Engineers - any sign of ash damage so far?
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ash and engine technology advancement
Does anyone know has the improvement in engine technology over the years diminished the risk of volcanic ash?
Are there any recent VA incidents with newer technology engines? Has improvements to seals, lubrication methods, filtering and bleed management either by design or consequence improved the situation over the BA Indonesia or KLM Alaska events?
One must assume that volcanic ash exist globally though in minute concentrations at location far from the origin. Does a regular well diciplined maintenance program catch these events and categorise them as for example component x replaced due to normal or abnormal wear and tear or will the new measure reduce maintenance interval inspections times to cater for the apparent increase in abrasive particulate damage?
Are there any recent VA incidents with newer technology engines? Has improvements to seals, lubrication methods, filtering and bleed management either by design or consequence improved the situation over the BA Indonesia or KLM Alaska events?
One must assume that volcanic ash exist globally though in minute concentrations at location far from the origin. Does a regular well diciplined maintenance program catch these events and categorise them as for example component x replaced due to normal or abnormal wear and tear or will the new measure reduce maintenance interval inspections times to cater for the apparent increase in abrasive particulate damage?
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I would have thought that nearly all advancements will have led to engines being more at risk from ash encounters.
As you design for effeciency the tolerences get smaller and smaller. Anything which distorts or alters the system will have greater and great effect on the over all system.
Car engines are an example and old carb low pressure ratio engine could take serious abuse. Timing belt goes stick another one in set the timing and carry on. Modern high pressure ratio engine timing belt goes you have bent valves cam shaft replaced seals blown and it has to go into the workshop to get the electronics sorted out.
As you design for effeciency the tolerences get smaller and smaller. Anything which distorts or alters the system will have greater and great effect on the over all system.
Car engines are an example and old carb low pressure ratio engine could take serious abuse. Timing belt goes stick another one in set the timing and carry on. Modern high pressure ratio engine timing belt goes you have bent valves cam shaft replaced seals blown and it has to go into the workshop to get the electronics sorted out.
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Hi everyone !
I’ve been following the debate on the other thread, but I thought that my question would be more accurate here. Before I ask my question, I would just like to stress that I am not involved in this industry, I’m just a passenger who got interested in this volcanic ash issue. I have no knowledge whatsoever about jet engines.
The topic of this thread being possible ash damages found on aircrafts, I’m surprised that no one has mentioned this event here? Curiously, it has only been related in the Italian press as far as I know. Here’s a link, and basically it says that an Air Berlin Boeing was allegedly found with ash in its engines, and the plane was therefore grounded in Olbia. The Italian press says this has to be confirmed, but no one did it. Does anyone here know something about it? For your information, this happened on the 19th or 20th of April.
Olbia: cenere vulcanica nei motori di un Boeing 737 Air Berlin - Servizi e Approfondimenti | Notizie turismo, News e cronache internazionali | Master Viaggi
Thanks!
PS: I hope I'm welcome although I'm not a professional
I’ve been following the debate on the other thread, but I thought that my question would be more accurate here. Before I ask my question, I would just like to stress that I am not involved in this industry, I’m just a passenger who got interested in this volcanic ash issue. I have no knowledge whatsoever about jet engines.
The topic of this thread being possible ash damages found on aircrafts, I’m surprised that no one has mentioned this event here? Curiously, it has only been related in the Italian press as far as I know. Here’s a link, and basically it says that an Air Berlin Boeing was allegedly found with ash in its engines, and the plane was therefore grounded in Olbia. The Italian press says this has to be confirmed, but no one did it. Does anyone here know something about it? For your information, this happened on the 19th or 20th of April.
Olbia: cenere vulcanica nei motori di un Boeing 737 Air Berlin - Servizi e Approfondimenti | Notizie turismo, News e cronache internazionali | Master Viaggi
Thanks!
PS: I hope I'm welcome although I'm not a professional
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Unfortunately, no details AT ALL of what was found where. Pity. If the incident occurred around the suggested dates, then there was presumably ash around in sufficient quantity to create problems, especially on the northern part of the routenear Cologne. Other question, of course, is where the aircraft had been on immediately preceding flights....although I doubt that anything would have been missed at Cologne with the 'heightened awareness' (aka panic) at the time.
Anyone know more / can track details of this particular flight and aircraft?
Anyone know more / can track details of this particular flight and aircraft?
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Concerning the high amounts of sulphur found in the oil of the NASA DC-8, what damage can high sulphur content in the engine oil cause? I have tried searching but can find no source for information on this.
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Over time you will have sulphidation of any of the nickel based blades / vanes, but I think you would have to have prolonged exposure.
Do a web search on type 1 and type 2 sulphidation.
Do a web search on type 1 and type 2 sulphidation.
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dubh12000
Thank you for that, it lead me to some good reading on sulphidation in a salt rich environment (marine), but all I can find is what it does to the turbine and compressor blades in the gas stream of the engine.
I am trying to find out whether high sulphur content in the lubricating oils is a concern or not, as found in the engine oil of the NASA DC-8.
Thank you for that, it lead me to some good reading on sulphidation in a salt rich environment (marine), but all I can find is what it does to the turbine and compressor blades in the gas stream of the engine.
I am trying to find out whether high sulphur content in the lubricating oils is a concern or not, as found in the engine oil of the NASA DC-8.
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High sulpher content in the oil is not a danger but an indicator.
It help to identify that an ash encounter has occurred, hence the checks. If it is high (yet the crew have not reported an encounter) then the AMM CH 5 ash encounter inspection must be carried out.
It help to identify that an ash encounter has occurred, hence the checks. If it is high (yet the crew have not reported an encounter) then the AMM CH 5 ash encounter inspection must be carried out.
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then the AMM CH 5 ash encounter inspection must be carried out
Is this a general convention or the rule applied to one (or a few) type(s) of aircraft?
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B737-100/200 AMM 05-51-261
B737-300/400/500 AMM 05-51-57
B737-600 to 900 AMM 05-51-31
B747-100 to 800 AMM 05-51-35
B757 to 777 AMM 05-51-31
MD-11 AMM 05-58-02
Airbus (All) AMM 05-51-25
B737-300/400/500 AMM 05-51-57
B737-600 to 900 AMM 05-51-31
B747-100 to 800 AMM 05-51-35
B757 to 777 AMM 05-51-31
MD-11 AMM 05-58-02
Airbus (All) AMM 05-51-25
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brooksjg chapter 5 of the maintenance manual gives conditional inspections for numerous things that may be encountered, these conditional inspections include amongst others, inspections to be carried out after A lightning strike, hard landing, overweight landing, encounter with volcanic ash OR sand etc etc.
These inspections ask you to look at certain areas and do certain tests, if you find any evidence then a further more detailed inspection may be required.
These inspections ask you to look at certain areas and do certain tests, if you find any evidence then a further more detailed inspection may be required.
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maintenance manual gives conditional inspections for numerous things that may be encountered,
Do all the extra checks in AMM Chap 5 (or wherever they crop up on different types) depend on physical evidence of ash found on / in parts of the aircraft? Or do they say things like: 'If high sulphur levels are found in engine oil AND the aircraft may have had a volcanic ash encounter, you MUST borescope the hot section of the affected turbine'?
It still seems to me from other information that there's unwise dependence on definite visual evidence before assuming the worst about less-accessible parts such as inside the turbine. Checks on filters on engine bleeds seems a sure-fire test for actual ash exposure, leading to a QUANTITATIVE result after weighing and/or microscopic examination of washings from the filter(s). Finding ash on a surface somewhere or high sulphur in the oil will remain only QUALITATIVE tests, indicating more checks need to be done...
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You keep banging on about checking filters on engine bleeds.
Mind enlightening us what they're fitted to/where & what they look like, as apart form older types that use coalescer bags in the aircon packs or ozone converters before the packs on newer aircraft - there aren't any that I know of.
Mind enlightening us what they're fitted to/where & what they look like, as apart form older types that use coalescer bags in the aircon packs or ozone converters before the packs on newer aircraft - there aren't any that I know of.
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re the ash
Anyway after all that ,at a certain large airline we have not really found any ash deposits ,just salt deposits of which volcanic ash does not have in it ,i have that from a very reliable source ..but as for stopping flying over the six day period ,i think it was the right decision ,better to be safe than sorry ...we seem to have stopped doing the extra inspections now as no ash present ....and i may be new on here but i'm not that new to the industry ,some 35 years i think swinging spanners
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You keep banging on about checking filters on engine bleeds.
Mind enlightening us
Mind enlightening us
I assumed (incorrectly??) that if the DC-8 design required such filters, they'd be fitted on later aircraft too.
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BBC Radio 4 'Report' programme aired Monday 2000 provided a good summary of the Ash Story So Far, with interviews with some of the key players from CAA, NATS, etc.
No mention, however, of any organised attempt or directive about what examination of aircraft should be done post-flight.
Assuming ash damage is cumulative and ash forecasting still depends on modelling. Any available quantitative data could be used to forecast the impact on specific engines and also to calibrate the ash forecasting model.
I'd hoped that evidence from aircraft that MIGHT have had an ash encounter would be considered valuable enough to be collected in an organised way. But it seems not.
No mention, however, of any organised attempt or directive about what examination of aircraft should be done post-flight.
Assuming ash damage is cumulative and ash forecasting still depends on modelling. Any available quantitative data could be used to forecast the impact on specific engines and also to calibrate the ash forecasting model.
I'd hoped that evidence from aircraft that MIGHT have had an ash encounter would be considered valuable enough to be collected in an organised way. But it seems not.
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No mention, however, of any organised attempt or directive about what examination of aircraft should be done post-flight.
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I was referring specifically to checks for volcanic ash.
Although Mark 1 Eyeball checks on pitot heads etc. and accessible surfaces where ash MIGHT collect are obviously part of what is done anyway, there is plenty of evidence (quoted here and nearby ad nauseam) that negative external visual checks do NOT necessarily correspond to what's actually happened to the inside of engines, in particular the turbine hot section. Please correct me if I'm wrong, but borescoping at least one engine on EVERY potentially-affected aircraft whilst parked at the ramp is not a viable option.
And what about cumulative data? Obviously, the same aircraft will fly multiple routes during a Volcanic Ash alert. OK - so it passes the visual checks every time with flying colours. But there MAY have been multiple undetected ash encounters, each one contributing to the total accumulation sitting in the turbine cooling system
And what about all the OTHER aircraft from other operators that will fly the same route?
If, as an expert in the area of ash checking and engine maintenance planning, you're totally happy with the existing checks and tests, fair enough.
Although Mark 1 Eyeball checks on pitot heads etc. and accessible surfaces where ash MIGHT collect are obviously part of what is done anyway, there is plenty of evidence (quoted here and nearby ad nauseam) that negative external visual checks do NOT necessarily correspond to what's actually happened to the inside of engines, in particular the turbine hot section. Please correct me if I'm wrong, but borescoping at least one engine on EVERY potentially-affected aircraft whilst parked at the ramp is not a viable option.
And what about cumulative data? Obviously, the same aircraft will fly multiple routes during a Volcanic Ash alert. OK - so it passes the visual checks every time with flying colours. But there MAY have been multiple undetected ash encounters, each one contributing to the total accumulation sitting in the turbine cooling system
And what about all the OTHER aircraft from other operators that will fly the same route?
If, as an expert in the area of ash checking and engine maintenance planning, you're totally happy with the existing checks and tests, fair enough.
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post/pre flight checks
Re Spanners last post,
As an ex engineer and now driver it is noteworthy and perhaps worth mentioning in the distant past, a post/preflight inspection was always carried out by an Engineer, regardless of where the flight terminated/began on the planet.
In the interest of cost saving some pre/post flight inspections are now carried out by flight crew, no less diligently I am sure but perhaps not as qualified to spot something amiss. I would say particularly new pilots with low experience.
I am not aware of any specific training given to pilots to cover this issue.....swiss cheese?
just a thought.
As an ex engineer and now driver it is noteworthy and perhaps worth mentioning in the distant past, a post/preflight inspection was always carried out by an Engineer, regardless of where the flight terminated/began on the planet.
In the interest of cost saving some pre/post flight inspections are now carried out by flight crew, no less diligently I am sure but perhaps not as qualified to spot something amiss. I would say particularly new pilots with low experience.
I am not aware of any specific training given to pilots to cover this issue.....swiss cheese?
just a thought.