Here’s the root end of the wing. Standard issue prior to the destructive wing test. Notice the root rib is not doubled; AKA “light wing” by BD. The Bob says these are fine as is, but he did make changes after the wing test:
Extend cap strips - too late for me unless I want to drill out 60+ rivets and refit the nose ribs. I don’t!
Use #4 rivets at the .032 skin/rear spar interface - I can do that!
Double #1 mid rib - Man, I hated the thought of pounding out two more mid ribs. The weakest link seems to be the #1 mid rib from the results of the test. I decided to distribute the load by creating a torsion box between the #1 and #2 mid ribs. This would be as light as another mid rib and easier to fabricate. Here I have replaced the stiffeners with .032 attach angles.