Time: 7 Hours
Today plan was to get all the countersinking done in the left and right spars. There are 72 nut plates in each side, 142 total. Each nut plate requires 3 countersinks, 2 for the flush rivet heads and 1 to accept the dimple of the overlying skin. So doing the math that’s 432 countersinks(CS) to drill! Well I will just eat this elephant one bite at a time and enjoy some college football at the same time.
Those photos show the all of the rivet CS’s done and the #8 screw holes done. Next up is the inspection plate cover screws which are a #6. I will use my #40 CS to do these holes but I will have to reset the depth as I was using it for the flush head rivets. Before I make that change I decided to go ahead one step and CS the the center section attach plate nuts. There are 2 on each wing and since I have the proper depth set this was a easy decision to complete this step now.
Once I finished the center section CS I moved on the the inspection plates. They are #6 screws so I reset the depth on the CS cage and started the process. It took me about 30 minutes to finish the 12 on one wing.