Brief Description: Rear tie-down block, vert stabilizer (part 2)
With the aft spar drilled to the tie-down block's hole pattern, I remounted the vertical stab to the aircraft and matchdrilled the aft bulkhead to the aft spar. I marked the holes (image 2) to be sure I didn't accidently drill the rivet holes to 3/16".
I dimpled the aft bulkhead's rivet holes with a pull-rivet dimple set, and countersunk the tie-down block's rivet holes to accept these dimples. I then riveted the tie-down block to the aft bulkhead with AN 427-4 rivets, facing the flush head rearward to lie underneath the vertical spar's aft spar.
Match-drilling aft bulkhead to aft spar's pilot holes
