Brief Description: Floor Stiffeners - Drill outer stiffener. Part 4.
Now for the outer stiffener. I thought I could locate the stiffener by drilling the end holes. Then I’ll put the bottom skin on and drill the stiffener flange through the skin.
Image 1 shows the firewall end and image 2 shows the aft main spar end clamped ready for drilling.
You better still put the center line down the stiffener because it will want to shift when you drill the flange. You still need the center line even though the ends are located. The center line for me is ½ the ¾” flange with. Not ½ of ¾”-0.07. 0.07 is the thickness of the floor stiffener angle.
