A380 modification because of the test results

[Grunf]

It seems that someone got straight and resolved the problem.

Hand twisting, apprently, did not work.

From FI:

Manufacturer to add strips to stringers after test rupture

Airbus has briefed A380 customers on the wing modifications it is making as a result of the premature rupture of the static test specimen in March at 1.45 times limit load.
The manufacturer plans to retrofit reinforcements to certain stringers in aircraft that have already been built and produce modified components for subsequent wings, said Airbus chief operating officer and A380 programme head Charles Champion at last week's ILA air show in Berlin.
"Our conclusion is that we are going to add a few strips on some stringers in the wing in the area involved," he said. The strips will be fitted on top of the stringers to "increase the resistance of the stringers at the limit [load]". The proposed changes have been submitted to the European Aviation Safety Agency for approval.
A380 product marketing director Richard Carcaillet says the modifications to already-built wings will add 30kg (66lb) of airframe weight, comprising 16kg for the reinforcement strips and 14kg for the attachment bolts.
The wing of the A380 static test specimen suffered a rupture below the ultimate-load certification requirement of 150% of limit load during trials in Toulouse.

[Wizofoz]

I'm sure it will be approved no trouble- just as soon as a modified wing is tested to it's REQUIRED limit load!!:D :D

[Colonel Klink]

Well, if the rumours were true and it still is a bit overweight, the extra 30 kg won't help. Maybe they will have to lighten the load by removing the swimming pool, libraray or on board shopping experiences!!!

A far cry from the original aircraft that was depicted to Virgin and others a few years ago, to, er, revolutionise travel!!!

[Joetom]

Am sure it will be ok after new parts fitted and tested.
Will be interesting to note at which time the FAA advise Airbus that full test will be required with new parts.
Suggest Airbus get a new wing ready for test ASAP.
Once the 380 gets flying with the airlines, Airbus can sort out the the problems with the 340-5/600. make the new 350, and support the 380 and the 340 IGW.
Then work on the 320/350/380 NGs.
Good Luck.......

[Big Tudor]

Shouldn't prove to be a problem to get the mods produced. Friend has said that the A380 wing team at Broughton are pretty quite at the minute. They've been churning them out so quickly there isn't any more room to store them! :D

[vapilot2004]

I think that the FAA rules governing this state that a re-test is required if the results are not within a few percentage points of the original test parameters (and they were not)

There have been instances where engineers were able to produce dynamic computer modeling data which precludes the need for another busted wing.

If a re-test is requested - it would not be un-precendented and considering the general Airbus engineering philosophy* , a re-test may be prudent.

Not sure where the EASA stands on this safety certification test/re-test.

* Not a knock - I am referring to the judicious usage of aircraft structure with the focus on structural design efficiency - hallmarks of any current Airbus product.

Did anyone see the LHR arrival - ????

The A380s Brilliant Arrival at Heathrow (http://video.google.com/videoplay?docid=9216364186426086877&q=airbus+A380+heathrow)

[411A]

Ah yes, reminds me of the 'straps' that Boeing fitted to certain models to prevent fuselage crown skin fatigue...or the modified wing panels to alleviate the same...fatigue cracking.

Never mind using properly strengthened designs...bandaids by the bucketful.

Why are we not surprised?

[chrisN]

As a matter of interest, does anyone know how repeatable tests are between one wing sample and another (of identical design level) and how close the correlation is between test and computer modelling?

(I imagine in both cases the answers would vary from one model to another, but I wonder if there may be some typical percentage variation.)

Chris N.

[Grunf]

Hello Chris.

First, tests are done on the whole a/c, not the wing only or at least that is the usual case. It would be insufficient to test only one element of the whole structure.

From what I have seen you modify the existing test article (i.e add the straps) and redo all the critical loads. Also, it is possible to wait for the next available a/c that will have modified wing (highly unlikely, it can work only if the issue is minor, which is not the case at the moment).

What you mention as computer modeling can help, of course to avoid modifications, only in one case: when the appropriate certification authority (EASA in this case, FAA with them on board, I would expect) accepts that argument.

But that already goes into willingness on the OEM side to step in and fight for its solution. It seems to me that it was easier to "strap" the weakest portion of the structure and continue your work. Not a big deal, at least not for those on the structures/engineering side.

However, for general public, it might look as an embarrassment.

I do not know of any typical percentage rate or any correlation for the repeated tests. Maybe someone else can give you better answer.

Cheers

[ICT_SLB]

Shouldn't prove to be a problem to get the mods produced. Friend has said that the A380 wing team at Broughton are pretty quite at the minute. They've been churning them out so quickly there isn't any more room to store them! :D
The actual wing design is being done in Airbus' office in Wichita, Kansas - after a lot of the original BAe wing team from Chester took up Raytheon's offer when they bought the 125 design. Understand the cargo version's wing final design has been put back while the mod's are done.

The British Aircraft Industry is alive & well and living in Wichita, Kansas.

[vapilot2004]

MARCH 10, 2006
WICHITA ENGINEERS PARTICIPATE IN OPTIMIZING THE A380’S WING

Airbus North America’s Kansas-based design and engineering team joined an international effort to develop and produce a large A380 wing component manufactured with more cost-effective material.

The Wichita team – working with Airbus engineers in Filton, England – applied advanced stress analysis methods that allowed A380’s underside skin panel to be manufactured from advanced, lightweight aluminum. This material costs less than the metals normally used for such a large component.

During the past year, engineers from Wichita and Filton established the viability of utilizing less expensive metal on the A380, applying advanced analysis techniques to enable its properties to be better understood and, therefore, exploited.

Korea Aerospace Industries manufactured the wing component to Airbus’ specification. This improved underside wing panel originally was developed for use on the A380 freighter, and now will be applied to the A380 passenger aircraft. The first wing pair of components is now on its way to Airbus’ wing manufacturing site at Broughton, England.

The Airbus North America Engineering in Kansas was established in 2002, bringing together some of country's top talent to work on the 555-seat A380 and other long-range Airbus programs. This facility has grown to employ some 210 engineers, and will be joined by in 2007 by a second U.S. engineering facility in Mobile, Alabama – which will be responsible for various interior elements of Airbus' new A350 aircraft.


Filton & Wichita working on the super jumbo -- - imagine that :)

However, for general public, it might look as an embarrassment.


Several industry rags also had huge headlines of "Airbus wing fails " or similar :mad: some with no mention of the fact that the wing was expected to fail - - - - typical media I suppose.........