The aft deck and a couple of spacers underneath it get riveted to the longerons. The small F-709 bulkhead gets attached to the deck. I was able to squeeze all but 4 of the rivets. With the aft deck on, the fuselage becomes quite rigid. No more twist! I had the rear top skin clecoed on when this was being riveted, so everything was squared up nicely. These prepunched parts are amazingly accurate.