Ask A Rigger | How Often Should I Untwist My Brake Lines?
Ask A Rigger
Wednesday, October 25, 2023
Even if you love rotini, you don’t want your canopy’s brake lines to resemble it. Brake lines twist up when a jumper lets go of the toggles, particularly on the ground after landing. Twists accumulate more slowly when a jumper keeps the toggles in hand after unstowing the brakes, but even the most careful jumper’s brake lines will eventually accumulate twists.
Twists reduce the life of the brake lines by adding additional friction points. Severely twisted brake lines can change the opening and flight characteristics of the canopy, bringing the tail down farther than designed on opening, bringing the stall point higher or, when one brake line is much more twisted than the other, inducing a slow turn. Twisted brake lines are also much more likely to grab suspension lines during deployment, causing what is known as a tension-knot malfunction.
To untwist your brake lines, first unstow your brakes. It helps to push the slider grommets down below the toggles on the rear risers. Then find the center of the canopy’s tail (usually where the warning label is, although Aerodyne marks the center of its canopies with a red tab). Work your way to one side until you come to the brake-line attachments. Most canopies have four of these. Separate them in order between the fingers of one hand and run that hand down these lines to the point where they meet (the cascade). This works any twists out of the upper steering lines. Now, without allowing any twists to creep back up above the cascade, pinch the lower steering line between the thumb and index finger of one hand and begin slowly smoothing your way down the line, pushing any twists down toward the toggle. Lines that have been severely twisted for a long time may develop a “memory,” which you will need to work out by massaging the line. Take your time; make sure that you smooth all twists out down toward the toggle. Once you have worked your way to within a few feet of the toggle, keep the line pinched in one hand and with the other, untwist the line from the toggle end. Keep working your way down the last few feet of line like this, passing the untwisted pinch-point through the guide ring on the riser, until all the twists are removed. Then set the brake and repeat on the other side.
Untwisting the brake lines is considered owner maintenance. Most hired packers will not untwist your brake lines for you! The more often you let go of your toggles, the more often you should untwist your brake lines. Jumpers who never let go of their toggles under canopy and who place the toggles immediately from hand to riser upon landing may need to untwist their brake lines only once per few dozen jumps. Jumpers who let go of their toggles after every jump may need to untwist their brakes lines at the end of every day.
Erin Orwig | D-35756, Coach and AFF Instructor
FAA Senior Rigger
Additional information on untwisting your brake lines is available here:
