The finding

I anticipate many posts on this topic since it's going to take quite some time for me to fix.
 
Recently I was working on a little upgrade of my fuel system. This involved removing a panel I never removed before, under which I noticed a crack on the fuselage structure. Sheesh. I immediately called my Pitts mechanics mentor and he confirmed what I feared: having to tear the airplane down. DoubleSheesh.

Here are progressively frightening pictures (not for the faint-hearted aviation geeks like me)

I made this lovely finding one day before leaving for a 2 week business trip, not really knowing what to do. I took this opportunity to make some research on my spare time abroad. Next post will be on the results of this research and on the different advices I got from many people I contacted during this trip. One thing to notice on the last picture is the grey paint mark on the purge valve cable sleeve. I'll explain my theory on why this happen also in future posts...