1. Place skin with holes along trailing edge centered on line drawn on rear spar and rib 14. Cleco inboard skin to outboard skin (skin will be held off from rib) and continue skin alignment. Leading edge of skin should be parallel to main spar. Clamp skin using bar clamps, spring clamps and/or cleco clamps.
2. Starting at rib 8 start drilling a #40 hole in each rib working your way to rib 14. Make sure there are no wrinkles in the skin.
3. Starting in center drill rest of holes in ribs, use a pattern to minimize any chance of wrinkles. Drill the holes in the main and rear spars last.
4. Continue drilling the inboard skin in the same manner as the outboard skin.
5. Before drilling holes on inboard end of the main spar, check the position of the holes on the spar. See the next 2 pictures for optimal placement of these holes. These are the most critical holes while drilling the skin, and will be close to the spar stiffeners on the left wing.
6. Repeat steps 13-17 for the other side of the wing.
7. Draw line 7/16” from one edge of the leading skin. Carefully wrap skin around the leading edge of the wing and place under outer skins. Skin is easily damaged if not handled properly. Align the line just drawn in the center of the holes in the skin on the main spar. Use ratchet straps and some wood to hold skin tight against the ribs. Holes on leading edge skin at rib 14 location should be in line with holes on outboard skin.
8. Align lines drawn on flange of ribs in the center of the holes on the skin. Drill #40 holes through skin and into flange and Cleco in position. Continue for all holes on leading edge skin.
9. Edge of leading edge skin may need to be filed to fit properly with the inboard skin.
10. Insert access panel doubler on lower skin of wing and up-drill to #30.
