For Yuks I took my G3.5 model of the Nitroplanes Stearman and set the wing incidences up to see how the plane would react.

With the lower wing incidence at 10 and the top at 0 it still flies just fine but it wants to nose down, and has LOTS of drag.

With the top at 1-2 it still flies ( lower wing left at 10 ).

Now, at 3 degrees, you guessed it, it does EXACTLY what you say.

Even 1/2 of a degree ( or 2.5 at the top wing ) puts it over the edge.



Now all of that said. 10 degrees of incidence on the lower wing looks absolutely wacky.

No one would ever fly a plane that looks so "off".



I still wonder if you actually had a combination of two factors at play. Which makes more sense to me.


1 - The C.G. was too far back or just at the edge of the recommended.

2 - You indeed had a high incidence, but not 10 degrees, say 5 instead. This is more plausible, but still a flaw with the construction of your plane... it shouldn't have been this high.

I would imagine that at 5 degrees or below the plane would not have that "wacky" look to it, and anyone would assume it was safe to fly.


However at this high of an incidence ( let's assume that the fixing posts at the front were too "high" giving you more than the plane should have, due to a manufacturing defect ), the C.G. then becomes absolutely critical. Just a little bit back of the forward most recommended point, and you would have an uncontrollable looping plane.