All other problems seem to be within the capabilities of current Boeing
construction techniques. A very large scale model is now flying. It's deep in
your court with a ton of top spin.......
Lynn E. Hanover
lehanover@aol.com

Where is this model flying? Dan Gray at Santa Paula was contracted to build
a fairly large blended wing model with a three HP chain saw like pusher engine.
Spun in and crashed after several flights. They gave up. Don't know who
sponsored it. It may have been NASA.

Lots of flying wings have been built by Horten, Northrup the British
(Vulcan bomber) and others. None of them have revolutionized aircraft design
or were widely copied. Possible reasons are:

A: Some of the aft wing area must be reflexed and used to provide
pitch stability and does not contribute to lift.

B: Lateral directional stability is marginal. The B2 uses computers
and split ailerons to provide a non-symmetrical drag for directional
stability. If the system fails you punch out.

C: Fowler flaps are difficult if not impossible to accommodate due high pitching moments.
Therefor for a given landing speed and runway length wing loading must be lower
and wing area greater resulting in excess wing skin friction drag at high speeds when
lift coefficients are low and the wing area is not needed.

There is nothing like a long fuselage with a tail on the end of it to solve
these problems.

BTW One of the last Horten flying wing designs in Germany also spun in
and crashed near the end of WW II. That one was jet powered.

Paul Lamar

vjaqua wrote:

I agree with the above - do not hold your breath waiting for Boeing or anyone else to field a
blended body. The multitube pressure vessels would work with not too much weight penalty - it
would be like living in the catacombs for the trip duration - with few windows - way over
there some place. By the time you faired over all those tubes to make a smooth surface your
skin friction term would go up. The bird would have a lower wing loading, so your rough ride
in turbulance wou;ld be magnified.. Boeing, like any other smart large company, spends a bit
of money out near the lunatic fringe, just to be sure they are not overlooking anything, so
they might well be flying a model. At Rocketdyne we regurely tried to use liquid oxygen for
cooling, even though most of the engine is made of heated fuel, and did manage to prove it
could be done - if you are very careful and a bit lucky. Vance

 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org