Reassembly Inspection Square Canopy—Main Line Replacement Procedure Disassembly 6.  Mark the location for the entry point for the cascade  line.  [Figure D] 5.  Tension the line using adjacent lines for reference.  [Figure C] 1.  Lay the canopy out on one side and straighten the lines. 2.  Remove the damaged line. If the cascade is undamaged,  remove the cascade line from the junction of the main  line. If the cascade is damaged, remove it as well. 1.  Cut a new main line approximately 24 inches longer  than the old one. 2.  Finger-trap a loop at the connector link end.  [Figure A] Make sure that the size of the loop duplicates the  original or adjacent lines. If the loop is made too small,  there may be difficulty in changing connector links  or risers as needed. Sew the fingertrap with either a  zigzag or bar tack. 8.  Return the canopy to the packing table, straighten,  and apply tension. Check the trim of the replaced line  against the others. •  Verify the line length is the same as the original with  the same tension. •  The connector link and canopy ends must be  sewn correctly. 3.  Pre-tension the line. With Spectra $^{®}$, load the line with  approximately 30 pounds for 30 seconds. Place the  line on the connector link. 4.  Feed the running end of the line through the slider  and directly to the line attachment tape on the canopy.  Make sure that there are no twists to the line or it is  around the other lines. Run through the attachment  tape and re-create the original knot.  [Figure B] •  Applicable products: Square main canopies. •  Description: Replacement of main suspension lines  of square canopies. •  Authorized repairmen: FAA Senior or Master  Parachute Rigger  •  Materials: E thread •  Machines: 308 zigzag—medium duty 7–11 SPI, 1  inch × 42 stitch bar tack (optional) •  Equipment: Scissors, seam ripper or scalpel, marking  pencil, 6-inch ruler, finger-trapping needle, and  60-pound fish scale or equivalent Many of the modern canopies are using Spectra$^{®}$ or other  aramid fibers in place of nylon or Dacron lines. These materials  are stronger, lighter, and less bulky. An example is the  825-pound Spectra $^{®}$ line common on many main canopies. The  strength is higher but the bulk is smaller than the 525-pound  Dacron used in the past. Accordingly, the techniques needed  to work this material are more refined and precise. 7-31