BACKGROUND. The following steps provide an overview of the procedure to follow.
STEP ONE.
The first thing the rigger must do is to inspect the parachute harness to identify the make and model
and determine the extent of the damage. In some cases, particularly for older designs, it may not be
practical or economically feasible to repair the harness. If the rigger determines that repair is practical,
he/she must then establish a repair plan for the project. There are two reasons for this. One, that
the project is done logically and efficiently. And two, if not having done this type of repair before,
having contacted the manufacturer for guidance, the rigger can explain what he/she intends to do to
effect the repair.
The rigger must make detailed measurements of the harness. Figure A shows a typical harness configuration
and the needed dimensions. On a situation where one side of the harness is intact and can
be used for reference, the rigger still needs dimensions to work against to determine how much
material to order or bill to the job. If both sides of the harness are damaged, great care must be taken
to ensure the correct measurements of the final repair.
STEP TWO.
Teardown and cleanup is the second most important part of the process. It is important that all the
old thread, glue, and damaged webbing are removed. Leaving any of these in place and sewing over
them will result in a poor appearance. Also, it is not uncommon to find additional damage or wear at
this point that was not identified during the initial inspection process.
STEP THREE.
After the teardown and cleanup, the replacement webbing can be measured, cut, and pre-sewn in
preparation for installation to the harness assembly. The construction sequence is followed. In certain
cases, it may be desirable to replace not just damaged parts but worn ones to give the final result
a more cosmetic appearance. An example is when replacing a main lift web, it does not look good to
reuse the old chest strap webbing when the main lift web is new material.
STEP FOUR.
After the repair is completed, a thorough quality control program is undertaken. This is especially
critical in a situation where the rigger is working alone and there is no one to rely on for crosschecking
the work. All the critical points of the repair must be identified and checked as well as
the finished dimensions.
1.0 DISASSEMBLY:
1.1 Remove all housings, leg pads, and any other parts that may interfere with the work from the
harness.
Disassemble the leg strap/horizontal back strap junction [Figure B].
Disconnect the upper main lift web (MLW) from the yoke
portion of the backpad if necessary.
1.2 Disassemble the junction of the diagonal back strap and
main lift web at the 3-ring attachment point [Figure C]. Be
very careful not to damage the diagonal back strap. If it is
damaged, it is a major project to replace this on most assemblies.
1.3 Lay out the main lift web assembly and check the measurements
against the initial dimensions. Check against the
opposite side MLW for symmetry.
1.4 If this side of the harness has a TSO or identification label
attached, carefully remove it for use on the new assembly. If
it is damaged, it may be necessary to get a new label to
replace it. Contact the manufacturer for guidance. They may
require the rigger to return the old label in exchange for a
new one.
2.0 REASSEMBLY:
2.1 Note that this configuration consists primarily of two main pieces of webbing. The front
MLW is TY-7 webbing and the rear is TY-8.
2.2 Measure the new webbing for the main lift webs. Add 5" for the riser end fold back and allow
at least 6" extra for shrinkage. While this may sound like a lot, nothing is more discouraging
than to get to the end of the project and find that the webbing is short by an inch or two. A
couple inches of scrap is a small price to pay at this point.
2.3 Starting at one end of the webbing, measure the riser end configuration. Fold back and glue
in place. If there is a toggle stow loop on the old harness, do not forget to glue in place before
sewing [Figure D]. Mark the 4 point W-W pattern and sew with the harness machine and 5-
cord nylon thread.
2.4 Install the steering line guide ring with a duplicate stitch pattern as per the original [Figure
E]. In some instances, the manufacturer may have used a special bar tack or other stitch pattern
to attach the ring. If the rigger does not have the same machine, it will be necessary to
contact the manufacturer for an acceptable alternative. This should have been identified in
phase one. Check the distance from the end of the riser to the top of the ring. The industry
standard is 4", but there may be special dimensions for some applications.
2.5 Install the toggle Velcro® keepers as per the original [Figure F]. Complete any other sewing
needed such as the end of the toggle stow loop.
2.6 If needed, reattach the TSO label at the appropriate location. If the label is the original one
and is made from material such as Ty-vek®, try to follow the original needle holes to avoid
perforating the material. Too many holes will cause the label to tear out.
2.7 Working from the measurement diagram in Figure A, mark the location of the 3-ring.
2.8 Working downward, mark the location of the chest strap, the ripcord pocket, and the bottom
of the upper leg strap [Figure G].
NOTE: It will be necessary to allow for a certain amount of
shrinkage during the sewing process. There will be four areas of shrinkage to allow for:
1. The harness stitching at the 3-ring.
2. The harness stitching at the chest strap.
3. The ripcord pocket.
4. The harness stitching at the leg strap junction.
The standard rule of thumb for the sum of these patterns
is approximately .75" for the length. In other words, the
marked length of the MLW should be .75" longer than
the desired finished length. Most of the shrinkage will
be in the ripcord pocket and the leg strap junction. If the
rigger has not done this operation before, he/she may
want to build a sample MLW to check the measurements
and the resultant shrinkage.
2.9 Sew the Velcro® in place for the ripcord pocket [Figure H].
2.10 Glue the chest strap in place. In this instance, don’t forget the housing loop.
2.11 Using the single needle, pre-sew the front and rear main lift webs. Use of the sewing pattern
in Figure J will accomplish this and at the same time will create the ripcord pocket. Sew the
chest strap 3-point W-W with the harness machine [Figure K].
2.12 Reassemble the upper diagonal back strap and the
3-ring hardware by threading the rear riser through
the large ring followed by the front riser.
2.13 Position the 3-ring at the mark on the main lift web and glue in place. Install the Ty-12 confluence
wrap below the 3-ring and mark the 4-point W-W pattern [Figure L].
2.14 Sew the confluence wrap with the harness machine [Figure M].
2.15 Re-create the leg junction. Glue the upper leg strap in place first and then the horizontal back
strap second [Figure N].
2.16 Mark the 4-point W-W and then sew with the harness
machine. Start the stitch pattern at the front
side of the MLW and complete with the overstitch
the full length of the pattern [Figure O]. This will
provide additional reinforcing at the upper leg
strap/MLW location.
2.17 Measure the length of the lower leg strap allowing
3.50" for the rolled stop end. Trim to length and
then install the stop end with the harness machine.
2.18 Reattach the backpad to the upper MLW using the
308 zigzag machine.
2.19 Reinstall the leg pads using the 308 zigzag machine.
2.20 Reinstall the ripcord and 3-ring housings and hand tack in place.
3.0 INSPECTION:
3.1 Check the finished dimensions against the original dimensions in Figure A. If only one side
has been replaced, check the new MLW against the opposite side for comparison. The generally
accepted tolerances for this type of construction are ± .25". In particular, reserve riser
length and the overall MLW length are the most important. If either of these are mismatched
to their opposites, then the flight of the canopies may be affected.
3.2 Start inspecting from the riser end working down. Use the inspection chart in Figure P as a
guide for the inspection points.
After the inspection, all appropriate paperwork must be completed. This includes the rigger’s
logbook, the packing data card for the parachute, and any shop or business forms or log.
