Flying through volcanic ash clouds

[cats_five]

From the BBC:

Flying through volcanic ash clouds
Imagine that the next time a volcano erupts in Iceland, the airlines are able to treat it as though it was no more than a simple weather hazard, like fog.

Scientists working on an ash cloud detection system believe that airlines will soon be able to do just that.

Volcanic ash and jet engines simply don't mix. The superheated particles turn to glass inside the engine and stop it dead.

So, those who manage the airspace above us go to great lengths to keep aircraft well away from the ash clouds that form during an eruption.

Full story:
BBC News - Flying through volcanic ash clouds (http://www.bbc.co.uk/news/business-16077139)

[Green Guard]

The AVOID device can measure the density of the ash cloud too, finding air corridors between different layers of ash.

"This device can be used in a tactical sense to let the pilot see the hazard and fly safely around it," says Dr Prata.

===========================
Easyjet's head of engineering, Ian Davies, is working closely with Dr Prata

He said existing models of ash dispersal assume that its evenly distributed throughout the atmosphere but their research shows that it actually "travels in clumps".

AVOID would let pilots "see those clumps and avoid those clumps," said Mr Davies.




and avoid them by ~ 1000 miles or become locked between them :}

[lomapaseo]

Can it also distinguish melting points of the ash particles?

Can it scan like a weather radar?

Does it display color images in the cockpit like a weather radar?

When do they anticipate that it will be certified for flight?

Who is paying for the development?

[Mike-Bracknell]

...or is it just an empty metal box with an "AVOID" sticker on it that allows them to tell the pilots to fly when Katla erupts?

[cats_five]

<snip>
Who is paying for the development?

From the article:
Easyjet has been funding research by Dr Fred Prata from the Norwegian Institute for Air Research (NILU).

[PAXboy]

Reported elsewhere:
The airline [EZY], which is sharing its findings with other carriers. is understood to have spent up to £1m on developing the system. That figure will increase sharply if it is installed across the easyJet fleet of 204 aircraft. But Ian Davies insisted “ We will not be putting ticket prices up. We are seeking to limit our losses”.

[Piltdown Man]

I think EasyJet needs a pat on the back for funding this research. Only by investing in projects like this will we be able to mitigate against the effects of volcanic ash.

Can it also distinguish melting points of the ash particles? Don't know

Can it scan like a weather radar? Yes

Does it display color images in the cockpit like a weather radar? Yes

When do they anticipate that it will be certified for flight? Don't know

Who is paying for the development? EasyJet

I hope they get a return on their investment.

[4Greens]

The invention has been around for over twenty years. It was not considered cost effective to fit as not that many volcanos erupt etc etc etc.

Perhaps time to fit.

[lomapaseo]

Who is paying for the development? EasyJet

I hope they get a return on their investment.



Something not quite right here.

Easy Jet should be in the airline operation business for their stockholders and not in a speculative development and manufacturing business.

I suspect that all Easy Jet is doing is to offer to install the thing once the development has moved far enough along to be certified airworthy. Sounds to me like either Easy Jet is speculating outside the box or there is money coming from somewhere else.

[PAXboy]

I can see how that might be your thought lomopaseo but EZY's Ian Davis is quoted as saying: "We are seeking to limit our losses”.

That statement makes this an investment in their own operations to keep flying in the future. They may, or may not, make money from selling the invention. However, no one else has stepped up to fund this. One might have thought that a European based aircraft manufacturing company - whose clients lost tons of money - could have funded the research with NILU and then made money selling it to all of their clients, as well as to the operators of their competitors aircraft. But, for whatever reason, they did not.

Accordingly, if they bring this to a certified solution, EZY wins:


Money by keeping flying in the next eruption
Their money back by selling it
Good PR in the airline world for sharing the technology
Good PR with the pax for developing it

[visibility3miles]

"We are seeking to limit our losses”.
This thread, albeit on JetBlast, could explain their concern:
http://www.pprune.org/jet-blast/412220-future-aviation-europe-if-katla-blows.html

per ORAC:
Experts are warning that an eruption could be imminent at an even more powerful Icelandic volcano than the one that paralysed air traffic last year.

Seismologists are nervously watching rumblings beneath Katla which could spew an ash cloud dwarfing the 2010 eruption that cost airlines two billion dollars (£1.27 billion) and drove home how vulnerable modern society is to the whims of nature. Brooding over rugged moss-covered hills on Iceland's southern edge, Katla is a much bigger beast than the nearby Eyjafjallajokul volcano, which blasted ash all over Europe for several weeks in an eruption that local scientist Pall Einarsson describes nonetheless as "small".
BBC: New Icelandic volcano eruption could have global impact (http://www.bbc.co.uk/news/world-europe-15995845)

Hundreds of metres under one of Iceland's largest glaciers there are signs of a looming volcanic eruption that could be one of the most powerful the country has seen in almost a century.

http://www.pprune.org/jet-blast/412220-future-aviation-europe-if-katla-blows-5.html

rp122 link (post #6) with a plot of the ash cloud in 2010 is interesting too.

[The SSK]

The European plan developed in the wake of the Eya… etc eruption in 2011 is based on airlines conducting Safety Risk Assessments and regulators accepting these SRAs. The idea is that flight plans filed by airlines with SRAs will be automatically accepted by the authorities in the national states overflown.

[disclaimer: what follows is from memory, it may contain some inaccuracies]

The ash cloud dispersal model distinguishes between medium concentrations of <4mmg/m2 and higher concentrations above 4. Most airlines have SRAs for <4 but noone as far as I am aware has had one approved for >4.

When this procedure was tested in May with the Grim… etc eruption, some states followed the new approach and never closed their airspace – except of course since nobody had an SRA for >4, nobody filed flightplans for >4 airspace (not quite true but almost). Some countries announced that they would close their airspace at >4 but follow the SRA model for <4.

The one exception was Germany, which (a) announced that it would only approve SRAs (for German airlines) at <2, and (b) insisted that non-German airlines would need German SRA approval to fly in German airspace. Consequently, for practical purposes this meant that while the rest of Europe was operating to a <4 threshold, Germany was at <2. It also meant that German airlines could not fly in <4 airspace over other countries because they did not have an SRA approved by their own CAA.

So, as to Easyjet’s motive, I suspect that it may have to do with obtaining CAA approval for an SRA for >4. If that were the case, they would be automatically allowed to fly through >4 airspace over those countries which had fully adopted the new procedure – airspace through which no other airlines (unless they had obtained their own SRA>4 approval) would be able to fly.

Obviously, the data gathered by this device during the next eruption will be invaluable in measuring the ash cloud dispersal and drawing more precisely the contours for medium and high concentrations – to the benefit of everybody.

[MathFox]

What I think is important is that with a measurement device (and logging of measurement data) one can research the cumulative effects of flying longer times through low ash concentrations. This allows answers on some important questions:

Is there an ash concentration below which there are no observable effects on jet engines?
What is the relation between ash concentration, flight times and overhaul intervals to sustain safe flight?

We know thick ash clouds are bad for planes; but little is knows about the effects of light ash concentrations. Applause for EasyJet to invest money in this research.

[bedix84]

Known as AVOID, it makes it possible for a pilot to see an ash cloud ahead of the aircraft at altitudes between 5,000 and 50,000 feet.
The budget airline, which tested the system on a microlight aircraft over Mount Etna, said the trials were successful and it hopes to install the equipment on its fleet next year.

In April 2010 the eruption of the Eyjafjallajökul volcano in Iceland crippled aviation across Europe, stranding an estimated 10 million passengers across the continent.

Since then the aviation industry has been trying to find a solution to prevent another lockdown of the skies.

One major change has been the decision to allow airlines to make a safety case to fly through low and medium concentrations of ash, subject to the approval of the Civil Aviation Authority.
easyJet believes its technology will enable pilots to adjust their route and avoid the thickest concentrations of ash.

Experts are predicting that Katia will be the next volcano to erupt. They also believe that it will be on a scale far larger than Eyjafjallajökul.
Dr Fred Prata, who invented the system, said that installing the equipment on 100 commercial aircraft would provide enough information to enable European aviation to continue operating.
“Safety is at the heart of the aviation industry which is why we saw the blanket shutdowns in reaction to volcanic ash over the past two years,” added Ian Davies, easyJet’s head of engineering.
“In the absence of proven technology thousands of flights were grounded. This large scale grounding of flights should not happen again, thanks to both satellite and airborne technology which can be used to accurately predict not only the dispersal of ash from volcanic eruption but also crucially the levels of concentration.”


Telegraph.co.uk

[Agaricus bisporus]

The superheated particles turn to glass inside the engine and stop it dead.

You'd think that with all the bolleaux that the media spout on aviation we'd not do it ourselves in this place. What an utter load of hogwash! Still, it would never do to let facts or accuracy get in the way of a good story, would it?

Easyjet never do anything that costs money unless it is confidently expected expected to turn a profit (and preferably huge bonuses too) so either they've found a market or this is another industry changing bombshell like the revolutionary and virtually fuel-less sonic cruiser from the renowned design stable of their genius chief aerodynamicist and aerostructures supremo (aka the breakdown mechanic). And we all know when the first of those is going to be delivered...

[lomapaseo]

You'd think that with all the bolleaux that the media spout on aviation we'd not do it ourselves in this place. What an utter load of hogwash! Still, it would never do to let facts or accuracy get in the way of a good story, would it?



I didn't see any problem with it as a simple way to explain to the public what's going on.

the original quote below

The superheated particles turn to glass inside the engine and stop it dead.

[Agaricus bisporus]

Well, its identical to the statement "Smoking cigarettes/eating hamburgers kills you instantly".
Both are utterly misleading and factually utterly incorrect. Both are idiotically overstated manglings of a concept that has some validity if quantified and none whatsoever without.

It is not quantified and is therfore journalistic soundbite fact-free misleading nonsense.

[lomapaseo]

It is not quantified and is therfore journalistic soundbite fact-free misleading nonsense.

Well the particles can get super-hot enough to melt which turns the dust to glass which then deposits on the vanes behind the burner which renders the engine unresponsively dead to the pilots throttle in about a minute.

I thought he came pretty close to nailing it.

Of course there is room to quibble just like your words of utterly, hogwash & bolleaux

but then how else does one add emphasis in grabber type headlines that the public will understand?

[Agaricus bisporus]

Well, I reckon anyone who doesn't know the difference between "can" and "will" has a serious problem or is perhaps under 3 years of age.
And even if it did melt dust, which no one is disputing, unless in massive concentrations it will only accrete slowly and progressively degrade performance. Which is nowhere close to "stops it dead".
So I stick by accurately calling it utter fact-free misleading bolleaux.

[awblain]

My - possibly limited - understanding of the issues for ash ingestion is that it gets into the cooling channels in the turbine blades, melts and block them. Then the first (and most expensive) turbine stage melts the next time it hits high temperature/power, leading to a very significant performance degradation and a very large invoice from the engine manufacturer.

In this picture, if you have a machine that tells you to inspect the engine before it gets very hot again, then you may save a great big bag full of money.

On the other hand, I can see a whole lab-full of Norwegians laughing hysterically as they all head down to the bank to pay in the cheque from easyjet.

[rottenray]

Agaricus bisporus (http://www.pprune.org/members/11154-agaricus-bisporus) writes:
Well, I reckon anyone who doesn't know the difference between "can" and "will" has a serious problem...Actually, it has. BA Flight 9. (http://en.wikipedia.org/wiki/British_Airways_Flight_9)
On 24 June 1982, the route was flown by the City of Edinburgh, a 747-236B (http://en.wikipedia.org/wiki/Boeing_747). The aircraft flew into a cloud of volcanic ash (http://en.wikipedia.org/wiki/Volcanic_ash) thrown up by the eruption of Mount Galunggung (http://en.wikipedia.org/wiki/Galunggung) (approximately 180 kilometres (110 mi) south-east of Jakarta (http://en.wikipedia.org/wiki/Jakarta), Indonesia (http://en.wikipedia.org/wiki/Indonesia)), resulting in the failure of all four engines.Will it happen every time? Prolly not.

We hear so much about airlines being unwilling to spend any money whatsoever regarding safety, I find it odd that a few folks are beating the monkeypoop out of EasyJet for funding this research.

Even if it only helps a little, only helps a few flights stay on schedule, isn't that worth what Easy is willing to put into it?

And really, who cares if they find an answer that really works? They're not going to sit on it 50 years like the USAF or the Royal would. They'll market it and airlines will buy it.

[Heathrow Harry]

Having been through Jakarta Halim just after the BA incident in '82 I can also remember a Singapore Airbus which had hit the cloud - the front fuselage looked like someone had worked it over with steel wire - all the paint gone and some severe surface damage. It was there for several weeks IIRC

[glhcarl]

Having been through Jakarta Halim just after the BA incident in '82 I can also remember a Singapore Airbus which had hit the cloud - the front fuselage looked like someone had worked it over with steel wire - all the paint gone and some severe surface damage. It was there for several weeks IIRC

One other problem that I have not seen mentioned is the damage to the cabin windows. In the early 80's replacement of cabin windows increased rapidly. An investigation revealed that volcanic was caustic and if the windows were not cleaned thoroughly after an encounter with the ash, crazing and delaminating could occurred.

[jcjeant]

Hi,

Under pressure from airlines, EASA proposes to amend the regulations so that flights through the ash clouds are possible under the responsibility of the operators.
Risks are known. They are listed in EASA CRD to NPA 2011-17
http://hub.easa.europa.eu/crt/docs/viewcrdpdf/id_136
http://i.imgur.com/5QPFE.jpg
The FAA does not agree and indicated very clearly in his comments: EASA should withdraw this proposal for the reasons explained below (page 8):
http://i.imgur.com/7b639.jpg
And this severe remonstrance against the EASA
http://i.imgur.com/U42v8.jpg

[Turbine D]

The superheated particles turn to glass inside the engine and stop it dead.

Agaricus bisporus said:
You'd think that with all the bolleaux that the media spout on aviation we'd not do it ourselves in this place. What an utter load of hogwash! Still, it would never do to let facts or accuracy get in the way of a good story, would it?

Actually the volcanic ash does turn into liquid glass once it is heated above its melting point in the combustor. Below is a photo of the Stage 1 HPT nozzle located just aft of the combustor from one of the BA 747 engines. The accumulation you see on the airfoils is melted volcanic ash (glass) solidified spatter.
http://i1166.photobucket.com/albums/q609/DaveK72/BA-engine.gif

The photo below is of a CFM56-2 Stage 1 HPT blade from a DC-8 that very briefly encountered a volcanic ash cloud. The leading edge is starting to erode and the cooling holes are starting to clog from the ash dust.
http://i1166.photobucket.com/albums/q609/DaveK72/fanblades.jpg
Recognition
Odor. When encountering a volcanic ash cloud, flight crews usually notice a smoky or acrid odor that can smell like electrical smoke, burned dust, or sulfur.
Haze. Most flight crews, as well as cabin crew or passengers, see a haze develop within the airplane. Dust can settle on surfaces.
Changing engine conditions. Surging, torching from the tailpipe, and flameouts can occur. Engine temperatures can change unexpectedly, and a white glow can appear at the engine inlet.
Airspeed. If volcanic ash fouls the pitot tube, the indicated airspeed can decrease or fluctuate erratically.
Pressurization. Cabin pressure can change, including possible loss of cabin pressurization.
Static discharges. A phenomenon similar to St. Elmo's fire or glow can occur. In these instances, blue-colored sparks can appear to flow up the outside of the windshield or a white glow can appear at the leading edges of the wings or at the front of the engine inlets.

TD

[WHBM]

I was thinking of this thread only last week as we entered the circuit for Catania in Sicily, on a good clear day. Mount Etna nicely smoking away (as it usually does) about 10 nm off the port wing.

I just wonder why the ash and lava thrown out from that has long been of little consequence to aviation; when we got to the visitor centre a few days later there was much evidence of the recent eruptions (including one in 1971 which completely overwhelmed the old visitor centre, the tops of which can be seen sticking out from the solidified lava !), and photographs of a huge ash cloud from 2002 taken from the International Space Station. But does anyone remember any disruption from these ? No, thought not.

Regarding the FAA's comments, they had a major experience with the Mount St Helens ash in 1980 (ash so thick that they needed to get the snowploughs out to clear the roads hundreds of miles away), which was well handled and no aviation problems arose. Perhaps those who did the good job then have all been sidelined by a new generation of overcautious bureaucrats.

[John Farley]

WHBM

I see your line of argument but going back to the dates you mention jet engine hot end design was very different (much simpler and ran at lower temperatures) and as a result was much less susceptible to the effects of atmospheric contamination.

Check out the post above yours. You do not have to be in an obviously visible cloud of ash to get those effects.


JF

[The SSK]

From what I remember of the very steep learning curve I was on in April 2010, the specifics of the Icelandic volcano were that the flooding of the lava by the melted glacier caused huge explosions, resulting in very small particle sizes that stayed aloft much longer. Etna's particles are larger and heavier and don't hang around the atmosphere.

[TURIN]

Easy Jet should be in the airline operation business for their stockholders and not in a speculative development and manufacturing business.

Good job BEA didn't feel the same way or we would still be diverting every winter.

Trident Autoland (http://hs121trident.co.uk/Autoland.php)


Yes, yes, I know BEA were a government owned organisation but you get the drift. (no pun intended). :ok:

[lomapaseo]

While looking at pics of volcanic ash encounters just remember that they represent the major degree of what is available in photos. Lesser degrees are not easily confirmed as anything more than accumulated everyday encounters with dirt.

EASA was buikding on this in their notice of proposed rule making while attempting to lay the onus on the manufacturers to define some level of wear out vs variable dirt that is OK.

I do use the word dirt because there are plenty of other particles out there other than from volcanos that will produce the same damage in varriable degrees. Accumulation vs time is the key to avoidance.

It is not the attempt to scare pilots to avoid all encounters but rather to alert pilots to minimize the accumulation of damage by controling the time and internal temperatures regarding the engines.

Most of the recomendations in this regard key on overt symptoms that require immediate action. It is anticipated that avoiding these symptoms as much as posible by route changes will allow us to operate safely and effectively.