A380 Broken Wings
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A380 Broken Wings
Just read this mornings Flight International and Noel Forgeard at EADS/Airbus is adamant that his ruptured A380 wing will not have to be retested even though it failed Below the ultimate Design Limit.
Any thoughts?
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Dated the 20th Feb 2006.
http://thestar.com.my/news/story.asp...49&sec=apworld
Airbus official says A380's failed wing test will not delay delivery
SINGAPORE (AP) _ Airbus's chief operating officer for customers said Monday the first delivery of the world's largest commercial jet, the A380, would not be affected by the failure of the jet's wing in a stress test last week.
"It's not a big problem at all in fact. We hope and expect it to be relatively minor,'' John Leahy said on the sidelines of an Airbus briefing ahead of the Asian Aerospace exhibition.
Before certifying an airliner for commercial service, aviation authorities set its "limit loads'' - the maximum strain each part is likely to be placed under during extreme turbulence or hard landings. New planes are required to resist loads of 1.5 times the limit.
The A380 wing had ruptured sooner than expected during ground testing in Toulouse on Tuesday, reaching only 1.45 times its limit load before breaking - 3.3 percent short of target. The wing had been bent upward by 24.3 feet at the tip.
Leahy said there should not be any major modifications to the design of the plane. "We have enough data from that test to know what needs to be done,'' he said. "This should have no impact on the delivery of the aircraft.''
Seven airlines in the Asia-Pacific region have ordered a total of 49 A380s, accounting for 31 percent of 159 firm orders so far for the world's largest passenger aircraft - but deliveries have been pushed back six to eight months due to production delays.
The 555-seater is due to enter into service with Singapore Airlines Ltd. by the end of the year. The aircraft has a list price of US$292 million (euro243 million).
The A380 will overtake The Boeing Co.'s 747 as the world's largest commercial jet when it enters service. Boeing announced late last year that it is launching the 747-8, a more fuel-efficient version of the double-decker plane, to compete with the A380.
Separately, Singapore Airlines said Monday it was evaluating proposals from Boeing and Airbus to supply long range aircraft, but a decision is unlikely anytime soon.
"We are evaluating (the proposals). The early submissions didn't meet our requirements in terms of delivery schedule and operational economics,'' Chief Executive Chew Choon Seng said on the sidelines of an aviation conference.
Singapore Airlines asked Boeing and Airbus in August to submit proposals for ultra-long range aircraft, to meet its fleet renewal needs and future expansion plans.-AP
Airbus official says A380's failed wing test will not delay delivery
SINGAPORE (AP) _ Airbus's chief operating officer for customers said Monday the first delivery of the world's largest commercial jet, the A380, would not be affected by the failure of the jet's wing in a stress test last week.
"It's not a big problem at all in fact. We hope and expect it to be relatively minor,'' John Leahy said on the sidelines of an Airbus briefing ahead of the Asian Aerospace exhibition.
Before certifying an airliner for commercial service, aviation authorities set its "limit loads'' - the maximum strain each part is likely to be placed under during extreme turbulence or hard landings. New planes are required to resist loads of 1.5 times the limit.
The A380 wing had ruptured sooner than expected during ground testing in Toulouse on Tuesday, reaching only 1.45 times its limit load before breaking - 3.3 percent short of target. The wing had been bent upward by 24.3 feet at the tip.
Leahy said there should not be any major modifications to the design of the plane. "We have enough data from that test to know what needs to be done,'' he said. "This should have no impact on the delivery of the aircraft.''
Seven airlines in the Asia-Pacific region have ordered a total of 49 A380s, accounting for 31 percent of 159 firm orders so far for the world's largest passenger aircraft - but deliveries have been pushed back six to eight months due to production delays.
The 555-seater is due to enter into service with Singapore Airlines Ltd. by the end of the year. The aircraft has a list price of US$292 million (euro243 million).
The A380 will overtake The Boeing Co.'s 747 as the world's largest commercial jet when it enters service. Boeing announced late last year that it is launching the 747-8, a more fuel-efficient version of the double-decker plane, to compete with the A380.
Separately, Singapore Airlines said Monday it was evaluating proposals from Boeing and Airbus to supply long range aircraft, but a decision is unlikely anytime soon.
"We are evaluating (the proposals). The early submissions didn't meet our requirements in terms of delivery schedule and operational economics,'' Chief Executive Chew Choon Seng said on the sidelines of an aviation conference.
Singapore Airlines asked Boeing and Airbus in August to submit proposals for ultra-long range aircraft, to meet its fleet renewal needs and future expansion plans.-AP
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a380 wing structural test
hello every one,
it is as simple as that: the test article wing failed below certification limits. OK. So be it. that's what testing is for.the only solution is to test a new/modified/beefed up/production wing to destruction & do it as many times as required until the thing passes the requirements. lobbying the certification authorities is definitely only going to strengthen the design on paper. that it will cost a lot of money & induce further delays in certification is for shure, but totally irrelevant. if i were mr. noel foregard i might have a word with my chief structural/stress design engineer.
last remark: i do not buy the argument that the tested wing is not identical to production wings. it's like testing a volkswagen to destruction & then going to mercedes to tell them they have a good car.
it is as simple as that: the test article wing failed below certification limits. OK. So be it. that's what testing is for.the only solution is to test a new/modified/beefed up/production wing to destruction & do it as many times as required until the thing passes the requirements. lobbying the certification authorities is definitely only going to strengthen the design on paper. that it will cost a lot of money & induce further delays in certification is for shure, but totally irrelevant. if i were mr. noel foregard i might have a word with my chief structural/stress design engineer.
last remark: i do not buy the argument that the tested wing is not identical to production wings. it's like testing a volkswagen to destruction & then going to mercedes to tell them they have a good car.
Last edited by blackmail; 15th Mar 2006 at 05:30.
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i do not buy the argument that the tested wing is not identical to production wings. it's like testing a volkswagen to destruction & then going to mercedes to tell them they have a good car.
You could restrict the A380 weight - which then means the aircraft is strong enough, as the load has then been reduced (which means no further testing, but I think this is unlikely). The mode of failure is also important (and I do not know how it failed), but if a part of the wing failed, leaving the main structure intact, then maybe only that part needs alteration. I would be interested to see the test results, but imagine these are kept fairly tightly under wraps.
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The test was undoubtedly planned to demonstrate 150% of some Max ZFW limit. As it happens, it failed a few percent shy of that value.
Another way of stating this is that Airbus have demonstrated 150% of some lower ZFW value (~3 to 5% reduction). Assuming all other tests are met, the initial aircraft could be delivered with a reduced ZFW. This would imply some financial penalty for Airbus because of the reduced profit potential for the airline.
Another way of stating this is that Airbus have demonstrated 150% of some lower ZFW value (~3 to 5% reduction). Assuming all other tests are met, the initial aircraft could be delivered with a reduced ZFW. This would imply some financial penalty for Airbus because of the reduced profit potential for the airline.
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Given that weight is such an important design element of an aircraft, ideally you would want the wing to fail at 150.00001 % of its design load. If it fails at 160%, you are probably carrying excess weight. I wouldn't be surprised if Airbus was purposely cutting their margins very fine in order to save weight. If the wing failed within a few percent of the target and if the results did indeed validate their finite element computer model then I would think that while structural modifications would definitely be required, a retest would not.
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a380 wing structure
hello jetstream,
you ask:"why not," then i can ask:"why, yes?". if the load bearing stucture of the wing is not identical to production types, what are we talking about? and, yes, a VW has a different shape than a mercedes, but that was just the point i wanted to highlight. that airbus now, reluctantly, has to introduce weight penalties is ok, but in my opinion it still needs a full retesting & please that no computer guru/engineer tells me that recalculations only would be sufficient.
you ask:"why not," then i can ask:"why, yes?". if the load bearing stucture of the wing is not identical to production types, what are we talking about? and, yes, a VW has a different shape than a mercedes, but that was just the point i wanted to highlight. that airbus now, reluctantly, has to introduce weight penalties is ok, but in my opinion it still needs a full retesting & please that no computer guru/engineer tells me that recalculations only would be sufficient.
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The certificating authorities are going to want to see their computer models. Presumably, Airbus will now refine their computer models based on the results of the static test. Those refined models should be able to predict the results that the static test produced. If they can, then the authorities (JAA/FAA) should be happy to use those models to validate the structural modifications that Airbus most definitely have to produce (with the resultant weight penalty that Airbus is conveniently leaving out of their press releases).
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a380 wing tests
hello gilligan,
if i were the certification authority, i would be happy to receive/review airbusses new computor models, but i would still insist they break a new wing in a full static test rig. amen.
if i were the certification authority, i would be happy to receive/review airbusses new computor models, but i would still insist they break a new wing in a full static test rig. amen.
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Hello all.
Blackmail:
In general CAA responsible for certification does not ask for additional tests unless there is a big problem. This problem can be resolved "on paper" or by adjusting the FEM.
It can result in some weight penalty but it might not since they (Airbus) can change their assumptions which will create a small change in loads which will result in a positive ore zero margin.
Anyway, we should not forget the impact of Airbus on EASA similar to the same FAA-Boeing connection. it is hard to say that this has nothing to do with lobbying etc.
Politics, politics
Blackmail:
In general CAA responsible for certification does not ask for additional tests unless there is a big problem. This problem can be resolved "on paper" or by adjusting the FEM.
It can result in some weight penalty but it might not since they (Airbus) can change their assumptions which will create a small change in loads which will result in a positive ore zero margin.
Anyway, we should not forget the impact of Airbus on EASA similar to the same FAA-Boeing connection. it is hard to say that this has nothing to do with lobbying etc.
Politics, politics
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Blackmail - I see what you mean, I thought you were saying that the test specimen would be stronger than a normal wing so breaking it doesn't prove much. Here's why yes!
As I said before it depends on the failure - for instance an aircraft may have a low Velocity never exceed (Vne) because the pitot tube breaks. Fix the pitot tube and the Vne can be increased - in other words a low Vne doesn't mean a weak aircraft. Similary a failure of an Airbus wing doesn't nescessarily mean a failure of the whole structure. It might be that the flaps broke off so the flap attachment needs further work - rather than the wing box itself - this would of course mean further flap tests, but not nescessarily further wing breaking tests. Without further info it is hard to judge.
Its is easy for Airbus not to incur a delay - bring the aircraft into service with a reduced ZFW, then fix it sometime later. It depends on the cost of delays, versus the cost of a lower ZFW.
As I said before it depends on the failure - for instance an aircraft may have a low Velocity never exceed (Vne) because the pitot tube breaks. Fix the pitot tube and the Vne can be increased - in other words a low Vne doesn't mean a weak aircraft. Similary a failure of an Airbus wing doesn't nescessarily mean a failure of the whole structure. It might be that the flaps broke off so the flap attachment needs further work - rather than the wing box itself - this would of course mean further flap tests, but not nescessarily further wing breaking tests. Without further info it is hard to judge.
Its is easy for Airbus not to incur a delay - bring the aircraft into service with a reduced ZFW, then fix it sometime later. It depends on the cost of delays, versus the cost of a lower ZFW.
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a380 winws
hello jetstream,
sorry, yes of course, if i am correct, airbus says production wings will be stronger than the test specimen that was broken. and again, if i can recall, the rupture was in significant, loadbearing structure.
sorry, yes of course, if i am correct, airbus says production wings will be stronger than the test specimen that was broken. and again, if i can recall, the rupture was in significant, loadbearing structure.
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Fair enough, be assured though that failure of structures is a lot more complicated than just "it broke" - there could still be a lot of things that would mean further destructive testing is not required. conversely, there could also be a lot of things that mean it is required. I would be interested to get more details on this - do you have any idea where I might discover more?
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Although I'm not a specialist in rocket science (or aircraft design) but generally speaking if certification authorities can accept the computer-generated changes into wing design as the proof of compliance to the standarts without any further actual tests why those tests have a place at all? Why not to accept the whole construction as "safe" based just on these computer models?
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Originally Posted by CargoOne
Although I'm not a specialist in rocket science (or aircraft design) but generally speaking if certification authorities can accept the computer-generated changes into wing design as the proof of compliance to the standarts without any further actual tests why those tests have a place at all? Why not to accept the whole construction as "safe" based just on these computer models?
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What Killed MD11
Was that it could not perform as published causing Singapore Airlines cancel the order and go for A340's instead. 3.3% does not sound much but it is a huge number. Deliver aircraft with lower than specified ZFW will have effects on it's performance and WILL cost Airbus money. What ever Airbus management says it is definately a problem. I am having a feeling of Dejavu.
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Oh dear! Pilots talking structural engineering. The A380 failure is immaterial because we are talking about failure within 3 % of limit load. This is supposed to be 150% of design load. If we assume that the A380's positive G rating is +4, then to even reach the design load would require an aircraft to do something like flying through a thunderstorm at absolute max gross.
To put it yet another way. If an A380 ever reached its limit load in flight, failure of a bit of wing structure (which is by the way fail safe, with redundant load paths) is likely to be the very least of your problems.
Pleases top bagging Airbus.
To put it yet another way. If an A380 ever reached its limit load in flight, failure of a bit of wing structure (which is by the way fail safe, with redundant load paths) is likely to be the very least of your problems.
Pleases top bagging Airbus.
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Was wondering when somebody was going to clarify that sunfish, the question in my mind is, is it a certification requirement to reach 150% of design load for certification, or is this just an "industry standard" so to speak??