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.

Here are the .032 blank... cross ribs? More false spars? I don’t know what to call them. The bottom flanges have been bent even with the mid rib flanges so the skin can be riveted to them. The flanges are long enough to capture rivets in line with those on the mid rib. You can see that I have marked the needed height for the top flange bend

I bent the top flanges, cut and flanged 4” lightening holes, then alodined and primed the whatever they are.

Here they are fitted to the wing. I’ll rivet the skin between the #1 and #2 mid ribs to the top and bottom flanges. I don’t think I have done any harm here and maybe I have added some strength to the root end of the wing.

Again, I’m no engineer. I did not run this by the Bob. I’m on my own here. You are on your own too!

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