Re: Wing vs. tail-mounted engines?

Date:         31 Mar 2001 16:43:13 
From:         leodmo@earthlink.net
Organization: EarthLink Inc. -- http://www.EarthLink.net
References:   1 2
Next article
View raw article
  or MIME structure

Those "heavy" engines have nothing to do with the wing bending up and down.
Since the B47 design in the late 40s, wings have been built to flex .

Keep in mind the the wings are doing most of the lifting,  even though as a
passenger, you might feel like the empenage is lifting the wings.

Thus, the weight of an engine on a wing is weight being directly lifted by
the wing on which it is attached and that weight is not affecting the wing
where it attaches to the empenage. If that engine were mounted at the rear
of the plane, the weight would still have to be lifted, but all of the
engine weight would be present at the wing root, thus increasing the amount
of bend.

Be of good cheer. Wings that bend work. B52 wings can flex 16 feet at their
ends. B52s have been flying since the early 50's and some are expected to be
in service into the 2040s. I stood near the end of a runway at Dyess AFB
(Abilene TX) and watched the entire takeoff roll. It was really interesting
the wing tips move from very low (near the runway) to very high as the AC
gained speed.

Dennis