TomAiello

I've split this off the "Non ZP PC" discussion, because it looks like useful information, that many people probably don't know (I've often seen PC's with many hundreds of jumps). -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Let me see if I can get some manufacturers to comment on this one. Here are some responses from manufacturers: Jimmy Pouchert, Vertigo: Adam Filipino, Consolidated Rigging: I love being involved in a sport that's small enough that you can get responses from gear manufacturers in less than a day. Thanks Jimmy and Adam! -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I'm not buying anything from a redneck like you. Seriously, though. Robert probably knows about a hundred times more than I do about parachute inflation. And I'm really curious about vent locations. I wonder if the vent locations matter at all? -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Try DivX. It usually gives me the best quality to file size ratio. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Also, do you know if this is true regardless of the location of the vent? In other words, will an apex vent have the same effect (or lack of effect) on opening as a vent located somewhere else (say, in a higher pressure area) on the PC? -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Robi, Do you have any research on this? I've seen vented PC's hesitate on go and throw deployments far more often than unvented PC's. I'm wondering if there is some other cause? I do know that the US military did a bunch of research in which they concluded that apex vents created noticeable increase in opening times. I don't know much about the aerodynamics of the various parachutes used (i.e. which were PDA, and which were not) but I do know that they tested both PDA and standard (non PDA) rounds. Let me see if I can dig up the reference material... -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I'd consider the experience level of the person you are sponsoring, at the discipline you are sponsoring them for. While this sounds elementary, I can't count the number of sponsored people I see with less than 50 jumps. Sounds insane, doesn't it? Yet skydiving sponsors do it all the time. They sponsor their freeflyers/swoopers/wingsuit flyers/RW jumpers/skiiers/snowboarders/etc with BASE gear, despite the fact that those people have very little BASE experience. This leads to some very bad things--like sponsored jumpers taking beginners on as students, when the sponsored jumper themself is really just a student. My advice: sponsor people for disciplines they actually know about, and have experience in. And don't just take their word for it. Ask other people if they really do have the experience and skills to be sponsored. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

It occurs to me that you'd need "regional" trust blessers. So, with this type of system, you'd need to have, say, 1 person designated for each forum, plus a dozen or so "floaters". Or perhaps each blesser would have a "home" forum designated, in which they agreed to read each post and bless as they saw fit. I guess what I'm driving at is that you might end up with all the "blessings" and hence all the future "trust" concentrated in one or two forums (like TB or General) with little or no useful activity in lesser used forums like CRW, or BASE. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Tom, are you 100% that vented PC of same size and construction has lower drag at same airspeed? Not at all. A properly constructed vented PC ought to have exactly the same drag as an identical unvented PC. It will just spill the air through the vent, rather than the around the skirt. However, I have yet to conclude that any vented PC is contructed to an ideal design. Also, and most importantly the vent may increase the chance of hesitation. This is well documented in round parachute openings, and is the reason that BASE jumpers tend to put a rubber band over the apex vent of a round used for BASE. The vent ought to have virtually no effect on drag, once the PC is open. But the thing that gets you at low altitude isn't low drag, it's hesitation, and the vent is definitely an issue there. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

He was answering me. I doubt that many skydivers would claim me as one of their own. But I'll try to make it to a dropzone and find out. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Since we've started a separate thread on opening shock, you might want to redirect this question into that thread. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Link to Relevant Discussion in General Skydiving Forum -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

My hardest ever opening was a 3 second slider down under an old PD-235. The tail pocket velcro was worn, and I'm pretty sure the lines dumped. At any rate, I lost consciousness. The landing was not pretty, but fortunately relatively uneventful. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Uh, yeah, what he said. Let me amend that to "any normal skydive". On the other hand, I've had some exceptional slider down openings that I'd bet were harder than _any_ skydive, period. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I'll second that. I think it would also avoid a lot of confusion, and some resulting hard feelings. I've seen flame wars started when someone asked "is it ok to do X?" and someone else quote chapter and verse from the US FAR's at the them, not realizing that they were in Australia (or wherever). I've taken to checking profiles before answering questions if I don't know where someone is from, because the correct answer to a host of simple questions (like, "where is it easiest for me to take a first jump course?") are highly location dependent. Showing location on each post would save me a fair amount of work (in addition to it's other benefits). -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Slim and Dwain offered a course, but I think they ended up cancelling it after protests from the Europeans whose sites they wanted to visit. And that was despite a 50 jump minimun for the course. Dwain did offer an aerial seminar held at a diving facility with a professional diving coach, followed up by a weekend at the legal span. If I recall correctly there were about five participants (I was one of them). Despite requests for a follow up, I don't think he ever ran another one, because it was a tremendous amount of work for him, and he wasn't charging anything for his time and effort (all the payments went to facilities and diving coach time). I wonder if we could drag Ron out to Idaho to teach an aerial seminar--I can arrange pool time, and probably rig up a belt system on the pendulator. I'd be curious to hear what kinds of intermediate and advanced topics people would like to see courses on. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Opening shock on a freefall slider down deployment is much harder than on any skydive. Anyone can get disoriented. Having 2000 skydives is good preparation, but there are no guarantees. Especially with an off heading, things can get pretty confusing to a student in a hurry. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I don't think there is a hard and fast rule. I generally discard a PC the moment I start to have doubts about it. If the PC fails, the rest of that stuff on your back isn't going to do you any good, after all. Thinking about when I've thrown out old PC's, it seems like I'm getting about 100 jumps from an F-111 PC and maybe 250 from ZP. But I'm pretty conservative on that (as I mentioned before). Let me see if I can get some manufacturers to comment on this one. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I think that Chris' list: Is a much better description of the people I've seen go in than Jan's: I've seen several people with all of Jan's attributes in spades, and still they've gone in. But those people also had several of Chris' attributes--and that's pretty much why they went in. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Why not post a set of suggested rules changes in the Suggestions forum? That's what it's for. Edit to add: While I doubt Sangiro has time to read all the threads in this forum, I bet he reads everything in that one. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

If you think tunnel discussion don't belong here, I'd advise you to post in Suggestions and Feedback, and add your voice to the (several) calling for a separate wind tunnel forum. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

"Selective" moderation (moving, editing, deleting, whatever) is not a sign of bias among moderators. It's a sign of overwork. Just because something doesn't get moved (or whatever) doesn't mean it's condoned, or that there is a special exception for that person. It just means that no moderator has gotten to that, or judged it important enough to do, yet. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Hey Chuck, Why not move it to "Suggestions and Feedback" instead? It sounds like it might be relevant (or parts of it might be relevant) there. Perhaps Sangiro's idea of sub-forums could be implemented here, with a "skydiving related discussions" sub forum? -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

Sounds good. Site selection is very theoretical in FJC's, because the site is pre-selected. I've lately thought we need an intermediate course that covers some of that sort of thing (and maybe even advanced, and instructor courses, eventually). Depends on the course, I think. Personally, I think the student ought to be given one thing at a time to focus on, which means that I cover packing after the first few jumps, so that the first jump doesn't combine the worry about "what is this BASE stuff?" with the worry about "will my first pack job work?". Sounds like more good stuff to include. In general, the student's progression is going to depend on the particular student, as well as environmental factors (are conditions good to jump the whole time during the course). If it all works out well, I believe that most FJC's progress from PCA to hand held to stowed by the end of the course. Usually, the instructor holds the PC, because the highway engineer at the legal span has asked that nothing be attached to the bridge. Also, from a technical standpoint, an instructor held PC will usually yield a better opening, because the instructor can judge when to release the PC, which a piece of brake cord cannot. Yep. I put a temporary one together for my course. But we expect to have a permanent one built by this summer. -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com

I've split this off of "I want BASE". -- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com