Kelleher Lark JK-1A
I made my first flight with the Stolspeed vgs installed today. It was only about an hour due to rain coming in. I must say I am VERY pleased with the performance numbers. I am flying a Kelleher Lark. Model JK-1A. (photo attached, prior to vg install.) A/C specs. 17ft long, 23ft wingspan, 100hp continental, NACA 2 R2 12 airfoil, 48in chord, no dihedral.
I installed the vgs at 4.75in from the leading edge. Installation was easy and straight forward. The instructions on the website were good. (it took longer to cut out the tape than to do the actual install)
Stall speed BEFORE install. 57mph IAS. Deep stalls were impossible to keep a wing from falling off even with full rudder inputs. Ailerons were ineffective.
Stall speed AFTER install. 47mph IAS. Deep stalls were fairly easy to hold with rudder AND I had some aileron control even in a full stall. Slow flight control was very responsive and easy to handle. I had done about 8 or 10 stalls just to comfirm the numbers. All were power off stalls and all were 45 to 47 mph IAS.
I was somewhat sceptical about what these "little feathers" would really do. But a 10mph drop in stall speed is truly impressive. I made 3 landings today and the hardest part was slowing the plane down. I am used to flying a 75-80 mph approach. Now I need to learn how to fly final at 65mph. I am looking forward to putting some on my horiz. stab. just to see what they do.
You have a great product. I would recomend them to anyone wishing to improve slow speed performance of their aircraft.