Isn't lift part of drag?

On Apr 25, 12:47*pm, "Peter Dohm" wrote:

There are a lot of trade offs,

Not always. There is no trade off between a model-T and a modern car.
Technology innovation allows for increased efficiency that does not
necessarily require any trade-off other than the RND time required to
develop.

-Robert

"Robert M. Gary" wrote in news:4dd3ec0a-5ece-405f-9103-
:

On Apr 25, 12:47*pm, "Peter Dohm" wrote:

There are a lot of trade offs,

Not always. There is no trade off between a model-T and a modern car.

There is, actually. You can drive a Model T across a field that even a jeep
would get bogged down in.

Also Ts are much more fun to drive.

Bertie

"Peter Dohm" wrote in
:

wrote in message
news:5d0da5e0-2006-442e-8e74-
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..
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/.../gallery.boein
g_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.


It's not going to be that big. The widebody Busses ( A 330 and 340) are
already massive with a much larger span than the 747 so it shouldn't be
an issue.

Bertie