Brief Description: Drill and countersink fuel tank attach holes (13-4
The inboard ends of the spars get 5 nut plates attached. Two for the spar and three for the fuel tanks. The two most inboard can be reached by the squeezer, but the fuel tank nut plates require bucking. I tried the first few mushroom set, but that didn’t work for the ones up against the thick section of the spar. So, I pulled out the big bertha bucking bar. I bought it awhile ago to help with the skins, but it worked really well here. You basically hold the rivet in place (factory head) like a backing plate, then use the back rivet to set the shop head side. This worked amazingly well.
