wrote in message
...
On Apr 25, 10:55 am, "Robert M. Gary" wrote:
On Apr 25, 5:23 am, es330td wrote:

Fortune magazine online has a photo essay about their new 787. On one
page,http://money.cnn.com/galleries/2008/...y.boeing_dream...,
they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. Did I
misunderstand?

It could be more efficient. The Mooney wing produces more lift for the
amount of drag than a Cessna wing.

-Robert

From the original statement, it seems clear that they're
referring to the increase in efficiency that come from aspect ratio. I
wonder, now, if that increased span was made possible with the use of
composites instead of aluminum? Longer wings flex more, and aluminum
fatigues faster, I think, than composite construction. And carbon or
aramid fibers are stronger per unit weight than aluminum.

Dan

There are a lot of trade offs, and the gate spacing might also be larger at
the airports that the Dreamliner is expected to serve. Also, IIRC, a few
years ago, Boeing talking about future aircraft with folding wing tips to
overcome some of the spacing problems at the gates. I also agree with you,
that advances in materials also play a major role.

Peter