Chapter 5
RIPCORD PULL FORCE
The correct packing is the most important aspect of
repacking a parachute, but the cosmetic appearance of the
container is important as well. This is true both for a pilot
emergency and a sport piggyback system. Pilots want
their parachute as snug and as flat as possible to keep the parachute comfortable when in use. Skydivers want theirs
as snug and streamlined as possible so it stays closed during
free fall. The key to these requirements is to make sure
the pilot chute is held down securely. To do that, the closing
loop needs to be as short as the rigger can make it and
still meet the requirements for the maximum pull force.
Under the TSO system, the maximum allowable pull
force for the ripcord is 22 pounds. Most riggers develop a
feel for the closing of the container and what the resultant
force will be. However, new riggers need to check their
packing technique to measure the pull force, which is
done without a seal or thread.
Start by having someone put on the parachute to replicate
the real shape and conformity of the parachute system. To
pull the ripcord while the parachute is lying on the table is
not realistic. The rigger then takes the ripcord handle
from the pocket and attaches a calibrated scale to it.
[Figure 5-64] Ideally, a recording scale should be used to
register the maximum force during the pull. Next, the rigger
needs to pull the ripcord in a smooth, quick motion,
duplicating the motion of the user and the test requirements
of the TSO. Take note of the force required to pull
the ripcord pin(s) clear of the locking loop(s) and activate
the system. If the force is less than 22 pounds, the rigger
can then re-close the container and seal the ripcord. If the
force is over 22 pounds, the rigger must make whatever
adjustments are needed, such as lengthening the locking
loop or re-stowing the canopy, to achieve a pull force
below 22 pounds.
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