5/25/2009 … Section 22-7 Step 4 and 5. RIVETING NOSE AND TOP SKINS. With the Flap Assembly in the cradle I began by inserting and riveting the Inboard and Outboard Nose Skins FL-1001A/B and the Top Skins FL-1001-C and the edge Main Ribs FL-1005=L/R to the Main Spar flange FL-1003-L with AN426AD3-3.5 and AN426AD3-4 as shown in Figure 4. Remembering not to rivet the last two aft rivets holes in the Top Skins until the page 22-8. Time for both Flaps about 4 hours.