"D" section nose ribs at the leading edge of my XL wing.
*I don't think that is a problem..* the plywood carries the load.
but.
The "D" section is very much a structural element of the spar.
I rebuilt a Taylorcraft L2 that had an altercation with the ground one time.
Damage to the left wing, landing gear, and vertical tail. The right wing was undamaged, and had been recovered within the last 5 years. Since I was going to have to recover everything else, I decided to recover it, too.
I was glad I did.
The L2 also uses a "D" section. It had some cracks and a couple of holes in it that had been covered over with duct tape.
Because of this, the D section was flexing, and the rib carrying the aileron load (number 7 on the Legal Eagle) had broken loose.
This airplane was being used as a trainer, and it was not far from having bad things happen..