Date:	9-1-2013
Number of Hours:	2.40
Brief Description:	Tail Spring Cutout
I skipped over bending the longerons and trimming the J-channels since the aft fuselage will need to be assembled before they can be used anyway. I started with the cutout in the F-779 bottom aft skin for the WD-409 tail spring mount. I first traced the full size cutout on drawing 27 (including a few rivet holes) onto tracing paper, then taped that to a piece of poster board and cut it out with scissors. I drilled out the marked rivet holes then clecoed the poster board cutout to the skin and marked the opening (photo 1). I tried to cut the F-779 skin with left and right sheet metal shears, but due to the thickness I couldn't get more than an inch or so into the opening. I finished up by drilling a series of #40 holes close together just inside the marked line (photo 2). I trimmed up the rough edges with a 1/4" burr in my die grinder. After a few trial fits and trimming with files, I decided I needed to clamp the bulkheads in place on the tail spring mount to get an accurate idea of how I was doing on the final shape of the cutout. Photo 3 shows that I'm fairly close, but the bolt holding the spring in the mount is bottoming out on the lower flange, so I need to trim that and drill the access hole in the skin before I trim the cutout any more. I'm also going to take a look at several other builders' logs to make sure I'm going about this properly.