darkwing

Come on now Jeanne, Camp Canada isn't any shorter a distance from the bar than the Hill-town hangar. -- Jeff My Skydiving History

I say that if practical results differ from the science, then the people "using" the science aren't very good at what they are doing. They need to study more science. Just becuase people claim (overtly or otherwise) that science doesn't work, doesn't mean the science is bad, it just means they are. -- Jeff My Skydiving History

Look at the fabric used on most modern reserves. It is very much like F-111. Think of it as ZP without the crinkle. As stated above, the term F-111 has roots as a trademarked name, but is almost always used these days to refer to non-ZP parachute fabric. I note that the internal ribs on my Pilot main are F-111-like fabric. -- Jeff My Skydiving History

It depends how old, fragile, and fat you are. I know you are old, but how about the other two categories? Maybe a water jump is in order. Better yet, just let the friend jump it. Show him a photo of what it should look like, so he will be less likely to cut it away thinking it is malfunctioning. -- Jeff My Skydiving History

after 30 years of jumping and you look your logbooks over, you will never find a single jump where you wish you had written less. For most, if not all jumps, you will wish you had written more. I wish I had written down the N-numbers of the planes I jumped out of. I wish I included last names more often, so I could find some people from the old days, I wish I had said more about the exit, lineup, and how it worked.... I wish... -- Jeff My Skydiving History

Here is a link to the official requirements for a ski jumping hill. Look at page 36 and beyond. I'm too busy to do the calculations now, but they won't be difficult, at least to get some reasonable numbers. Note that ski-flying hills are "badder." -- Jeff My Skydiving History

I think this is not a Wings-specific issue. I have heard complaints from many jumpers, with a wide range of gear. I second the notion that it is pilot chute size most likely. ALso I don't discount related factors such as a very tight container, and sub-terminal deployment, which can be mitigated by a bigger pilot chute. -- Jeff My Skydiving History

Blue Sky Adventures is about 45 minutes from downtown Charleston. Easy to get to. I can PM directions if you desire. We have a Grand Caravan. This Saturday is Safety Day, so hope to see you for festivities beginning at 8:00 am. We have a fun mix of FS and FF jumpers. I live in Charleston, so give me a holler if I can help with anything. -- Jeff My Skydiving History

I don't have the article in front of me, but it is surely several months at least. -- Jeff My Skydiving History

Unfortunately, the drogue takes care of pitch and roll, but not yaw. So, a skydiver with a sufficiently flexible suit could do it without a drogue, at least I see no reason why. -- Jeff My Skydiving History

The month of June is considered the beginning of hurricane season, but there are very few storms in june. You shouldn't worry. -- Jeff My Skydiving History

Not sure why you say that, is it because he didn't have the freefall skills? Or due to some other factor? -- Jeff My Skydiving History

Typical new batteries seem to give 6300-6500 during startup. After several cycles, mine, which were new a month ago, have settled at 6360. -- Jeff My Skydiving History

My first post "I think not" was based on a hasty interpretation that you wanted to re-trim the canopy. There are, as mentioned above, other techniques for reducing the necessary force to pull down the front risers. They are simple and effective at a 50% reduction, but if that isn't enough you might have to get really tricky. -- Jeff My Skydiving History

I think not. -- Jeff My Skydiving History

It can be both fun and frustrating to listen to a bunch of people with just enough knowledge to sound expert discuss technical issues, in this case, physics. There are a couple of current threads with lots of physics in them, and it regularly happens to various degrees, where there are plenty of expert-sounding posts, from people with varying experience levels. It is a reminder to me that on issues where I am not expert I have to be very careful in evaluating expert-sounding postings. Having lots of jumps doesn't make anyone an expert in physics. Heck, I'm living proof that it doesn't even make you a good skydiver. One reason we have jump numbers and rigger ratings in the profiles is so we can use them to make credibility value assignments to the poster's comments. Although such simple pieces of information in the profiles are not unflawed, they are better than nothing. Unfortunately, lots of people can make physics-talk sound correct, and we have little, if any, way to assess their actual expertise. So, when I'm watching mountain climbing (for example, since I know nothing about it) on TV, and there is a lot of serious, technical sounding commentary, I just hearken back to all the RealTV episodes about skydiving that sounded authoritative, but were laughably, absurd. -- Jeff My Skydiving History

My initial comment encouraging caution was based on factors such as, is there a cypres present? If so, battery leakage can be a serious reality. Also, do we know anything about the storage conditions, humidity, fumes, sunlight.... I think we do not, so my cautionary advice still stands. I am in complete agreement about parachutes stored in ideal, and unambiguous conditions. -- Jeff My Skydiving History

It isn't necessarily bad, but there are some bad possibilities. You shouldn't consider buying it until it is thoroughally inspected and tested by a rigger. -- Jeff My Skydiving History

I've been around a long time and I'm not nearly as jaded as Derek. I think what you heard was atypical, and unfortunate. -- Jeff My Skydiving History

I don't disagree with you, but as you correctly point out, that outward force is on the anchor point in the center, and most people who use the term "centrifugal" apply it to the object that is rotating. -- Jeff My Skydiving History

Do you mean the sort of SOPs that are posted for every jumper to read? Or do you mean SOP that include administrative, emergency, and other procedures? If the former, then I'd like to see examples posted here, so that we can all avoid reinventing the wheel. -- Jeff My Skydiving History

absurd. -- Jeff My Skydiving History

Very roughly $200 for a line set, including installation. Without having very good facilities it took me 2-3 hours to replace them on my main. Most people just send them to the factory or a loft, where the limiting time factor is usually shipping time, not actual labor time. -- Jeff My Skydiving History

Do you mean the most recent Nationals, or do you mean "have you ever competed" or "have you ever participated"??? -- Jeff My Skydiving History

I teach physics at a major producer of undergraduate physics majors, and we are always wondering where the students gets this stuff about "centrifugal" force. They certainly don't get it from any college physicist I know of. We blame the high schools. -- Jeff My Skydiving History