Actually Dave, vortex generators are WELL proven. They have been
since the 50s. That's why nearly every airliner and military aircraft
in the US uses them.

In the past VGs were considered a "band aid" and many aircraft
designers were too proud to use them ("...*my* wing doesn't need
them..."). This is starting to change as more and more aircraft
companies are realizing the benefits of VGs.

The other big reason VGs haven't taken off quicker has been the price.
Most STCed versions run up to and over the $1000 mark and that's just
too much for most folks to spend.

They aren't for every aircraft. In fact most modern/clean sailplanes
won't benefit from using them on your laminar wings (though zig-zag
and dimple tape, a version of VGs, often works very well). But for
non-laminar airfoils, especially for STOL aircraft that need to
operate safely when low and slow (like your tugs), my vortex
generators are just the ticket.

In fact don't take my word for it... visit my site and check out the
links to other companies making VGs. I've listed them in the "info"
section. I think you'll find that VGs, as well as those of us that
market them, are far from "flim flam".

If you're still not convinced then go read a good aero design book
(Hoerner's books, etc) or read the numerous NACA and NASA reports, or
look at any of the wind tunnel studies done on VGs by major
universities (Ohio State, etc). All of them say that VGs will do
exactly what I say they will.

Joa
www.landshorter.com





(David Bingham) wrote in message . com...
Be real careful about unsubstantuated claims for much better
performance. Show me an unbiased independent appraisal of the
performance of an aircraft with and without these vortex generators
that shows a measurable improvement. I bet you can't. There are so
many flimflam products on the market that promise the world but
deliver nothing. If there really is an improvement why
haven't the manufacturers of aircraft ALL been using them? What's one
of the timeless truths concerning life? Buyer beware! There is always
a sheep to be sheared.
Dave