Fitting the F-623 Corner Rib – 2 hrs

Tuesday May 31, 2011

Tonight I set about to fit and drill the F-623 corner ribs. I studied the plans on this a while because they are certainly not clear on what to do and where to do it. I ended up following the lead of Jason Beaver who has some pretty clear pictures on his web site. First I cut the ends of the left F-623 corner rib to be flush with the F-705 bulkhead in the front and half way between the skin holes in the aft end. For alignment I just made sure the outboard edges of the rib were flush with the edges of the skin and the elbow of the rib lined up with the corner of the skin. I had to flute the rib a little to get it to lay flat to the skin. Then I measured and made the doublers out of scrap .032 aluminum alclad. Here is the aft doubler plate after I drilled through the skin from the far side. It is a little bigger than shown in the plans to give a little more edge distance on the small end.

Here is the forward doubler after I drilled through from the far side. It is also little bigger than shown in the plans to allow all five holes to be picked up, not just the three on the left.

In this shot I have drilled through all the skin holes and this side is done. I made the doublers for the other side and trimmed the rib the same way but I did not have time to drill it tonight.