It's good to be back at work. I'm really having fun with this project, despite the 3 steps forward 1 step back kind of progress.
Preparation of the AST skins was pretty straightforward. no complications or retraced steps. (Those are on the next page… :(
I could have not pulled the blue plastic from the inside until after drilling the final holes in the back—that would have accomplished the removal of chips at the same time. The ribs are riveted in place w/o any complications.
Foreshadowing the next step 08-03, the control arms are to be riveted onto the medial surfaces (excuse me; inboard) of the ribs. Perusal of VAF reports those are a pain to get to and there are several recommendations to rivet the control arms to the rib, then rivet the rib to the skin. Needless to say, I had already riveted in the rib.
I tried punching out the center mandrel bit, but quickly realized that I would damage the AST in the process. I elected to try a different technique and drill with the mandrel in place. Oddly enough, it worked great. A #40 bit centered very nicely in the hole in a LP4-3 and stayed centered even when it it hit the mandrel remanent. The #40 went straight through and then using a #30 and some precessing I was able to pop off the heads without damaging the underlying skins. The control horns are then attached the ribs and the ribs re-attached to the skins.
The last conundrum is that the admonitions to be very careful in labeling the horns and the skins appears to be for naught. There is no way that the correctly labelled parts are correct. I read ahead many pages to ensure that the control arms are bent outboard from each other and will have a clevis between them. If you assemble things the way they are labelled, that isn't what results. I feel like I am on the right track with that because when I watched the "How To" video, they also state to be very careful with the labels but you can clearly see them attaching the L Control Horn to the R AST Skin.