FrogNog

Would decompression sickness be a concern (even for short jumps such as 13,000 feet)? My earlier, lengthy readings of theoretical space elevator details indicated the ride up would be very fast. As to the original question, I think a new category of jumps would have to be invented: space jumps. Certainly a few previous super-high-altitude jumps would qualify under the new class, which would concentrate less on the way one got to the top and more on what the jump is like. This is consistent with how BASE jumps are and have been different from (modern) skydives, I think. -=-=-=-=- Pull.

Please don't confuse acronyms with initialisms. TLA, for example, is an initialism. (Unless you go around pronouncing it "tlah".) -=-=-=-=- Pull.

The countdown is not for the computer, it's for the powering of the cutter. The battery is zinc-air, which is good at supplying modest power requirements for a long time. To ensure proper operation, the cutter requires a big bite of power for a short time. So at a certain point the computer decides it needs to spend some time sucking power out of the battery into an intermediate pool from which it can generate the fast cutter firing burst. This is all my understanding and I make no claim it is correct in part or whole. -=-=-=-=- Pull.

A true skyhook save need not be altitude-related; a horrible spinning cutaway that would have caused line twists not recoverable before impact with terrain or ground or air hazards would also be a skyhook save. Of course, it's hard to know whether that "would have happened". -=-=-=-=- Pull.

N/A

Supposedly in 1972 a S/L student goes in with a double-mal of some sort, and only breaks his nose and loses some teeth. Does anyone know anything? -=-=-=-=- Pull.

I don't think that kind of humor could be called "sarcastic". It was more deadpan surrealism. -=-=-=-=- Pull.

Spiral fracture fibula, jump 273. Lessons learned: 1. don't rush; 1b. if I am missing major standard pieces of skydiving equipment, I shouldn't jump because it means I rushed. 2. I'm not as good as I think I am. 3. four months of not jumping sucks. 4. two months of not being able to carry anything sucks. 5. returning to jumping after 4 months off is not as adrenaline-pumpingly scary as I had hoped it would be. Sacrolumbar strain, while riding in a boat instead of skydiving. Lessons learned: 1. I need to spend more time skydiving and less time boating. 2. when the boat starts skipping on the waves, No, you can't just speed up to make it better. 3. The guy with the steering wheel has more to hold onto in a boat so he doesn't bounce as high. 4. don't go too fast in salt water. 5. thinking I have a broken spine sucks major. 6. finding out I don't have a broken spine is the greatest news I've ever heard. 7. "minor" back injuries can hurt. A lot. For quite some time. -=-=-=-=- Pull.

One stopped jumping when he died in a bad landing... -=-=-=-=- Pull.

What if the new non-velcro velcro meets or beats 1,000 jumps and is non-abrasive? Would you try it? Would you not really have a preference? -=-=-=-=- Pull.

Synthetic gecko foot-stick created. They don't mention anything about the following: * degradation from repeated sticking and unsticking * variation in unsticking force due to force application direction * unexpected sticking to unintended objects etc.. But it could make tuck tabs look like velcro. (In another decade. ) -=-=-=-=- Pull.

To be fair to the tree-huggers, isn't cadmium toxic to people, who could absorb it directly through the skin, mucus membranes, and digestion, and indirectly by eating plants, animal flesh, and animal milk in which it can accumulate? Species extinction I may or may not care about. Me and my friends getting sick I do care about. -=-=-=-=- Pull.

How long has it been since you cleaned and lubed the cutaway cables? -=-=-=-=- Pull.

This is my pedantism minute: Hook, can you attach a spreadsheet of the cutaways you aggregated to get 99%/1%? And can you describe the metric for a cutaway-and-reserve-deployment that was executed "in time"? -=-=-=-=- Pull.

"Safe" is, of course, relative. Some people hold their own tert-canopy in front of them in a bag of some sort and exit the plane back-to-the-wind and toss it away. Of course, I usually hear of them doing this for cutaway jumps, so I don't know how "safe" you would call that.

Most skydivers like to be able to repack their mains without having to first search through corn fields to find their deployment components. That's why our bags are tied to our canopies, i.e. they are not "free". If you mean to ask why the rubber-bandless bags don't just use a pair of rubber band-based locking stows to close the bag (which would make it possible to keep the bag closed with more than a single "perfect" canopy size), and stow the rest of the lines in a pocket by carefully folding them, reducing the quantity of rubber bandage used in the same manner as a reserve bag, there are some people who have done that with their own deployment bags. But it's a halfway measure: the number of rubber bands is reduced but not brought to zero. Back to the issue of why it requires a "perfect" size of canopy to keep these locking stowless bags properly closed: a bag has to be locked closed somehow, or the canopy will either escape during packing or at the start of deployment, when the pilot chute attempts to lift the bag (which contains a heavy canopy) out of the container. One way to lock bags is with rubber bands that go through grommets and around lines. Another way is with tuck tabs, similar to how some riser covers and pin covers close. A bag closed with bights of line passed through rubber bands passed through grommets is opened when the bights are extracted from the rubber bands, or when the bands break. A bag closed with tuck tabs has to be opened by pulling on the bag hard enough that the tabs' holding ability in their pockets is overcome. However, we don't want the tabs to pop out of their pockets immediately after the pilot chute pulls the pin and accelerates the bag off the jumper's back. So the tabs have to hold tight enough to keep the canopy in when the bag is yanked at first, yet hold loose enough that the bag will open when it gets to the end of the lines and now the pilot chute is attempting to accelerate the jumper as well as the canopy, via the taught suspension lines between them. To make this happen, the bag is sized so when it is stuffed correctly, the tabs' grip will be within a proper range - not too weak, and not too strong. If the bag is overstuffed, the tabs could hold on too strong because their noses can't "push" the bag contents out of the way so they (the tabs) can exit their pockets. If the bag is understuffed, the tabs might not hold on strong enough, and the resultant deployment would be similar to having no bag at all. Rubber band bag closure is more adaptable. But once there are two rubber bands to continually replace, I guess most people would go ahead and add more bands to use for stowing the rest of the lines. Note: from a practical perspective, there are few people less expert about these bags than me. I've never made, jumped, or sewn one. But this is my understanding about how these work, from what I've read here. (Yeah, if you read it on dropzone.com, it must be true.) Now, if someone comes up with another way to keep the bag closed and open it at the right time, we may have something. The tricky part is reliably telling the bag-locking device when line stretch has been reached. I suppose we could attach a curved pin to one of the suspension lines and close the bag with a loop through one or more small grommets. -=-=-=-=- Pull.

Ditto. If I forget my goggles ever again, I'm riding the plane down unless the plane breaks. SHAGG. -=-=-=-=- Pull.

I came about 100 feet from learning the hard way that visiting outs before landing there is not a bad idea at all. There's ONE damn wire inside the Veterans' cemetery and if I hadn't set up to land as short as possible, I would have found it the hard way. (The really experienced jumpers told me later, when I asked, that the other end of the cemetery is better because although it has lots of plaques, it has no wire.) -=-=-=-=- Pull.

The pin isn't "held in" by that thread. The thread is just a tamper indicator. -=-=-=-=- Pull.

I wouldn't jump without mine because I'd consider it prima facie evidence that I screwed up on the ground big enough that I should not get in the plane and, if already in the plane, I should not jump out of the plane. My personal rule is "If I get to the plane missing any major piece of equipment, I won't get in the plane / jump" - even if that means losing my money. -=-=-=-=- Pull.

I use low hop-and-pops to work on my body position. There's something motivating about that level of ground detail in the door. -=-=-=-=- Pull.

Right. Because no-pulls are genetic and only bad skydivers have no-pulls. Didn't we establish over 35 years ago that the best of the best skydivers occasionally low/no-pull? -=-=-=-=- Pull.

This seems to be happening more and more lately. Any ideas as to why? I assume it's not a big trend, but a change in reporting, reader awareness, or just a coincidence. I say that without any real statistical evidence to back it up. Of course, my claim is that nobody has any real statistical evidence to say this problem is happening more and more lately. -=-=-=-=- Pull.

I think you just learned the difference between precision and accuracy.

At what altitude did her line twists start? How did she know what altitude they started and that she was out of them at 1,400 feet? (I assume she looked at her alti, but just checking.) Was she checking altitude the whole time? Or did she "forget" about altitude/time from start to finish? -=-=-=-=- Pull.