KellyF

Guys, please don't "test" how well your parachute opens by deploying in a sit, or head down! Your asking for major problems! It would be quite easy to rip your reserve container off your rig, break your collar bone, or worst of all, get ejected from your rig! If you want to do high speed deployments (which I don't recommend), just go head down for a while, get face to earth, and deploy before you slow down. This will distribute the opening shock through the harness the way it was designed to.

As Riggerrob said, it is HIGHLY impractical. With the Infinity, the main container is the base that everything is built on, and most other containers are the same. In order to change the reserve container (or main container) you have to take the harness off, then the backpad, and then separate the reserve and main container. Then cut out your new pieces and start building your new rig. Starting from scratch is by far the most cost effective way, since you are going to do all the work anyway, but you don't have all the time and labor of disassembling the original container.

There is no such thing as a perfect engineer, sewing machine operator, QC inspector, rigger, packer, or jumper. Keep that in mind. Shit happens in this sport, even when everything is done correctly.

You could get a demo Spectre 170 from PD and see if it fits in your rig.

There are a couple of different ways to flat pack. A stack pack will have the nose pointed at the ground with the rest of the canopy stacked on top of it. This "should" result in an on heading opening. The other way to flat pack is called a roll pack- where the nose and tail are rolled towards each other after the canopy is flaked on it's side. This results in the canopy going into the bag 90 deg. off heading.

Those would be the most reliable numbers, and seem pretty accurate. As a general rule of thumb, published pack volumes are notoriously inaccurate. If you look at the numbers for a Sabre and a Stiletto of the same size in the back of Para-Gear, they say that the Stiletto packs larger than the Sabre, but anyone who has packed both side by side knows that a Stiletto packs smaller than Sabre.

Put some more jumps on the Skybandz, they generally don't break that frequently.

According to Advisory Circular 105-2c, Part 11 on page 186 of the 2001 Skydiver's Information Manual: "A. The assembly or mating of approved parachute components from different manufacturers may be made by a certificated appropriately rated parachute rigger or parachute loft in accordance with the parachute manufacturer's instructions and without further authorization by the manufacturer or the FAA. B. Assembled parachute components must be compatible. Each component of the resulting assembly must function properly and may not interfere with the operation of other components."

Bill, One idea that could help ensure that risers are built correctly-- If you were to produce a tool similar to the jig RWS uses in the production of 3-Ring risers, and make it available for riggers or manufacturers. Or maybe include the dimensions to make one in the back of the Riser Construction Manual, of course if RWS made the tool, they could ensure that the tool is within specs. and made out of materials that wouldn't bend or distort with use or abuse. Just a thought.

The collapse sequence is controlled by the geometry between the canopy, bag, and center (kill) line. The pilot chute, bridle, and bag have a fixed geometry, that is, nothing changes significantly during the deplyment process. The "magic" comes from the kill line that is attached to the apex (center) of the pilot chute and the bridle attachment at the top of the parachute. When the parachute is packed and the pilot chute cocked, the bag and bridle (with the bottom of the pilot chute attached) is essentially moved closer to the parachute. During deployment, when the bag comes off, the outer edge (skirt) of the pilot chute tries to keep separating from the parachute, taking the bag with it (like the freebag on a reserve), however, the apex of the pilot chute is attached to the parachute. So while the bag, bridle, and skirt of the pilot chute are moving away from the parachute, the apex is staying the same distance, so the pilotchute collapses, and only after the bag comes off of the parachute and the pilot chute has done it's job. The catch line (the second one inside the bag) is not really necessary for this process to take place, it's job is to allow the bag and bridle to only move far enough for the pilot chute to collapse fully, thereby reducing wear on the rest of the components in the system. I hope all this jibberish helps :)

This is one of the things that concerns me with people jumping with 22-24" Dia. pilot chutes. They are so small to begin with, that any loss in efficency will certainly result in a less than desirable situation. IMO, 28" is a great all around size.

A stainless steel curved pin is lower maintenance than a piece of plastic covered cable. There is less friction between the pin and loop, and you generally won't find a nick or gouge (or manufacturing inconsistency) deep enough in a curved pin to create a dangerous situation. There was a tandem incident a few years ago caused (I believe) by a drogue release made out of the black plastic covered cable. It got a nick in it that the J/M couldn't pull through the release loop. And as a side note, the yellow and black cable is NOT Teflon coated. It is a nylon called Lolon F(yellow) and Lolon G2(black). Jump Shack is the only manufacturer that I know of that uses actual Teflon coating on their cutaway cables (it's red).

My take on it is this: IF you have a horseshoe, the Catapult is your friend, but, IF you have a hesitation on your primary, it COULD be your enemy. I would put money down that most everyone that went through their student training with a spring loaded pilot chute had at least one PC hesitation, but less than 1% of us have had a horseshoe on the same system.

Correct.

Openings are broken down into three stages- snatch force, snivel, and inflation. With a larger PC, snatch force will increase, since you just presented the canopy to the airstream at a lower airspeed than you would have with a smaller PC. The jumper will then re-accelerate the canopy to his own speed. The greater the difference in speed, the higher the snatch force. Imagine a rope 15 feet long tied around your waist, and tied to a wall on the other end. When you walk away from the wall and reach the end of the rope, it will tug at you and make you stop. Now imagine running away from the wall at full speed. When you reach the end of your rope, you will be jerked quite violently (and painfully!). This is snatch force. A higher snatch force could affect the snivel also, by putting higher initial loads on the canopy, and disturbing the packjob. Actual inflation speeds should be about the same, but could be different because of the shock put on the canopy with the higher snatch force.