Servo mounting on .15 pattern plane
 

I am installing standard servos in a Tango .15 pattern plane and for the aileron servo I have a small problem. If I cut all the way through the wing to make the servo flush will it weaken the wing considerably or do I just need to build a mount and have it stick up like it is in the photo? I would rather make it flush if all possible. the belly pan will hide the bottom side of the servo. I was planning on cutting out a piece of ply on both sides bigger than the servo and epoxy it to the wing for strength.