A380 Wing Comes Off

[ocnus]

This has just popped up on ATI:

"The wing of the Airbus A380 static test specimen has suffered a structural failure below the ultimate load target during trials in Toulouse, but the European manufacturer is confident it will not need to modify production aircraft."

[Eva San]

Isn't that title a BIT misleading...?
More details here (http://www.flightinternational.com/Articles/2006/02/17/Navigation/177/204716/Airbus+A380+test+wing+breaks+just+below+ultimate+load.html)
...

[captjns]

Just like the vertical fin separating from an American Airlines Airbus departing from JFK in November 2001, the French will rule that the test bench operator was to rough on the equipment, like the pilot of the airbus that crashed.

Long live the manufacturer of disposable aircraft!

[luoto]

How would Mr Boeing play this though?

Let's hope that disposable passengers don't become in vogue!

[Hand Solo]

I seem to remember the C17 wing broke early too. Sometimes it happens, usually because the test loading of the wing is not adequately representative of the in-service loading.

[captjns]

The MD-90 split in two during testing hard landings too.

The bottom line is that the majority of problems are found during testing rather than during passenger operaations.

[acbus1]

Hmmm.

The rig "proves" the Finite Element Model (with some error), so redesign of the wing based on the FEM is OK.

Hmmm.

:hmm:

[jamesbrownontheroad]

Long live the manufacturer of disposable aircraft!

It's called designed obcelesence: the basic rule of American car design for at least thirty years :}

*j*

[notdavegorman]

Is it just me, or has anyone else noticed how often posts are made by individuals how are willing for the A380, in fact Airbus in general to fail.

I fly the 737 and work for an all-Boeing airline. I can see their strong points and their weak points, and I'm quite happy to comment on them, however without any experience of Airbus products, save a few times paxing on them, I don't really feel qualified to comment on their merit.

I wish others would do likewise.

PS I hope the A380 is a big technical and commercial success. Success improves the breed in general.

[ExSimGuy]

the majority of problems are found during testing rather than during passenger operaations

One would HOPE so!!!!

[Grunf]

I am just curious how much time Airbus marketing has spent before they came out with this.:}

As for EASA (and FAA consequently) it would be interesting what change is Airbus proposing in order to justify this.:confused:

Catch is that usually local CAA allows some test flights based on limit loads only and then the rest of the stuff based on the ultimate loads (1.5 x limit loads).

If you go to break the wing that means all the other test went smoothly. No it is unclear if they have finished ultimate loads tests or no. Also there is no word for what loadcase did the structure failed.

Still this is embarrassing and the only thing they could say is that "FEM was correct". Too bad.

Stating they will "use calibration of FEM" is, ahm, questionable. One can always do this with bad results so...

As someone said once in the end Airbus=EASA, Boeing=FAA and thus the way things will resolve themselves.

[tilewood]

Better to find it now, if true, than too late like the Comet.

That is what testing is all about. I think it is what is called 'no news'.

[Faire d'income]

Just like the vertical fin separating from an American Airlines Airbus departing from JFK in November 2001, the French will rule that the test bench operator was to rough on the equipment, like the pilot of the airbus that crashed.

Long live the manufacturer of disposable aircraft!

I find your remark quite facetious and insulting to all involved in that tragedy..

[Roadtrip]

Well, If you can't meet the standard, change the standard. Problem solved.

[Cool_Hand]

Testing is there to prove analysis, any data whatsoever that came out of this test is useful. They can only test for a very limited amount of loadcases and represent them as best they can. The tests are not completely accurate.
The results will be used to parallel the more comprehensive analysis and if they correlate the assumption that the rest of the analysis is good will be made.
Every test I have been involved in has had the conclusion of failure, you rarely get the opportunity to see how it breaks and test articles are not cheap.
I agree as above, this is no news. All part of aircraft development.

[barit1]

I suspect this could be handled by a 3% reduction in MTOW for existing hardware, and a bit of beefup in subsequent airframes...

And if they planned the test well, the test specimen might have been a bit undersize, in which case the analysis could possibly show that production standard hardware needs no modification. :8

[captjns]

I find your remark quite facetious and insulting to all involved in that tragedy..

Got an issue... get a tissue.:{ :{ :{ :{ :{ :{ :ugh: :ugh: :ugh: :ugh:

[captjns]

Well, If you can't meet the standard, change the standard. Problem solved.

That's why American refuses to by any additional Airbus products even though regardless of the financial advantages offered by Airbus... which reminds me of an autmobile offering it's customers cash insentives.

[AlexL]

I'm not sure some of you have read this correctly

“This static test airframe has the first set of wings built, and we have refined the structural design for subsequent aircraft due to increased weights etc. We will use this calibration of the FEM to prove the adequacy of the structure on production aircraft.”

Bascially what they are saying is that the current one failed close to the point predicted in the FE analysis. The wing has been redesigned anyway, and now they have calibrated the FE model and it is accurate they are happy to take the FE analysis of the new wing as read.
Whats the problem? Standard practice, calibrate an FE model at a few test points and then use the model. If you don't like that process then don't get in an aircraft, or a boat, or a car, or .....

[Sunfish]

Umm, sorry but this is no big deal. What it shows is that the Finite Element Modelling and the testing rig produced failure within 3% of where it was supposed to be - which is nothing.

I haven't found out the Airbus G limits but the failure load was 1.45 times the +G limit so it has no effect on aircraft performance or weights.

Furthermore, both Airbus and Boeing use failsafe design techniques so that the failure of one structural element does not cause the rest of the structure to fail (absent the tail attachments).

This testing will go on forever, with cracks appearing and being fixed etc. etc.

[Big Tudor]

It never ceases to amaze me how cynical Ppruners can be. The same people who lamented the technological backward step when Concorde was retired are hell bent on deriding Airbus for trying to push the aviation boundaries once more. All I can say is that I'm glad Pprune wasn't around when the Wright Brothers were doing their thing. We'd still be travelling by horse if some Ppruners had their way.

Gentlemen, this aircraft SHOULD be something the aviaiton world supports and welcomes. Yes, there will be problems along the way. Yes, those problems should be discussed openly and constructively. But why the hell are we trying to condemn one of the biggest aviation developments in 30 years to the graveyard before it has even finished its' testing phase? :hmm:

[Grunf]

Well,
I guess, as I said, they won't tell for which loadcase that happened. So they will fix it, adjust the loading limit for that specific maneuver, for example.


Sunfish:

I would somewhat disagree with you. In my opinion this is sort of a big deal since they made it public. Maybe info leaked outside of Airbus so, in order to prevent rumors, they went public which is OK. Failure during test is a bit embarrassing, after all, since you do assume that the structure was designed with some overshot. Going on the zero margin will save weight but it will bring you too close to the edge.

One more slight correction: from what I am aware last 30 years all aircraft are not fail-safe anymore but "damage tolerant". That means they can sustain some damage that can be then followed by proper inspections etc. etc.

Cheers

[747FOCAL]

It's no big deal. If it is not strong enough they just add more structure to compensate. Adds weight but then it will make the requirements.

:)

[False Capture]

During testing the Boeing 777 wing failed at 154% of the design load. The Boeing engineers were hoping the B777 wing would fail at 157%.

The A380 wing failed between 145% and 150% of the design limit. For all intents and purposes, it sounds like the A380 wing failed at the expected limit of approximately 150%.

[Grunf]

False capture:

That is right as long as you're on the other side of 1.5 mark. If you go for zero margin assumption you're exposed to either this or flight test results that are actually requiring a cert report update.

In Boeing's case there was no need for changes.

Still it seems to me we do not have enough info. Are loadcases comparable (your examples)?

Are these the most critical load cases? Is it the same part of structure?

Too many unknowns...anyway nothing is unsolvable.

Just a little bit of pre-emptive PR.;)

Cheers

[False Capture]

Grunf,
For certification purposes they're allowed a 3% margin of error/spread. As a result the failure was within limits for certification and almost 50% more than what you refer to as the "zero margin".

[vapilot2004]

Using typical remarks, they are saying everything is beautiful and nothing is wrong here.

Isn't the 1.5 load factor a certification requirement ?

If so, how will Airbus address this structural failure below the set limit ?

EDIT - Answered my question FC ! - you must have posted when I was :)

[Roadtrip]

Maybe they should snap 9 more and see what the average is.

[Ultralights]

slight topic drift, but still on topic, during these structural tests, are flight control movements tested at the same time? eg, the wing is stressed to 125% of its design limit, are all flight controls then tested through their full travel to ensure full control if the wing sees such loading in flight?

eg during unforseen severe turbulence, it would be a bad thing if the wing is stressed to 100% or slightly higher, and the aileron control jams or deflects causing temporary loss of control...

[matkat]

As an ex-airbus engineer I can only re-iterate that this is a non-event the whole idea of the FEM is precisely to catch this problem and as AB say the production models have been re-engineered due to weight change requirements if the wing then failed now that would be a problem and a possible redesign.

[Volume]

As a result the failure was within limits for certification and almost 50% more than what you refer to as the "zero margin".
You are confusing "factor of safety" with "margin"
Factor of safety is the relation between ultimate load and limit load, generally a 1.5 (or 150%) is required here. Some special factors may apply.
Margin is between rupture load and ultimate load.
Zero margin means rupture at ultimate load, or at 150% limit load.

are flight control movements tested at the same time? eg, the wing is stressed to 125% of its design limit, are all flight controls then tested through their full travel to ensure full control if the wing sees such loading in flight
No.
Everything tested above limit load is not "seen in flight" (at least it should not).
The rule requires flight testing of the control system up to 80% limit load and ground testing (or analysis) of the control system up to limit maneurvre load.
Nothing above limit load is tested in combination with other loadcases or other systems.

If in doubt, read the rule. It´s available on the web.

i.e. CS-25

CS 25.305 Strength and deformation
(a) The structure must be able to support limit
loads without detrimental permanent deformation.
At any load up to limit loads, the deformation may
not interfere with safe operation.
(b) The structure must be able to support
ultimate loads without failure for at least 3 seconds.
However, when proof of strength is shown by
dynamic tests simulating actual load conditions, the
3-second limit does not apply. Static tests conducted
to ultimate load must include the ultimate deflections
and ultimate deformation induced by the loading.
When analytical methods are used to show
compliance with the ultimate load strength
requirements, it must be shown that –
(1) The effects of deformation are not
significant;
2) The deformations involved are fully
accounted for in the analysis; or
(3) The methods and assumptions used
are sufficient to cover the effects of these
deformations.


CS 25.683 Operation tests
(a) It must be shown by operation tests that
when portions of the control system subject to pilot
effort loads are loaded to 80% of the limit load
specified for the system and the powered portions
of the control system are loaded to the maximum
load expected in normal operation, the system is
free from –
(1) Jamming;
(2) Excessive friction; and
(3) Excessive deflection.

(b) It must be shown by analysis and, where
necessary, by tests that in the presence of
deflections of the aeroplane structure due to the
separate application of pitch, roll and yaw limit
manoeuvre loads, the control system, when loaded
to obtain these limit loads and operated within its
operational range of deflections can be exercised
about all control axes and remain free from-
(1) Jamming;
(2) Excessive friction;
(3) Disconnection, and
(4) Any form of permanent damage.

[luoto]

Can I state that I am not an aircraft engineer and I do want the A380 to work (as long as it doesn't mean I am stuck in the back row of a high density A380 with fat passengers!).

But could this wing have broken after being given a lot of other stresses, and thus been weakened? Or should the wing always be able to take that much stress through cycles (i.e. 20,000 flight cycles at maximum loading).

[Erwin Schroedinger]

There's a misconception that "beefing things up" will always give increased failure load.

The opposite effect has sometimes been the unexpected outcome (well, unexpected until you consider, for example, the redistribution of loads caused by "beefing up"). :uhoh:

[Grunf]

Volume thanks for the explanation.

To all of you thinking this is a non-event:

OK, so if that is really the fact then why did Airbus came public with that info?

It should stay within their realm, right?

[tallsandwich]

Why this news is "made public", and why does this thread exist? Because the destructuve tests are far more news worthy than the non-destructive tests.

Is it normal practice to validate an FEA model based on empirical data? Yes, absolutely.

Is 3% a significant error margin? Not really, what is significant is what is done with the result afterwards.

Should we be more interested in details such as the crack propogation rate that was caused by the non destructive cyclic testing (that represents real world loading scenarios)? Yes, but this is dull so won't get the same tabloid attention.

What I would like to know is if the component(s) that failed in these tests were the same component(s) that first exceeded their elastic limit in the FEA modelling.

[RMC]

Guys - A few points
1. Airbus has more than one structural test wing set. 150% will be achieved on a set built closer to the final build standard (see below).
2. Luoto - the final destructive test is only completed at the end of the life cycle tests. So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%
3. 150% may not sound like much but if you check out the pictures you will see the wing tips at around 90 degrees to the horizontal before the final failure. Hands up who has ever experienced anything like this in flight.
4. Throughout the 18 months of extreme fatigue testing minor failures are induced (this happens on every aircraft type). The repairs weaken the wing prior to the final destructive test. See coments on stress allowances below.
5. At day one development wings are weaker than the production wings for two reasons.
First - The first seven aircraft each have hundreds of miles of Flight Test Instrumentation cable passing through scores of extra holes drilled in the rib / spar wingbox structure.
Secondly - Despite the fact that Airbus assembly personnel have massively superior training than their American opposite numbers...EVERY first off aircraft ever built has hundreds of design "concessions" on each wing. These are , for example, slightly oversize holes...drill runs...tooling causing loss of land on hole edges.
These errors are a fact of life in the E Fatigue and E Static wings and Flight Test only aircraft... but are iorned out before the production batch. Stress engineers will theoretically factor these weaknesses into the final stress calculations. If you have ever spoken to a stress engineer though you will know that they are the most conservative people on the planet. Built into their calcs are huge comfort factors so a critical concession which could cause a 10% reduction in rib 2 strength will either be assumed to have no effect or, they will begrudgingly allow between 1 and 2% to the fatigue testing people.
Bottom line wing set probably achieved closer to 160% rather than 150%. It really is not a big deal.

[luoto]

Could Airbus be disclosing this to avoid any legal problems in the future "just in case" and to show open ness?

[Grunf]

RMC:

Being one of those "conservative people" :E I would still say that this news needs far more explanation then there is room in FI or anywhere else in public.


It can be open to discussion and there is no valid info out there (and it shouldn't be).

Rumors yes, but valid news no.

As for the personnel training I hope you were employed at both sides ( Airbus and Boeing or Northrop or Lockheed) in order to comment on their skills.

They all do make mistakes, more or less, the same way.

As for the stress and testing I am sure that public picture will be right in the end (as will the official EASA side as well). It is hard to explain all that in plain English to general public assuming that this is the FI's target audience.

Slight problem might occur if the whole thing was designed for a 0% margin (I've seen these type of requirements) although it is still avoidable with "conservatively" mentioned above.

I am happy to hear they can do the fatigue test in 18 mths - a very fast schedule comparing to others, at the same task.

As tallsandwich I would also like to hear the crack propagation scenarios. This would tell us more how good this structure really is.

[Sunfish]

No it doesn't and the wing didn't come off either. A component simply broke.

[What Red Line?]

Good post ocnus, thanks starting this thread and for letting us know this important information.

It's getting to the stage where it just won't be safe to be outside for fear of getting hit by Airbus fins or wings and things dropping out of the sky.

Wouldn't happen to a Boeing you know. No way! Just try to imagine a fin falling of a Boeing. Impossible! Although some clown once tried to tell me that a fin dropped off a 747 in Japan. What rubbish! Only happens to Airbus.

[Milt]

Congratulations to Airbus and British Aerospace for getting it so close.

The wing is supposed to break at ultimate if all of the design is right. That is what ultimate means.

If you build a wing stronger than ultimate then it is too heavy so then you might consider some weight improvement. Trouble with that is - you then may need to repeat all of the fatigue and load testing again.

In this case the fatigue testing may have initiated a small undetected crack which slightly weakened the piece of structure which broke. Simply polishing the surface of that structure at the break point may be enough to guarantee the strength to be above ultimate.

All of you potential A380 pilots should be elated.

A good question begging for an answer is
"What load exceedence spectrum was used for the fatigue testing and for how many equivalent hours of flight time?"

[RMC]

Grunf,
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.

[captjns]

Grunf,
I have worked as a contractor in the US and am able to comment on skills of "assembly personnel". I was not directing the superior skills comment at design engineering personnel.
Basically a traditional UK assembly worker/fitter/mechanic will have an apprenticeship of 4 to 5 years. The first year is spent in a training school, no where near an aircraft, before being released on the shop floor with at least 12 different experienced fitters in 12 different sections over the three to four year period. Most of the US fitters are what we refer to as "semi skilled" having training measured in months rather than years. For evidence go and have a close look at 2 new 737 leading edges. You will see they are not the same with steps and gaps clearly visable to the naked eye. Then check out an airbus leading edge..all are identical with steps and gap tolerances checked with fine feeler gauges.

You're full of crap slick. You must be one of them thar semi skilled contractors.

After many cycles any airplane will get that middle age spread. During heavy checks, aircraft are torn apart and put back together so they are re-rigged to zero time tolerances. Aircraft flown over here are maintained inspected in Europe too. With these so-called gaps or other blemishes visible after a heavy check has been completed, is it because, as you say, are the engineers here semi-skilled?

Pretty arrogant of you don't you think... athough no... since you made the comment regarding semi-silled labour.

[RMC]

CAPTJNS- Sorry you dont like the facts. Read my reply I specifically said check out the leading edges of two NEW 737s....ie just delivered. I spent a year in France Delivering new Airbus aircraft to customers and know about the differences between Airbus and Boeing specifications.

[Grunf]

RMC:

As long as you've been exposed to both sides it is OK to comment. I did support both sides, namely in liaison stress, so I've seen same kinds of problems both ways.

In terms of QA prior to delivery I would assume both sides would work hard on that. Sadly I think money still talks stronger so some discounts, concessions etc. will bring that acceptance from the customer side, always.

As for the competence of designers - I shouldn’t comment, being a stress guy:rolleyes:

As for skills in North America it is worth say that if you worked in few place, they are definitely different, depending on where they work.

To get back to A380 wing it is fine. Still no explanation into why this info got public. I do not think this is a valid info for general population, not even for educated amateurs. It is too complex to be discussed in FI.

[RMC]

Grunf-Only spent 6 months in Seattle (too bloody cold) and I am specifically refering to assembly fitters on the line (not design guys or even the maintenance guys who have to meet far higher standards than the factory bods). A case in point was the 747 which had a tailstrike (JAL?). The designed repair was fine. The product support mechanic (drawn from the factory) fitted one line of rivets along each side of the repair (not two as drawn by the design engineer). You know better than I that one line of rivets on the critical rear pressure bulkhead would never be entertained as an adequate repair...even a European factory cat would not fit that but tragically that repair was completed and signed off.

[Grunf]

RMC:

I understand. I would like to say bad luck but this guy was really sloppy. No explanation for that except what you've said.

Cold-wise, try to work in Montreal:E

Anyway it is good for Airbus they got so close to 150%. Although it is always better to have a little more over 150 and then show some weight reduction that always looks nice with customers.

Cheers

[Volume]

What Red Line? :
Wouldn't happen to a Boeing you know. No way! Just try to imagine a fin falling of a Boeing. Impossible! Although some clown once tried to tell me that a fin dropped off a 747 in Japan. What rubbish! Only happens to Airbus.

What rubbish ! indeed !

Just try to imagine a horizontal stabilizer falling of an Airbus. Impossible ! Just happened to a 707 (Dan Air, Lusaka).
Just try to imagine the upper portion of the fuselage falling of an Airbus. Impossible ! Just happened to a 737 (Aloha, Hawai).
Just try to imagine the bulk cargo door falling of an Airbus. Impossible ! Just happened to a DC10 (THY, Paris).
Just try to imagine the engine No. 1 falling of an Airbus. Impossible ! Just happened to a DC10 (Continental ? Chicago ?).
Just try to imagine several engines falling of an Airbus. Impossible ! Just happened to a 747 (ElAl, Amsterdam).
Just try to imagine a worn jackscrew causing a horizontal stabilizer falling of an Airbus. Impossible ! Just happened to a MD 8x (Air Alaska).

[mono]

2. Luoto - the final destructive test is only completed at the end of the life cycle tests. So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%

Not being a test engineer but an engineer all the same Are you sure about this??

I thought that you had to destructively test a "virgin" as well as a full cycle piece. Didn't the Comet problem occur because a full cycle fuselage was used for the pressure tests and the subsequent "work hardened" fuselage passed the tests only for the relatively low cycle in service fuselages to fail? Or did I get the wrong end of the stick?

[rotornut]

AP
Airbus: Test Won't Delay A380 Delivery
Monday February 20, 7:06 am ET
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.

[Volume]

So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%
Are you sure about this??


nope, he is not shure (or he might be, but he is wrong)
The wings completing more than 2 simulated lives is still beeing tested in Dresden (http://www.ima-dresden.de/englisch/infonews/35.htm). The one in Toulouse was never tested in fatigue.

And for the Comet, it was the other way round. The test fuselage (section) used for fatigue testing was used for static tests before, "coldworking" all the high stressed areas. This led to a high fatigue life of the specimen, which was misjudged at that time to the best knowledge of engineers and authorities.

[vapilot2004]

Help me sort out the ....*ahem * .... truth please

So is failure at:

1.46
1.47

or is it 1.45 times the certified number ?

3.3 percent below is not good if the FAA requires 3 pct for an easy certification.

...... geez . . . so typical - - - conficting data/reports and secrecy :suspect:

[Grunf]

Mono:

Destructive test goes after completed static tests so the guy was right.

If everything goes well they will do that, I am sure.

To add here an excerpt from Airbus VP Eng's statement fro FI:

"Garcia says the trial was an “extremely severe test during which a wing deflection of 7.4m [24.3ft] was recorded” and that the A380 wing was designed to have “no margin” at ultimate load. “We had a weight-saving programme and ‘played the game’ to achieve ultimate load,” he says."

So they did (expectedly) go to "zero margin". Whoever asked before since this was mentioned before. s I said they were saving weight.

In the end they will get out with slightly different cert reports.

"Jonathan Howes, technical director of UK-based certification consultants AeroDAC and, until recently, leading structures certification specialist for the A380 at the UK Civil Aviation Authority, says the rupture “was so close to the ultimate target that it is almost certain to allow approval to be given without the need for a re-test, but this will be subject to a negotiation between Airbus and EASA”.

[RMC]

mono / volume,
No way is a virgin wingset used for the destructive test.Apart from anything else Branson would go his nut.
:)

[Volume]

RMC,

I didn´t say virgin wingset, I just said the static test article was never used for fatigue testing, so the statement "So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147% " is wrong as well.
The wingset in question was not virgin, but not a slut either. Just been tested a few times before for several static load cases, flap system gap checks under deformation etc. sometimes exceeding limit load.

[Sunfish]

Certain comments here are somewhat misguided. Comparing leading edges gap quality or whatever on B737 and Airbus aircraft as an indication of build quality and indirectly safety, is misguided at best, and totally off the beam at worst.

Quality is not about beautiful smooth curves and so on, its about fitness for purpose. To put it another way, if the ragged edge makes no difference to performance and safety, then leave them exactly as they are - don't guild the lily, it adds to cost.

If the Boeing designers designed an aircraft in such a way that it can be constructed by semi skilled workers, then no one has a right whatsoever to draw meaningless comparisons with Airbus on the basis of the quality of its labor force.

[RMC]

Sunfish,
You are corect about fitness for purpose.
I used leading edges as an example because a ragged leading edge does make a huge difference to aerodynamic performance. One of the reasons Airbus aircraft are so much more fuel efficient than Boings. Not exactly a meaningless issue with fuel costs as they are.
Yep Boeing over engineer their aircraft and this makes build quality less important. Checkout the Zero fuel weight of an A320 and a 737 designed to carry the same amount of people. Not meaningless either.
I do have to agree with you however there is some guilding of the lilly which is unnecessary and Airbus quality standards have historically been too high for their own good. The reality is just like cars....if you want an over egineered , badly put together thirsty beast buy American. If you want something else pay a bit more and go for something from Japan/Germany etc.