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jws3

Pocket on Reserve Bridle of RI Rigs

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theonlyski

it's for getting the bag out of the container during a horseshoe.



Too bad it will not work...:

From Bill Booth, talking about the pockets as well:

"Let me clear up one myth right now. The free bag system WILL NOT pull your reserve bag out of its container in the event of a horse shoe malfunction. A horse shoed 16 foot long, 2 inch wide, free bag bridle generates only about 2 pounds of force on the bag at terminal velocity. Most reserve canopies weigh over 5 pounds, not counting force required to extract them from the reserve container, especially if the main container is still closed. What the long wide bridle will do, however, is stabilize the bag, (if you reach back and throw it out of the container) so that it won't tumble through its own lines as it deploys.
So, if you ever experience a horseshoe malfunction of your reserve, don't just lie there and wait to hit the ground, sit up until you feel the reserve bridle hit you in the back of the head, reach back and pull on it until the free bag is out of the container, and then let go. The drag of the bag itself, helped out by the bridle, will then carry it to line stretch. I put out a film about this about 15 years ago, but a lot of people seem to have forgotten."

and

"The pull generated by a 2" reserve pilot chute bridle in a horseshoe configuration is about 2 pounds. I published a video recording that fact about 20 years ago. Reserves weigh at least 5 pounds. Plus, all modern reserve containers add a "containment" force to keep the reserve bag in the container during pilot chute hesitations, to prevent out-of-sequence deployments (which, by the way, have killed several jumpers using older containers without this safety feature). So, it usually takes at least 10 pounds of force to remove a reserve bag from its container. Therefore, a horse-shoed reserve bridle does not generate nearly enough force to pull your reserve bag out of its container. This is a good thing, because it prevents out of sequence deployments due to pilot chute hesitations.

The basic problem with two reserve pilot chute systems like my Vortex (which I developed years before the Catapult, but did not market) or the Catapult itself, is that they cannot tell the difference between a pilot chute hesitation (very common) and a reserve horse shoe malfunction (very rare). So, the second pilot chute on these systems can easily pull the reserve free bag above a hesitating primary (spring loaded) pilot chute, allowing that pilot chute to get into the lines below the free bag, thus totaling your reserve. So, the Catapult system actually encourages out of sequence reserve deployments, which as I said above, is a very bad thing. I tried to solve this problem with the Vortex, but was unable to do so. The Catapult does not solve it either."

and

"The freebag system only "Works" if the bag is first "ejected" from the container by some force OTHER than the horse shoed bridle. On the Paraflite dummy drops, this force was supplied by the tumbling dummy. Once the bag is out of the container (at terminal) it will blown upward by its own drag. A horse shoed 2" bridle only supplies about 1 pound of drag. Most reserves weigh at least 5 pounds, and it takes at least 10-15 pounds to pull the bag out of most modern containers. This is a good thing because of the likelihood of reserve pilot chute hesitation. If your bag falls out of the container while your pilot chute is hesitating, and gets above that pilot chute, you could be in a lot of trouble."

and

"In my tests, a horse shoed freebag bridle pulls only about one pound at the freebag end. Pockets on the bridle don't pull much more, and certainly not enough to pull a freebag out of a modern container. This is good, because the last thing you want during a pilot chute hesitation (common on internal spring-loaded pilot chute systems) is for your bridle to pull your bag out of the container and above the hesitating pilot chute. Reserve totals are rarely fun."

and

"With your main container (and riser covers) closed, it can easily take over 15 lbs. of pull to remove your reserve bag from the container. It takes a pilot chute of about 13" finished diameter to do that. Pockets on the bridle won't generate nearly that much drag. But the most important thing to consider, is that the second pilot chute can't "tell" the difference between a reserve horse shoe (which is very rare) and a reserve pilot chute hesitation (which is very common). Ask yourself this simple question: "Do you really want your reserve bag pulled out of the container by the secondary pilot chute while your main pilot chute is hesitating right above?" Sounds like a recipe for an entanglement between the heavy, spring loaded primary pilot chute, and your reserve lines to me."

and

"Question: So why do we have 2" bridles in the first place?
Answer: Para-flite started it over 20 years ago. When they came out with the first square reserve, the Safety Flyer, they decided to "tinker" with a lot of other things too. The "free-bag" with its bungee "safety stows" and 2" wide "anti-horseshoe" bridle was the result. The Safety-Flyer was marketed with the Swift container system which had no pocketed corners. As a result, when you pulled the ripcord, the bag would simple fall out of the container. When they drop tested this combined system with a built-in "horseshoe" malfunction and a tumbling (unstable) dummy, the bag would simply be ejected from the container because of centifugal force (angular acceleration) and be pulled to line stretch by the force of the relative wind on the bag. The super long bridle allowed the lines to unstow, and the freebag allowed the canopy to open. The 2" width merely provided stabilization so that the bag did not tumble through the lines as they unstowed.

The anti-horseshoe system worked in those test conditions. However, as stated earlier in this thread, it will not work with a stable jumper using a modern piggyback system. The long, wide bridle has persisted out of inertia. i.e. No one wanted to go against an existing, "proven" system. Even though, I suspect, the wide bridle helps create and lengthen pilot chute hesitations, because of the drag it creates in the burble right above a stable jumpers back on initial pilot chute launch.

I have made one change recently, however. I had to shorted the bridle a bit to make the Skyhook work correctly. I kept the 2" width because of the stabilizing effect I noted above."

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I always thought those pockets were just for show. I have video of a reserve deployment of mine (fairly violent mal) a couple of years ago that clearly shows those pockets fully inflating and helping things along--it was a clean deployment though, not a horseshoe

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R.I.'s bridle pockets look like an ancient Russian idea re-visited. The ancient (1950s) Russian system used a static-line to deploy a sleeved canopy.
The sleeve remained anchored to the jumper's shoulders until the KAP-3 AAD got scared.
The sleeve had large pockets sewn to the top. Their (roughly) 1 meter diameter made the sleeve pockets pull as hard as a conventional pilot-chute. Note that this system was perfected before the Russians learned how to wind spiral springs for pilot-chutes. Those pockets served two functions: first, they stabilized the sleeve, much like modern tandem drogues. Secondly, those pockets worked like pilot-chutes after the KAP-3 AAD got scared.
This system allowed the Russian army to use the same hardware for static-line and free-fall soldiers.
Yes, it was more like "drogue-fall" .... but was overly-complicated for low-altitude drops.

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