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windytoo, you're spot on. This is just hypothetical argument. I'm certainly one of the few who seem to have a problem with what happened, so I accept I may well be a protaganist. Unfortunately we keep bouncing back and forth about what the risk is or isn't. Yet, I maintain my probelm is not so much with whatever apparent risk may have been out there but with the manner in which it was handled and ultimately decicded to not exist.
I just get tired of people telling me no aircraft have crashed from ash in the past as if that means there is no risk. Then when the same people admit that ash does carry risk, they then say as long as you not within a few hundred miles of the eruption you're OK. Get your hands on one of the early satellite images from last Thursday and tell me you would have been happy flying over Scotland or Scandinavia. Yet we should be fine since we're so far away. And on and on the argument goes. Cars and road deaths compared to ash encounters is just pathetic IMHO. If you are a pilot then you train twice a year for an engine failure at V1, brief for it every single day and plan for it on every single departure at HUGE COST to the industry in lost payload and excess engine wear. Yet how many engine failures at V1 have occured over the last 50 years. The one in MAN recently was the latest I know of and maybe a handful before that. That makes it much less likely than a car crash, so why bother worrying about it by your logic. Apples and Oranges mate. I'm just frustrated that we seem to be happy with a completely rushed assessment of the danger which flies in the face of previous thinking without proper analysis, for a problem that would go away, at least for the short term, within a matter of days. Talk all you like about risk only being in the immediate vicinity of an eruption. Research aircraft found visible and significant layers of ash in UK airspace. One of these aircraft was grounded to due the risk of possible damage sustained. Military jets suffered damage in various areas and were grounded. Civilian airliners have had suspected damage. Why oh why is that so easy to ignore? I suppose all involved were just drinking heavily the night before and don't really know what they're talking about. All the talk about visible ash being the only issue is all rubbish also. How many ash clouds have you seen from the air? How can you all be so sure you'd be able to recognise it? It's not some black gritty looking cloud for Christ's sake. What about embedded ash? On and on it goes. I tell ya my head is sore from banging it off this wall. :ugh: Pace, check the latest London VAAC charts. But, as I said you're right, this is a circular argument and maybe I'm just missing the point entirely. Maybe ini years to come I'll look back and say what a **** I was to have been so worried. Let's hope that's the case. So I at least will leave it there. Safe flying everyone. |
We will continue to debate this til the cows come home. There will be no resolution until there is something in writing from both the manufacturer and the regulator that clearly states a policy.
For instance, unless the manual states "approved for flight in icing", would you launch into an area of forecast icing on the premise that it would be possible to see and avoid icing conditions, i.e. mk 1 eyeball style. I was once faced with a dilemma that that set "legal" against common sense. Location: tropical island Temp 32C Weather:3/8 Cu/SC 1 Pitot heat failed, spares 24 hrs away. Sector: 50nm, not above 6,000' Freezing lvl:15,000' Mel: Pitot heat, No. fitted 2, No. reqd 2 I was a new Capt. raring to go, but as my C.P said, if you blew a tyre you would get nailed for the MEL infraction even if it had nothing to do with it.:rolleyes: |
Originally Posted by Seat0A
Have any of you actually been up there this last week?
Originally Posted by Seat0A
Are any of you actually airline pilots?
Originally Posted by Seat0A
If so: have you refused to fly this week?
Guess If I'm extremely unlucky, new guidelines regarding the allowed VA contamination will ensure that my life coverage is paid in full to my dependents. Slight downside is that I'm not a cargo pilot. |
Oh good lord, I said I was done here! The air in a jet engine.....oh never mind. I just can't do it anymore. A bird and an ash particle are kind of difficult to compare don't ya think? Look at some bird ingestion test and tell me if you see the bird drifting towards the outside of the intake from centrifugal force before it hits anything.......
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Originally Posted by brooksjg
(Post 5658816)
Err - no. The (now very old) USGS report on Pinatubo includes several notes about aircraft damage found well AFTER flights that could have caused it! The authors commented that the reason that there's no location given for some of the tabulated incidents is that no-one knew where they happened!
Originally Posted by USGC incident 91-14
Indications that aircraft flew through volcanic ash cloud were apparent only after aircraft underwent ground inspection in Kuala Lumpur, which revealed abrasion of plexiglass landing light covers and navigation lights, which were totally opaque. Cowling intakes were abraded and rough to the touch, while compressor blades were remarkably clean. Landing gear bays were covered in ash with ash sticking to oily surfaces. No apparent damage to windshields
USCG to make the point that for several years there were issues with window and paint degrading and sulphate build up in hot sections for aircraft effected by the gas cloud (which was across the whole of the Northern Hemisphere). |
We will continue to debate this til the cows come home. There will be no resolution until there is something in writing from both the manufacturer and the regulator that clearly states a policy. There will always be second-guessers. The fact that there were no ash incidents gives clear evidence that the Eurocontrol policy was successful. There is no way to tell how many incidents or mishaps there would have been without the policy. Airlines now want the governments to pay them for the money they think they lost. What would have been the cost of even ONE crash due to ash injestion? I think the airlines may have saved money... |
[quote] It's a law of physics. You start to give ANY MASS a rotational velocity around a point then its going to move outwards.
Sorry but even if the forces are tiny and the movement is small the effect is still there. However i'm not in a position to state without facts or figures if there would be any difference in ash density into the non-bypass airflow. /quote] :ok: The bigger stuff gets thrown out further, The stuff at the fan blade roots doesn't get much acceleration, same with birds. The spinner shape is also critical to particles heavier than air. Pretty easy to model once you've defined the particle size. claims-counter claims are just that unless you want to take it to the technical section :) |
Oh windytoo..
I do agree that the experts in engineering and airframe design are the best people to assess the actual damage to aircraft there are some precedents which make your logic most uncomfortable. Challenger space shuttle for a start. O rings which were stiff and amenable to bypass gas when cold. This knowledge was available prior to the flight but was not acted upon by political, managerial and financial pressure. Does that sound familiar? I strikes a definate chord with me in the volcanic eruption saga. If you wish to compare flight safety in the way you do then you accept the lowest common denominator of safety. If 100,000 people died each year in the UK because of aircraft accident then no one would fly. Is flight safety paramount or something that can be degraded? Of couse life is a risky thing since birth but risk evaluation depends on known factors or trust. In real life people evaluate risk against benefits. I am not forced to get on any aircraft but that is an absolute. If I do not get on an aircraft then me dying in an aircraft crash is minimal ( but not impossible- the aircraft may crsh into me on the ground). I choose to pay the fare and get on an aircraft because I want to go somewhere of benefit to me. Its not an absolute, its a spectrum of risk. Am I prepared to get on an aircraft not only with the risk of it crashing but me spending days or weeks at great cost not being able to get back to home? In the past two weeks I have put a plain sheet of A4 paper on my patio table, and guess what - ash deposits. Not every day, but enough for me to wonder what is really up there. I'm no engineer and I have no idea if the accumulated dust on my little A4 amounts to a signficant engine-failing quantity but it makes me think. The difference between "could " and "will" is easily quantified. Its Murphy's Law. |
Boeing tells you not to fly into volcanic ash clouds. Eurocontrol and several member nations published a clear policy that prohibited IFR flight into areas they deemed unsafe due to the volcanic ash cloud. They assessed the risk and decided it was too high for continued IFR flight. That is the basis of sound risk management when it comes to aviation safety. The issue was not flight into volcanic ash cloud, the issue was flight in an airspace that could have had VA particlates. There will always be second-guessers. The fact that there were no ash incidents gives clear evidence that the Eurocontrol policy was successful. There is no way to tell how many incidents or mishaps there would have been without the policy Airlines now want the governments to pay them for the money they think they lost. What would have been the cost of even ONE crash due to ash injestion? I think the airlines may have saved money... |
Brucewayne
If you can tell me the difference between a volcanic ash cloud and airspace that "could" have ash particulates in it then that would solve the huge multimillion quid probelm that airlines in Europe face. I dont want to get hard-nosed on logic but you cannot use burden of proof on the fact that accidents have not occurred. Burden of proof can only be validly applied on an event that has actually happened. My Latin is a bit rusty but reductio ab absurdum is the term which fits. In this context it means that you would accept any risk because you do not recognise it as a problem. |
I have to give Thompson Kudos for this approach...
Thomson Airways ... Personal Update! - Key Publishing Ltd Aviation Forums Good on them :D:D:D |
Some perspective on this. The only incident where there is no indication the crew knew about the ash at the time is Can't believe we're quoting from the same document!!! The one I'm looking at is The 1991 Pinatubo Eruptions and Their Effects on Aircraft Operations by Thomas J. Casadevall,1 Perla J. Delos Reyes,2 and David J. Schneider3 In that report incident 91-09 is perhaps the best example of an undetected encounter with NO external evidence on the aircraft yet still severely trashed turbines. There are several others where no primary incident location is recorded, for several possible reasons. As the original authors state: The detail of information was variable, especially concerning the locations of encounters and damage. In some cases, carriers were reluctant to discuss encounters, owing to concerns over possible future liability. In other cases, pilots may have been unaware that their aircraft had flown through an ash cloud, and damage to the aircraft might not have been noticed until the aircraft was later inspected on the ground. This partly explains why there are position data for only 11 of the incidents (fig. 1; table 1). BUT the key feature that is common to this AND the later NASA DC-8 incident north of Iceland AND probably some aspects of the Finnish F-16 Hornet ash incident two weeks ago is that there ARE many well-documented cases of significant turbine damage when the pilots were completely unaware of any ash encounter. You may not like these facts but unfortunately they are there in black and white, from multiple independent sources. |
Concord:
It's a law of physics. You start to give ANY MASS a rotational velocity around a point then its going to move outwards. Sorry but even if the forces are tiny and the movement is small the effect is still there. However i'm not in a position to state without facts or figures if there would be any difference in ash density into the non-bypass airflow. To put it another way, rotational motion in both Compressor and Turbine gas streams is wasted (rotational) energy. |
Hmmm - I wish I'd never mentioned centripetal forces acting on ash particles in the first place!
Suffice it that an ash particle entering a high-bypass engine near the cicumference of the fan will DEFINITELY go down the bypass duct and cause no problem, a particle near the hub will DEFINITELY go into the core and might not emerge at the other end! Other particles at other points between hub and circumference will have varying chances of going 'through' or 'round' the hot section. The point that even with a high bypass ratio, the core must still eat tons of air to get enough power to turn the fan is well taken. Bottom line: only engine manufacturers can offer definitive numbers for the max ash particle density per cubic metre of intake air, taking account of everything that might happen to the air and the particles going through their turbine. |
Originally Posted by Intruder
(Post 5659587)
There will always be second-guessers. The fact that there were no ash incidents gives clear evidence that the Eurocontrol policy was successful. There is no way to tell how many incidents or mishaps there would have been without the policy.
We live in an imperfect random world that is inherently not perfectly mesurable - zero tolerance policies are inherently dumb. Find any VA ? - have to close airspace. That's the easy part. Now how do you reopen it ? How do you prove there is zero VA ? How many test flights over how many days (remembering you've just grounded your test aircraft for repainting, after the eruption started...) have to come up clean ? What if you didn't cover the whole area and missed some ash, what if your instruments aren't sensitive enough, how do you prove there is zero VA so you can re-open airspace ? Answers on a postcard to the relevant authorities, they need your help because their previous plan looked like: 1. IF find VA THEN close airspace 2. Hope (1) never happens |
You are forgetting that between each row of blades in both Compressor and turbine there are stator blades whose job is to ensure that precisely what you think will happen (rotational motion) does NOT happen. To put it another way, rotational motion in both Compressor and Turbine gas streams is wasted (rotational) energy. The rotational motion only lasts between the aft side of the spinning blade and the entrance to a stator row. However it is within that distance that the heavier particles will deflect outward. Very significant between the back of a fan blade and the inlet to the core. I believe that there are some patents filed on this very basis (GE, Boeing, etc.) |
We live in an imperfect random world that is inherently not perfectly mesurable - zero tolerance policies are inherently dumb. Find any VA ? - have to close airspace. That's the easy part. Now how do you reopen it ? How do you prove there is zero VA ? How many test flights over how many days (remembering you've just grounded your test aircraft for repainting, after the eruption started...) have to come up clean ? What if you didn't cover the whole area and missed some ash, what if your instruments aren't sensitive enough, how do you prove there is zero VA so you can re-open airspace ? How many of those airlines would have accepted strict liability for any damage and/or injury caused by ash ingestion? I suspect not one. |
Intruder
I am glad you have the complete confidence in the "experts" The trouble with that is that everyone has their own interests their own backs to watch their own agenda. Zero ash tolerance was abandoned in a matter of days for plucked out of the sky percentage ash? More like sock it and see? Even the new limits are riddled and based on a fairly constant level of ash over a large distance. Where are those samples taken and what happens in the areas not taken? You may get a suitable level in one area which fits within the limits but half a mile away a much denser area which has been completely missed. In the Alaskan eruption Ash circulated the globe three times before completely dissipating. 1000s of aircraft probably penetrated low density ash ridden air without even knowing about it. Maybe what the eye doesnt see the heart doesnt grieve? The pilot as in any situation is best placed to determine whether a flight is safe or not. Not some politician or Quango leader who has no aviation experience whatsover and is more intent on watching his/ her back or lining his or her colleagues hands in gold. As in any other atmosphere threat whether thunderstorms, bird strikes, strong winds, fog etc the pilot has the data but makes the decisions. More aircraft have been downed by thunderstorms, More aircraft downed by fog, more aircraft downed by in flight turbulence and windshear, more aircraft downed by bird strikes, more downed by strong crosswinds, more by ice than ever in diffused ash. Yes those pilots fly within minima and regulations but they fly. Why is ash any different? If we never flew because of a potentail threat albeit how small the skies would have been empty a long time ago. Pace |
The pilot as in any situation is best placed to determine whether a flight is safe or not. Not some politician or Quango leader who has no aviation experience whatsover and is more intent on watching his/ her back or lining his or her colleagues hands in gold. Or the affect on profitability over the longer term that results in UK/European aircraft not being economical to run due to VA damage? (Not that any of this seems to have surfaced so far and it's academic as we have taken the decision to run the experiment). |
In the Alaskan eruption Ash circulated the globe three times before completely dissipating. |
Pace, you really do have a point. If the end of the world was nigh and volcanoes were active all over the place, you can be very sure we would all be flying around in whatever came out of them because that would be the only way an acceptable level of operations could continue. Regulations would be tightened up and the risk mitigated as much as possible. All the phenomena you mention are just like that - too widespread and frequent for simple avoidance to be a realistic option. Personally I don't think ash falls into this category but:
If I thought that what we had just done was exactly that - carefully worked out the real risk and the likely result of an increase in exposure both in the shorter and longer term, then I feel none of us could really take issue with it. That is just what has happened with so many other threats. But the difference here is through a misjudgement by the industry we never bothered to look into it in any great detail. Suddenly we were caught out and the pressure was on for a quick decision. My only question to you would be how can you be happy with the way the new procedures were created? 2 days is an absolutely incredibly short time for so many sections of the industry to come up with an answer. And in particular how can you be happy with it in the light of the fact that test flights, military flights and civilian flights, have appeared to have continued to suffer problems that the new regulations said would not occur? Genuinely, I would like to know what you think. Maybe you have some other nugget that might make me see this whole thing differently.... |
If I thought that what we had just done was exactly that - carefully worked out the real risk and the likely result of an increase in exposure both in the shorter and longer term, then I feel none of us could really take issue with it. That is just what has happened with so many other threats. But the difference here is through a misjudgement by the industry we never bothered to look into it in any great detail. Suddenly we were caught out and the pressure was on for a quick decision. My only question to you would be how can you be happy with the way the new procedures were created? 2 days is an absolutely incredibly short time for so many sections of the industry to come up with an answer. And in particular how can you be happy with it in the light of the fact that test flights, military flights and civilian flights, have appeared to have continued to suffer problems that the new regulations said would not occur? Genuinely, I would like to know what you think. Maybe you have some other nugget that might make me see this whole thing differently.... On this part I cannot disagree with you. In areas of known ash I would limit operations to daylight only where pilots will have a better chance of seeing denser areas of ash and avoid. My instincts (and that is all they are) is that if you can see it the ash clouds, mist etc MAY do harm. If you cannot see the ash clouds mist in daylight VMC in all probability there will be no harm. It is important to differentiate between two types of harm. Harm that could down an aircraft and cause loss of life and harm that would shorten engine life. The very diffused ash in all probability MAY shorten engine life but that becomes the bill payers problem. I totally agree that it is more than likely that the new limits were picked out of a hat but apart from having a long and detailed analysis the new limits are a starting point. Even with a long detailed analysis and testing we never really know what is what until tested in the field. I know car manufacturers can drive thousands of miles in testing conditions and only discover problems when the cars are on the road in daily use. There are threats in the air that we live with and accept every day which have and do bring down aircraft. To date even dense ash has not killed anyone (unless your a smoker ;) Is the ash threat bigger or mainly a media driven hype? NO!!! in low density ash its more likely to cost in the pocket rather than lives. I am afraid till something happens to prove otherwise. Pace |
Well, seeing as the decision has already been made there is probably little point in me occupying the dark side anymore. I gues ultimately your right. Engine monitoring programs will have to carefully watched over the next few months. They should be enough to prevent any catastrophic issues.
Isn't a shame and in my mind very damning of this industry, that we need to rely on a previously instated and successful safety measure to protect us from the potential ill effects of brand new "safety" measure? But there lies the truth about the world we work in. The there have been many cases over the years of regulators bending to the demands of the industry. September 11th infuriated me as a light aircraft pilot in the US. Commercial airliners knocked down two buildings. Every single aircraft is grounded. Two days later commercial traffic is flying again and it takes two full weeks before light aircraft are allowed up. Many small businesses collapse as a result. How could light aircraft be a greater threat than an airliner? Wel,, they're not. The just can't lobby as effectively. I think we have just witnessed something similar again.... Thanks for the reply Pace. |
I gues ultimately your right. I do not know whether I and others are right or not so maybe add "ultimately HOPE your right" ;) Life is a risk and many things we do is about risk assessment someone obviously decided it was a tiny risk worth taking. Pace BTW have enjoyed your posts thanks |
Indeed you are right. Very nicely put, Pace
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What a con job it was!
This was the greatest example of bureaucratic backside-covering the world has seen. Thank heavens the politicians have now intervened.
Here is an volcano close-up video and pronunciation guide - The Icelanders did not restrict how close to Eyjafjallajokull an aircraft can fly - the decision-making was left where it should have been left. in the cockpit. How many lives were lost because patients could not get to their hospitals and doctors? How many because medications, organs, and radioactive isotopes were not delivered? How many were lost because people drove long distances instead of flying? Let's hope the damage done on this occasion leads to a re-think about "nervous nelly" regulation. |
One awsome video of the Mt. Aye - ya - fyah - dla - jow - kudll ,eruption up close.
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Looks like I was right all along.
Please re-read my post nr. 819 posted on april 18th.
Looks like I was right all along! Please read this article: "The ash cloud that never was: How volcanic plume over UK was only a twentieth of safe-flying limit and blunders led to ban." As a Belgian, I do not know the reputation of the "Daily Mail", but please take the time to read the article. I think it's spot on! Best regards, Sabenaboy |
The Icelanders did not restrict how close to Eyjafjallajokull an aircraft can fly |
Engine Costs
Do any beancounters read this forum? I am wondering about the effect of flying through an ash cloud that was sufficiently dispersed to not be an immediate danger to the particular flight but which would gravely shorten engine life. A poster has already said that it takes about ninety minutes to check an engine that may have been exposed to volcanic ash. This is after the ginger has finished his tea break, finished the must do job, and got his tools together. It would be risky to assume the aeroplane would be declared serviceable until the inspection was complete. Also, who is to judge, and on what data, that the aircraft was exposed to ash?
Can anyone shed any light on the costs involved? I am wondering if it was judged to be cheaper to ground everyone at least until the cost of not doing so was known and a method of forecasting the extent of the ash cloud had been developed. |
Dangerous Ash?
We as professional pilots know that commercial pressures have won out.
Where is the evidence to back up these new so called safe limits and who exactly measures them? Its one thing for the public to be fooled where is the voice of reason from our own community. This problem will occur again NOW is the time for various pilot representatives to be vocal if the governing agencies wont protect the traveling public then surely we MUST!! |
We as professional pilots know that commercial pressures have won out. Where is the evidence to back up these new so called safe limits and who exactly measures them? Its one thing for the public to be fooled where is the voice of reason from our own community. This problem will occur again NOW is the time for various pilot representatives to be vocal if the governing agencies wont protect the traveling public then surely we MUST!! This is more than than engine testing, it also has to do with geological, weather and routing. Take that data and weigh it against the historical experience of what has been safe, what has been unsafe , and what corner of the spectrum are we in today. I suspect that this has already been done with all the parties in conjunction. From my read most of the nail biting has to do with lack of knowledge about what corner are we in today, the known or the unknown? |
The FAA's current position on ash...
SAIB NE-10-28 Apparently the EASA will issue their position soon. C2j |
They're not really saying anything:confused:
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About Aviation color code of volcanic ash.
A question is asked from Japan.
We operation the helicopter (EC135) in Japan. Since there is only zone of Eurocontrol, Safety Information Notice which EC135 manufacturer's Eurocopter took out should teach it. The Meteorological Agency of Japan Aviation color code is not use. Is Aviation color code of Eurocontrol and ICAO(USSG) unified? As for Eurocontrol, zone 1:black zone, zone 2:red zone, and ICAO (USSG) are green, yellow, orange, and red. To what is the definition about zone1 and zone2 of Eurocontrol specified? Best Regards. :sad::eek::( pitchpitchjapjap Eurocopter SIN2197-S-00(SUMMARY) Due to the eruption of the volcano in Iceland EUROCOPTER has been contacted by many operators asking for advice on how to proceed with their operation under these circumstances. Flying in an atmosphere containing volcanic ash may affect the behaviour of the helicopter. Depending to the variety of the particles (size, weight, density, chemical composition…) it may increase the probability of a partial power loss, engine flame out, navigation and piloting instruments failure or other helicopter malfunctions. Flight in such conditions may also decrease visibility and accelerate erosion of certain helicopter parts. In the past, on EC helicopters, engine flame outs have been experienced after flight through industrial smoke. As a consequence EUROCOPTER advises operators to avoid flight in area of high density volcanic ash contamination (named zone 1 or black zone). |
The FAA's current position on ash... SAIB NE-10-28 now what was the question again? |
I love the way an event like this brings out the I was right all along brigade. Who cares! Bully for you.
Its easy for people to sit back and criticise when they don't have to step up and make the hard decisions. They don't get much harder than this. With hind sight it was a very expensive over-reaction but in the future hopefully the data collected (and still being collected!!) and lessons learnt from the way the whole "crisis" was handled will prove invaluable. Its like an aircraft accident. So many crucial lessons are taken from a disastrous event. |
Part of the problem is that, should a pilot make a wrong decision - particularly of this magnitude - then they are castigated, investigated, possibly prosecuted and more
i.e. held to account. We are waiting...... |
Its easy for people to sit back and criticise when they don't have to step up and make the hard decisions. They don't get much harder than this. With hind sight it was a very expensive over-reaction but in the future hopefully the data collected (and still being collected!!) and lessons learnt from the way the whole "crisis" was handled will prove invaluable. Its like an aircraft accident. So many crucial lessons are taken from a disastrous event. |
Pilots Only
Where is the empirical evidence from engine/airframe manufacturers to warrant anything but zero tolerance?
This situation is absolute madness where is the communication from airline pilots representatives worldwide? This situation is possibly putting peoples lives at risk due to commercial expediency Show the public the evidence. The time to say and act is now before the next eruption! If you are a professional pilot use this forum to voice your concerns and if you ado not have any concerns PLEASE SAY WHY NOT HERE |
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