Saturday, April 7, 2018

Wings, Top Wing Skins (Part 19)

Well, with 1,576 rivets to install in the Top Wing Skins, you don’t turn down free labor from experienced help.  My buddy Doc offered to help, so he was hired (and about halfway through, Jeff helped me finish.....I guess he was hired also).  We started on the Right Wing with the Inboard Top Wing Skin.  As the plans instructed, we clamped the Main Spar down to the work table and placed wood under the Spar at various locations to keep it level.  I used a level at several places along the Spar to ensure it remained straight.  Additionally, we were cautious not to introduce any warping or twisting to the Wing.  Below are a couple pictures of how we did it.....



The plans state in order to get the tightest Skins possible to start riveting in the center of the Skin and work your way to the tip and root.  The picture below shows the completed Inboard Wing Skin, minus the horizontal J-Stiffener in the center (which will be installed after the Skins).  

Initially, we followed the guidance from the plans and back riveted the Skins using a large bucking bar and extended back rivet set.  This method required the Flanges of the Wing Ribs to be slightly “moved” out of the way to keep the set straight on the rivet.  As we progressed toward the top and bottom (forward and aft) of the Wing Rib, it became harder to move the Wing Rib.  So, we transitioned to the old method of shooting with a rivet gun and bucking bar.  This way seemed to work out better and produced a better product.....and went faster.  I plan on shooting all the rivets from here on out.

Here is the opposite side of the completed Inboard Wing Skin.  If you look closely, you can see the shop heads of the rivets along the Flanges of the Wing Ribs. 

On the inboard edge of the Inboard Wing Skin, there are eight nutplates that get installed on the Flange of the Wing Rib.  Here you can see seven of them.....one is hidden under the Aileron Torque Tube Support Bracket Assembly.   


Well, my free labor had to go.....so, until next time.