Customers: These VGs Are Cheap Way to Enhance Aircraft
Performance and Safety
If Harrison Designs, LLC is right,
the most affordable way to increase performance and safety is to
add after-market vortex generators. According to Harrison, most
customers see stall speed reductions of 4-12 mph and decreased
takeoff and landing distances of 10- to 30-percent with no
noticeable loss in cruise speed. Website testimonials indicate that
when Landshorter! VGs are added customers are reporting significant
improvements in low speed handling and response and feel their
airplanes are much safer.
"As soon as I put VGs on my Rans S-7 I noticed a big improvement
in low speed handling as I went around the pattern, the stick just
felt much more solid," said company President Joa Harrison.
"My first landings with VGs were floaters, I was coming in too
fast. Once I realized what was happening I was able to drop my
approach speed down 15 mph and then consistently make shorter and
bounce-free landings." Harrison continued, "What really amazed me
was what they did for my stall speed, it dropped from about 35 mph
down to a solid 27mph. With a little power and full flaps I can
safely make turns in any direction at speeds in the low 30s. For a
plane with a cruise speed of 115 mph it's really incredible to be
able to go that slow and not feel like it's falling out on
you."
Harrison's website explains that vortex generators are small
fin-shaped pieces that are temporarily taped or permanently glued
to the upper front portion of an aircraft wing just behind the
leading edge, usually around the 10-percent chord point. They spin
the air allowing it to stay better attached at higher angles of
attack. By increasing the wing's angle of attack before the air
separates the aircraft's stall speed is reduced and the pilot is
able to takeoff quicker, climb to altitude faster, and land
shorter. Vortex generators have been shown to enhance nearly all
airfoils and Landshorter! vortex generators are specifically sized
and shaped to provide the optimum mix of effectiveness and low
drag.
Harrison Designs, LLC provides a complete manual with all the
templates needed for most general aviation aircraft.
"I tried to keep things as simple as possible for folks so they
would be comfortable with their purchase," said Harrison. "They're
really easy to apply, it usually only takes me about an
hour-and-half for a whole kit when I use tape."
His vortex generators are usually first applied with
double-stick tape and then later permanently applied with one of
Harrison's recommended glues. "When I tell people about my 100%
satisfaction guarantee policy they usually ask how they would take
the VGs off if they had to." Harrison explains that if tape is used
then a little bit of kerosene or rubbing alcohol will remove the
adhesive without damaging most paints or coverings.
He also notes, "Normally what happens is folks take them off to
glue them permanently and then decide to go around the pattern once
just to see what it was like before they put them on. It scares
them pretty bad because they've gotten use to the great handling
with the VGs and so they land and glue them on right away."
The design of Landshorter! vortex generators is very efficient.
Harrison says, "they're molded from a very clear and attractive
G.E. Lexan, the same stuff used in bulletproof glass. Because
they're molded instead of made from heavier aluminum extrusions
like the other guys use we're able to design in a curve to the VG
base that better matches the curvature of the airfoil and provides
for better adhesion and a more efficient product. They are also
lightweight, a complete set of 100 VGs weighs less than an
ounce."
"Out of several hundred sets I've sold now I've improved every
plane that's used my VGs. Even though I tell folks I'll give them
all their money back including shipping if they don't like them I
haven't had a single set returned yet from anyone that's put them
on their plane." According to the company literature VG Guy vortex
generators are for experimental aircraft use only or for use with
certified planes with FAA field approval.