thnaks every body.
yes i will fly it whith a OS .61 FX i think it is good enaugh !!
about the dehidral , i've decided to ake its wing in two parts, and madular. because it W.S will be 76"
so I should make it whith 0 degree in dehidral !!
I built a 69" wing span one which crashed while inverting!! here is its picture

appreciate any suggestion !!
[img][/img]