Originally Posted by cccjbr6
I would think and extra 18 inches of wing span would increase useful load somewhat.
If you are assuming that the gross weight is based on meeting a minimum climb rate (like in FAR23) that would be true, but RV's have never had any problems meeting the common minimum performance requirements.
Originally Posted by Bubblehead
Be careful here. Extending the wings increases bending moment at the root, and increasing load will do the same (plus increasing shear load).
This would be the main reason to be careful.
If you increase the span you would automatically increase the bending moment slightly (longer lever arm), even if you used the same max. gross weight value.
If you increase the span and
increase gross weight, the bending moment on the wing goes up even more.