After this weeks mishap with BumbleBee, (is that the 5th or the 6th time I’ve stalled it recently) and after a comment by someone at the field (does it always stall in the same direction) I thought perhaps I had better do some research.
After all the repairs & CF strengthening at least there has been no damage of late (other than broken folding prop blades) so that at least is good. Also, after the repairs (including re working a lot of the original repairs) the BumbleBee is actually flying better than ever.
Now back to the issue at hand, the stalling (tip-stalling or whatever you wish to call it).
After reviewing a lot of the BumbleBee videos it appears to always drop the left wing as it goes into its death spiral. Chris (Hoppy) had already pointed out to me that the AutoPilot always give full up elevator as the plane stalls & that I need to disable the AP to be able to recover. I also noted in the earlier crash videos (before I started killing the AP to recover) it also gives full right aileron deflection (opposite to the spin). This has no effect what so ever on counteracting the spin.
With the AP OFF, I have been applying full down elevator (which works to increase air speed) and full right Aileron, which does nothing, and according to some reading I have been doing actually makes it worse.
Next time, and I’m sure there will be a next time I will kill the AP, apply full down elevator but leave the ailerons at neutral and then when airspeed picks up give a bit of up elevator (to get away from the hard) and apply power at the same time. With luck it may just recover.
I am also 3D printing some vortex generators to fit to the outward 1/3 of each wing which is supposed to greatly soften the tip-stall characteristics.
A lot of this is purely supposition on my part so feel free to correct me if I am wrong and you know far more about the subject than I.
By the way Tuesday looks like another nice flying day (as does next Saturday) so I’ll put up the calendar at least for Tuesday.