these large ash clouds are associated with the initial 'explosion'. That initial explosive release of pressure that has been building up for years. Once the mountain has blown its top and that pressure has been realeased, the violence will subside.

I am no geologist, but I think this whole drama of airspace closures will be behind us in a few days.

However with the small margins airlines operate under these days, I hope all will recover from a couple of days sitting on the ground. :bored:

DB :ok:

I recognise the problem of dealing with public perception of danger, but I do feel that the reaction to this problem seems to have erred strongly toward risk aversion rather than risk management.

The ash plume is a three dimensional and largely predictable pattern. In the military we had algorithms for managing flow patterns (eg downwind chemical hazard); we could then operate around the threat. It wasn't difficult science. Why doesn't NATS have the same approach? It seems to me that they have taken an overweening approach.

More pertinently enormous areas of operating airspace appear to have been closed down, but not by operators. Operators deal daily with operating hazard - it seems odd to me that nobody is equating ash with dust/sand that forms a routine risk assessment in many parts of Africa and Asia.

Just a thought. But many correspondents might like to dwell on what they are told to do (and readily accept) by people who never step out of the bunker - and what the rest of us routinely manage as part of our daily approach to life.

Cash flow, or lack of it , took it's toll on airlines after Sep 11. Lets hope this is no longer than 2-3 days. Obviously the European based airlines are going to be the worst hit due to the fact that is their home base.

I hope you're right ! But.........
 

Desert Budgie

Wish I could share your optimism my friend. However, from a purely scientific basis I cannot. For example, your comment:
"However from recent violent eruptions I am of the understanding that these large ash clouds are associated with the initial 'explosion'. That initial explosive release of pressure that has been building up for years. Once the mountain has blown its top and that pressure has been realeased, the violence will subside. I am no geologist, but I think this whole drama of airspace closures will be behind us in a few days."

Here's the rub - in the case of a truly violent eruption (think Mount St. Helens) you would perhaps be correct and stand a reasonable chance of measuring the problem in days. These event usually occur with "Composite" or "Cinder Cone" type volcanoes that build up energy over long time periods, then suddenly release it very quickly in an explosive manner.

Unfortunately, the Iceland event is a "Shield" type volcano and these types behave differently, releasing their energy -heat, lava, ash, gas, etc.- over a longer, much less violent manner. Think of it like the difference between bursting a balloon with a pin versus letting the air out slowly.
Also, Iceland sits on the north end of the Mid-Atlantic Ridge, which has always made it a bit extraordinary geologically speaking. Said ridge is huge, spanning both northern-southern hemispheres of the Atlantic. It's one of the most energetic regions on the planet, spewing lava, gas & ash along its length constantly. Iceland just happens to be the part of it above sea level.

Per my previous post, and in-line with Skyhook One's post above, I think one should look at the long-term, do the science and engineering, and start trying to manage and/or plan around this problem. I sincerely hope I'm wrong. We're planning a family trip to the UK this summer !

Regards,
LoboTx, geologist at large

volcanic ash advisory latest map from met office website. Received at 0031 on 16 April 2010

http://www.metoffice.gov.uk/aviation...1271374304.png

Doesn't look promising for the airspace to open tomorrow however there maybe a chance for Irish airspace. I suppose we will have to wait until 0330z for the latest update from NATS

I think this is all a bit overdone.

We know that the ash that BA009 encountered was too much.

Is that all we know?

How much, for example, is of no significance? (in ppm)

How much is the level over, say, London today? in ppm or some other unit.

If it had happened during the Battle of Britain... blah blah blah:}

I'm glad the subject has been studied by scientists.

So what is the maximum SAFE concentration of ash?




Zero? :rolleyes:

I have just walked back from t'pub under a clear, starlit sky. There is no way that an aircraft would encounter volcanic ash tonight (25 miles from LHR). This is a massive over-reaction.

When Mt St Helens blew in 1980, the actual plume was shown on the met charts and we planned around it. Some ash covered most of North America but it didn't cause any problems.

On 24/2/90 I operated LHR-ANC. There was a large plume to the north of the airfield (Mt Redoubt), so we flew past the airfield and approached from the south (KLM had previously decided to fly through the plume).

My point is that it is still possible to operate during volcanic activity, so long as the major plume is avoided. To close an entire airspace in absolutely clear conditions has dubious logic.

Dave

Skyhook One:

barbiesboyfriend:

I'm sorry to have to tell you that it is not overdone.

First stage turbine blades in jet engines are operating in a gas stream well above their melting point.

They are cooled by an internal flow of cooling air that exhausts through hundreds of very tiny holes, providing what is called "film cooling".

Volcanic ash in the cooling air melts and clogs these holes. The result is blades overheating and failing. Failure = no thrust.

As far as I know, the only data on "How much" ash will cause this condition is supplied by Two or Three accidental flights through ash.

I don't believe anyone wants to risk aircraft or passengers in test flights to prove some theory about acceptable levels of airborne ash, or others about ash concentrations or flow patterns. As far as we currently know, the acceptable level is zero ash.

The blades look something like this, and they are very, very expensive.

http://www.pilotfriend.com/training/...o/images/6.gif

A lot of talk here about ash damaging/clogging engines, but what
about the toxicity of the upper atmosphere? If there are large amounts
of sulphur etc then that's going to be drawn in to the packs and the
air con. So whilst the ash particulate size/dispersal may not be a hazard
in a couple of days (falls due to gravity) what about the noxious gasses?
Who wants a lung full of that? :eek:

A4

What would you do?
 

It's apparent that a lot of people are very sceptical about whether the relatively thin dust cloud over the UK would bring down a plane.

You may be right, it may not bring down a plane. But you may be wrong. Who knows?

But consider this, if you had to make the decision whether or not to let the 500,000-600,000 people who's flights were disrupted today, get on board their aircraft and give it a go regardless, what would you do? Would you send your own family up there to try it out? I for one would not take that risk! The absolute number one priority of any airline and regulator is quite rightly safety.

Factor into it that airlines (mine included) would not want to risk causing any damage to their billions of pounds worth of equipment by flying it through that dust that can cause very real damage to an aircraft, even if it doesn't bring it down.

I say well done NATS for having the balls to make a difficult decision :D

UK Airspace now closed until 1900 local at the earliest...

'However, flights in Northern Ireland and the Western Isles of Scotland to and from Glasgow and Prestwick may be allowed up to 1300 (UK time) today, subject to individual co-ordination. North Atlantic traffic to and from Glasgow, Prestwick and Belfast may also be allowed over the same period'

"I have just walked back from t'pub under a clear, starlit sky. There is no way that an aircraft would encounter volcanic ash tonight (25 miles from LHR). This is a massive over-reaction."

Next time you're outside, have a quick look at the ozone layer and see how that's holding up, would you?

I said much earlier on this thread that I had been in the Indian Ocean/Indonesia incident when the a/c lost all four engines simultaneously. This was daytime - bright sun "clear" visibility - yet all four engines stopped. Restart was achieved only at a much lower altitude as the glassification dislodged. It was slow - one engine at a time. Just because you can't see the bl**dy stuff from the ground doesn't mean it isn't there!

Some hours ago listening to a very famous Vulcanologist i took 2 main ideas...
First, when this "Lil Bad Boy" had his last "euphoria" was around the beginning of 1821 and last until 1823..Ouchhhh:ooh:
Second, this "lil Boy here" has a brother some miles to the north, but with one "little detail"...shouldnt bother him cause this one its the double size...and if this one already can does such messy, one could really imagine what a double sized vulcano could do...!!????:confused:

Not all aircraft have this vulnerability
 

I hope someone does some work soon to base the closures on the actual conditions in combination of the vulnerability of the aircraft type for the flight.

I'd like to see charter operators, with piston engined equipment, make the money they should as soon as it can be determined that it is safe for them to do so.

BA9 Was at night
 

@ Royalist

History shows that the incident happened at night in darkness...

Thank God for the CAA in closing the airspace. No need to waste our breath arguing with the passengers. Perhaps this may have saved some press-on-itis operators from an incident or accident. :ok:

Royalist,

your memory seems to be failing you:

http://www.ericmoody.com/Page1.pdf

Top of right hand column:

"...the night was moonless but clear..."