<January 6, 2008>

Notched Longerons

There sure are lots of little things to do on this fuselage. In what seems like a never ending list of things to do on the center section, I took care of what I think are the last two items on the list before I mate the aft and center fuse sections. I fluted the top flange of the F-715 Seat Ribs and I notched the longerons to clear the way for the horizontal stab attach bars.



The edge of the outboard edge of forward seat floor has a slight curve to it, so fluting the tops of the seat ribs is in order. I marked the rough locations of the holes in the top flanges of the F-715 ribs and removed the floors again. I am not going to drill these holes yet (as the instructions say to do), but I am going to wait until after the side skins are installed and drilled the ribs. I don't know if it will provide and benefit, but it seems to make sense.

I fluted the flanges between the hole marks I had just made and tested the curve against the floors. Everything seems to line up pretty well, so I clecoed the floors back into place.

I then turned my attention to the real work of the evening; notching the longerons. I took a very conservative approach here, making sure I had everything aligned just right, double and triple checking everything before I drilled or cut anything. Per the plans, I clamped the aft deck into place and used it to mark the locations of the notches.

With it marked, I drilled a 5/32" hole at the outboard side of the notch and cut to the edge. I didn't want to risk anything going wrong with a power tool so I did the cuts by hand with a hacksaw. I then finished the holes by filing and sanding them to their final shape. I used my digital caliper to ensure the notches were wide enough for the horizontal stab bars to fit.

All done. The plans say that the radius should be 3/32" in two places rather than one larger radius, but my round needle file isn't that small so I went with one larger radius. I hope it works out, but if not I will cross that bridge later.

With the longerons now notched and everything else ready, I had to make some adjustments to the layout of the shop to accommodate the size of what is to come. I am not sure if I like it like this, but I can always make more adjustments later.