787 wing flex

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?

Kingfish wrote in news:1194483058.729399.260680@
19g2000hsx.googlegroups.com:

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?



The wing

Bertie

Richard Riley wrote in
:

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.



Bertie

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

Airbus wrote in news:473298a3$0$7119
:

In article ,
says...


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?

You said the magic word - publicity.
The extreme flex is due to the composite nature of the artist's
imagination. There's little doube when the 787's are on the ramps and
in
our skies they will look much more like other planes than Boeing
advertising execs want us to think at this stage.



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

Great video, but unrelated to the OP's question - not to mention
different airplane. . .



It is completely related and the flexibility of the 787's wing would
have been known by Boeing at an early stage.



Bertie

On Nov 7, 6:50 pm, 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?

The 777 wing flexes that much as well, I guess you must not have
noticed.

On Nov 7, 7:58 pm, Bertie the Bunyip wrote:
Richard Riley wrote :

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

Bertie

Maybe if you didn't spend all day on Usenet you'd know that 4% is a
mile to an engineer, k00ky boi.

buttman wrote in
oups.com:

On Nov 7, 7:58 pm, Bertie the Bunyip wrote:
Richard Riley wrote
:

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

Bertie

Maybe if you didn't spend all day on Usenet you'd know that 4% is a
mile to an engineer, k00ky boi.


Nice try, fjukktard.


And it's not a mile, BTW, it means that you'll reach structural
deformantion by pulling only minimal extra G

Not that anyone will ever give you the cnace to find out.



Bertie

In article ,
says...


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?

You said the magic word - publicity.
The extreme flex is due to the composite nature of the artist's
imagination. There's little doube when the 787's are on the ramps and in
our skies they will look much more like other planes than Boeing
advertising execs want us to think at this stage.



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

Great video, but unrelated to the OP's question - not to mention
different airplane. . .

On Nov 8, 1:02 am, wrote:
On Nov 7, 6:50 pm, 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?

The 777 wing flexes that much as well, I guess you must not have
noticed.

I was referring to the pics of the 787 and 747-8 on Boeing's site -
however I did have another look-see at the xwind 777 landing videos on
Jay's site and the flex isn't even close to what is depicted in the PR
drawings. Like Airbus said it's probably just the artist taking a bit
of poetic license.