winsor

It's a matter of opinion, basically. I, personally, prefer the standard Racer PUD, but have rigs with both BOC and PUD. In both cases you're reaching for a handle in the same place, and the both work just fine (in general). When the pullout was first introduced, it was going up against the bellyband-mounted throwout, so there were more significant differences between the two systems. The biggest drawback to the BOC, from where I sit, is the potential for an open container with the pilot chute still stowed. A high speed malfunction that requires the reserve pilot chute and freebag to clear the mess trailing behind you is not always survivable. Pilot chute extraction problems and pilot chute malfunctions (usually because of entanglement between hackey and bridle) seem less likely to occur with pullouts, as well. All things being equal, the comfort factor of the jumper is a big consideration. It's your life on the line, and if you have your procedures down pat with one, you may well stick with it. Hesitation kills, and if you are uncomfortable with a system - even if it's "better" - your actions may not be as swift and sure as with the system you trust. They have both been used successfully for millions of jumps, and it is largely a matter of personal preference. Blue skies, Winsor

Quote He entered a thread in the "Safety and TRAINING" forum rather with brisk words and when asked to elaborate, said it wasn't his problem or care. There's something wrong with that. If he doesn't care, why post?Quote The not caring part is regarding your analysis. To a great extent it really doesn't matter whether the reason why someone gets out with sufficient separation is physically valid - so long as they somehow provide for that separation. If you simply read numbers off a table and give the indicated exit count, that can work. You don't need to perform a detailed analysis every time you exit the airplane, and doing so won't eliminate rogue variables such as people tracking hell for leather at odd altitudes and pitching high, etc.. Thus, there is a difference between knowing HOW and knowing WHY. When people who have a pretty good handle on the how part of the deal conclude that they therefore understand why, I have a problem with it. Particularly when they're wrong. If someone gives a good count of 10 before jumping, I'm fine with that. That's the safety part of the deal. If they do it because the moon is in Aquarius and they saw a cat on top of a red car that day, I would rather not know. I am primarily concerned with the fact that they stay the hell away from me in the air. If someone wants to postulate an invalid model as the physical basis upon which they base their decision, I can't be bothered to hold their hand and lead them through it. It has been done to death on numerous occasions, and the information is available to anyone who takes the time to look. The "Safety and Training" part is, again, give sufficient time between groups to ensure adequate separation, and exit the airplane such that you can land somewhere safely. If you limit your focus to those issues, you should do okay. Blue skies, Winsor

It appeared that your argument was that separation only depended on winds at opening altitudes, and that uppers were irrelevant. Nope. Separation is a simple function of exit speed with regard to the airmass at a particular altitude. The minimum is typically the airmass at opening altitude (with an upwind jumprun) or at exit altitude (with a downwind jumprun). The speed of the uppers with regard to the ground is a consideration for spotting, but is irrelevant in and of itself for separation. These are related, yet very different, concepts. And something about 1000ft of separation. [But you kept it rather vague, and unexplained, with lots of wiggle room. I'll go see now if your notes are more clear.Quote Knock yourself out. If you can improve upon them, by all means do so. Blue skies, Winsor

So billvon and winsor don't seem to be in agreement here... at least the way I'm reading this. We're talking two different things here. Regarding the speed of the aircraft over the airmass at opening altitude we're in agreement. The other factor is TOT - time on target. If you have 7 groups getting out, and figure the minimum "safe" separation requires a 10 second delay, it takes 60 seconds to clear the plane. If, however, the length of time during which you can exit and make it back to the DZ without problems is 90 seconds (your time on target), you may well use the full 15 seconds between groups instead of the nominal 10 seconds. You take the extra time for the same reason as Fido - "because you can." There is no disagreement regarding the fundamentals of which I am aware. Blue skies, Winsor

The notes from my seminar at WFFC are here. Tammy turned it into HTML from Word, so I simply used it as is. No, I have often been impressed by how many people of my acquaintance have advanced degrees (MS & PhD) yet never got beyond the level of expertise at the basics that they achieved during Freshman year. They may be able to set up second-order partial differential equations just fine, but if faced with, say, rotational dynamics, through which they struggled to get a C, they would do well to show C level comprehension even now. I'm not trying very hard. From where I sit it's pretty obvious, and it is often most difficult to convey something that seems inherently apparent. The point being? That scenario has two parts - freeefall separation and window of opportunity. Freefall separation is based on the minimum relative speed of the aircraft with regard to any stratum of air throught which the jumpers pass. The extremes are generally found at either exit altitude or opening altitude, and the delay necessary to maintain separation at exit airspeed it the very least delay you should consider taking. Without wind direction reversal (more common than most think), the speed of the aircraft w.r.t. the air at opening altitude is the lowest pertinent value. With a tailwind, speed of the aircraft v.r.t. that air at exit altitude is the lowest. As the last part of my presentation describes, the window of opportunity on a pass is a function of speed over the ground. With a tailwind, your time on target can be short enough that you can get only one group out per pass without someone being hosed. With a headwind that reduces groundspeed to zero, you can put out one group after another all day long and maintain adequate separation at all times. I no longer teach Physics for a living. If you are an engineer, you should have the study tools to find the readily available resources and figure it out for yourself. It's pretty basic stuff. John Kallend is a professor, and actually has the patience to convey the fundamentals to a never-ending stream of neophytes. Bill von Novak is a skydiving instructor, engineer and pilot, and also has much more patience than do I. Ask them. Blue skies, Winsor

I took a lot of physics too. Did you pass?

The basic premise here is sufficient headwind to have zero groundspeed at exit. Think an AN-2 into 40 knot uppers. With no tracking or sliding, people (bellyfliers) are going down at 100 knots and horizontally at 40 knots - they are traveling along an incline. For 2,500 feet of vertical separation there is a 1,000 foot horizontal component. It's like being on an escalator. Everyone gets on at the same point, and off at the same point, but nobody is directly over anyone else. It's basic physics - freshman stuff (at least where I went to school). Blue skies, Winsor

The point you think you proved is entirely invalid. Everyone can open at precisely the same point and yet maintain 1,000 feet horizontal separation - if they do not open at the same time. Think about it. Blue skies, Winsor

Not hardly. With sufficient uppers, everyone can exit at one over the ground and open at another point over the ground - and still have plenty of horizontal separation! How's that, you ask? Simple. Remember those winds we mentioned before? They are busily blowing the first group downwind long before the next group gets there. It's only when you try to occupy the same place at the same TIME that things get dicey. If you throw in the extra dimension of time, you get a different picture. No, it's more like why a dog licks his balls - because he can. If you have the opportunity to take more time between groups and still get back, by all means use it. About the only factor that dictates a longer delay with more headwind is the difference between winds at exit altitude and winds at opening altitude. That's where the groundspeed plus winds at opening altitude (minus if the directions are opposite) comes in. No. Blue skies, Winsor

For the record, no, we are not in agreement. Winds aloft, in and of themselves, have nothing in particular to do with separation. If you want to consider separation at opening altitude, the relevant parameter is airspeed with regard to winds at opening altitude. Groundspeed (like from the GPS) plus the magnitude of winds at opening altitude (the headwind component, at least - it's actually vector subtraction) gives you this value. Rather than rehash the whole thing again, or have you spend a semester studying Kinematics, you would do well to simply do a search on the subject on DZ.com. Be advised that many people put forth physical models therein that are complete hogwash. A good rule of thumb is that if they disagree with John Kallend, they're wrong (I'm serious). Blue skies, Winsor

What you said was; "If spotting for the release point, then separation would have the same effect." That is wrong. My point is that what you said displays a fundamental lack of comprehension. Rather than discuss it here, the most effective way for you to come up to speed is to review some of the very good material covering the subject. It's out there and available. As I have said before, physics is not subject to solution by quorum. What's to debate? I do not wish to hurt your feelings. I would like it if you would do your homework before holding forth on this subject. Blue skies, Winsor

If you're running stock pipes on your motorcycle, I highly recommend upgrading to a good set of aftermarket pipes, all the difference in the world! My Harley has had straight pipes since I put it together. My last ringding had stock pipes, but that was pretty much a function of its peculiar geometry. The RZ-500 runs the exhaust pipes from the rear two cylinders (it basically has siamese engines) under the seat (hot roasted nuts are rumored to be standard equipment), and anything afterrmarket tended to be race-team proprietary. Then again, the chambers that came with it were pretty impressive, and if you want a hell of a lot more than 110 horsepower on a

Blue Skies, Black Death

If spotting for the release point, then separation would have the same effect. No. Spotting is a three-dimensional problem, but separation is four-dimensional. For spotting you only need to know where, but for separation when is important. It has been done to death. Please review enough of the readily available materials that it sinks in, since it is important for safety and you don't quite get it. Blue skies, Winsor

Winds aloft have more of an effect on spotting than separation. Check out John Kallend's simulation to see what I mean. Blue skies, Winsor

So students are really a different category on this subject. Grounding them for 30 days puts them out of currency and perhaps gives them too much time to dwell on the negative. If the instructor feels it was a "forgiveable" fuckup, maybe better to sit them one or two weeks and then get them back in the air? For the rest of us, 30 days seems like a good chance to reflect. If you're a student and aren't paying enough attention to saving your life to stay out of CYPRES territory, maybe 30 days is appropriate to contemplate if this pastime is really your cup of tea. Screw currency - if you have a CYPRES fire as a student, you might be well advised to start from scratch (if you return at all). There are a couple of very basic principles that you appear to have missed on this go-around. Blue skies, Winsor

I doubt that Elsinore is enforcing this rule so it wouldn't take much to drive down the street and jump there. I have been impressed with how well the S&TA network can work with things like this. Some time back someone misbehaved at Raeford, and Gene Paul Thacker grounded the hell out of him. Knowing that all he had to do was find another drop zone, he said fine and left. It turns out that he was unable to get in the air at Chester, North Raleigh or Barnwell, since the principals there checked the guy's bona fides before letting him jump. The bottom line was that if Gene Paul says you're grounded, you're grounded. There may be competition between DZs on one level, but there tends to be cooperation on an operational basis. Even if two DZs are competing fiercely for business, my experience is that the word of the S&TA at one is taken seriously by the other. If a call comes in regarding a questionable jumper, information provided that they are an incident waiting to happen is taken seriously. Some things slip through the cracks, but this sport is a particularly small community and you tend to earn the reputation that follows you around. Blue skies, Winsor

Quote>If you have a CYPRES fire, you are on free time for the rest of your life. I'd have to disagree with that. There are people who pull low because they are trying to avoid someone above them and have a cypres fire. An incident which would have ordinarily resulted in nothing more than an argument over better tracking now becomes a 'cypres save.Quote The thread is primarily about CYPRES fires due to loss of altitude awareness, and I limited my comments to those who had their skydive interrupted by a self-actuated reserve without so specifying. My bad. Sure, someone fighting a mal so their CYPRES just beat their reserve pull or someone with a snivel that took them into CYPRES terrirory fall into another category. I just have images of the footage at the beginning of Tom Sanders' WFFC tape in mind. People who think "keep pulling handles 'til your goggles fill with blood" is just a clever saying are the ones who concern me. The documented cases where people chopped and went back into freefall, wishing to be stable when the CYPRES activated, really worry me. I think the CYPRES is terrific. I have 4 of them. I do not, however, consider the system a panacea, and do not expect the system to save my ass if I am not heads-up enough to do so myself (I do hope it does, but...). The same survival policy that applies to cheesy horror movies is good for skydiving: stay the hell out of the basement! Blue skies, Winsor

Why aren't there mandatory suspensions for other accidents which can result in death? i.e. making a low turn..? If you make a low turn and pull it off, good on you. The mandatory suspension from not pulling it off is typically enforced by the policies of the ICU, not the S&TA. Sometimes the next skydive made after a botched low turn is an ash dive. Check out the fatalities page if you think I'm being overdramatic. 30 days on the ground is a minor inconvenience compared to the results if you didn't have the CYPRES handy. I am not impressed by people who are so cavalier about the effects of loss of altitude awareness. At least half the time I jump without an AAD. IMHO, if you wouldn't leave the plane without an AAD, you might give some thought as to how much responsibility you really accept for the outcome of the skydive. Blue skies, Winsor

I'm a Chemical Engineer, not a homemaker. I look at it from the standpoint of surfactant efficacy, dye migration, etc.. In general, Skymama's advice is sound. Something color-safe like Cheer in cold water allows a greater range of compatibility between colors. Blue skies, Winsor

Okay, there are some basic lines that you shouldn't cross if you want things to come out satisfactorily. Red and warm-colored things should be washed separately. Cold/cold, no bleach. Whites do best separately as well. Bleach or bleach substitute can't hurt, and raising the temperature is okay, too. Jeans and dark fabrics should be separated. Cold/cold is fine, no bleach. Greasy or seriously grimy duds should be washed separately. I break the rest down to cool colors and khaki/tan/yellow loads. Cold/cold, no bleach. Underwear and socks go in these (elastic likes cool temperatures). Since I have enough clothing to go a couple of months or more without doing laundry, I can usually put together full loads of each type (don't overload - it defeats the purpose). With a family, it takes a LOT less time to build up a sufficient backlog. Blue skies, Winsor

The shit that I've seen happen in this sport often requires the services of a coroner. A CYPRES fire changes the outcome from a closed-casket funeral to a repack and a NSTIWTIWGTD story. If you have a CYPRES fire, you are on free time for the rest of your life. You played Russian Roulette, got the chamber with the cartridge - and it was a dud. If you had a CYPRES fire because of inattention, you should likely take up another hobby. Letting you back on the airplane at all, even after 30 days, is an act of consummate generosity. Sending you somewhere that you can have fun without so great a likelihood of killing yourself is doing you a massive favor. Everyone is not cut out for this sport. It is not, and should not be considered, mainstream. The CYPRES has somewhat reduced the Darwinian nature of the sport (though I think the "Watch This!" landings have picked up much of the slack), but having a mechanical gizmo change your life expectancy from 6 seconds to decades is hardly a non-event. I would suggest an instant 30 day grounding and an attitude review by a board before reinstatement - if you can detail the series of grave errors that led up to the incident and have a game plan to ensure that it never happens again you are subject to reinstatement; if you say "I did nothing wrong," the grounding becomes permanent. Blue skies, Winsor

At first I thought the subject was like ice racing - talk about a serious sport! As far as winter riding goes, I have been a 12-month rider since the late '60s. I figure any conditions in which I would ski I would ride. Needless to say, in Northern Illinois or Massachusetts in the dead of winter the trick is to ensure you don't have an inch of skin exposed. With a snowmobile suit, full-face helmet with a throat-coat, Hippo Hands over the controls and so forth it becomes quite doable. I once went into a bank without thinking about it, and think the guard came close to peeing on himself before I got the helmet off (it was around 0F, so I left it on for warmth when outside). I found an O2 mask with appropriate tubing was necessary in really serious cold to keep the visor from turning into a block of ice. Running a step or two hotter on the plugs and inhibiting the cooling on the engine is a good idea, as well. Blue skies, Winsor

Bush may be a problem, but a pair of lawyers is anything but a solution. We had not endorsed Bush previously. We were, of course, appalled by the choice of Kerry as his opponent (though not surprised that it should be someone of his ilk).

Okay, from a skydiving standpoint I see two key issues. 1) I don't want to see a good DZ shut down because someone shows up positive on a tox screen after an incident. The pressure could come from either litigation or such organizations as the DEA; the relative legality of the intoxicant being significant only in the case of the latter. 2) There are people with whom I won't jump because I consider them a threat to my safety and well-being. Being under the influence is certainly a factor, but the cases where I begged off and an intoxicant was involved were where aggression and bad judgment were present along with indications of alcohol use. I have jumped with people who had red eyes and an illegal smile, but was confident that they were well in tune with their responses in that condition. I really don't know about people doing much else, but if someone was behaving like a clumsy dullard such that I found it alarming, I wouldn't be reassured if they had a prescription for whatever induced their stupidity. Thus, jumping under the influence is a bad idea from the standpoint of the health of the DZ. Scratching from a load where someone is under the influence is something with which I agree and which I have done. Blue skies, Winsor