riddler

I really like my Neptune, but doing four-way with some people last week that had Protracks, we saw that there was some differences in recorded speeds. My Neptune has the latest software, and we saw as much as 25 MPH difference in average speed between it and the ProTracks. There were some differences - one jumper had his ProTrack in his helmet, which will affect the pressure reading some, and I had mine on my hand. I don't know how accurate any of the computers are supposed to be, and I don't know who's computers were closer to the true speed, but that seems like a pretty big difference. Trapped on the surface of a sphere. XKCD

I wonder how long it takes to deflate once you're on the ground Maybe the vacuum-pack will come back in style soon. Trapped on the surface of a sphere. XKCD

Oh, I see - it the Unisyn, vs. standard harness. I understand now. I think you're right about the Unisyn always having the chest-strap articulation - that's part of the system AFAIK, and I don't think you can get it without. And it does look like it may be more susceptible to the hip ring moving back. But I'm sure getting a proper fit would alleviate that. Trapped on the surface of a sphere. XKCD

Maybe it's just me, but 115 jumps doesn't sound low-time to start putting a camera on your head. I remember our former DZO - many of whom thought was too strict with rules - posting guidelines that said you had to have at least 50 jumps to start wearing a camera at the DZ. Obviously, it's going to come down to the type of camera setup, your own skills and awareness and a lot of other factors. But judging just from jump numbers, 115 doesn't sound bad. Or maybe I need to spend more time over in the camera forum? Trapped on the surface of a sphere. XKCD

Lightning more frequently happens inside clouds than going from a cloud to the ground. There are great potential differences from say the top of a cloud to the bottom, or from one end to the other. If the potential difference is great enough to overcome the resistance of a path between them, the discharge will happen from point A to B, regardless if point B is on the ground, or in the air, or even if it's you. Any lightning strike on your body is dangerous - don't listen to people that try to explain it like you are some node on a power grid and whether or not you are electrically neutral. Your body and tissues form complex organism with a lot of potential electrical paths. The voltage by itself is dangerous - high voltages can actually cause shear, which in high doses will literally tear limbs from your body. But more dangerous is the current. Currents as little as 1/10th of an amp can be fatal, depending on the path they take through your body. The path from your left hand to your right foot has nerve pathways that go right by your heart. Currents starting at 1 amp can set your skin on fire. Point is, lightning is dangerous

Could this be a change in design for the Mirage containers? In other words, since (I think) yours is an older rig, could ALL of the new Mirages have the extra fabric connecting the leg straps to the hip ring? I mean, regardless of the chest articulation. Or do you think the difference on the hip rings is only for containers that have chest articulation too? Trapped on the surface of a sphere. XKCD

I would not recommend wasting time with your second step ("quickly check rings and pop them free if still coupled"). A PC-in-tow is a high-speed malfunction. Don't waste any more time doing any extra steps. As far as procedures, I recommend reading the 2004 SIM, Chapter 5, section E. Both methods are acceptable, but you should decide which method you are going to use before your next jump. Trapped on the surface of a sphere. XKCD

I doubt I would get much use out of it. My openings are categorized as "normal", "twisty" and "hard" - occasionally "very hard". I don't have much need to know how fast the deceleration was - it would probably only make me grumpy If you could also get horizontal speed and distance out of it, it would be nice to know, for instance, how far and fast I track, or how much I backslide when freeflying. But integrating those values without good starting criteria (for instance, how fast is the plane traveling? How do the upper winds affect the initial acceleration?) would be challenging - you would have to make some assumptions that would give you less than accurate results. Trapped on the surface of a sphere. XKCD

Darn! Can't find it. Page? Page? Trapped on the surface of a sphere. XKCD

It's never happened to me, but I think I understand that: P/C in tow is usually caused by a stuck closing pin or stuck bridle. If you then deploy the reserve, it increases the chance of the closing pin or bridle of the main becoming un-stuck and opening the main. This is because the container deforms somewhat, since the reserve is no longer in it, and that deforming container may pop out the pin, or shake out the bridle. If you opted to cutaway before deploying the reserve, the main (if it comes out at all) will release, which my increase or decrease the chance of an entanglement, depending on what happens. If you did not cutaway first, then you have a two-out scenario, which poses it's own risks. Pick your poison Trapped on the surface of a sphere. XKCD

By "test jumping", are we referring to a rig that is setup for intentional cutaways? I know there's one or two out there for intentional cutaways on the skyhook, but I kinda doubt they would let just anyone jump it. If so, I wonder how long the waiver is for that? Trapped on the surface of a sphere. XKCD

Not quite a personal experience, but one of my rigs was purchased from a jumper that made one reserve ride on it. He has just replaced his main rubber bands with tube stows, and he had a bag lock on the subsequent jump. It's possible that the tube stows were improperly installed (although I don't know how you can install them improperly to cause a bag-lock). Trapped on the surface of a sphere. XKCD

Clicky! From what I've read, the Vigil looks like it's going to be an excellent product. I also think the CYPRES is an excellent product, but it's nice to see some competition in the market. Neither computer is perfect, but if perfect computers existed, I wouldn't have a job I would jump with a Vigil with no worries, but I would never count on a computer to save my life. Have there been any Vigil saves yet? Trapped on the surface of a sphere. XKCD

Also, if you have one break line that is more twisted than the other, it will result in one being shorter than the other, which will result in an uneven flare. You don't need a built-in turn when you're getting ready to land. Trapped on the surface of a sphere. XKCD

The one and only Porter I jumped from (Eloy holiday boogie, 2002) had seat belts for all positions. They actually made the ride quite uncomfortable, since the bolts on the floor were always jammed into my knee or ankle. I would still prefer seat belts, but that's the last time I plan to jump a Porter

What is a cloud waiver? Is that something filed with the FAA? Or is it more like a dropzone wind-limit waiver? Trapped on the surface of a sphere. XKCD

I've seen people chuck their office chairs full-force at those windows, and those chairs bounce back like it's bullet-proof glass. I don't think parachutes are a very adequate escape system. #1 people don't know how to use them. #2 trying to get a parachute for every person in a building would be a logistics nightmare - kinda like how the Titanic didn't have enough lifeboats. There is a Japanese fire escape system that looks feasible. Maybe you should just buy one of those? Trapped on the surface of a sphere. XKCD

I don't think it's the DZOs job to make people be safe. But it seems like having people die at your DZ would be bad for business. Or maybe it would just bring in more thrillseekers? Trapped on the surface of a sphere. XKCD

Now there's an idea! First annual NAVY boogie. Hosting jumpers on an aircraft carrier - take off the jumps plane (or helicopter) from the deck. The landing area is well defined! If you land off, it gives their water rescue units a chance to practice their skills. Trapped on the surface of a sphere. XKCD

Came across this while online today. I have to wonder how prevalent is skydiving in the Navy? Trapped on the surface of a sphere. XKCD

Mark - as an aside - do you find it harder to clear your ears with earplugs? I have a hard enough time without them Trapped on the surface of a sphere. XKCD

Here's the original thread from a year or so ago. Not a perfect solution, but I think it's a start. There are a lot of pre-A license jumpers that ask me "so when should I start downsizing?" Usually, it's before they've even bought their first set of gear I hand them a copy of that chart and show them how it's used, and point out that it's just a guideline. Yeah, it's not an easy guideline, but I don't like the simple solutions I've heard. I wish there were an easy "sound-byte" that I could give to students about downsizing, but I think this is one of those times it takes a more complicated answer to get it right. Trapped on the surface of a sphere. XKCD

Question - wouldn't mashing or whacking increase the chance of bending the reserve pin? Edit to add: Yep, pretty certain the reserve risers have not been fanned. Trapped on the surface of a sphere. XKCD

I think the logic is the sooner you fuck up, the sooner you can downsize. Let's see, I usually fuck up whenever I jump a new canopy for the first time, so at that rate, I can downsize after every jump Edit to add - how about this for a WL recommendation? It's not perfect, but it gives newer jumpers something to think about before downsizing. Trapped on the surface of a sphere. XKCD

I have Linux, I love Linux, but if you don't love tweaking computers, stay the F away from Linux! Not only is it harder for the average user, but you will get NO support from anybody to fix problems - it's all you, baby! And even if you love computers before Linux, you will hate them after. It's still not made for the average user. I also have a few Windoze boxes that are required because that's what all my customers use. As an OS, it's gotten better. Much, much better. And just to show how everything eventually comes full-circle, for a lot of people, I recommend Macs! I used to hate Macs - they weren't made for people that need to get inside of the OS and tweak thing, like me. But with the BSD kernel, they've finally started to get a respectable OS, and they do make nice hardware. If you've got the money, get a Mac. Probably will be my next machine. Whenever I get p*ssed at M$, I like to watch video of Bill Gates after his 100th jump. Makes me feel better. Trapped on the surface of a sphere. XKCD