The International Cessna^® 170 Association

Kyle Wolfe wrote:Recently saw this on u-tube showing how to intsall the sportsman STOL kit...

http://youtube.com/watch?v=h1tfjmTpU0g

Hey, that's my video. Yep, finished the install and still testing the changes. Unfortunately the only real testing I did prior to the kit was glide ratio. Since they advertise 13:1 glide ratio with the kit, I thought that would be the easiest improvement to verify. Unfortunately, I'm only getting 9.5:1 glide ratio with the kit, that's only slightly better than the 8.8:1 I got prior to the kit. I'm still waiting to see how it does on floats this summer. Before I had to get up above 50 MPH before it would start flying on floats. Hopefully it will be quite a bit lower now. You will like how slow the plane can safely fly. I can cruise above the runway in ground effect at 28 indicated, 32 MPH on the GPS. If you find a headwind in MX, you'll be able to go plenty slow for the people to hear you. The best thing is when it does stall, it's so mellow and easy to correct that very little altitude is lost. Just have plenty of time available for the install. They aren't kidding at least 40 hours for an experienced person and 60+ if it's the first Sportsman you've put on. There are over 400 rivets that have to be drilled and counter sank AFTER everything is trimmed and positioned.

I have been involved in the installation of the Horton and the sportsman. They have different contour blocks and the Horton has only 2 leading edge pieces per wing. The horton also has the glass wing tips in the kit. Speaking from experience the Horton is by far the best bang for the buck.

Sorry Corey for not giving you credit! Thought I recognzied that bird. And I enjoyed your son's little show too.

Good idea to have taken the video of the install. Pictures are truly worth a thousand words.

And I enjoyed the music - it will be stuck in my head the rest of the day

Paul

alaskan99669 wrote:

Kyle Wolfe wrote:Recently saw this on u-tube showing how to intsall the sportsman STOL kit...

http://youtube.com/watch?v=h1tfjmTpU0g

Hey, that's my video. Yep, finished the install and still testing the changes. Unfortunately the only real testing I did prior to the kit was glide ratio. Since they advertise 13:1 glide ratio with the kit, I thought that would be the easiest improvement to verify. Unfortunately, I'm only getting 9.5:1 glide ratio with the kit, that's only slightly better than the 8.8:1 I got prior to the kit. I'm still waiting to see how it does on floats this summer. Before I had to get up above 50 MPH before it would start flying on floats. Hopefully it will be quite a bit lower now. You will like how slow the plane can safely fly. I can cruise above the runway in ground effect at 28 indicated, 32 MPH on the GPS. If you find a headwind in MX, you'll be able to go plenty slow for the people to hear you. The best thing is when it does stall, it's so mellow and easy to correct that very little altitude is lost. Just have plenty of time available for the install. They aren't kidding at least 40 hours for an experienced person and 60+ if it's the first Sportsman you've put on. There are over 400 rivets that have to be drilled and counter sank AFTER everything is trimmed and positioned.

Yep... that kid, did a good job on his performance....
In fact corey, sportsmans is my first option on the STOL kit that have in mind, and maybe will install the VG on the leading edge afterwards. Do you thing that would be a good idea? What you guys think?

Be careful how you spend your money. VGs don't do much, if anything, for a Cessna wing. They are gangbusters on most Pipers but not on Cessnas.
However, the VGs on the horizontal stabilizer of tail wheel Cessnas seem to improve low speed elevator authority. If you decide to go with them, I suggest you get some very accurate before and afer air speed figures.

blueldr wrote:Be careful how you spend your money. VGs don't do much, if anything, for a Cessna wing. They are gangbusters on most Pipers but not on Cessnas.
However, the VGs on the horizontal stabilizer of tail wheel Cessnas seem to improve low speed elevator authority. If you decide to go with them, I suggest you get some very accurate before and afer air speed figures.

Now that you mentioned, I was thinking and considering VG's because a friend installed those on his Piper tripacer and improve a lot its stol performance. Wonder why could be that much difference on the performance of the VG's on the piper and the cessna wing?

As matter of fact, he only mentioned that it was improved the aileron control and handling on the stall practice with the VG's on his tripacer.

Hi,

I put VG's on my 1958 tailwheel 172 and wish I had my money back. I too was intrigued by the difference that I had seen first hand on a Super Cub but the difference they make on the Cessna wing is just not worth it in my opinion. They may be better on a Cessna wing with a STOL kit but I don't know for sure.

My friends that did the V.G. testing on the Cessnas tried them on the C170, C-180, and C-182. Same results on all of them, which is understandable since all the wings are essentially the same aerodynamically. The sole improvement was the improved low speed authority on the elevators. The guy in charge of the testing is a retired aeronautical engineer.
As I previously mentioned, everyone agrees they're gangbusters on a super cub.

Be careful how you spend your money. VGs don't do much, if anything, for a Cessna wing.

Well, it depends on what your looking for. If you pay any attention to the the development and the purpose of Vortex Generators - VG's, is to improve or direct the laminar flow over the wing and flight controls. VG's have been used on airplanes and helicopter for 40 years, look at the wing of a 737 or a tail boom of a Bell 212 or 412. VG's are used to correct airflow designed errors and improve aircraft performance.

The two best known kits are (Boundary Layer, sold by Cub Crafter's and Micro Aerodynamics). both achieve similar results. It can be argued that you want to see better numbers, but that isn't whats being sold.. What is sold is better flight control performance, because of improved, and directed airflow. The biggest beneifit of the VG's is that they save lives. From the point of trying to get a VG equip aircraft to stall, it is very gentle with little to no wing drop, something that won't happen in a clean wing 170, and you would be very hard pressed to get a VG equipped aircraft to spin or stay in a spin. Our preference is Boundary Layer VG's , due to placement further back on the back on the wing, compared to the Micro's. I've know numerous people who have removed the Micro's and replaced them with the Boundary Layer kit on 180/185 aircraft. Both the Green Bean and the PA-18-95, have the Boundary Layer and yes both are STC'd approved.

Green Bean wrote:

...purpose of Vortex Generators - VG's, is to improve or direct the laminar flow over the wing and flight controls. VG's have been used on airplanes and helicopter for 40 years, look at the wing of a 737 ....

Careful when making such comparisons, however. VG's on jet aircraft are usually for the opposite speed-regime. VG's on most Lears, Boeings, etc etc are primarily to prevent boundary separation at HIGH speed.... not low.

Gahorn, As I said," to make improvements"... And while were on that subject, are you going to come to Alaska this summer, or did you forget?