Stolspeed VG's

[500AGL]

IMG_0158.jpg If you zoom in on these photos, you can see the VG’s on the slope of the leading edge. We can ask Virgil to put a straight edge up and measure back, but as I recall and looking at the photos I’m thinking it was 2-2.5” back from the LE, horizontally.

That would equate to 3.5-4% of the 60” chord.


DSC03727.jpg

[AKKen07]

Right on, thanks for the intel. It’s encouraging that so much variation seems to yield good results.

Gosh that Patrol is a good looking airplane. But I definitely don’t want to build another plane… definitely…

[rodsmith]

Completed installing Stolspeed VGs on the wings yesterday at 7% chord and had my first flight today with them. You have to experience the difference with them. I normally take off with flaps 2, lift the tail at around 30k and lift off at 50k. I didn't get the tail up to level before leaving the ground, according to Flysto.net that was at 37k. My Vso has been a very repeatable 46k. I did four flaps up stalls and they all occurred halfway between the 41 and 42 on the airspeed tape. With flaps 2 the stall was occurring at 39k. Flaps 3 and 4 I could only get to 38k with full elevator and it wouldn't stall, just developed a very high sink rate. I thought I had ordered Vgs for the stabs at the same time but turned out I didn't, so I had to place another order. They are supposed tp arrive tomorrow, can't wait to see what they do. Hopefully with them in place I can get the plane to stall at flaps 3 and 4. Lots of testing to do now. I did not check my cruise speed or top speed. With what they have done for the stall speed and the overall solid feel of the airplane in slow flight, I don't mind sacrificing a couple knots on the top end.

[Battson]

Glad to hear you like them Rod, this is much the same as my memory of first flying with them. They transform the aircraft. I would never want to own a Bearhawk without Stolspeed VGs installed.

[Nev]

Completed installing Stolspeed VGs on the wings yesterday.....

Excellent results Rod.

A interesting exercise is to perform a number of stalls with power ON to keep the elevator authority going into the stall. It can change the outcome markedly with a much higher pitch attitude (28° in my case) before dropping wing. Having an aft CG on mine also keeps the elevators active at low speed and changes the stall characteristics. My lowest stall speed (F3 or F4) at 2200 lbs is also around 37-38 KIAS.

Good work !

[BarrysLSA]

With my LSA, I am easily getting in and out of a grass strip in 400 feet or less at 80 degrees with a stock o200A, Catto prop and Vetterman exhaust. Not too shabby. It handles very well at low speed with no complaints. The stall is a non event and very docile but it does stall pretty much across the wing as it does not have washout. I flew other small planes with VG's and was impressed. I bought a set of Stolspeed's and was wondering if anyone has used them on the LSA. If I can make it land a few kts slower and not lose any cruise speed for less than $200, I am all in. If I place them at 5 percent as Stolspeed suggests, this will be 3 inches back from the LE. I think 4 percent would be be better for this Riblett airfoil. This would be 2 1/2 back. I wonder if placing them that far forward will affect cruise speed.