Ash clouds threaten air traffic
Beady Eye
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The airspace closure was done by NATS, not HMG, and only to IFR flights in class A airspace. Several jets (private / small charter) left U.K. airspace on Thursday and Friday VFR, low level. By Friday evening CAA (the governing body) were still advising that NATS closure was recommended and that if people tried to circumvent it a more general closure would be put in place.
Presumably, sometime over the weekend, CAA took charge? Otherwise , how did it become the case that it was the CAA spokeswoman outside of the DFT on Tuesday evening rather than a NATS spokesperson?
Presumably, sometime over the weekend, CAA took charge? Otherwise , how did it become the case that it was the CAA spokeswoman outside of the DFT on Tuesday evening rather than a NATS spokesperson?
Cynics amongst us may say that HMG hid behind NATS skirts so as to make it appear that NATS were the baddies of the piece and HMG rode the white charger to 'save' the airline industry. In reality everyone did exactly what they were supposed to do.
BD
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The problem has not gone away! Inverness closed to traffic due to ash at 1800 last night and not opening again until 1300 today at earliest. Keflavik is now affected with Icelandair flights between the USA/Canada and Europe operating via Glasgow with a flight from Glasgow to Akureyi for Iceland bound passengers.
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Please can we defer trying to allocate blame, and get on with developing the the policies and procedures to deal with what may be an ongoing problem. We have plenty of time to deal with blame, but volcanoes wait for no-one.
Alaskan Airlines have had to live with frequent nearby eruptions and have developed some basic guidelines. Why not take a look at them, and adapt/expand/improve them.
Alaskan Airlines have had to live with frequent nearby eruptions and have developed some basic guidelines. Why not take a look at them, and adapt/expand/improve them.
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Exactly.
WHERE is the hard evidence about the characteristics of the ash cloud as it developed (locations AND particle sizes AND densities per cubic metre - yes - you need ALL of these to come to a valid conclusion about safe routes to fly.
As far as I can tell, if you discount freelance flights by operators which were as much to do with PR as scientific data collection, there was very little extra data collected over and above what was available on 14/4/10. OK - the computer models might have been tweaked but there was (apparently) very little REAL data collection going on in UK, apart from redeploying some cloudbase LIDARs and a few flights by D-CALM and ???. How effective upward-pointing LIDARs are at collecting specific ash data for the different flight levels immediately above, I don't know. Nor how many and where they are. Especially at high ash levels, I don't see how upward-firing LIDARs could cover all the flight levels anyway: 'particles hiding behind other particles' problem.
WHERE is the hard evidence about the characteristics of the ash cloud as it developed (locations AND particle sizes AND densities per cubic metre - yes - you need ALL of these to come to a valid conclusion about safe routes to fly.
As far as I can tell, if you discount freelance flights by operators which were as much to do with PR as scientific data collection, there was very little extra data collected over and above what was available on 14/4/10. OK - the computer models might have been tweaked but there was (apparently) very little REAL data collection going on in UK, apart from redeploying some cloudbase LIDARs and a few flights by D-CALM and ???. How effective upward-pointing LIDARs are at collecting specific ash data for the different flight levels immediately above, I don't know. Nor how many and where they are. Especially at high ash levels, I don't see how upward-firing LIDARs could cover all the flight levels anyway: 'particles hiding behind other particles' problem.
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People who dare to make unflattering comments about the safety establishment are often branded as 'cynics'. There is nothing wrong with a healthy dose of cynicism as it helps to strip away the b**t and get to the truth. However I prefer the term realist. The opposite of realism is idealism
So this debate seems to be down to the Idealists versus the Realists and I'm quite happy to be the latter.
So this debate seems to be down to the Idealists versus the Realists and I'm quite happy to be the latter.
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Scientists have no standard for what concentration of ash is safe and what is a danger to aircraft, but ash cloud does scatter enough with time and distance to not threaten jets. Fallout from Mount St. Helens actually circled the globe three times before fully dispersing, but flights were grounded only within a couple hundred miles of the source.
Alaska airlines have been dealing with this and flying for years. They have built up their own operating procedures.
What comes up time and time again is the lack of knowledge about what concentration of Ash is safe?
Even the latest standards seem a tentative guess rather than figures based on extensive testing.
I am not an engineer or scientist but would have thought specialised engine testing, ground based in a wind tunnel where engines could be run for hours in various concentrations of ash would give a better answer?
Maybe someone could ellaborate on whether this is possible or has already been done?
Pace
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Coolguy,
This is not about being right or wrong, it is not about labelling people or 'winning' arguments with your philosophical opponents. What it is about is finding real solutions to a real problem.
If you have any I am sure we would all like to hear.
This is not about being right or wrong, it is not about labelling people or 'winning' arguments with your philosophical opponents. What it is about is finding real solutions to a real problem.
If you have any I am sure we would all like to hear.
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Forgive me if this has been answered already as I am only joining the debate now.
I am very, no, extremely worried how regulations and best practice have been adjusted to suit and calm an industry which was complainaing of loss of earnings as a result of the recent clampdown. I will be the first to admit that the initial reaction was heavy handed, but I am at a loss as to how we have reached the place we are in now.
Specifically, and most recently, the RAF have grounded their Tornados because of ash deposits discovered in their engines. The BBC have quoted the CAA as saying that these jets suck in vastly more air than civilian airliners and therefore are a completely seperate case and the public need not worry.
Can someone explain to me how a 9,800lb thrust engine on a Tornado needs "vastly more air" than a 115,000lb thrust B777 engine? Even allowing for the high percentage of thrust developed by fans on modern engines, lets call it 85% on the 777, that would leave 17,000lb being produced by the core. That's about the same as an afterburning Tornado. WTF am I missing here? How can ash levels affect a fighter but not even be considered as a risk to commercial traffic?
Fighters are high performance aircraft because they have a very high thrust to weight ratio not because they have massive engines that produce more power than an Airbus. Strap a CF6 to a Tornado and wouldn't believe what it could do. To discount the RAF situation on the grounds of their machines being "high performance aircraft" borders on criminally negligent.
This whole situation stinks. Simply because once again this industry has decided to ignore it's own experience of hasty regulation and incomplete analysis in favour of ensuring revenue continues to spill in the front door. That's for both the airlines and the authorities.
I am very, no, extremely worried how regulations and best practice have been adjusted to suit and calm an industry which was complainaing of loss of earnings as a result of the recent clampdown. I will be the first to admit that the initial reaction was heavy handed, but I am at a loss as to how we have reached the place we are in now.
Specifically, and most recently, the RAF have grounded their Tornados because of ash deposits discovered in their engines. The BBC have quoted the CAA as saying that these jets suck in vastly more air than civilian airliners and therefore are a completely seperate case and the public need not worry.
Can someone explain to me how a 9,800lb thrust engine on a Tornado needs "vastly more air" than a 115,000lb thrust B777 engine? Even allowing for the high percentage of thrust developed by fans on modern engines, lets call it 85% on the 777, that would leave 17,000lb being produced by the core. That's about the same as an afterburning Tornado. WTF am I missing here? How can ash levels affect a fighter but not even be considered as a risk to commercial traffic?
Fighters are high performance aircraft because they have a very high thrust to weight ratio not because they have massive engines that produce more power than an Airbus. Strap a CF6 to a Tornado and wouldn't believe what it could do. To discount the RAF situation on the grounds of their machines being "high performance aircraft" borders on criminally negligent.
This whole situation stinks. Simply because once again this industry has decided to ignore it's own experience of hasty regulation and incomplete analysis in favour of ensuring revenue continues to spill in the front door. That's for both the airlines and the authorities.
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This whole situation stinks. Simply because once again this industry has decided to ignore it's own experience of hasty regulation and incomplete analysis in favour of ensuring revenue continues to spill in the front door. That's for both the airlines and the authorities.
Nothing in aviation happens fast if we had waited "normal" periods for complete analysis and normal regulations by the time they were out there would be no Airlines left in the UK who were still solvent to apply the new regulations to.
Pace
Cool guy,
like you, I have no idea why my reply was deleted.
I think your analysis was partly right, but my point was that RR et al, and BA et al, were publicly saying No-flying when ash was more than zero.
No-one in the CAA could over-rule that.
As neither the engine manuf., nor the operators were willing to work to change the ICAO standards, it needed someone to work through the log jam.
It appears to have been the CAA that forced BA and RR, amongst others, to do the test flights this past weekend. The BA flight was not Willy's idea - it was the CAA's. (Times, 23.04.10).
The CAA bloke in the Grauniad article seems to have taken the initiative.
For once, perhaps, it appears that it was not a Regulator's foul-up, it was a BA/RR et al foul up..
PS - No, I do not work for the CAA!
like you, I have no idea why my reply was deleted.
I think your analysis was partly right, but my point was that RR et al, and BA et al, were publicly saying No-flying when ash was more than zero.
No-one in the CAA could over-rule that.
As neither the engine manuf., nor the operators were willing to work to change the ICAO standards, it needed someone to work through the log jam.
It appears to have been the CAA that forced BA and RR, amongst others, to do the test flights this past weekend. The BA flight was not Willy's idea - it was the CAA's. (Times, 23.04.10).
The CAA bloke in the Grauniad article seems to have taken the initiative.
For once, perhaps, it appears that it was not a Regulator's foul-up, it was a BA/RR et al foul up..
PS - No, I do not work for the CAA!
Last edited by Ancient Observer; 23rd Apr 2010 at 10:57. Reason: Clarity
Per Ardua ad Astraeus
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Paddy - I can make no comment on the possible problems for our motors other than to point out that a mil fighter will spend a significantly higher % of its time in the levels where the ash mostly exists and thus will be exposed to more ingestion than an airliner spending most of its time at cruise.
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captainpaddy- with you 100%- I have been involved in industry (all be it not aviation) setting specification levels (and validating them) for 20 years - I cannot understand what has happened here- there is no way that any new levels can have been set and validated in 5 days!!! Has anyone seen any interviews/or documentation that has taken place from/with any of the manufactures of these engines- I would be amazed if anyone in the industry has signed off on these new levels- if they have I think they must be mad- as those signitures are going to be where the buck stops for any claims for damage -or worse. I would have walked away from my job before I would have signed off that specification! What happens next if the testing analysis is undertaken and it is found to be different to the new limits- whoose call is it to change these new limits as it seems that they have been set by the regulators. The usual process below is now in reverse- 1.the science is undertaken 2. measurements presented to regulatory bodies. 3. regulators agree or revise down if not happy with the resluts. This time the tail has wagged the dog. not sure how it can go from here.
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CaptainPaddy
Nothing in aviation happens fast if we had waited "normal" periods for complete analysis and normal regulations by the time they were out there would be no Airlines left in the UK who were still solvent to apply the new regulations to.
Pace
Nothing in aviation happens fast if we had waited "normal" periods for complete analysis and normal regulations by the time they were out there would be no Airlines left in the UK who were still solvent to apply the new regulations to.
Pace
Secondly, I'm actually at a loss that so many people seem to agree with the philosophy of rushed regulations. What you are saying is it is better to get flying now, disregarding the lessons of the past, without knowing what the consequences will be in order to keep business operating, instead of doing what we all claim is our first priority - move people and cargo around safely. How can it be safe if it is unknown. That has always been the mantra we supposedly hold oursleves to.
Thirdly, this is not some abstract threat. The Natural Environment Research Council have had D228's and 146's in the air above the UK since Tuesday. They say "Results from both flights revealed the presence of sulphur dioxide and a number of layers of volcanic ash of varying sizes between ground level and 20,000 feet. These discreet layers of fine material are particularly difficult to spot with the naked eye." In other words you could see them if you knew where to look and what you were looking at. We are not talking about invisible, extremely diffuse ash concentrations here. Yet we are flying around like there's no risk.
Fourthly, I agree the RAF may have flown around at low level for longer periods, but the point is that damage was sustained. That means damage is possible. If it was only because they were at low level for 2 hours or whatever, should we then limit holding at LHR to 30 minutes before you hvae to climb above FL200 again to mitigate the risk? You're talking yoursleves into this. If it is only a low level risk, what level is too low and for how long? None of those questions have been answered. At the end of the day if you sustain visisble damage after a particular period of time, you can not say less time means no damage. There is a cumulative longer term effect that must be taken into account.
Lastly, all authorities are going on the basis that the ash concentration is effectively minute and uniform. The NERC flights have proven that to not be the case. Yet they have carried on regardless.
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Captain Paddy
When I made my comments to you they were more in relation to ongoing eruptions of the Volcano and ongoing periods of airspace closure.
Such a situation would be untenable for aviation if passenegers did not know if going on a busiess trip or holiday might not see them back in the UK for days and the Airlines having to pick up the tab for hotels and costs every time.
There would be no uniformity of operation and with all the other problems and expense that would incur would infact mean that the airlines might as well be grounded.
I take your point that very low levels of Ash would be difficult to see but then are very low levels a hazard? You dont know, I dont Know and as far as I can see the authorities dont really know either.
In Alaska the airline has experience of working around volcanic ash. Interesting that they limit flight to daylight so I presume that more is visible to the pilot of threat densities of ash than many have given credence too.
But that is the big question! what is a threat density of ash?
At the moment the authorities have upped the zero levels a little and I am sure are monitoring what is going on in the field.
With the fighters they have only claimed evidence of ash not damage as yet.
Fighters spend a lot of time up and down sub 20k while us jet jockies spend most of our time above 20K. Fighters probably have higher IAS low down so maybe more prone to lower levels of ash?
Pace
When I made my comments to you they were more in relation to ongoing eruptions of the Volcano and ongoing periods of airspace closure.
Such a situation would be untenable for aviation if passenegers did not know if going on a busiess trip or holiday might not see them back in the UK for days and the Airlines having to pick up the tab for hotels and costs every time.
There would be no uniformity of operation and with all the other problems and expense that would incur would infact mean that the airlines might as well be grounded.
I take your point that very low levels of Ash would be difficult to see but then are very low levels a hazard? You dont know, I dont Know and as far as I can see the authorities dont really know either.
In Alaska the airline has experience of working around volcanic ash. Interesting that they limit flight to daylight so I presume that more is visible to the pilot of threat densities of ash than many have given credence too.
But that is the big question! what is a threat density of ash?
At the moment the authorities have upped the zero levels a little and I am sure are monitoring what is going on in the field.
With the fighters they have only claimed evidence of ash not damage as yet.
Fighters spend a lot of time up and down sub 20k while us jet jockies spend most of our time above 20K. Fighters probably have higher IAS low down so maybe more prone to lower levels of ash?
Pace
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Nice link.
I think the key part of the whole thing is from 6:00 onwards.
For anyone not bothered to listen to it. There was no visible indications of an ash encounter whatsoever. No St Elmo's fire, no signs of abrasion on the fuselage, nothing. Yet $3,000,000 of damage was done. And they were 200 miles away from where the cloud was predicted to be.
I think the key part of the whole thing is from 6:00 onwards.
For anyone not bothered to listen to it. There was no visible indications of an ash encounter whatsoever. No St Elmo's fire, no signs of abrasion on the fuselage, nothing. Yet $3,000,000 of damage was done. And they were 200 miles away from where the cloud was predicted to be.
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Pace I understand where you are coming from, but I just sincerely hope we're not looking at more cost to the industry in the long run. Engine changes are expensive!!
The RAF have said ash deposits were found in engines. I take your point that they have not said they were damaged, but I really don't see how you could possibly determine that ash accumulated INSIDE the core of a jet engine without having caused any damage. For me, of course damage was done. No brainer. They are hardly going to sweep it out and that be the end of it.
What scares me the most is fellow professionals convincing themselves that everything is fine. I suppose it makes us all feel better about going flying this afternoon or tomorrow morning or whatever. Like qualifying the RAF's experience by saying they haven't actually said they suffered damage. (No offence meant at all Pace) Common sense seems to have been lost entirely.
As for the visible versus invisible ash question - see ZQA'a link.
The RAF have said ash deposits were found in engines. I take your point that they have not said they were damaged, but I really don't see how you could possibly determine that ash accumulated INSIDE the core of a jet engine without having caused any damage. For me, of course damage was done. No brainer. They are hardly going to sweep it out and that be the end of it.
What scares me the most is fellow professionals convincing themselves that everything is fine. I suppose it makes us all feel better about going flying this afternoon or tomorrow morning or whatever. Like qualifying the RAF's experience by saying they haven't actually said they suffered damage. (No offence meant at all Pace) Common sense seems to have been lost entirely.
As for the visible versus invisible ash question - see ZQA'a link.