Skyranger

Yesterday I started the day by testing my Sky Ranger without VGs: stall clean, small flaps, full flaps, no throttle, and with 3,500 RPM, plus landings in the same configuration. Then I mounted the VGs according to your advice, 7% chord from the tip of a VG, and flew again.

First of all, to my surprise, I noticed a much bigger stall speed difference at 3,500 RPM than with no throttle. The plane was simply hanging on its prop at about 50 km/h. To be honest, although it was still stable, I didn’t have the courage to push further because the nose was higher than I had ever seen before.With no throttle, the difference in stall speed was still clearly noticeable, though smaller, about 4–5 km/h less before a gentle and very short nose drop.

So, coming back to the airfield, I assumed, “OK, there’s clearly some difference, though not that dramatic after all.” I was wrong. The real difference was during landings. It felt like flying on an air cushion. For the first time in a Sky Ranger, I was able to touch down below 60 km/h, keeping 70 km/h on approach. I wouldn’t advise anyone to try it, but I have to say it felt very safe flying slowly with full flaps and a little throttle, just over the grass, like a powered paraglider.

Next, I tried leveling up higher, then simulated a ballooning mistake after the first main gear touch. Previously, the Sky Ranger had a nasty habit of bouncing high after such an event, like a kangaroo. Not after installing the VGs. Now the plane smoothly touches down, even from a higher flare or balloon. Again, I don’t recommend anyone try those potentially dangerous attitudes, but I have to say they don’t feel so dangerous anymore. Amazing.

I dare say that with VGs, the Sky Ranger would outperform the CH701 in every respect, with very docile and pleasant flight characteristics.

Good job JG, I got my money’s worth.

Piotr, Warsaw, Poland

I have another Sky Ranger now and installed another VG set. This time, I installed 20 on each wing, spaced 6 cm apart, with tips 7% from the leading edge. The rest were spaced 9 cm apart, arranged in a slight V shape by placing the tape about 2% farther back near the fuselage.

Results:

1. I can fly solo at 45 km/h with 2,200 RPM (Rotax 912S) with no break.

2. I can fly solo at 50 km/h with 1,800 RPM; the very gentle stall comes at around 45 km/h.

3. With full load and my instructor on board at 3,800 RPM, the plane flies at no indicated airspeed. The angle of attack is so high that the pitot tube no longer works. GPS showed 26 knots groundspeed in calm air. We then made sharp turns around 55 km/h, fully loaded. At that speed, the plane turned like it was on rails and stayed far from a spin.

John, you have made me a much happier pilot. Now, with tundra wheels, I feel like I can fly and land anywhere. I touch down at 55 km/h and keep the nose wheel up even below 50 km/h. Snow, sand, mud, and soft fields are no problem anymore. An alternate landing spot is practically anywhere, as long as it is free of trees, fences, or wires.

Best regards,
Piotr Jeuté