The Empennage has been done and on the shelf for a while now, and in that time, a new service bulletin was issued for the horizontal stab that addresses potential cracking of the aft spar at the outboard elevator hinge points.

This SB requires continual inspections for cracks and if you find them depending on severity you can install a doubler front and back or you may have to replace the spar.

If there are no cracks, you can eliminate the need for annual inspection, by preemptively installing the external doublers from the SB kit but in this case (no existing cracks) you don't need to add the internal ones.

The instructions call for drilling a 7/16" hole in the end rib, drilling the existing hinges and some skin rivets off, inspecting/sucking debris through the 7/16 hole, and reinstalling doublers and new steel hinge angles with Cherry rivets.

I know I don't have any cracks since this h/s has never been in service, so I elected to skip the 7/16 hole as well as the cherry max fix.

I drilled out enough skin rivets that I could get a tungsten bucking bar in there and after appropriate cleanup and deburring, shot the new parts on with conventional rivets, which is an alternate method of compliance. This h/s is brand new and unpainted, so it just made sense to me to do it this way and once I figured out how many rivets I needed to drill out it was probably just as fast and trying to built a ship in a bottle through a 7/16 hole and then mess around with lubricating Cherries and hoping I could get them to pull right with a hand puller.

This all went well, just a bit time consuming. The only thing I have left to do is ream out the center holes to take a hinge bolt. It's hard to get a picture but I sighted through the holes an they all line up. In one of the pictures below you can see that I shined a flashlight back toward the camera from the other end and you can sort of get the idea