hello,

i'm new to this forum (as you can see) although I have been reading it quite often.

I'm no pilot, no engineer, no meteorologist, no expert. I like planes, I try to understand as much as I can about them, so forgive me if what i'm just about to say is complete nonsense.

This volcano erupted. The ash cloud is moving and incidentally is covering Europe.
My first question is: is it possible that the same concentration of ash found in the sky around the volcano is the same one found near, i don't know, Heathrow airport for example? if yes, does that mean that when someone blows the smoke of a cigarette away, this very smoke has the same concentration always and will never disperse? I apologise in advance if this sounds mad to you, my physics studies stopped quite early.

Second question: I live in the north of Italy and the ban has been applied to our airspace as well. It's been raining for the past two days and here and there i've read that if the wind changes and along comes the rain, everything will be cleared away and no more ash. So, if that's true, why is it that no planes are allowed here? (i live near BGY). Shouldn't the rain have cleared away the ashes? But of course if it's the same concentration found near the volcano, then it makes sense.

And also, if it's true that the ash could spread all over the hemisphere, what's going to happen? haven't other volcanoes erupted in the past years and spread their ash all around? were there other accidents involving planes flying in ash clouds? was the BA the only plane ever to fly through it?

Last question: weather forecast says that there are not going to be any noticeable changes in the wind/pressure meaning that the ash could hover around for days. Isn't it weird that Europe is always subjected to a very tempremental weather and now out of the blue no wind, no rain, no low pressure?

I'm sorry for asking so many questions, but I can't seem to find a satisfying answer anywhere. Thank you.

shirayuki

KLM pilots reported "operation normal" to Maastricht UAC shortly after reaching FL410. Now let's wait for the results....

shirayuki,
Clouds as large as this one disperse and diffuse very slowly; especially in quiet weather. I would not be surprised if peak concentrations above the UK were 80% or so of when the cloud left the Icelandic coast.

That's true for the lower atmosphere; however a large part of the ash is above the rain clouds.

MathFox

thank you for the clear answer.

Would UAV be any good to check the "intensity " of the cloud or the consequences?

Is ash worse than Harmattan?
 

I have flown in Nigeria for many years, and for 6 months of the year, up to about FL100 there is constant Harmattan dust in the air. Sometimes so thick that the visibility can be reduced to 400 M. Yet everyone keeps flying in this dust/sand from the Sahara. Yes, over time it erodes the turbine blades and things, but engines do not stop.

I understand that the BA Aircraft that had all engines stop flew through the thick plume created by the volcano near Indonesia.

So why is invisible ash deemed to be so dangerous?

new enhanced satellite photo
 

Looks like ash concentration over the continent is pretty minimal?

http://www.dwd.de/bvbw/generator/Sit...rty=poster.png

Rispud :ugh:, because it erodes engines, windscreens, leading edges.
I'm glad there's nothing good on telly, this is so entertaining.

Flight status display

Look at this! This Russian fleet is flying like nothing has happened. Do they have more info on concentration and the effects on a/c?
Might check other sites, I bet they are operating as usually. Difference - they have military ATC, not civilians.

Tim
 

I think you will find that the ash clouds that have done the damage in the past to eg. BA009 and the NASA aeroplane were in visible ash cloud, not invisible ash cloud. Emperor and new clothes comes to mind.:)

Regards

Well....this applies even more to people resting in their arm chairs uttering something like "What the hell...only hysterical overreacting cowards everywhere....let them fly, and if some drop out of the sky, who cares"....

The risks of flying through volcanic ash clouds is well documented by various incidents. Its a KNOWN RISK.
The risk level in dependence on the particle concentration, composition of the ash cloud, etc might be not fully understand, but 'real life experiments' with thousends of passengers to assess this risk 'in more detail' are definitely not the way to go.

So the 'better safe than sorry' logic of the desicion makers is the only right option in my eyes. And in contrast to the 'arm chair dare devils', those guys might actually feel responsible for aviation safety and also have a fair chance of being sued if anything happens.

As already suggested above, real test flights are the only option to assess the risk more precisely. Now is the perfect time to do this. This KLM flight is the right step forward.

Regards, ihg

test flights made in France and Belgium as well?
 

Reuters is quoting Dutch officials as saying there were also test flights made today in France and Belgium at the request of the EU? Does anyone have any info on these?

Why would anyone have a UAV already kitted out with the necessary instrumentation?

(You could gaffer-tape a sticky lampshade to the fuselage, examine it on landing and say "yep, there's sharp glass bits somewhere up there". But designing and building instruments that can tell you anything quantitative is going to take, er, a few days.)

It's your turn to look up the turbine blade temperatures on a range of jet-propelled UAVs and compare them with those for a range of commercial aviation donks...

Too much doom and gloom on here today when we should be concentrating on overcoming the worst of the situation.

At least there are some test flights in the air flown by people who know what where and how to conduct test flights.

Not all ash is disasterous and without the sampling one can not tell what altitudes are the most risky vs operating temperature of the engines. remember we have operated for 50 years with volcanos. A little bit of science and risk management goes a long way to live in this world.

Let the scientific knowledge and risk management do what's needed. That's the way aviation has always worked.

Volcanic ash is very different from sand:

- Sand usually has a much higher melt point (1300C and up) than volcanic ash (600C). This means that sand goes through a turbine with abrasive effects only, volcanis ash melt and adheres, causing other issues.

- Sand is usually far more "rounded" and worn down grains of material than volcanic ash, which is usually very sharp shards of a glass like substance. Inhaling this can quickly cause respiratory issues.

-A

KLM explanation
 

KLM presedent Hartman explaned:
Its been enough he said: this morning there where test flights in germany.
There was no problem at all !
Also investigators from NASA explaned that the concentration dust is low and no danger for airplanes.

But Its impossible to talk with eurocontrol in brussels he begged to fly again.
Untill now no permission and eurocontrol is not prepared to talk. and Hartman is frustated about this.

The flight kl 705 will be inspected directly after landing.
(tonight he will come with results)
When nothing is wrong than flights can leave from far destinations on there journey to europe allready.

he said that when this happens other airliners will start fly destination Schiphol tomorrow.

Seems that Hartman indeed has hot feet and is going for war........


(Dutch text)
,,Het is genoeg geweest. Het heeft nu lang genoeg geduurd, we willen vliegen”, aldus KLM-topman Hartman. ,,Vanmorgen zijn in Duitsland enkele proefvluchten uitgevoerd tussen Munchen en Frankfurt. Er blijkt niets aan de hand”, aldus de KLM-baas.
Volgens Hartman zeggen ook onderzoekers van NASA dat de concentratie stofdeeltjes meevalt en waarschijnlijk geen gevaar oplevert voor de luchtvaart.
,,Tot onze ergernis viel er niet over te praten. We smeken daarom nu bij Eurocontrol in Brussel om weer te mogen vliegen, maar tot dusver krijgen we geen toestemming”, aldus een gefrustreerde Hartman.
Volgens de KLM-baas zal het toest direct na aankomst uitgebreid geïnspecteerd worden. ,,Wanneer er niets aan de hand is kunnen kort daarna vanuit verre bestemmingen ook toestellen met passagiers aan de reis naar Europa gaan beginnen.”
Indien dat het geval is zullen waarschijnlijk morgen ook andere maatschappijen hun dienstregeling van en naar Schiphol weer willen opstarten.

PIK - Ark Royal disembarking 8 Harriers in 4 pairs....
BA were planning to send the B747 & B777 that landed from the USA this morning back there this evening, but seems not to be happening.

worth having a look at the volcano itself webcams at the moment - looks like its just had a very powerful explosion indeed

now 1300 tomorrow

Statement on Icelandic volcanic eruption: Saturday April 17, 2037

The volcanic ash cloud from Iceland is moving around and changing shape. Based on the latest information from the Met Office, NATS advises that the restrictions currently in place across UK controlled airspace will remain in place until at least 1300 (UK time) tomorrow, Sunday 18 April.
We will continue to monitor Met Office information and review our arrangements in line with that. We will advise further arrangements at approximately 0300 (UK time), Sunday 18 April.

ihg you're right to criticise the rash tone of earlier posts; but "better safe than sorry" doesn't cut it unless there's also an explanation of why this eruption is so much more dangerous than scores of others we've seen around the world. In every other case the risk -as with all the other risks we face daily -has been monitored and managed. Not met with a massive indefinite airspace closure!