A while ago I built a Windrider/HK Mig-3. A wonderful bird to look at but it turned out to be a beast in the air. When flying at lower speeds it did just fall out of the air - tip stall without any warning, its name was Mig-3.
After some crashes and rebuilds I gave the Mig-3 to a colleague and forgot about it.
Well, almost - when I stumbled over a HK Mig-3 on eBay I know I had to try again and this time make it fly, and fly well.
Isolate the issue
The Migs tip stall issue comes from several causes.
One is the
wing geometry, a wide wing in the center and quite small tips. While scale in appearance (and true to it - the original Mig had quite unpleasant stall characteristics) its always cause for alarm. Its problem is that on such a wing the tip tend to stall before the root. Several things can be done to prevent this from happening:
- reshape the wing - gives good results as the VQ Mig-3 shows but impossible to change later for an ARF bird (and besides it does not look scale anymore!)
- geometric twist, decrease incidence of the outboard leading edge by some degree - usuall works fine but also impossible to change later as well. The Mig-3 has no such increased incidence at the tips.
What is possible later is to raise both of the ailerons a few degrees. This reduces lift but also the tendency for a stall however only slightly.
- different airfoils tip / root. Likewise impossible to change for a ready-made plane.
Well, that leaves one more thing:
Tubulators
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