I haven’t talked about it much in the blog up to this point, but I’ve had an ongoing dispute with the F-01406C and F-01406A-L Bulkheads. Specifically, the area in question, is the area circled in the picture below. There are four holes in the circled area (counting the one the cleco is installed in). The hole containing the cleco is dimpled #30 in both bulkheads. When I initially installed the AN426AD4-4 rivet (with my pneumatic squeezer)....well, let’s just say, it was absolutely terrible.....the rivet was not completely installed in the hole when it expanded. This resulted in the holes in each bulkhead to become enlarged and were WAY to large for the required AD4-4 rivet. Well shit! What now?
Moving up to #5 rivet wouldn’t be good because it has dimples for a #4 rivet (and I don’t have #5 dimples.....do they even make them?). I couldn’t just install a screw because the holes are dimpled and would not be flat on the aft side of the hole. So, I bit the bullet and just ordered two new Bulkheads. The picture below are the two “new” Bulkheads after being prepared and installed in the Fuselage.
Now, with that dispute settled....on to the next one. The two Seatbelt Lug Assemblies get riveted to the same two Bulkheads as shown in the plans excerpt below. The top part of the Lug Assembly bends down and gets in the way when trying to set the top rivet. I tried several different ideas/way to set the rivets, but couldn’t come up with a suitable install method. (I’m sure one exists, but I couldn’t figure one out.....maybe an offset rivet set??)
So, to solve the second dispute, I decided to install structural screws in the holes instead of solid rivets. Each Lug Assembly received two screws and associated hardware. I used four AN525-8R6 screws, four NAS1149FN832P washers, and four AN365-832A nylok nuts. Here are the two locations the hardware was installed in the Bulkheads.
Here is a close up of the right side Seatbelt Lug Assembly (and properly installed 470 and 426 rivets in the Bulkheads).....
.....and the left side Seatbelt Lug Assembly (and properly installed 470 and 426 rivets in the Bulkheads).
So, all disputes have been solved with the Bulkhead.....I WIN!