Thorp Air Command - T18.net

I came across an interesting crack on the stabilator while doing condition inspection & was wondering if anyone has seen anything similar:
on bottom of LH stab, 2nd rib, there is a crack in the skin. It starts at the middle rivet (through the tube spar) . See photos.
Looks as though it had been there for some flight hours as it had signs of 'smoke'
No other signs of distress on either side.
If it were not on the spar I might be tempted to repair. but due to that it is time for a new stab.

That is an interesting place to have a crack. A few years ago, when we had that stab failure on Spanky’s bird, the entire structure aft of the spar was wrinkled. The anti servo tabs were creased. The stab itself had what looked like a sign wave from the fuselage outboard. The inboard aft ribs failed and the skin was buckled to a point right about where your crack is. When you take it off, check the aft spar and inboard aft rib.... just for curiosity.
Cubes

I'll let you know what i find when I perform the 'necropsy'