Ash clouds threaten air traffic
Playing Devils advocate
Now that airlines are allowed to fly through some of the ash clouds providing the engine manufacturer has certified their engines are up to the task, where will the liability lie if there is (perish the thought) an incident?
The engine manufacturer for stating their engines can cope in the ash?
The airline for taking the engine manufacturers word?
The regulator for accepting the idea?
Hmmm the lawyers must be rubbing their hands in glee and anticipation!
Now that airlines are allowed to fly through some of the ash clouds providing the engine manufacturer has certified their engines are up to the task, where will the liability lie if there is (perish the thought) an incident?
The engine manufacturer for stating their engines can cope in the ash?
The airline for taking the engine manufacturers word?
The regulator for accepting the idea?
Hmmm the lawyers must be rubbing their hands in glee and anticipation!
Now that airlines are allowed to fly through some of the ash clouds providing the engine manufacturer has certified their engines are up to the task, where will the liability lie if there is (perish the thought) an incident?
- GY
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Lomon
That is a tricky one! Where does the liability lie if damage is sustained flying through hailstones in a known area of thunderstorm activity which we operate through on a regular basis.
Where does liability lie with Bird ingestion through known migration paths or at sea based airports?
What is the difference other than the two above have caused loss of life and known engine damage while to date there has been no loss of life caused by Ash in even dense encounters in over 50 years of aviation.
There is far more risk to crashing on landing and takeoff and loosing your life within acceptable wind and shear limits than ever being killed by an ash encounter. Maybe we should call for zero wind for takeoff and landing in the next safety based campaign
Pace
That is a tricky one! Where does the liability lie if damage is sustained flying through hailstones in a known area of thunderstorm activity which we operate through on a regular basis.
Where does liability lie with Bird ingestion through known migration paths or at sea based airports?
What is the difference other than the two above have caused loss of life and known engine damage while to date there has been no loss of life caused by Ash in even dense encounters in over 50 years of aviation.
There is far more risk to crashing on landing and takeoff and loosing your life within acceptable wind and shear limits than ever being killed by an ash encounter. Maybe we should call for zero wind for takeoff and landing in the next safety based campaign
Pace
Last edited by Pace; 19th May 2010 at 12:43.
Pictures here.
Engine Damage Photos Misunderstood As Ash Damage — Civil Aviation Forum | Airliners.net
Engine Damage Photos Misunderstood As Ash Damage — Civil Aviation Forum | Airliners.net
(engines don't often snuff out all the flame but they do run out of air in the combustor, but not fuel, until they are shutdown following a major failure.)
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Playing Devils advocate
Now that airlines are allowed to fly through some of the ash clouds providing the engine manufacturer has certified their engines are up to the task, where will the liability lie if there is (perish the thought) an incident?
The engine manufacturer for stating their engines can cope in the ash?
The airline for taking the engine manufacturers word?
The regulator for accepting the idea?
Hmmm the lawyers must be rubbing their hands in glee and anticipation!
Now that airlines are allowed to fly through some of the ash clouds providing the engine manufacturer has certified their engines are up to the task, where will the liability lie if there is (perish the thought) an incident?
The engine manufacturer for stating their engines can cope in the ash?
The airline for taking the engine manufacturers word?
The regulator for accepting the idea?
Hmmm the lawyers must be rubbing their hands in glee and anticipation!
Where does the liability lie in those cases ?
The aircraft / component mfr. who designed to the (inadequate) tests ?
The regulators who set the tests ?
The airlines who carried on flying, based on the certification, after previous incidents showed inadequacies ?
Surely if you look at the list of previous pitot incidents almost all with one type of probe, it was obvious they weren't good enough... and clearly a bird ingestion standard based on only one 4lb bird is totally inadequate for flying near flocks of geese. Obviously (if you are an ambulance chaser) someone should have spotted those issues and taken action before people died. Who ? Whoever has the money (or just sue them all).The regulators who set the tests ?
The airlines who carried on flying, based on the certification, after previous incidents showed inadequacies ?
VA, on the other hand, hasn't managed to down an aircraft yet. A few broken, or prematurely worn, engines will be sorted out between the airlines and the mfrs. There's probably more money in hitting the poor delayed punters with "sue for a refund" scams.
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Even scientists can be gullible...
First:
And then, after someone exposed it as a hoax...
Yeah sure! 
There are pictures of what looks like severe ash damage to a Citation engine circulating on the Internet. They are horrendous. If they are genuine, they will silence our sceptics. Does anyone have a provenance for those pictures?
Thank you, forget, I am aware of the rumors, but want to know if anyone has a provenance
Last edited by sabenaboy; 19th May 2010 at 14:27.
Garage Years:
Very, very simple. Erosion and overheat damage to turbine blades and nozzle guide vanes associated with glass clogged cooling holes.
By the way, the diffusion of responsibility between engine/airframe/ Met office/airline/insurer/crew and regulator in the event of a series of extremely costly Ash damage incidents is exactly what has kept you grounded until enough research and negotiation could be done to understand and manage the risks.
First question - how would anyone prove the ash concentration that caused such an incident was above or below whatever (arbitrary) level was stated to be safe. Not being flippant but the evidence has a tendency to blow away.... i.e. the ash cloud itself.
By the way, the diffusion of responsibility between engine/airframe/ Met office/airline/insurer/crew and regulator in the event of a series of extremely costly Ash damage incidents is exactly what has kept you grounded until enough research and negotiation could be done to understand and manage the risks.
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Very, very simple. Erosion and overheat damage to turbine blades and nozzle guide vanes associated with glass clogged cooling holes. Very simple really.
Sorry cannot agree with you that its simple really
You could quite easely have an area marked as below the accepted limits in Ash and have one cloud which is unique and solitary but of a much denser level than the remaining area.Nothing is constant sadly in our atmosphere.
I can well remember flying a twin to Malaga single pilot with only the owner on board airways at FL120 Near Madrid. Radar gave me help with storm cloud avoidance as did my on board radar. I picked a way between two cells in VMC. The ground temperature was 42 deg C.
As I passed well clear and between the cells I experienced something I had never done in 20+ plus years. The IAS shot from 160 kts IAS to 65 kts IAS in seconds and the aircraft felt as it had flown into a vacuum. No control response, No Pitch response, No increase of speed with power.
The aircraft sank vertically like a towerblock lift for 2000 feet as if in a vacuum and then came alive again.
You simply cannot prove anything in the atmosphere as being constant! ash density or otherwise especially with computer predicted movement. One area may be ok while a few hundred metres and its not.
The best indicator with storms or otherwise is to use your eyes and your instincts and knowledge as relying on aids only whether aircraft based or land based will give you a shock you dont want.
That is why I dont hold with the science but do with pilots and good old see and avoid.The SCIENCE is an aid to the captain not the CAPTAIN and for me thats the whole basis of my arguement with this thread. Listen to the airlines and the pilots and thankfully that message seems to be proving correct.
The same goes with ASH which to date has not harmed anyone in I repeat over 50 years when there were no fancy gizmos to mislead anyone which sadly also now seems proved to be a costly mistake.
Pace
Last edited by Pace; 19th May 2010 at 22:02.
Keeping Danny in Sandwiches
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And unfortunately the stuff being blown over from Iceland is not sand dust, it's glass dust, that melts at the temperatures you find in jet engines... unlike sand.
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Not quite.....
Glass is made by mixing silicon dioxide (sand) with various other chemical substances and heating it.
The result is a somewhat odd material, neither liquid nor entirely a solid, but with a melting pointing considerably below pure silicon dioxyde.
Hence the problem...
CJ
Glass is made by mixing silicon dioxide (sand) with various other chemical substances and heating it.
The result is a somewhat odd material, neither liquid nor entirely a solid, but with a melting pointing considerably below pure silicon dioxyde.
Hence the problem...
CJ
Pace:
I'm afraid you just don't get it.
1. See and avoid doesn't work by day with fine ash clouds as has already been demonstrated. It certainly doesn't work at night.
2. With at least 1000 flights per day to and from Europe, we are talking about the balance of probabilities of finding ash. It is irrelevant if one aircraft or ninety aircraft make it through without ash damage. Your personal experience is irrelevant.
This is about managing risk for a fleet of 1000+ aircraft engaged in European travel at any given time. As I said many pages ago, the penalty for getting the ash forecasts wrong is hundreds and hundreds of damaged aircraft sitting on the ground for months as they wait for their engines to be rebuilt by overloaded maintenance facilities staffed by exhausted engineers.
To put it another way, there are not hundreds of spare engines sitting around in Europe or America for some mass engine change.
To put it yet another way, suppose the forecasters get it wrong, or the volcano decides not to cooperate and Forty B747's need engines changes as a result. Are you going to sit there and argue that Boeing/GE/RR or the airlines should have had 160 spare engines just sitting around unallocated against this possibility? I can tell you they don't.
There are relatively few spares around against birdstrikes etc. The engines are monitored on the wings and then scheduled to be removed (sometimes as modules) during heavy maintenance and from there scheduled into engine overhaul and from there scheduled either to sit as a spare for a while or back onto another aircraft. The idea with that is to ensure that engine "Life" is managed so that engine changes due to time expired components don't happen except at scheduled heavy maintenance. Spares (blades and vanes) are usually ordered as sets, or overhauled as sets to fit in with the engine maintenance schedule.
It is a complex process and if you throw in anything other than the ordinary level of unforeseen engine changes, you will quickly run out of serviceable engines in the resulting chaos as well as suffer massive cost overruns.
Sorry cannot agree with you that its simple really You could quite easely have an area marked as below the accepted limits in Ash and have one cloud which is unique and solitary but of a much denser level than the remaining area.
Nothing is constant sadly in our atmosphere.
I can well remember flying a twin to Malaga single pilot ................
...............The best indicator with storms or otherwise is to use your eyes and your instincts and knowledge as relying on aids only whether aircraft based or land based will give you a shock you dont want.
That is why I dont hold with the science but do with pilots and good old see and avoid.The SCIENCE is an aid to the captain not the CAPTAIN and for me thats the whole basis of my arguement with this thread. Listen to the airlines and the pilots and thankfully that message seems to be proving correct.
The same goes with ASH which to date has not harmed anyone in I repeat over 50 years when there were no fancy gizmos to mislead anyone which sadly also now seems proved to be a costly mistake.
Nothing is constant sadly in our atmosphere.
I can well remember flying a twin to Malaga single pilot ................
...............The best indicator with storms or otherwise is to use your eyes and your instincts and knowledge as relying on aids only whether aircraft based or land based will give you a shock you dont want.
That is why I dont hold with the science but do with pilots and good old see and avoid.The SCIENCE is an aid to the captain not the CAPTAIN and for me thats the whole basis of my arguement with this thread. Listen to the airlines and the pilots and thankfully that message seems to be proving correct.
The same goes with ASH which to date has not harmed anyone in I repeat over 50 years when there were no fancy gizmos to mislead anyone which sadly also now seems proved to be a costly mistake.
1. See and avoid doesn't work by day with fine ash clouds as has already been demonstrated. It certainly doesn't work at night.
2. With at least 1000 flights per day to and from Europe, we are talking about the balance of probabilities of finding ash. It is irrelevant if one aircraft or ninety aircraft make it through without ash damage. Your personal experience is irrelevant.
This is about managing risk for a fleet of 1000+ aircraft engaged in European travel at any given time. As I said many pages ago, the penalty for getting the ash forecasts wrong is hundreds and hundreds of damaged aircraft sitting on the ground for months as they wait for their engines to be rebuilt by overloaded maintenance facilities staffed by exhausted engineers.
To put it another way, there are not hundreds of spare engines sitting around in Europe or America for some mass engine change.
To put it yet another way, suppose the forecasters get it wrong, or the volcano decides not to cooperate and Forty B747's need engines changes as a result. Are you going to sit there and argue that Boeing/GE/RR or the airlines should have had 160 spare engines just sitting around unallocated against this possibility? I can tell you they don't.
There are relatively few spares around against birdstrikes etc. The engines are monitored on the wings and then scheduled to be removed (sometimes as modules) during heavy maintenance and from there scheduled into engine overhaul and from there scheduled either to sit as a spare for a while or back onto another aircraft. The idea with that is to ensure that engine "Life" is managed so that engine changes due to time expired components don't happen except at scheduled heavy maintenance. Spares (blades and vanes) are usually ordered as sets, or overhauled as sets to fit in with the engine maintenance schedule.
It is a complex process and if you throw in anything other than the ordinary level of unforeseen engine changes, you will quickly run out of serviceable engines in the resulting chaos as well as suffer massive cost overruns.
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Engine Damage Photos Misunderstood As Ash Damage — Civil Aviation Forum | Airliners.net
A friend forwarded to me, I would like comments from engineers more knowledgeable that I.
john
A friend forwarded to me, I would like comments from engineers more knowledgeable that I.
john
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Mate, someone's driven a tank down that intake, it has absolutely 100% got nothing to do with ash! To my knowledge, nobody has found any ash damage in a commercial aircraft these past few weeks
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Aren't Internet forums wonderful?
I posted a question yesterday about a set of purported pictures of ash damage:
These are the same pictures to which jonwilly referred earlier today. The answer appears to be no, no one knows where they came from.
Let me pose the same question again today: does anyone have a provenance?
I found it particularly amusing that two people, Pace and sabenaboy, suggested I was being gullible, presumably on the basis of what they read on other anonymous forums on the Internet. Folks, maybe it is time to look up the meaning of "gullible"?
From what I understand of the physics and chemistry of ash damage to engines (and it is not much, but it is more than many here seem to understand), it is quite possible for an engine to shed a blade or three if affected parts overheat and the engine isn't shut down. And what you then look at is a broke engine, much as these pictures show.
PBL
I posted a question yesterday about a set of purported pictures of ash damage:
Originally Posted by PBL
Does anyone have a provenance for those pictures?
Let me pose the same question again today: does anyone have a provenance?
I found it particularly amusing that two people, Pace and sabenaboy, suggested I was being gullible, presumably on the basis of what they read on other anonymous forums on the Internet. Folks, maybe it is time to look up the meaning of "gullible"?
From what I understand of the physics and chemistry of ash damage to engines (and it is not much, but it is more than many here seem to understand), it is quite possible for an engine to shed a blade or three if affected parts overheat and the engine isn't shut down. And what you then look at is a broke engine, much as these pictures show.
PBL
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I found it particularly amusing that two people, Pace and sabenaboy, suggested I was being gullible, presumably on the basis of what they read on other anonymous forums on the Internet.
Dont you also think its amusing That both SabenaBoy and myself actually fly jets albeit SabenaBoy flies larger jets than I do?
The majority of ATPs I know appear to come from the same mould on views of this whole charade which has cost the industry a fortune and charade it is.
Thankfully as I dont want to see our already struggling industry brought to its knees by unfounded media hype and scaremongering some of us have tried to balance that aspect with a bit of sense.
You refer to yourself as a researcher yet appear to only add to unfounded scaremongering by desperately jumping at anything which may add to your cause.
Normally a researcher researches until they get facts which they then put out to the media.
You though plant a link to a picture with comments that if true it may convert the sceptics to your way of thinking.
Thankfully the pilots and airlines way of thinking is proving to be correct.
There are pictures of what looks like severe ash damage to a Citation engine circulating on the Internet. They are horrendous. If they are genuine, they will silence our sceptics
suggested I was being gullible, presumably on the basis of what they read on other anonymous forums on the Internet
Pace
Last edited by Pace; 20th May 2010 at 09:56.
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1. See and avoid doesn't work by day with fine ash clouds as has already been demonstrated. It certainly doesn't work at night.
This is about managing risk for a fleet of 1000+ aircraft engaged in European travel at any given time. As I said many pages ago, the penalty for getting the ash forecasts wrong is hundreds and hundreds of damaged aircraft sitting on the ground for months as they wait for their engines to be rebuilt by overloaded maintenance facilities staffed by exhausted engineers.
To put it another way, there are not hundreds of spare engines sitting around in Europe or America for some mass engine change.
To put it yet another way, suppose the forecasters get it wrong, or the volcano decides not to cooperate and Forty B747's need engines changes as a result. Are you going to sit there and argue that Boeing/GE/RR or the airlines should have had 160 spare engines just sitting around unallocated against this possibility? I can tell you they don't.
To put it another way, there are not hundreds of spare engines sitting around in Europe or America for some mass engine change.
To put it yet another way, suppose the forecasters get it wrong, or the volcano decides not to cooperate and Forty B747's need engines changes as a result. Are you going to sit there and argue that Boeing/GE/RR or the airlines should have had 160 spare engines just sitting around unallocated against this possibility? I can tell you they don't.
Remember my question from post 2646: "Sunfish, could you enlighten us please and give us ONE example of an aircraft that had extremely costly damage to the engine, after flying through an ash cloud so thin that it wasn't noticeable to the eye! Juste ONE example! PLEASE...!!!" Still awaiting an answer!!
Nothing catastrophic is going to happen if you fly through ash concentrations so low that it stays invisible to the eye. Maybe -with emphasis on maybe- there could be an increase in maintenance cost and for extra engine checks, but these costs will surely be much less then grounding thousands of airliners without a very good reason.
And pardon me for saying so, but looking at your profile and the a/c you're type-rated on, you're not really in a position where you can call yourself an expert. I think you will be in more danger by forgetting the carb heat on your Rotax, then you will be by volcanic ash in an airliner! Please don't forget what the "Pp" stands for in Pprune!
Ok, the above sentence is a cheap shot, and something I don't usually do, but the way you have been hanging on to your "oh boy, we're gone crash"-scenarios without valid arguments are getting very boring.
Best regards,
Sabenaboy
Last edited by sabenaboy; 20th May 2010 at 14:25.
Pace and sabenaboy
So, both of you are pilots, in what way does that qualify you to make judgement on the engineering aspects of volcanic ash damage? I am not Jet engine engineer, but I will defer to the better knowledge of the manufacturers who disagree with your opinions. You are both obviously quite wrong and its a little disturbing that you think that you know better than the experts simply because you hold an unrelated qualification.
So, both of you are pilots, in what way does that qualify you to make judgement on the engineering aspects of volcanic ash damage? I am not Jet engine engineer, but I will defer to the better knowledge of the manufacturers who disagree with your opinions. You are both obviously quite wrong and its a little disturbing that you think that you know better than the experts simply because you hold an unrelated qualification.
