RE: Skymaster Gripen with scale features
Hello all
Let me say first that I'm sure that many of you know some of the things I will comment about, this is just for your information stuff, if I have some facts incorrect pls let me know tks.
Please remember that the full scale Gripen has a cg that is farther rear that we would ever be able to fly without a computer so some of the control movements and deflections are possible due to relaxed stability and computer control.
The canard of the SM Gripen is also much smaller than the real Gripen and suffers from reduced Reynolds numbers like all our models do. So at the lower airspeed like landing I'm sure that the canard is not producing nearly percentage of lift possible with the real Gripen.
We fly all of our SM Gripens with 147 mm to 153 mm cg At this cg we have found that the canard throw needs to be minimal, otherwise it is very easy to get into a PIO or Pilot induced oscillation on the flare during landing.
If you are going to try and take off using lots of canard make sure you have a way of changing the throw in-flight. During your takeoff roll leave your controls neutral until speed builds to let the wings and canards start to have laminar flow. If you hold full control like a soft field take off it will take longer to get the surfaces flying, and then bang they will become effective all at once and you will jump into the air.
We were able to reduce the take off roll on our F-18E this way by at least 100 ~ 150 ft.
If you get some other control movements to work please let us know, I would be very interested to see what you find, just be cautious.