Well, I have Micro Aerodynamics VGs on my C 170, and I'd never do it again.

The VGs removed the pre cursor buffet from the stall. Wing still stalls, but very little if any pre stall buffet.

I used to be able to work the airplane into a tight spot by working the buffet on short short final. Ironically, now with the VGs, I have to approach four to five mph faster to make sure it doesn't drop out from under me with no warning.

I HATE the things on this wing.

On a cub or scout wing...they are a distinct improvement, but at least on this Cessna wing (and tail) they are a uniquely BAD idea. The airplane was honest before, but you can't feel the stall now.

MTV

Mike
Should only take an hour to pull them off
Why do keep them on your bird?
Is it just the 170 wing on floats? Or does it do the same on wheels with more AOA
Gt

There are a couple of different STC holders on the market for the application of VGs. Micro's and ATS (also sold by Mid Continent, Cub Crafters, and BLR). There was a big soap opera that has been discussed here before on the origination of each of these entities so I will not bother with more details on that, but I have some experience through my job with certification of various projects and have compared both manufacturers. Micro takes a one size fits all approach, VGs on the wing at around 4% chord, and on the horizontal and vertical. VGs are one size on the wing and smaller on HT and VT. ATS has their VGs placed further aft on the wing, (larger VGs for larger chord wings, and smaller for smaller) and sometimes on the horizontal and vertical (smaller still). It just depends on the kit whether they are on the horizontal and vertical. The ones on the tail will help with effectiveness of the elevator and rudder. This effect is more noticeable on when the tail is small or not that effective to begin with. What MTV experiences with the pre-stall buffet is unfortunate, and most likely because the VGs are placed further forward on the wing than optimum. One size fits all doesn't always give the best solution. In my opinion, the ATS kits have more engineering work in them, but Micros are marketed better.

M6RV6 wrote:Mike
Should only take an hour to pull them off
Why do keep them on your bird?
Is it just the 170 wing on floats? Or does it do the same on wheels with more AOA
Gt

I don't take them off because they take the paint with them. If money was no issue, I'd install a Sportsman cuff, and get rid of the VGs. The cuff would cover the paint flaws.

The airplane on wheels is where I notice this most. Very slow touchdowns on floats aren't that necessary in most situations, since seaplanes decelerate well once on the water.

MTV

Terryd23 wrote:I put VG's on my 1976 172M.

Tail or wing?

mtv wrote:

M6RV6 wrote:Mike Should only take an hour to pull them off
Why do keep them on your bird? ...

I don't take them off because they take the paint with them. If money was no issue, I'd install a Sportsman cuff, and get rid of the VGs. The cuff would cover the paint flaws.........

Nobody would see the missing paint on the top of the wings on a float plane except you, when you're refueling. If they were a detriment to my flying on my airplane, they'd be gone in a heartbeat.

Nothing some rattle can white wont fix!

Make that yellow....

Gump

Gump,

Yer screwing up my rationalization for justifying a Sportsman kit.....

I was once told by a really smart aerodynamics engineer and test pilot that "VG's are something you use to fix some ugly aerodynamics that you created with a faulty design...."

MTV

mtv wrote:Well, I have Micro Aerodynamics VGs on my C 170, and I'd never do it again.

MTV

I took VG's off my Camberlift 185 to put on a Sportsman Kit.
The VG's will not go back on, and I'm still on the "Fence" whether I like the Sportsman Kit!
Not saying both are'nt good products, just miss the way it used to fly

My 18A is a bit nose heavy. I like it that way because I can load a lot of crap in back & be well within CG limits.
Bad thing is the horiz.stabs are always trying to pull the tail down... drag. She flies faster with a load.

I put VGs on, close to the LE, as per JerryB, and the resulting lift on the trailing edge tried to lift the tail more, making me have to crank the horiz.stab down more. More drag. They cost me about 5MPH in cruise, and I didn't feel any difference in wing performance. After the rebuild, I didn't buffet or stall, just mush & lose altitude. (too) Slow turns, again just mush, nose drops & she's flying again. I was mainly looking for better aileron response, didn't feel (much) difference there either.

Yesterday I peeled 'em off (magic 3M double sided tape is wonderful). Went for a fly & was able to crank my horiz.stab back almost 3 cranks. Got my 5 MPH back again. I reckon my wing is good.

Couple other things I'm dickin' with, life is good!

Had friend of mine put VG's on BOTTOM of Horizontal Stab -- he said it did wonders for elevator effectiveness at low speed landings. Added VG's on vertical fin for more directional control --- This is on a early-mid 1950's Cessna 180. Nothing on wing except Sportsman STOL kit .

SkyTruck wrote:

mtv wrote:Well, I have Micro Aerodynamics VGs on my C 170, and I'd never do it again.

MTV

I took VG's off my Camberlift 185 to put on a Sportsman Kit.
The VG's will not go back on, and I'm still on the "Fence" whether I like the Sportsman Kit!
Not saying both are'nt good products, just miss the way it used to fly

I still have them under the Stab and on the Vertical, and agree they perform well there.
This is especially true when flying with a typical mid-to-forward CG.
Although I still need to remove them to stay compliant with the STC

182 STOL driver wrote:Had friend of mine put VG's on BOTTOM of Horizontal Stab -- he said it did wonders for elevator effectiveness at low speed landings. Added VG's on vertical fin for more directional control --- This is on a early-mid 1950's Cessna 180. Nothing on wing except Sportsman STOL kit .

What's the paperwork situation on that? The NMicro VG kit for C180/185 shows VG's on the horizontal vertical & wings. Might it be possible to get a field approval for just the horiz/vertical part of the install?

182 STOL driver wrote: Had friend of mine put VG's on BOTTOM of Horizontal Stab ....

I believe that's the standard location for them-- never seen one with VG's on the top....

hotrod150 wrote:

182 STOL driver wrote:Had friend of mine put VG's on BOTTOM of Horizontal Stab -- he said it did wonders for elevator effectiveness at low speed landings. Added VG's on vertical fin for more directional control --- This is on a early-mid 1950's Cessna 180. Nothing on wing except Sportsman STOL kit .

What's the paperwork situation on that? The NMicro VG kit for C180/185 shows VG's on the horizontal vertical & wings. Might it be possible to get a field approval for just the horiz/vertical part of the install?

I doubt you'd get that field approved. ANY aerodynamic mods have to go to Engineering these days. It's possible that they'd issue a field approval, but.....

And, that configuration isn't in compliance with the STC, so.....

MTV

I fly a 1975 172m. It has the factory camber lift wing and the Horton aileron seals, stall fences and flap gap seals. I play a lot on the gravel bars of the Fraser river so i was look to land slower. I usually run about 2000lbs and cg at 42.5 to 43, middle of the envelope. I went up to altitude and spent a whole bunch of time doing stalls in different setups. It quickly became clear that on my plane the horizontal stab would always break loose first. This caused the wing to lose angle of attack and the nose would drop in a classic stall. I thought vg's on the tail would stop this so i phoned the micro vg people and asked if i could just install the vg's on the tail only and the answer was NO. I bought and installed the complete kit and i am very happy with it. There is way more air staying on the control surfaces at low speed and it is noticeable on the control feel. With my new angle of attack capability i can now land tail first and still have the mains 18" in the air, some caution required. A friend put them on his 170 and they added better low speed control but did not really allow him to land much slower because if he increases his angle of attack to the stall he will land tail first with the mains 3ft in the air. Extended gear and 31" wheels would change help him. VG's on the bottom of the horizontal stab make a big difference, so does a 50lb water bag at the back of the extended cargo bay.
KenW

175 magnum wrote:I fly a 1975 172m. It has the factory camber lift wing and the Horton aileron seals, stall fences and flap gap seals. I play a lot on the gravel bars of the Fraser river so i was look to land slower. I usually run about 2000lbs and cg at 42.5 to 43, middle of the envelope. I went up to altitude and spent a whole bunch of time doing stalls in different setups. It quickly became clear that on my plane the horizontal stab would always break loose first. This caused the wing to lose angle of attack and the nose would drop in a classic stall. I thought vg's on the tail would stop this so i phoned the micro vg people and asked if i could just install the vg's on the tail only and the answer was NO. I bought and installed the complete kit and i am very happy with it. There is way more air staying on the control surfaces at low speed and it is noticeable on the control feel. With my new angle of attack capability i can now land tail first and still have the mains 18" in the air, some caution required. A friend put them on his 170 and they added better low speed control but did not really allow him to land much slower because if he increases his angle of attack to the stall he will land tail first with the mains 3ft in the air. Extended gear and 31" wheels would change help him. VG's on the bottom of the horizontal stab make a big difference, so does a 50lb water bag at the back of the extended cargo bay.
KenW

No offense, but exactly how did you determine that your tail was stalling, and not your wing?

A tail stall is a VERY nasty event, and the manufacturers generally design their airplanes such that you simply can't achieve a true tail stall.

I'd also like to see some video of that C170 with its tail wheel on the ground and wheels 3 FEET in the air.

How about posting some. Pics?

MTV

mtv wrote:....I was once told by a really smart aerodynamics engineer and test pilot that "VG's are something you use to fix some ugly aerodynamics that you created with a faulty design...."

You could say the same thing about a leading edge cuff, wing extensions, gap seals, or any other aerodynamic mod.Or any airplane mod in general, which is correcting a faulty design (such as not enough horsepower, etc).

The pricing for a few pieces of plastic on the underside of the tail seems really steep to me ($1500). I don't want VG's on the wing. Is there anyone with a tail-only STC for a terrestrial price?

Might be time to took at doing a one time STC for your application. Might not be that much money, but you would have to be patient working with the FAA. Just a thought.