Yes , you have an "aft CG " marginal stability aircraft,....keep the nose down and the speed up..... I hope you can fix it......perhaps your wind-tunnel friend can make a quick Styrofoam model and put it in the wind tunnel.
OK, looks like, this will be more ore less final configuration. Spend some time to make sure that it is inline with airframe. Wondering if this whole thing will make tail boom stronger and eliminate deflection under load.
This definitely turned into a pretty solid structure to my surprise. For sure I will not be afraid to fly with it. And maybe I’m reading too many books lately, but it looks better this way. But maybe it’s in my head.
Not if. This contraption is already attached to the rear fiberglass.
My plan is to create flying foam plug. Should be possible to add or remove foam between tuft test flights. If I see any drag improvement at all, then I will park airplane and finish this plug. So, I can make molds from it.
After removing molds this whole contraption will be destroyed down to original rear fiberglass afterbody. That old fiberglass should have very little damage to it. So I can still fly and use new mold to build new afterbody right in my living room in January.
I was trying to find pictures of very successful German aircraft - flight design. I wanted to see how smart people with wind tunnel capabilities designing rear fuselage. And I found these pictures on their website.