It's been raining all spring here in the Northeast, so I'm spending way too much time fussing over an ancient Goldberg Eagle trainer in the shop. I was checking the wing for warps and washout when I decided to check the wing-tail rigging angle.

Much to my surprise the tail came out 2-1/2 degrees positive compared to the wing mount platform. A lifting tail? I checked the plans and sure enough, the designer put the LE of the tail several degrees up compared to the wing's flat bottom.

Aero theory can give you a headache, but I always thought tails should lever downward to balance a CG well ahead of the center of lift. Pitch stability is a good thing in a trainer, especially the way I fly.

Anyone have any idea why Goldberg would have angled the tail up that way?

- Balsacutter