I recently installed some Experimental VG's on my Horizontal stab only. My tail has always stalled before my wing and this mod is supposed to help alot with my particular plane. Here's a write up I did on another forum.



On my initial takeoff I did my normal thing and the first thing I noticed was the tail came up extremely quick. Climbout felt normal. I went to 3500ft msl to try and get out of the heat. During the climb the stick was farther forward than it used to be.

Once the OAT got down to 75 or so I started doing various stalls. I started with a power on and right away I noticed that there was a noticeable buffet and break which I never used to have. Not sure of the speed as I was damn near vertical.

After that I went into slow flight I was cruising easily at 45mph IAS flaps UP. Flaps down I was able to stay level at 40ish. Before anything below 45 and I was falling out of the sky.

Next was power off. Flaps up before power off stall was 44ish. After was 40 with a noticeable buffet and break once again more like a Cessna. Flaps down stall was 35-36. Overall I decreased my stall speed by 4-5mph.

After the stalls and falls I opened her up and headed back to the airfield. The stick in cruise is farther forward now than it used to be. I flew my first approach at my normal speed of about 55 on final. Pitch felt way more solid. I did a stop and go. On the go I held the brakes and shoved the stick full forward with the flaps at 15 degrees and I was able to lift the tail and hold it level without moving. I could NEVER do that before. I let off the brakes and the tail dropped some but I was able to pull it off slower for sure. On my second approach I flew it at 50 which before would work but without a lot of power I would touch TW first. 50 felt great so I tried my next one at 45 hanging on the prop which I anticipated a TW first landing and plop onto the mains which happened but it was about the same as flying an approach at 50 before.

I can't wait to get my taller gear on. With that I think I can comfortably fly an approach at 45 to get in super short.

Keep in mind these numbers are just my numbers on my indicator. As a trend I was able to fly approx 5mph slower all the way around which in the world of STOL is pretty huge. I'm happy with the results and it was pretty cheap. I think I'm gonna go ahead and put them on my wings next and try it.

I went out today to do some more playing after installing my VG's on the tail. I'm sold on this mod. It helped alot with the slow speed handling. I spent over an hour flying around in terrain low and slow. My approaches are easily 5mph slower which makes a huge difference when trying to get in short. I set her down a couple times today and also flew around for a while with the doors open.

Love flying with the doors open

Nice write up.
Which VGs did you use?
I am going to put the little plastic ones on my plane soon & keep wondering how you come up with proper placement.

Thanks for sharing the good report!

I've been toying with the idea of putting VG's on my C150/150TD. I like the looks of those clear plastic ones from STOL-Speed and the price is sure right, but since it's a certificated airplane I'm pretty much stuck with Micro's as the only option. Two things holding me back:
1) I've heard of both good and indifferent results with the cessna wing, esp with reducing the stall speed. Most cessna folks say to get a leading edge cuff instead, but since the Sportsman cuff costs about $2K just for the kit I'm more inclined toward the VG kit at about $700. Mine stalls (power-off,full flaps) at around 40 IAS which is already pretty good. The VG kit also includes some for the vertical stab-- I have plenty of low-speed aileron authority but my airplane is kinda weak in the rudder department, this would be one area where I'm pretty sure there'd be an improvement.
2) I self-fuel with gas cans & the VG's go right where I stand the gas cans on the wing. I'm sure it's not an insurmountable problem but it looks to be a PITA & I'll probably be replacing flattened-out VG's on a regular basis.

I put them under my stab only and noticed much more control on landings... I used the small plastic ones and they're great... I will go do bunch of stalls to see how they make a difference. BCT

Did you put VG's on your leg too??

Jiminy Christmas AvidFlyer! What did you just miss in that first photo?

Nice report! Sounds like a great improvement. That was really good information.

Did you put VG's on the top and bottom of your horizontal, or just the bottom? If the tail came up faster on takeoff, that would usually only happen with VG's on the top, and if it allowed you more stick-back pitch control at the slow end it would indicate VG's on the bottom.

Skystrider wrote:Jiminy Christmas AvidFlyer! What did you just miss in that first photo?

Nice report! Sounds like a great improvement. That was really good information.

Hahaha my intent was to try and show I had some of myself out in the slipstream but I guess I scared everyone by showing too much skin. EZ flap the VGs are only on the bottom.

emflys wrote:Did you put VG's on your leg too??

that's not his leg.

then he BETTER put VG's on it!

Avidflyer and BCT I am very curious how you make out. Avidflyer with the vg's on the wing and BCT on the H Stab.

I just purchased the Stolspeed kit and plan to put them on someyime this weekend if my hangar doesn't get blown away in Irene

I would like to achieve a little less back pressure on the stick when landing as I am somewhat nose heavy and at the forward edge of my CG range. Right now I'm pretty much going to full nose up trim on landing. I'd rather not add weight in the rear if I can avoid it.

A knee without some scars? Where did you grow up, Sonny? Did ya have a protected childhood?

lc

Avid, did you do any placement testing before gluing them on? What distance on the chord of the wing did they end up being placed at?

I'm also curious...Did you put any on the top part of your Hor stabilizer, or only the bottom?

I have a new set of Hall Bros. VGs for lightsport/experimental aircraft...I'm impressed with the quality. They are metal, extremely light and are even formed to have a curve to match the curve of that part of the wing. Will be testing them soon, as soon as a new prop gets cleared from Customs.

I have a RANS S-7LS (factory built lite sport). Modifications are not possible. Would it be worth re-registering as an experimental. I would like to add VG's and maybe 8.50's or 26". Advantages or disadvantages please. Self maintenance is not a big issue with me.

Guys I didn't put them on my wings only my stab. From everything I've read they don't help much on the wing in this type of plane unless you can get it into a full deep stall which I cannot because of my forward CG. Here's a flight write up I did copied from another forum.

Well I finally got around to installing these things today. I put the tips of them at 4" from the gap between the horizontal and elevator. It's a lot of further forward than any other airplane I've seen. This was per the instructions I received via email from Stolspeed and it's also what he has published on his site so I went with it. Here's a bit of tutorial on the install.

First off because they were made for a wing they have a very slight curve and the instructions call for a slight rub on some sandpaper to flatten them out some to go on the flat surface of the stab. I used 220 and just a couple of passes.

So step one...sand sand sand, then wipe on a rag of denatured alcohol, then set aside.

Luckily the Stolspeed comes with their adhesive laser cut to fit the foot of the VG.
You have to peel the first layer off the 3M adhesive with the tip of an exacto. They come right off.

Next stick the VG to the adhesive. All of this is somewhat time consuming but not too bad. I did all of this at home in about an hour.

I used a pencil to mark out 5 or 6 marks at the 4" point. Rather than draw on my fabric I used some painters paint to make my line.

The stolspeed VG's come with two templates in the kit. The one for the stab is 30mm spacing. Once you get going with the template the actual install goes pretty quickly. I put 36 on each side. The adhesive they use is a 3M product and works well. It's fairly easy to peel one off if you don't' like the placement. Here are some pics of the install.

The sanding, cleaning, sticking station...this part is a bid tedious but not too bad.



Some shots of them installed before I pulled my tape line.







And now what you've been waiting for...well do they work??

Conditions: OAT 98 degrees Winds 10 degrees off at 7kts Field Elevation 120ft Density Altitude 3200ft Empty wt 535lbs 9 gallons of fuel on board

On my initial takeoff I did my normal thing and the first thing I noticed was the tail came up extremely quick. Climbout felt normal. I went to 3500ft msl to try and get out of the heat. During the climb the stick was farther forward than it used to be.

Once the OAT got down to 75 or so I started doing various stalls. I started with a power on and right away I noticed that there was a noticeable buffet and break which I never used to have. Not sure of the speed as I was damn near vertical.

After that I went into slow flight I was cruising easily at 45mph IAS flaps UP. Flaps down I was able to stay level at 40ish. Before anything below 45 and I was falling out of the sky.

Next was power off. Flaps up before power off stall was 44ish. After was 40 with a noticeable buffet and break once again more like a Cessna. Flaps down stall was 35-36. Overall I decreased my stall speed by 4-5mph.

After the stalls and falls I opened her up and headed back to the airfield. The stick in cruise is farther forward now than it used to be. I flew my first approach at my normal speed of about 55 on final. Pitch felt way more solid. I did a stop and go. On the go I held the brakes and shoved the stick full forward with the flaps at 15 degrees and I was able to lift the tail and hold it level without moving. I could NEVER do that before. I let off the brakes and the tail dropped some but I was able to pull it off slower for sure. On my second approach I flew it at 50 which before would work but without a lot of power I would touch TW first. 50 felt great so I tried my next one at 45 hanging on the prop which I anticipated a TW first landing and plop onto the mains which happened but it was about the same as flying an approach at 50 before.

I can't wait to get my taller gear on. With that I think I can comfortably fly an approach at 45 to get in super short.

Keep in mind these numbers are just my numbers on my indicator. As a trend I was able to fly approx 5mph slower all the way around which in the world of STOL is pretty huge. I'm happy with the results and it was pretty cheap. I think I'm gonna go ahead and put them on my wings next and try it.

I got my VG's from http://www.stolspeed.com He's a nice guy, the instructions are clear, and the product is nice. Sheesh I wish I could leave this thing alone.

JG is a great guy and gives good support.

Just be glad that adhesive is laser cut!! Cutting all those VGs out on adhesive took hours with an exacto. I developed the laser cut adhesive on our laser cutter/engraver at my business for John and he has now implemented them in the kits. Its sooo much easier.

The adhesive is great too - just push on the VG sail for few seconds and they pop off. But you'll never lose a one!!

His site has lots of info and directions.

AvidFlyer wrote:Guys I didn't put them on my wings only my stab. From everything I've read they don't help much on the wing in this type of plane unless you can get it into a full deep stall which I cannot because of my forward CG.

I've heard reports from other RR owners that their stall speed and take-off distance have decreased significantly after installing VGs. Based on these positive reports, I decided to get some VGs for the RR. So, your statement here is very interesting to me, since except for the flaperon, our wings are very similar.

Avidflyer:
Nice report, did you put them on bottom of stab only?
EZFLAPS comment seems to make sense to me on VG placement

EZFlap wrote: If the tail came up faster on takeoff, that would usually only happen with VG's on the top, and if it allowed you more stick-back pitch control at the slow end it would indicate VG's on the bottom.

Next question would be, why wouldn't you put them on top & bottom of stab??

senior wrote:Next question would be, why wouldn't you put them on top & bottom of stab??

I'm equally interested in this question, sent out a few email inquiries but no replies yet.