Stolspeed VG's

[Utah-Jay]

I am a believer in results, here are some real world results with the Hall Brothers VG’s on my Companion. The Flysto.net says I have done 8 touch & go’s, but I have never done a touch and go, so the data is a bit skewed from doing low passes over strips for inspection purposes. The dots in the black circle are some of the so-called touch & go’s, but they are still calculated in the average so the average is higher than actual touchdown speeds.

Debate all ya want, here are results!
IMG_1116.jpg

[Battson]

How far back did you place them?

I understand that they are best positioned so that when the wing is at the highest angle of attack, the VG is fully exposed to the oncoming airflow i.e. at the highest point of the wing. That's how I arrived at my recommended location for install, and practically it's proved a winner. You can apply the same approach with your aerofoil, all you need to know is the AOA at stall (in landing configuration). You want them at the highest point of the wing, when it's at the stall AoA.

My understanding comes from a lot of pre-reading, watching other guys testing on Youtube, practical experience on my own plane (the modified NACA Bearhawk-A aerofoil), and discussing the Breeden's experience from testing VGs on their Cubs in AK. Bob Breeden reached the same conclusion as I did, highest point on the aerofoil at stall AoA.

I note that the % chord would vary based on the aerofoil. So if Cub guys are saying 12% and Vans guys are saying 7%, that doesn't necessarily mean it would be ideal for the Bearhawk. We know people have tried them further back on the Bearhawk and it yielded poorer results.

You want one straight line across the wing, not a staggered arrangement.

I would follow STOLspeed's recommendation about spacing, and use the templates provided. They specify tighter spacing in the outer section of the wing.

Here's my post about where I installed mine:

https://bearhawkforums.com/forum/flying-and-flight-testing/2251-who-is-using-vgs/page3

[Rspencer]

Bearhawk recommends 3-5% in a text with them today for the 4A. What’s everyone thoughts on 3% in front of the ailerons with the tighter spacing, and 5 % on the rest of the wing? Further assist in keeping the ailerons functional during a stall?

[Utah-Jay]

How far back did you place them?

I can measure tomorrow, they are placed a certain distance from a Rivet line

[Fred Williams]

As per FlySto.net my average touchdown speeds is 38 mph IAS, and that includes all the early landings when I was learning the plane some of which were over 60 mph IAS.

My typical landing nowadays is 35-37 mph IAS.

Slowest was 32 mph and the plane was still flying.

I never flew without the VG’s, never felt the need after I saw the data that Chris sent me. And they were a lot easier to install prior to hanging the wings

How far back did you place them?

[Utah-Jay]

How much difference did they make? What are your stall speeds with and without? Where did you place them. I've got a Patrol but inquiring minds want to know... TIA

As per FlySto.net my average touchdown speeds is 38 mph IAS, and that includes all the early landings when I was learning the plane some of which were over 60 mph IAS.

My typical landing nowadays is 35-37 mph IAS.

Slowest was 32 mph and the plane was still flying.

I never flew without the VG’s, never felt the need after I saw the data that Chris sent me. And they were a lot easier to install prior to hanging the wings

[Fred Williams]

I saw a YouTube video of a Patrol owner who tried them and Stolspeed. His biased opinion was stolspeed was slightly better for a handful of reasons. Based on that and MANY other Stolspeed recommendations and writings, I went that route. Got them painted tonight. So ready to go on tomorrow.

I've recently received the StolSpeeds for my Patrol as well. Haven't painted them yet but am trying to gather info on where to place them. I'll be checking back here to see if anyone can provide good guidance on where to place them and what it did for the performance of their Patrol. TIA

[Rspencer]

I saw a YouTube video of a Patrol owner who tried them and Stolspeed. His biased opinion was stolspeed was slightly better for a handful of reasons. Based on that and MANY other Stolspeed recommendations and writings, I went that route. Got them painted tonight. So ready to go on tomorrow.

[Fred Williams]

Based on my touchdown speeds in my Companion, I think you guys are missing out not using the Hall Brothers VG I am using. I am not the first to use them as the testing was done by a Patrol owner who is not building a Companion.

How much difference did they make? What are your stall speeds with and without? Where did you place them. I've got a Patrol but inquiring minds want to know... TIA

[Utah-Jay]

Based on my touchdown speeds in my Companion, I think you guys are missing out not using the Hall Brothers VG I am using. I am not the first to use them as the testing was done by a Patrol owner who is not building a Companion.

[jaredyates]

If you've seen a different number it is probably worth reaching out to verify. I don't have high confidence in my notes being right.

[Rspencer]

Ok. Good to know. I saw his old YouTube video on his 5 wing (very different) and he decided 5% wasn’t good but 7% was. Obviously lots of conversation in this thread alone, but not a real consensus on the 4A wing location. Anyone else agree for 3%. And anything special for the horizontal stab location?

[jaredyates]

I don't want to speak for Virgil but I know he's busy. This question came up at Oshkosh and I wrote down in my notes that his answer was 3%. I was thinking about installing them but have been holding off for now. I remember him saying it was farther forward than the starting point but that they had tested a few locations and liked that point.

[Rspencer]

So, what is the consensus on the best % of chord to install the STOLSPEED VG’s on the 4A wing? Got a set and got them painted today. Will put them on tomorrow or day after.

[BarrysLSA]

I just removed the VG's from my LSA. Last year while flying to Lakeland, I landed at an airport with a serious gusty crosswind - at least 15 gusting to 25- and managed to land on pavement with no issues. Yesterday I encountered a lesser gusty crosswind and it was a chore to keep the airplane planted on the ground. With every gust it wanted to fly when I wanted it to stay on the ground. Another problem I had was it was almost impossible to do a 3 point landing. I would run out of elevator when flying solo. Of course, I could put VG's on the tail to help that but the crosswind episode helped me decide.