A380 wing snaps before design load limits..

[LJDRVR]

Wow! of course you want it to fail at 1.501. A wing that is legally strong enough but not overbuilt. Back to the drawing board! Literally! This illustrates a common pilot misconception though, many of us are fonded of saying "Don't worry about it! there's a margin built in!" True, but anything beyond that load factor limit will result in permanently bent metal. (1.01 and above.)

EADS is gonna lose their shirt on this airplane. Hey, anybody been over to airliners.net yet to see how the kids are spinning this?

 

[SkyBoy1981]

Typical, it's French, it surrendered before it was supposed to.

Nice. I love the avatar. :beer:

 

[habubuaza]

EADS is gonna lose their shirt on this airplane. Hey, anybody been over to airliners.net yet to see how the kids are spinning this?

Yeah that's where I got the link from! They were saying that someone actually tried to "snuff" the link out..

 

[LJDRVR]

OMG, I just went over there and read it. I half considered registering and attempting to educate those morons, but alas the old arguing with an idiot saying comes to mind here. I like it when the software engineer makes bold proclamations about how things are supposed to work with airplanes.

Here's why the A380 will fail: Too small a market, too ugly an airplane. Name for me one ugly airplane that was ever successful. You can't.

 

[habubuaza]

Just as a side note... Those kids on Airliners.net although sometimes goofy they do some good work in digging up information. They kinda remind me of an eager beaver intern at a law firm doing all the nitty gritty as far as researching stuff.

Here's a recent near disaster at KMDW that was put out by one of these kids...

http://www.liveatc.net/forum/files/kmdw_315_670.mp3

I mean who the hell can find this $hit?

 

[joe_pilot]

Here's why the A380 will fail: Too small a market, too ugly an airplane. Name for me one ugly airplane that was ever successful. You can't.

I completely agree about the 380, but the SkyVan/Shorts was/is one UGLY(but so beautiful) airplane. I would call it successful.

 

[LJDRVR]

Nothing ugly about the shorts at all.

 

[Rally]

So from what I see the United interpreted the Position and Hold as a takeoff clearance? Or am I missing something.

 

[EagleRJ]

"This is within 3% of the 1.5 target, which shows the accuracy of the FEM.”

Within 3% ON THE WRONG SIDE!!!

Part 25 specifies not "about 1.5 times design load" or "1.5 times design load- +/- 5%", it states:

<H5>§ 25.303 Factor of safety.

Unless otherwise specified, a factor of safety of 1.5 must be applied to the prescribed limit load which are considered external loads on the structure. When a loading condition is prescribed in terms of ultimate loads, a factor of safety need not be applied unless otherwise specified.
[Amdt. 25–23, 35 FR 5672, Apr. 8, 1970]

In other words, a wing that holds at least 1.5x the design load passes under Part 25. A wing that holds only 1.47x design load FAILS!

The way I see it, Airbus has two choices: it can redesign the wing and re-test a new article to failure, or it can certify the aircraft at a lower maximum weight (despite the fact that the aircraft is already over its design weight and is unable to carry the payload Airbus promised).

....and the A380 has yet to pass the 90-second passenger evacuation drill, a test some experts think it doesn't have enough doors to pass! No pass- no pax.
What a disaster.

 

[mzaharis]

Within 3% ON THE WRONG SIDE!!!

Part 25 specifies not "about 1.5 times design load" or "1.5 times design load- +/- 5%", it states:

</H5>In other words, a wing that holds at least 1.5x the design load passes under Part 25. A wing that holds only 1.47x design load FAILS!

The way I see it, Airbus has two choices: it can redesign the wing and re-test a new article to failure, or it can certify the aircraft at a lower maximum weight (despite the fact that the aircraft is already over its design weight and is unable to carry the payload Airbus promised).

....and the A380 has yet to pass the 90-second passenger evacuation drill, a test some experts think it doesn't have enough doors to pass! No pass- no pax.
What a disaster.

But FAR 25.305 follows up with:

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.

I suggest that they may be able to go with (2) and (3), and argue that their FEM is close enough (with a .03 fudge factor ) to qualify a redesigned structure without building a test article.

If not, they're going to have a big bill for the new test article and significant project delay, which doesn't do any good for their ROI.

I think that their plan was to do the evac test with some ridiculous number of passengers (800) so that they would not need to redo the test if they ever sold a short-haul single-class (think ANA 747SR) version. If they get close to service, I'd imagine that they could pop off a test with "only" 500-550 to get the thing into revenue service with the likely number of seats most airlines will use.