RE: AKM SU-27 Flanker-Does Look Good
Depends on how big a gap that is. It looks big in the photo like 1/4 inch, but I'm sure its not. I would probably just add a piece of hard balsa, the full length of were the gap begins, and start sanding a little at a time. Start in the middle and work your way to the front of the rib.
I hate it when things like that happen.
Jim