In article ,
(R. Wubben) wrote:

I've just bought a '62 Cessna 172 with the Horton STOL kit and madras
droop tips and have a question:
My dad took it up for the first time (it's in WI, I'm in NC) and was
curious about if these modifications change the "V" speeds in any
significant way...? Apparantly there is no change in the POH after
these modifications, but obviously there must be some difference.
Specifically how Vx and Vy would be different, best glide, and what to
approach at. He and the instructor were using 75-80 as the approach
speed (which seemed high to me). Does the sink rate increase noticably
with these modifications?

I fly 206s that have a Sportsman STOL kit (leading edge), VGs and the
WingX STOL wingtip extensions. There is a significant improvement in
the performance of the airplane with these mods, yet the only speed
change was a reduction in Vne with the WingX extensions.

As I understand the companies in their adds will make claims of
performance gains, but make no "official" claim of a change in a/c
performance negating a lot of expensive testing to get approval. Make
no claim and you don't have to prove anything.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html