Every vehicle you've ever travelled in throughout your life so far has had fatigue cracks in critical areas 5% of the way into it's service life.
I call B.S. unless you can document every other aircraft which have experienced significant and numerous fatigue cracks on it's wings within 5% of it's service life. There is a reason this has been revealed, and similar circumstances with other aircraft have not been revealed, is that this situation is NOT the same as every other vehicle that I have been in.
This is clear evidence of a failed airframe design, and one of these planes is going to lose a wing at takeoff or landing within a decade in the absence of major corrective action.
Last edited by DJGMaster1; Jun 14, 12 at 10:14 am..
I call B.S. unless you can document every other aircraft which have experienced significant and numerous fatigue cracks on it's wings within 5% of it's service life.
At no point did I say the cracks in every other vehicle you've travelled in were significant, or even numerous. I merely said that cracks existed.
Notice that the first and last graphs have a non-zero crack size for N=0 (i.e. a new component), and that the interpolated curves of the second graph have positive slope from N=0, showing that cracks grow from as soon as the component enters service.
Last edited by cblaisd; Jun 14, 12 at 2:14 pm..
Reason: Merged poster's two consecutive posts
I call B.S. unless you can document every other aircraft which have experienced significant and numerous fatigue cracks on it's wings within 5% of it's service life. There is a reason this has been revealed, and similar circumstances with other aircraft have not been revealed, is that this situation is NOT the same as every other vehicle that I have been in.
This is clear evidence of a failed airframe design, and one of these planes is going to lose a wing at takeoff or landing within a decade in the absence of major corrective action.
What is the basis of your claim? IMO the two reasons it got such publicity was
because this was discovered on the heels of the engine incident with Qantas A380, and
A380, being a new aircraft, still has a lot of interest out of curiosity and bias from Boeing enthusiasts.
Your opinion is very good example of the latter.
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Every sub component of a ceitical component is not critical. Spars,fewer in number thant ribs, not ribs are the main loadbearing structural members. I am sure that their is enough design tolerance that even complete failure of a rib would be serious. To be sure, it has to be repaired. It's possible that stress analysis of some ribs did not capture stress they would be subje ted to. I am not saying it is so, but making a guess. Atmost it's a minor flaw, not critical failure that some people here, without any technical knowledge, and overwhelmed by their fears, are claimimg it to be.
Last edited by cblaisd; Jun 14, 12 at 2:14 pm..
Reason: Merged poster's two consecutive posts
15 of 21 EK A380's have been out of service for at least a month, if not two. This says more about the problem and its solution timingwise than anything else posted here as it applies to 20% of the A380'2 in existence.
What is the basis of your claim? IMO the two reasons it got such publicity was
because this was discovered on the heels of the engine incident with Qantas A380, and
A380, being a new aircraft, still has a lot of interest out of curiosity and bias from Boeing enthusiasts.
Your opinion is very good example of the latter.
I'm not a Boeing enthusiast, so your comment relating to point 2 is incorrect.
The reason this got publicity, is that it is significant. I guarantee you that they will be making major corrections to address this issue. If this were not the case, they could safely ignore it - but they won't be ignoring it - which is why there is already significant corrective action being engineered and planned as we speak - it's because they know damn well it's a real issue.
The reason this got publicity, is that it is significant.
It's significant for Airbus and its shareholders, and of minor significance to the airlines who will lose use of the aircraft for "a few days" according to the article. It is not significant for passengers.
And I will accept mine over yours. You know what they say about opinions - we all have them, just as we all have parts of our anatomy.
Some opinions are formed from experience and education, others are available simply through the chance of anatomy. I know how my opinions developed over the years.
Quote:
Originally Posted by DJGMaster1
I made the specific comment about the cracks being in critical areas. Brand new airplanes do NOT ALL have fatigue cracks where the wings are attached to the fuselage - which is the specific cracks we are referring to here.
You have no idea what kind of cracks they are.
Quote:
Originally Posted by DJGMaster1
I assure you, I will ALWAYS avoid traveling in/on any metal conveyance that develops fatigue cracks in critical areas on a consistent basis less than 5% of the way into it's service life.
Enjoy your life of walking. Try not to walk over or under any bridges or through any tunnels.
Quote:
Originally Posted by DJGMaster1
Particularly if the obvious consequence of failure would be a catastrophic loss of that conveyance and it's passengers.
The only obvious thing in this discussion is that you have absolutely no idea what you are talking about.
Quote:
Originally Posted by DJGMaster1
I call B.S. unless you can document every other aircraft which have experienced significant and numerous fatigue cracks on it's wings within 5% of it's service life. There is a reason this has been revealed, and similar circumstances with other aircraft have not been revealed, is that this situation is NOT the same as every other vehicle that I have been in.
It was revealed because these types of stories sell ink and generate clicks.
Quote:
Originally Posted by DJGMaster1
This is clear evidence of a failed airframe design, and one of these planes is going to lose a wing at takeoff or landing within a decade in the absence of major corrective action.
The sky is falling, the sky is falling!!!!!
LOL this one statement totally blows your own argument out of the water. There is NO CHANCE, none whatsoever, that this minor technical issue will come anywhere close to having a wing fall off. Honestly, I have never read a more stupid statement on this site. And that is saying a lot, as I spend a lot of time in Omni P/R.
Quote:
Originally Posted by DJGMaster1
The reason this got publicity, is that it is significant. I guarantee you that they will be making major corrections to address this issue. If this were not the case, they could safely ignore it - but they won't be ignoring it - which is why there is already significant corrective action being engineered and planned as we speak - it's because they know damn well it's a real issue.
The reason it is talked about is all about selling ink and clicks. It is not significant, not to safety and not to passengers. Even the airlines will not consider it significant as they will file a warranty claim for any costs incurred in the repair and any downtime.
I'm not a Boeing enthusiast, so your comment relating to point 2 is incorrect.
I don't insist that I was right about that. The possibility that's left is less flattering.
Quote:
Originally Posted by DJGMaster1
The reason this got publicity, is that it is significant. I guarantee you that they will be making major corrections to address this issue. If this were not the case, they could safely ignore it - but they won't be ignoring it - which is why there is already significant corrective action being engineered and planned as we speak - it's because they know damn well it's a real issue.
There is chasm between not just our opinion, but also possibly between our fields of education, expertise and reasoning. I don't know what your reasons for sticking to your refrain, despite having been given very sound technical advice in terms within grasp of those without relevant education or experience. It matters not. If you have any sound technical arguments, other than it's in the news, to support your view, I would be happy to change my mind.
You do know that news stories are not the complete reality and often only remotely connected to reality. Their function is to sell stories, and report a happening. If journalists had the ability to resolve technical issues, we would have had Peter Jennings, Dan Rathers and Tom Brokaw in a committee headed by, maybe, Walter Cronkite, instead of Richard Feynman, Neil Armstrong and Eugene Covert, headed by Bill Rogers.
There is chasm between not just our opinion, but also possibly between our fields of education, expertise and reasoning.
I've always left open the possibility (or even the significant probability) that you are less knowledgeable and qualified than I am in that regard - particularly the reasoning aspect.
The simple fact is, this airframe is extending the knowledge base beyond where it has ever been, in terms of the magnitude and frequency of the loads that have ever been placed on a frequently re-used civilian aircraft. The cavalier nature with which the assumptions derived using much smaller and lighter airframes are being extended into this more extreme application are a significant red flag. I'm reminded of the Columbia disaster, where the ease with which the assumption was made and relied upon that a light piece of insulating foam falling from the vehicle just a short distance would not be able to generate enough force to critically pierce the skin of the vehicle and cause it's destruction. That was considered by the "experts" to be a bedrock solid assumption until it was tragically proven wrong by an actual catastrophic failure.
Incidentally, journalists DO have a highly relevant skill set here: They are the best trained folks on the planet in smelling out BS and overconfidence among the "experts" patronizing the general public whom they are chartered with protecting.
I'm quite sure that the likes of Richard Feynman, were he still alive, would and will be quite capable of identifying the failure mechanism in this case, after a failure occurs. The problem is, neither he nor his surviving peers are on this job now, in a pre-emptive manner - the folks who ARE on the job now are giving us dismissive statements about how there is no risk, which smack of incredible and unjustified over-confidence.
Last edited by DJGMaster1; Jun 15, 12 at 10:35 am..
I've always left open the possibility (or even the significant probability) that you are less knowledgeable and qualified than I am in that regard - particularly the reasoning aspect.
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Having lived through the beginnings of the application of Fracture Mechanics to Aircraft as a result of failures of the D6AC Steel Wing Box on the F-111, and the subsequent development of Damage Tolerant Design for Aircraft, I feel quite comfortable that the cracks mentioned are not critical in a meaningful sense. Typical Design Criteria require safe operation with a crack that will grow to critical length in two inspection intervals, just in case it is missed in the first. Since we now can reliably define the minimum inspectable crack, all flight critical parts are assumed to have a flaw oriented in the least favorable direction that is just below the threshold on inspectibility. Rarely do such cracks exist but there are countless internal flaws of lesser size as the result of the Casting, Forging, Machining and/or Installation of the part
Granted, they appear early in the life of the A-380 but the repairs and maintenance steps are entirely consistent with a safe operation. Predicting air loads in flight compared to design loads are a tricky business but major structural loads are quite reliable and design margins sufficient to ensure safe operation with the required inspections.
IMHO, this is a case of the internal loads being somewhat different from design and the result is typical for the introduction of a new aircraft.
I would sooner fly a new A-380 than a 30000 hour anything.
Cheers
__________________
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Having lived through the beginnings of the application of Fracture Mechanics to Aircraft as a result of failures of the D6AC Steel Wing Box on the F-111, and the subsequent development of Damage Tolerant Design for Aircraft, I feel quite comfortable that the cracks mentioned are not critical in a meaningful sense. Typical Design Criteria require safe operation with a crack that will grow to critical length in two inspection intervals, just in case it is missed in the first. Since we now can reliably define the minimum inspectable crack, all flight critical parts are assumed to have a flaw oriented in the least favorable direction that is just below the threshold on inspectibility. Rarely do such cracks exist but there are countless internal flaws of lesser size as the result of the Casting, Forging, Machining and/or Installation of the part
Granted, they appear early in the life of the A-380 but the repairs and maintenance steps are entirely consistent with a safe operation. Predicting air loads in flight compared to design loads are a tricky business but major structural loads are quite reliable and design margins sufficient to ensure safe operation with the required inspections.
IMHO, this is a case of the internal loads being somewhat different from design and the result is typical for the introduction of a new aircraft.
I would sooner fly a new A-380 than a 30000 hour anything.
Cheers
Since I have FINALLY received a reply from someone with expertise in this arena that was NOT laden with the hubris and a patronizing tone that I considered to be one of the glaring red flags that concern me, let me discuss with you, X3Skier, why this is a concern to me. I have no doubt at all that it is quite possible to insure with a proper inspection and maintenance regimen that these aircraft remain safe in operation, despite the fact that they are showing these sort of cracks much earlier in their operational life than is normal. What I am concerned about is that rigorously doing so is not cost-effective, in the highly cost-sensitive area of commercial aviation, and the attitude that the aforementioned tendency for cracks to develop and propagate has been treated with arrogance and dismissiveness by those who are responsible for maintaining the safety of these birds. That attitude suggests to me that the sort of inspection regimen outlined by X3Skier might not be rigorously hewn to, and far too much reliance upon the supposed redundancy built into the design will actually end up being the last line of safety, and that this may itself not be anywhere near as reliable a line of defense as is assumed, because this largest and heaviest of all commercial airframe designs does expand the working knowledge base of civil aircraft development engineering. The commercial aviation industry has a history of seeking cost-saving shortcuts in maintenance, and it was just such maintenance shortcuts that caused an AA DC-10 to lose an engine and crash on takeoff over O'Hare in the 1970s, and an Alaska MD-9 to have it's rudder jam and bring down the aircraft off of the California Coast in the 1990s. You can certainly use robust maintenance to keep these planes safe in operation, but robust maintenance costs money, and experience has shown that short-cuts will be taken to save money. That is why the design itself needs to be robust against failure to in order for us to really be sure. And the attitudes reflected both in the statements from Airbus and several of the folks who supposedly have expertise here in this forum cavalierly dismissing the issue's severity ought to raise alarms everywhere, if those attitudes reflect the level of diligence being applied to reviewing the safety of these planes and the inspection regimes that they are being subjected to.
