787 wing flex

Richard Riley wrote in
:

On Thu, 8 Nov 2007 03:58:11 +0000 (UTC), Bertie the Bunyip
wrote:

Richard Riley wrote in
m:

On Wed, 07 Nov 2007 16:50:58 -0800, Kingfish
wrote:

I noticed in all the publicity pictures of the 787 and 747-8 that
the
wings flex to the point that the tips are well above the top of the
fuselage. Just a guess here, but is this due to the composite
construction of the plane? I'm assuming the spar(s) are composite as
well as the fuselage barrel. Then again, the 747-8 is all metal
IIRC.
What gives?

http://www.youtube.com/watch?v=6Uo0C01Fwb8



Pretty col to watch OK. Amazing how fine they cut the design criteria,
though. only 4% to spare.

Yep, every extra percent is wasted weight. And that 4% gave them
margin to increase the gross weight for freighters and such.

Of course, the A380 broke 4% under the target.



Did it? I didn't know. Just one of dozens of major problems they had,
eh?
I really thought the thing would never get certification at one point.

It's just incredible the way the wing breaks apart whne it reaches load
limit. Not what I would have imagined, but of course it makes sense if
you think it through. thousands of rivets suddenly out of their depth
once the first bits let go and bang, an aluminum **** storm.


Bertie