Some problems for A380...

[biker_thai]

As previously noted, Airbus has already redesigned the wing for one reason or another. I would doubt that they will build another wing, just to break it again. Megga Bucks!!!!

They would most likely take the 3% shortfall, and re-calibrate their analysis. and see where they are short. Not every portion on the wing has low margin. They would most likely look at only the area with the low margin and beef that area up.

Re-design occurs all the time. So it may not be a big deal . . . a million here , a million there . . . (a lot less than a publicity campaign). Ultimately it does give Airbus a publicity black eye.

[DFW]

The issue is probably less about the cost of building another test wing, but rather the delay caused by inserting it into the production line. There's probably only one production line for wing fabrication (tooling is not cheap). Customer X is already upset about past delays, and now you want to bump him (and customers after him) down one timeslot.

[chornedsnorkack]

As previously noted, Airbus has already redesigned the wing for one reason or another. I would doubt that they will build another wing, just to break it again. Megga Bucks!!!!

They would most likely take the 3% shortfall, and re-calibrate their analysis. and see where they are short. Not every portion on the wing has low margin. They would most likely look at only the area with the low margin and beef that area up.

Re-design occurs all the time. So it may not be a big deal . . . a million here , a million there . . . (a lot less than a publicity campaign). Ultimately it does give Airbus a publicity black eye.

Er, no.
The MTOW of Airbus 380-800Passenger is around 560 tons now. Which means each % of the wing strength is about 3,74 tons or so. 4 % means 15 tons.

Several planned A380 routes already are limited by payload and fuel. 15 tons is the weight of 200 passengers. Well, if the MTOW decreases, some of this weight is luggage and some is fuel saved by flying lighter on a long distance, but hundreds of tickets on a plane which had a total of 470 planned anyway costs a lot, very fast.

It might be very much cheaper to build an extra wing, break it and show it can take all 150 % or all the 560 tons MTOW.

[biker_thai]

I'm not a Structure Analyst, but if you know one, ask him or her how confident that if Airbus built another wing, and break it, they will get better results?

I'm pretty sure if they built the same wing and test it again, chances are they would not fail at the same value. If a previous post is correct in saying that the failure was upper surface, then the failure mode is in the realm of what we call buckling or post buckling AKA black magic.


And if they get significantly better results than predicted, they would get into a statistic Catch 22. Do they take the high results or do they have to consider the variation? Which would force them to use even lower values.

All this makes my head spin . . .

[DFW]

Well, Airbus is saying that prior to the test failure they had already redesigned the wing because of a change in requirements. They feel confident that they can show analytically that the redesign can handle 1.5 FS, given how "close" they were with the original wing design actually tested. Whether EASA will be convinced of that remains to be seen.

So they wouldn't test a wing identical to the first one tested.

[lastrow]

2) The 3% short fall would mean that unless Airbus redesign some portions of the wing, any A380 aircraft flying with configuration as tested will have to fly a 3% below max gross weight . The airplane can still fly. It just have to fly with less cargo.

just a question before all of you start about thinking that the MTOW of an A380 is reduced by 15 tons: Is the rule that

3% less ultimate load threshold -> 3% less MTOW

set by any authority or just your idea? just asking because only few things in construction and engineering (especially when it comes to three-d structures) are linear. could be also something like 3% miss in the ultimate load test results in 0.5% less MTOW weight?

-lr.

[biker_thai]

You are right, 3% reduction in Ultimate in may not translate linearly to 3% reduction in MTOW. I was using that as a simple example. The limit load on the wing/airplane does vary depending on which portion of the flight you are on.

So if you take a theoretical condition such as pulling out of a steep dive right after the aircraft reached crusizing. The airplane weight at that point is used for caluclation. From there you back track to see how much fuel is burned from the time of take-off . And because fuel burn rate may not be linear with aircraft weight, the resulting MTOW may not be linear with the loss in Ultimate Wing strength value.

Besides, few airline fly at MTOW anyway. They carry enough fuel to reach destination (with reserves). So unless the airline is flying max passenger/cargo at max distance, they can easily live with the 3% reduction in ultimate wing strength.

[RC20]

Not an option. Airbus already has a black eye when the A340 (forget series) were delivered way overweight.

We still do not know what the actual A380 fuel burn figures are (or what the actual aircraft weight is). If there are issues there (and not likely to be on the positive side with Airbus), then it really blows up.

All the airlines ordering this aircraft are basing revenue decisions on it meeting specifications. Some of those (as in the case of the A340) mean that it can’t even do the mission, let alone hit the revenue targets for which it was purchased.).

Upshot is that they will have to meet the criteria, and they should put a set of production wings on the test stand to do so

[CX]

The most worrying thing for the A380 now is that it wont' meet its specifications... And they should stretch the A380 quick to make it 'more special' than 555 seats compared to the 747, for example.

[fleabyte]

it would seem a failed test generates a requirement for a new test? We will see in December.

when I said scary, yes I was referring to such a large craft, with so many persons, with a wing that did not meet the test requirements. I have read articles in past of airframe writeoffs for I think it was 707 that encountered extreme turbulence and permanent, unrepairable damage to the wings, what was the 707 wing test results? Does anyone know? Also saew pics of a DC8 that lost the end of it's wing in same type condition.

[bits44]

Airbus may be required to redo wing failure test!


http://www.telegraph.co.uk/money/main.j ... xcoms.html

[SAS_MD80]

The most worrying thing for the A380 now is that it wont' meet its specifications... And they should stretch the A380 quick to make it 'more special' than 555 seats compared to the 747, for example.

Keep in mind that the A380-800 is in fact not the basic version of the A380. The basic version is the A380-900, with capacity for 650 pax, the -800 being a shortened derivative.
From its inception the A380 was designed with that in mind and for very long term. That's why its wing looks so abnormally large in comparison with the -800's fuselage: it was designed to accomodate for the longer -900 and future -1000 versions. There is also plenty of extra potential fuel capacity in the wing box.
The reason for the -800 having been launched first (which may seem rather strange at first glance) is that the market wasn't ready yet for the -900. But both ILFC and Emirates whare the opinion that in 10-15 years, the -900 will be the dominant version.

[Ovostar]

so the actual A380 will be the shortest version of the A380 ?

[SAS_MD80]

Right now that's the way it looks. A shortened version would probably have a weight penalty which would make it uncompetitive compared to the 747-8. As opposed to that the -900 version will have even better costs per seat.

[edwin]

i wonder when airbus will deliver the A380 to the companies... considering all these delays. Does anyone know what routes Lufthansa is using the A380's?

[A350-lover]

I read a lot on luchtzak about the 747 combi. Will there be such a version of the 380?

[Gate-A1]

I read a lot on luchtzak about the 747 combi. Will there be such a version of the 380?

maybe but it depends of the companies

the 747c was created because somes of the customers were not able to fill their 747 already ordered (e..g Sabena)

[SAS_MD80]

DLH is planning to use their 388 on their high traffic intercontinental flights from FKT to JFK, LAX, SIN, HKG, PKG for example.

[edwin]

ohh interesting.... off topic--> DHL should replace there 727 kinda getting old.... even though its a beautiful aircraft

[SAS_MD80]

I agree with you and I still like the 727 (though I like the MD80 better). Just to make sure, DLH is Deutsche LuftHansa. But I'm sure you didn't mistake it for DHL.