Believe what BalsaUSA said. I've built several of their bipes and all flew best with negative 1.5 to 2 degrees on the upper wing, 0 on the lower and all required about 3 to 5 degrees downthrust and some right thrust to fly at their best. Just a half degree change in the incidence of the upper wing can change a doggy flyer into a nice flying plane. If you can, build it to allow a little experimentation on this, you may need to fine tune it a bit.