What is very interesting is that the airplane ... flew almost trim free requiring only a couple of clicks of roll trim and no pitch change the first flights with the incidence "screwed up". And after the incidence reduction, you didn''t mention elevator pitch trim at all.

A strong warning needs to be voiced here. If the amount you tighten the wing hold down bolts affects the wing incidence, you''ve got a major problem with that sucker. The wing underneath the hold down bolts should be rock solid. The bolts should snug up to something that has no give at all. Once securely tightened, the wing should be at the incidence that flies best. Your descriptions so far suggest that you can tune the incidence with the hold down bolts. That really should lead to one of two things. Death of the airplane when the wing wears around the bolts and rips off, or an airplane that needs elevator trim about every outing.

Changing the incidence of the wing actually changes the AOA the tail has to work with. The pilot directs the airplane''s pitch with the elevator. At whatever speed the pilot chooses he winds up needing elevator deflection to maintain level flight. We usually trim that amount of elevator so the plane holds level flight hands off. At that state, the wing will be at whatever AOA it needs. And the rest of the airplane winds up pitched however the wing incidence pitches the fuselage etc. And we wind up having elevator trim adjusted for all that. That elevator trim is really a result of what AOA the stab/elevator was pushed into by the wing/speed/pilot/etc. So........ If you fly an airplane with let''s say 5degrees too much incidence and then fly it with that 5degrees removed, what the tail has seen is a difference in it''s AOA between the two flight being 5 degrees. Tails generate a bunch different lift when their AOA changes that much. One would really expect the elevator trim to be quite different between the two flights in the example.

But bottom line isn''t the difference in elevator trim. It''s having a model with a rubber wing that is the bottom line.