I mounted the servos out in the wing bays with no problems encountered. That was driving upper and lower wing ailerons too. Becuase I was using a heavy engine, I mounted my radio equipment along with the rudder and elevator servos in the rear of the fuselage. I cut a hatch in the bottom for access. I mounted the servos inside, not with the tops sticking out. I also cut a hatch in the lower front of the fuse to for tank and engine bolt access.