TM 10-1670-287-23&P 0005 00  0005 00-16  Change 1  Line 1C Line 1B  9 ±  1-IN  12 ±  1-IN.  Line 1C  Line 1D n.  Grasp canopy fabric near lines 1B and 1C attachment points. Moving to center of canopy, stretch  and compare lengths. Line 1C should be 9-inches ( ±  1-inch) longer than line 1B.  o.  Grasp canopy fabric near lines 1C and 1D attachment points. Moving to center of canopy, stretch  and compare lengths. Line 1D should be 12-inches ( ±  1-inch) longer than line 1C. 