New Aviation Product Announcement: Affordable Vortex Generators

Just a quick product announcement.... would you like to make your
landings slower, shorter, and safer? We promise that with our vortex
generators (VGs) you will! 100% money-back guarantee. Non STCed: for
Experimental category or Certified with FAA Field Approval only. A
low price of only $95 + S&H per set.

Check out our site at www.landshorter.com for more information. Pass
this info on to your towplane buddies too!

Joa
www.landshorter.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

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

Joa, I think there is enough data to say that VG's operate essentially as
you and your competitors claim - especially when used on the relatively poor
airfoils found on GA aircraft. i.e. they do reduce stalling speeds.

But, would that benefit a glider tug? I notice no claims that the climb
speed at a typical towing speed of 70 knots is improved in any way. I would
expect little improvement from VG's in the climb rate @ 70 knots.

Just for your edification, a tow plane has some special requirements. For
example, there is the need to get a heavily ballasted glider up to aileron
control speed as quickly as possible. ( An open class glider may have more
than 600 pounds of water in its wing tanks.) The 0-60 acceleration time is
very important. VG's don't help here.

Perhaps you are unaware that a fully ballasted glider will have a stalling
speed significantly higher than a Pawnee's. A nightmare scenario is a tug
that lifts off and starts to climb away at a speed near the stalling speed
of the glider it's towing. VG's might make this situation much worse.

I expect that a Pawnee would land slower if equipped with VG's but they land
pretty slow as it is. Perhaps a slightly shorter landing roll might shorten
the turn around time between tows but even here the landing roll is usually
determined more by the need to clear the airport boundary fence with a 250
foot rope dragging behind. Perhaps there would be a small increase in the
service life of tailwheels and main tires with lower touchdown speeds but
again, few tuggies like to hang in the air waiting for the airspeed to
dissipate and the weight to be transferred to the wheels on gusty
afternoons.

Now, the Pawnee isn't by any means a perfect tow plane. It probably
consumes 80% of its horsepower pulling itself through the air leaving only
20% to tow the glider. However, I doubt VG's would help with that either.

Now, if we were talking about a candidate tug whose only shortcoming was a
high stall speed, adding VG's might make sense. PA-28 - 235's maybe?

Bill Daniels

"Land Shorter!" wrote in message
m...
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

At 17:00 30 August 2004, David Bingham wrote:
Be real careful about unsubstantuated claims for much
better
performance. Show me an unbiased independent appraisal
of

Several Genesis 2 owners used VG's on the wing root
and adjacent fuselage area (located at the high camber
point) They prevented the separation bubble from forming.
They do produce some drag, but solved the problem.
Later Bob Salvo showed us how to make a wing root &
fuselage fairing that did the same thing, but without
the drag of VG's. BTW the B-52 has them (VG's) all
over the outer wing panels just forward of the spoilerons
(no ailerons)
:) JJ who logged 2000 hours in the belly of the buff,
any other RN's out there?

(Land Shorter!) wrote in message om...
Actually Dave, vortex generators are WELL proven. They have been


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.

Actually VG's are of some use on laminar wings, especially those that
are sensitive to bugs,dirt,and rain. Keeps the boundary layer
attached rather than seperating. This may be of little use to glider
folk that need/want the last bit of L/D but sure helps the canards of
some power planes.
===============
Leon McAtee

Bill,

Thanks for the Pawnee education, good stuff, much of which I wasn't
aware. Though this whole discussion is a touch moot since that's a
certified plane I still stick to my guns that if you put a pilot in a
VG equipped Pawnee and one without nearly all would choose the one
with the VGs since they allow the pilot to land slower and safer (and
what pilot doesn't want that). As far as the tow speeds, that's all
up to the pilot, it wouldn't be the VGs fault if he got too slow and
caused issues with the tow VGs give slightly higher climb rates
because they increase the coefficient of lift at any given airspeed.

Speaking of the Pawnee....I use to own an Ercoupe (great little plane
for what it was designed to do BTW). It's designer, Fred Weick had an
autobiography called "From the Ground Up". It has great information
on the development of the Pawnee which was super revolutionary for
it's day (same as the Ercoupe). Fred Weick designed both as well as
the initial low wing Piper series. At the time he was also the
world's leading authority on propeller design. Anybody with an
interest in aviation history, especially early ag planes (future
glider tugs), would really love this book. And no, I don't sell the
book in case you were wondering I should though

Sorry, this is getting off topic. I did operate my Ercoupe as a
glider once though

Joa
www.landshorter.com