Following up on the control stick 'holes' (approx 4"x4") in the F-639 and F-640 fwd seat floors.
When these holes are cut into the seat floors, it also requires the flange on two ribs to be 'removed' from the 4" hole and installation of 3/4" angle to create a new flange on the other side of the rib web. This is done on both pilot and co-pilot sides.
In addition, the nutplates that were previously factory installed on the flange of the F-604 bulkhead have to be removed in cutting out the rib flanges.
I probably went overboard on the rivets, AD4's spacing at 1" - you can see four of the rivets to the left (aft) of the copper cleco. This is the pilot side Co-pilot side is a mirror image. Shooting and bucking these rivets was difficult, and I'd do 2" spacing on a re-run.
The removable rib (factory fabricated) had been riveted incorrectly by the first owner, and will need a new nutplate.
In the process of fabrication, I confirmed the fwd seat floors, (F-639 & -640), must be replaced - they are drilled incorrectly ... didn't allow the full wing spar space. Rivet holes all wrong.
