0 1 2 3 1 2 3 1 2 3 1 2 3 Nose up Nose down Pitch(deg) Right wing down Left wing down Roll (deg) AFT INBD AFT Plumb bob Plumb bob attachment  Plumb bob stowage clip  Right main wheel wall AFT bulkhead Grid plate Special dihedral board with  spirit level incorporated Straight edge and  adjustable level Figure 2-83. Grid plate installed. Figure 2-84.  Checking dihedral.  2-49