Brief Description: Preparing to Mount Leading Edge
To protect the main spar flanges, I made 5 2x4 blocks 7 5/8 inches long and secured them underneath the spar. Where I could make use of the lightening holes, I tied a string underneath the wood and took the string up through the lightening holes and tied it to the threaded rod at the top of the leading edge ribs. Thats the threaded rod which holds the ribs rigid. Towards the outward end of the spar there are no lightening holes. I fed the tie down straps down under the bottom skins between the skin and the main spar flange and out the opposite (top) side skins. I let that strap support the 2x4 loosely until they got winched up tight. Then they were held in place. I started in the middle and alternated to each side back and forth slowly winching tight the straps. The skin needed to be shifted slightly as it was pulled into shape. To make that easier, before the skin went on, I ran a line of clear packing tape down the middle of each rib. That made it easy to slide the skin without scratching the inside aluminum. I used pieces of scrap angle, and scrap aluminum strips to clecoe at the top skin where it meets the leading edge skin. The overlapping portion of the scrap pieces held the top skin tight to the spar while I winched the straps. I spent much time with a 3 foot dowel pushing ribs into exact centerline position so I could see the red marker line through the holes. Then I put the 1 1/2 inch x 36 inch extension flange between the 1st (A) rib and the skin and line it up with the 3/4 inch mark I made on it. It must extend toward the fuel tank that much so nutplates can be riveted to it later in order to help hold the fuel tank on. By the way, taking off the protective plastic from the inside of the skins was a bear. Its been on there for over ten years. Got it off and the aluminum looked very very good. Who would have thought.
2x4 blocks keep the main spar flange stiff while tightening the straps.
The working portion of the straps disappear inside the bottom skin where they go underneath the spar.
Once the top is drilled and clecoed, continue on the bottom side.
