Hi Phil!
I don' t know the reason why it crashed.
When I started, the model was very sluggish on the rudder. I hardly could make a turn. Straight on, it flew about 300 feet and at the next turn, it lost hight and crashed nose down into the ground.
First, I thought of a wrong CG, but it was OK.
Wind conditions were good, and I started right into the wind.
Well, I read the improvements for the Gyrace at http://www.autogyro.com/models/grceinfo.htm and there Jim wrote to use Clark Y airfoil blades.
So I don' t know what to do: build again new flat paddle blades or try to fly with the airfoil shaped ones.