TM 10-1670-287-23&P  0006 00  15. 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.  16. Move to trailing edge of canopy and ensure connector links are held even with one another. 17. Locate line 1D and 8D.  NOTE Pull both lines evenly before looking at ruler to ensure an accurate  measurement can be obtained. Adjust knot at the toggle to obtain  correct length.  12 ± 1 IN.  Line 1C  Line 1D 0006 00-21  Change 1 