Line A B C D UST LST BK-TOG 10 Left 1 9 2 8 3 7 4 6 Right 5 5 6 4 7 3 8 2 9 1 10 A Procedure Square Canopy—Trim Check and Re-trim Disassembly such as elliptical canopies, may have nonstandard trim  measurements that require more detailed measurements. The  rigger should consult the manufacturer’s manuals or technical  data for these canopies. Checking and re-trimming main canopies is a common  requirement for riggers. All canopies and all kinds of  suspension lines get out of trim in time with use. The rigger  that knows how to quickly check the trim on a customer’s  canopy, and then determine how much work it takes to return  it to the original configuration is performing a valuable  service. In most cases, as long as the suspension lines are  in good condition, re-trimming a canopy adds hundreds of  jumps to the life of the canopy and returns the performance  to almost as good as new. The chart shown in  Figure A  is  tailored to apply to normal ram-air canopies. Certain designs,  4.  Start with the top outside right front corner line of the  canopy. This line will be line 1A. Depending on the  number of cells to the canopy, on a 7-cell canopy, the  left corner line will be line 8A. On a 9-cell canopy,  this line will be line 10A. Make sure that the canopy  is oriented correctly so that the measurement sequence  follows the boxes on the chart. •  Equipment: Scissors, seam ripper or scalpel, marking  pencil, 6-inch ruler, 25-foot tape measure, and  pony clamp •  Machines: 308 zigzag—medium duty 7–11 SPI or 1  inch × 42 stitch bar tack (optional) •  Materials: E thread •  Authorized repairmen: FAA Senior or Master  Parachute Rigger  •  Description: Re-trimming the suspension lines of main  canopies to return to the original trim specs •  Applicable products: Square main canopies 3.  Anchor the end of the tape measure even with the zero  mark at the end of the lines using the pony clamp.  [Figure B] 2.  Start by laying the canopy on the left side, anchor  the connector links, and flake it out as if for packing.  Most canopy lines are measured from the inside of  the connector links, which is called the zero point. 1.  The first thing the rigger must do is to complete a  measurement of the lines of the canopy. The chart  in  Figure A  shows a matrix for measuring the lines  of the canopy. Simply fill in the boxes for each  dimension measured. 7-37