Machine countersink the holes in the F-1093 Vent Doors and F-1070-L and -R Middle Side Skins to place the flush face on the outboard side of the aircraft. Disassemble the F-1086A and F-1086B Vent Brackets and F-1096 Vent Doublers from the F-1070 Middle Side Skins. Disassemble the Vent Door Subassemblies. Deburr, clean, and prime all parts.
30-2, Step 1
Drill the F-1038 Step Support Block per the callouts in Figure 1.