|
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 |
Bárđarbunga - looks a bit angry! Heads up everyone!
|
|
Also interesting to look at the tremor measurements nearby at http://hraun.vedur.is/ja/oroi/grf.gif
|
Well,at least they're easier to say!
|
|
Easyjet were testing an Infrared detection system, not LiDAR.
|
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. |
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. |
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 |
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. |
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. |
volcanic ash has happened in different parts of the world since aviation begun 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). |
.... 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 |
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: |
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 last time was a ridiculous fiasco with computer generated prediction flows which were totally inaccurate and for what? 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. '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. |
Here's an article more fitting for you Mr ShyTorque. ;)
http://www.imeche.org/docs/default-s...Ash_Report.pdf |
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. |
Argon isn't volatile. You are breathing about 0.9% argon at the moment with no ill effects.
I suspect you meant something else. ;) |
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]. 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. |
'all flying was stopped even private flying' err no it wasn't. I think you'll find there was quite a bit of GA around enjoying using bits of airspace in the UK that are normally not the easiest to access.
|
I remember it well as I had to drive home from a trip. That was fun !
The relevant point is that it is not easy to see volcanic ash in the dark. The sensible answer would appear to sit somewhere between what happened last time and doing nothing. |
The relevant point is that it is not easy to see volcanic ash in the dark. The sensible answer would appear to sit somewhere between what happened last time and doing nothing. |
The best link for updated explanations of the situation at the volcano I've found: Iceland geology | Volcano and earthquake activity in Iceland
|
I find it troubling how many supposedly educated, professional pilots still can't grasp that the reason for such a severe clamp down last time was not just because modern aircraft are designed to tighter limits than old, the technology changing as much as its susceptibility tot he ash, but more critically that the highly idiosyncratic circumstances of the eruption made the ash particularly hard to observe and simultaneously particularly threatening to engines. Comparisons to other events only serve to demonstrate those individuals' lack of comprehension of the technical elements of the event. Equally troubling is their blind dismissal of the tests carried out by several military aircraft which were subsequently found to have significant engine deposits and damage.
|
There's a HUGE difference between flying yer wee Cessna and operating a civil jet transport carrying fare paying passengers when there's a chance of running into volcanic ash.
My off the cuff judgement? If it's going to be on track, don't go. |
It was a complete mess up scientists as well hence why RyanAir reacted the way they did and did their own thing.
There has to be confidence in the science and frankly there was none. as stated in the history of aviation no one has been killed flying into volcanic ash while many have been killed by bird strikes |
no one has been killed flying into volcanic ash However, your "history of aviation" doesn't have enough data to tell you what damage you can do to rather expensive engines ! Nor does it tell you the extent to which ash/dust can contaminate other areas through its ingress. |
It was a complete mess up scientists as well hence why RyanAir reacted the way they did and did their own thing. There has to be confidence in the science and frankly there was none. |
|
In 2010 the dispersion models actually worked very well. The concentration measurements that were taken verified the model results. The main problem at the time was that engine and airframe manufactures and ICAO had not developed standards relating specific particle concentrations to likely damage (or not), so the initial reaction was to prohibit flying where there was any non-zero predicted level - hence the large 'prohibited areas'. Hopefully there will have been some research since 2010 to enable more considered decisions to be made if required in 2014?
|
I think the permitted level was something equivalent to a thimble full of ash in a volume equivalent to a 4 bedroom house :ugh: and yes a lot more research needed to be done rather than picking figures out of the sky.
There are two aspects Firstly the density of ash likely to stop an aircraft flying and endangering lives The density over a prolonged period of time which will diminish engine life and the financial implications Pace |
Pace when you think how much air gets sucked into a jet engine every second and then look out how big the turbine blades are and how little of the contaminate is required to severely reduce there efficiency. Never mind the fact that minute quantities are required to block the cooling holes that run through them which if block means the blades over heat and burn up.
Actually its rather a lot. I am very happy that the choice about flying has been given to professional engineers and out of the hands of airlines and pilots. As this thread has showed pilots are pretty clueless about the risks involved. And the goat blowers in commercial have even less than the pilots. |
Part of the problem at the time was the weather. From memory, there was a stationary high pressure system sitting over the NE Atlantic, and stuff was going round and round, rather than the air mass clearing to the east. I remember it well as I was working with my brother building a shed in his back garden. Putting the roof on I got slightly sunburned. In the UK in April!
|
@Pace
I think the permitted level was something equivalent to a thimble full of ash in a volume equivalent to a 4 bedroom house To help give this apparently insignificant figure better context, consider that a modern aircraft engine (with 118" fan diameter) has an intake fan area of about 7 m^2. When travelling at 250kts (aprox 125 m/s) this will ingest AT LEAST 875 cubic metres of air per second by virtue of mere 'ram air' effects, without any consideration for the significantly greater volume actually drawn in due to induction when producing thrust. This is equivalent to ingesting around 4 grammes of ash as a minimum, EACH SECOND, or a WHOLE KILO of the stuff every 4 minutes. The reality is the figure would be considerably more for the reasons given above. Given the significantly lower melting point of the clogging constituents of the ash than the turbine temperatures, I would certainly not wish to be the subject of live experiments with such quantities of ash in any engine that was keeping my backside from hitting the ground! |
I am no expert, but the quakes are getting stronger, more frequent, shallower and closer to BungaBunga. According to the table we have had 4 over 3.0 since midnight for the first time this week.
Don't know if we can draw any significant conclusions or guesses from that, I will leave that to the seismologists. |
This report from the NASA DC-8 should also be relevant...
http://www.alpa.org/portals/alpa/vol...8ashdamage.pdf I don't think anybody would want to fly with engines like that for too long Lurking... |
Visit Nicarnica for updates & science:
|
I am no expert, but the quakes are getting stronger, more frequent, shallower and closer to BungaBunga. According to the table we have had 4 over 3.0 since midnight for the first time this week. |
There are two fundamental problems with flying in volcanic ash:
a) We don't have a good method of determining where it is and at what concentration, and b) We don't have a good understanding of at what concentration it becomes hazardous to aircraft. Bird strikes can be (and have been) a problem - so there are standards and regulations. Manufactures need to demonstrate that their aircraft/engines can deal with a defined bird strike threat before they can be certified. No one has ever done a test on a high bypass jet engine to determine at what concentration ash becomes a problem. We know the ~1gram/cubic meter that the KLM 747 experienced was a big problem. But what about 1 milligram/meter, or 1 microgram/meter? And how sensitive are different engines - would a concentration that was OK for a 1970s JT9D be OK for 21st century GEnx (or visa-versa)? No one knows, and no one is willing to fund the necessary investigations and developments (at least so far). So for the time being, the only viable answer is complete avoidance. |
| All times are GMT. The time now is 15:52. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.