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-   -   Iceland volcano eruption risk level raised for aviation (https://www.pprune.org/airlines-airports-routes/545915-iceland-volcano-eruption-risk-level-raised-aviation.html)

101BOY 18th Aug 2014 20:17

Iceland volcano eruption risk level raised for aviation
 
Iceland volcano eruption risk level raised to orange for aviation

Intense seismic activity at the Bardarbunga volcano indicates the potential for a disruptive ash event similar to 2010

Iceland volcano eruption risk level raised to orange for aviation | World news | theguardian.com

tripilot 18th Aug 2014 21:47

Bįršarbunga - looks a bit angry! Heads up everyone!

TopBunk 19th Aug 2014 04:18

See also Vatnajökull - earthquakes during the last 48 hours (Preliminary results) | Vatnajökull | Earthquakes - all regions | Seismicity | Icelandic Meteorological office

Triskelle 19th Aug 2014 10:03

Also interesting to look at the tremor measurements nearby at http://hraun.vedur.is/ja/oroi/grf.gif

farefield 19th Aug 2014 11:40

Well,at least they're easier to say!

Gargleblaster 19th Aug 2014 20:00

Here's some help on the pronounciation :-)

http://www.mbl.is/frettir/innlent/20...e_bardarbunga/

Nemrytter 19th Aug 2014 20:52

Easyjet were testing an Infrared detection system, not LiDAR.

Skyjob 19th Aug 2014 21:03

Fortunately aviation has progressed since 2010 in not closing all airspace but only areas likely affected.
Similarly airlines have put into place procedures for flight planning and in-flight re-planning for these events which caused so much havoc in 2010.

Let us hope the progression of measures combined by all parties enables minimal disruption this time around if/when it happens.

Volume 20th Aug 2014 07:22

Let us hope that after finding out in 2010, that stopping all air trafic is much too conservative, we do not find out this time that just avoiding the most poluted areas is not safe enough...
It would be more than typical that after an overreaction the next time there will be not enough reaction. It typically needs several oscilations around the optimum to find it.

Pace 20th Aug 2014 07:53

The last time was a ridiculous fiasco with computer generated prediction flows which were totally inaccurate and for what?

You would think that Volcanic eruptions was something new like some unknown new virus that is plaguing the earth.

volcanic eruptions and volcanic ash has happened in different parts of the world since aviation begun.

There has never been a fatality in the history of aviation although there have been close calls flying into thick dense ash easily visible to the eye in daylight while flying in clear air.

The same excellent safety record regarding volcanic ash cannot be attributed to bird strikes which have killed people.

Yet we do not see bird tracking predictions in the migration season with big chunks of airspace closed down

B Fraser 20th Aug 2014 08:00

The BA 747 that went into a cloud at night over Jakarta is enough of a warning for anyone. Flying the aircraft with shot-blasted windscreen panels was "like trying to navigate one's way up a badger's @rse without a torch". Captain Moody and crew were terrific. Google the story and you will be amazed.

In the recent eruption, the Finns (mad as a box of frogs) intentionally flew a jet into the cloud, the results were not pretty.

Pace 20th Aug 2014 08:19

Fraser

Obviously if you fly into thick dense volcanic ash there will be a problem
we have all seen the towering cumulous like black dense clouds of ash billowing out of a volcano.

As with any particles in clear air whether moisture or volcanic ash they are visible in day light in clear air in the form of clouds or mist.

The argument as before is how dense does that ash need to be to risk the safety of an aircraft and its occupants?

As stated in the history of aviation going back to times when there was not the technology available today there has never been a fatality cause by an intrusion into ash.

the same cannot be said for bird strikes which have bought aircraft down.
One is perceived risk the other demonstrated risk.

Volume 20th Aug 2014 08:39


volcanic ash has happened in different parts of the world since aviation begun
Since the beginning of aviation engines have developed quite a bit. Pressure ratio and hence peak temperature have increased significantly since the De Havilland Ghost (actually the other way round, higher temperature capability of modern material has allowed the pressure ratio to increase, but temperature is the critical parameter when discussing melting ash). Modern engines depend on electronics and sensors, readings out of the normal due to clogged pressure sensors or contaminated temperature probes will trigger a shutdown or run the engine out of its intended parameters which will not improve its performance and life. Modern engines have highly sophisticated internal air cooling of some turbine blades through tiny holes, which may clogg. Modern engines internal aerodynamics are cutting edge technology these days, they do not take that much of molten lava in the turbine as older models.
But nobody knows the exact limits. There are no requirements, there are no standards. There is not even standard ash available, every vulcano is different.
So it is fine to be a bit conservative, but 2010 was far over the top. The 2014 statistics is already poor, we do not need another airliner in the dust (or the ocean).

B Fraser 20th Aug 2014 09:18

.... wot Volume said.

The ash particles have a low melting point and when they stick to film cooled blades, do not make for a happy outcome.

There's more here...

BBC News - Scientists assess flight risks from Iceland volcano ash

ShyTorque 20th Aug 2014 09:53

B Fraser,

That four year old article was aimed (I would hope) at the general public and not at professional pilots who, if not in 2010, by now should already have an understanding of the issue. The reaction by the authorities four years ago smacked of a panic from ignorance.

:ok:

Nemrytter 20th Aug 2014 11:39


As with any particles in clear air whether moisture or volcanic ash they are visible in day light in clear air in the form of clouds or mist.
Ash layers are not always visible in daylight, it's possible for them to be completely invisible - as happened in some areas after the 2010 eruption.

The last time was a ridiculous fiasco with computer generated prediction flows which were totally inaccurate and for what?
As far as I remember the modelled ash dispersal was actually reasonably accurate. The concentrations were not.

There has never been a fatality in the history of aviation although there have been close calls flying into thick dense ash easily visible to the eye in daylight while flying in clear air.
There's never been a fatality associated with flying a widebody aircraft inverted under the Sydney Harbour Bridge either...but that doesn't mean we should try it.

'This has never happened' is a terrible argument to use, just because something has not happened thus far is no guarantee that it will not happen in the future.

B Fraser 20th Aug 2014 14:10

Here's an article more fitting for you Mr ShyTorque. ;)

http://www.imeche.org/docs/default-s...Ash_Report.pdf

ZOOKER 20th Aug 2014 14:45

It's O.K. avoiding the possibly detectable pyroclastic cloud, but what about the invisible volatiles?
Hydrogen Flouride, Hydrogen Sulphide, Boron, Argon, and Hydrogen Chloride, (to name but a few), cannot be good news for the engines or the respiratory systems of the crew and pax.

B Fraser 20th Aug 2014 14:58

Argon isn't volatile. You are breathing about 0.9% argon at the moment with no ill effects.

I suspect you meant something else. ;)

ShyTorque 20th Aug 2014 15:14

B Fraser, your link leads to a document which seems to counter your own argument!


The most alarming of these encounters, involving temporary engine failure, have naturally received disproportionate publicity. But the fact that only 10 such incidents have been recorded in 26 years gives an indication of their rarity. Although few quantitative details are available, it is clear that the most serious incidents have all occurred in the 'soup' relatively near the volcano.
A well documented example occured on 15 December 1989 when a KLM Boeing 747-400 encountered flameout of its engines due to ash when flying near an eruption of Mount Redoubt in Alaska[16]. The damage was estimated to have cost some US $80m to repair. There was 80kg of ash in each turbine and the calculated ash density was 2g/m3. Given the air ingestion rate above and if all the ingested ash was retained, then 62/3 minutes exposure would have been sufficient to collect 80kg. However for the limiting density on which the no fly ban was initiated, 4mg/m3, only 160g would have been ingested, emphasising the huge range of densities from the flame out magnitude down to the level of the flying ban.
But safety is not the only consideration. In 2007, it was stated that[17] “the economic cost of volcanic ash to international civil aviation is staggering. This involves numerous complete engine changes, engine overhauls, airframe refurbishing, window re-polishing and/or replacement and pitot-static system repair, etc., and the inevitable loss of revenue due to aircraft down-time while the foregoing is accomplished. Delays to aircraft and their rerouting around volcanic ash has caused considerable expense to airlines operating in regions prone to volcanic eruptions. Also to be included is the cost of volcanic ash clearance from airports and the damage caused to equipment and buildings on the ground. Various estimates have been made, most citing costs to aviation well in excess of $250 million since 1982”.
These figures are small compared with recent estimates of the cost of the 2010 disruption, "EU Transport Commissioner Siim Kallas said the economic impact of the weeklong crisis had caused losses of estimated between a1.5–a2.5 billion"[18].
That paragraph is quite telling.

The disproportionate reaction of the authorities in banning all movements by air caused far more disruption and loss than the volcano would have if everything had been left as it was.

Don't forget, all flying was stopped, i.e. recreational and other forms of private aviation, not just that of airliners, which, it could be argued, are most likely to be badly affected.


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