The factory published a service letter detailing the installation of optional stiffeners to prevent the tailcone skin from buckling. At some point I picked up the required parts – nothing more than a couple pieces of prepunched angle – and decided to install them today.
The service letter details how to measure and mark the initial hole locations, by drawing radius marks at specific distances from certain preexisting rivets:
To lay out the required rivet locations I found it easiest to use a couple of precise and expensive Starrett tools to draw lines with a Sharpie… what's the difference between accuracy and precision again?
Match-drilled the stiffeners from the outside:
Deburred, dimpled, primed, and riveted in place. I was able to squeeze the first three rivets on each side, but I used MK-319's for the bottom two because I have places to be and things to do. Also I didn't relish the idea of bucking rivets inside the crowded, narrow tailcone.
