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Well, Todd, I learned something today! That is one more aspect of Tandem "certification" being taken over by USPA that may need further discussion. Assuming that what you heard from them is "official", it seems "some manufacturer" was concerned enough about safety to require a fairly high jump number to video tandems, but is much less concerned now that USPA is taking over more of the responsibility.

Thanatos340 was kind enough to post links to the legal documents related to that case (a few posts up from this one). Have you had a chance to look at them?

It is good that you have done some tests. In my opinion the real test would be to electronically record the fall rate (on a number of jumps) of 2 jumpers of extremely different sizes/weights jumping by themselves in a relaxed body position (both jumpers sit-flying or head-down, whichever you are testing.) These would need to be experienced jumpers who are honestly trying to fall in a relaxed position and not compensating. Edited to add: Another way would be to have a very small experienced sit-flyer adjust the weight in a skyball so that it is as effortless as possible to fall with it while jumping solo. Then give it to a very heavy experienced sit-flyer and have them report whether they can match fall rate in a relaxed body position. If they can, it means the heavy jumper has the right amount of drag. All of my fall rate studies are based on skydivers wanting to easily match fall rates, and then using their body position changes to compensate for the normal things that cause fall rate changes on a skydive. But, after all the fall rate research is considered, what I wrote earlier is probably closest to reality: "...sit-flying is mostly just a small step in the progression to freeflying and head-down flying, so a person might as well get a sweatshirt or freefly jumpsuit..."

You know why? Because if you are sit-flying for the sake of sit-flying alone, and to have fun sit-flying, they work! "Sit-suits" were designed to have a "standard fall rate" much like Gary Carter's FliteSuit was many years ago. But now sit-flying is mostly just a small step in the progression to freeflying and head-down flying, so a person might as well get a sweatshirt or freefly jumpsuit, that way they won't be seen as uncool. There is just one problem. What do you do when a 250 pounder wants to "sit-fly" with a 100 pounder? No amount of "learn to fly your body" is going to be able to allow them to fly at the same fall rate (comfortably). None of this will make sense to the people who are close to "average" in size, and whose body position will allow them to adapt to the fall rate. (It is apparently a generational thing now too, considering some of the comments I am reading in this thread.)

No, you are not being contrary, you are just using your experience and common sense. Question for all: How many accidents or fatalities have been attributed to slightly bent reserve pins? (Not including anything related to an RSL ring, etc.)

I'm sorry, all of that would be very inaccurate, (almost like Bill himself wrote it). I would tell you look up the pertinent legal documents, but I can tell from the way you wrote that sentence that you do not wish to investigate any further.

So are you now saying Jan Meyer is a "loose cannon"? Being a BOD is all about "representing skydivers", and now we will have one fewer very experienced BOD member that will do that during the next term. Well, no, wait a minute. I think she will probably continue to represent skydivers......

We did that many years ago. We got busy doing other things so we never continued with the study. In other words, you can ignore the statement saying, "The experiment is in progress. Full results will be released in the future." I think it would be much easier now because there are more wireless data collection system available. Check out the wiring inside the suspension lines. Pretty crazy stuff. Honestly, the data was so confusing to interpret that we hardly knew what to make of it. However, our research has been oriented toward parachute inflation much more than the canopy in flight. http://www.pcprg.com/psap.htm

Skymama indeed! I can just envision you saying that. Andrea, the only thing we are missing now is an avatar of you shaking your finger at them. (Thank you for your work as a moderator.)

I recall similar problems years ago when I tried to do something similar, when I was working on the equipment color programs I wrote. I just now loaded your file and a number of different graphic files and had the same result, but you can create a new file in MS Paint and color it. They can be painted in Paint Shop Pro just fine. I changed the number of colors in PSP to more, and to less, but it still did not work. Then I did a screen save and pasted it to PSP and saved it to a file. MS Paint liked it then. I read what some others had posted about grey scale attributes, but when you change a file to 16 million colors that grey scale stuff should not matter. I'm glad I have PSP.

That's entirely possible, and a good idea! It wouldn't surprise me if someone is working on that now. Update: I just got a PM from someone who said they didn't realize that their reserve had Velcro type toggles, and had a difficult time unstowing the brakes during the excitement of a reserve ride. That is something I had never thought of. I guess Velcroless toggles have been around long enough now that some people may not know about the Velcro type. Riggers and manufacturers, you might want to make note of this for your customer briefings and owners manuals.

If a person is open-minded enough, a number of methods can be used, for example: http://www.pcprg.com/slstow.htm No. And, the only disadvantage I can find to using Velcro on reserve toggles is that after a person has a reserve ride that they are so excited that they forget to mate the toggle Velcro to the riser Velcro when they land, and the hook Velcro might catch on the lines. (Of course some lines are not susceptible to this at all.) In all other regards (properly maintained) Velcro is superior, and unless a rig has a lot of reserve rides on it, or if the above mentioned issue exists, the maintenance is zero.

You can add me as usual....

It may be, but it is good advice! Well put. Man, Terry, you are getting bold in your old age, either that or you received an asbestos suit for Christmas.

That was a good price on the vacuum pump, I saw it listed elsewhere for a lot more. It is interesting to see such a different chamber design, one designed for altimeters. Yours is a very inherently strong design. There is a lot of difference in skydiving altimeters. Most of the older Altimaster II and III models are very accurate if they have been treated well. Galaxy models are often a bit low, however, still in spec. I needed the accuracy of the aircraft altimeter for things other than testing skydiving altimeters.

Ah, now we're getting somewhere. You have been attacking Jan regularly because of what two USPA BOD members have been telling you. How about believing two other BOD members that tell you otherwise?

I took it to the DZ this weekend, and after telling some of they guys that I didn't think they needed to test their altimeters any higher than 15K, after I left the room they took it up to 21K. We found that most of the student Alti-2 Galaxy altimeters were about 200 feet low at 9K (within spec) and 2 of them were about 400-500 feet low, (which indicates sending them back to the factory would be a good idea.) At least now I can explain with confidence the discrepancy to the students. It was driving me crazy seeing them always different from my Alti II and Alti III.

D: Skyride? What's that? . . .The persecution of Jan Meyer. B: So you want to them to take action against Skyride - and be OK when a director helps Skyride win lawsuits? Bill, Jan Meyer did not "help Skyride win a lawsuit". Besides, no one won anything, there was a "settlement". Give it up!

I know, but I'm a lot better at soldering than I am standing around in Lowes trying to figure out what all those fittings are. I was hoping someone would come along and go, "Yeah, those typical A/C vacuum pumps have a so-and-so sized fitting, and here's what all that stuff is called and here's how you do it." Not expecting much am I? Good advice, I will put some filter material in the line and see how long it takes to see any oil. How long did it take until you did?

We just upgraded our altitude chamber (for testing altimeters, etc.) with a cool new electric vacuum pump, and I finally wrote an article on it, including enough details to make your own if you want. It can be found on our Instrumentation page at: http://www.pcprg.com/prginst.htm Comments welcome, especially from anyone that can tell me more about what all these hose fittings are that I had to look through to find the right ones.

I look forward to more Installments, all of that was well put. You wrote: "..but the single most important factor is the dropzone owner. I too have been saying that for quite some time, in this form: "Safety starts with the DZO (operator), be it the business owner (or the club President)."

Thank you Richard, that is a really good set of questions. It helps people think about what questions they really want answered. And it's a different question for each person. The DZO might ask, "How can I get more student skydivers to the DZ." The instructor might ask, "How can we get more first time jumpers to skydive again?" The experienced jumper might ask, "How can we get our freshly licensed skydivers to jump more and get good so we can do better skydives with them?"

How about a nice easy way for moderators to quickly remove (individual) posts without removing threads. I found yet another post of mine that was removed, and for the life of me, I don't know how that thread could have disintegrated into something that needed thread removal. Perhaps a checkbox they could use as they scan a thread, and then at the top or bottom of a page ask if they want to change all the checked posts. Another possibility is to leave the actual post but change the post to say "removed by moderator".

What!? JP, say it's not true! (Sounds of drama, strife, etc.) OK, I'll just continue. You know, all I ever hear about that rig is how "safe" it is compared to older designs, blah, blah. I'm thinking that people need to tell the manufacturer about that. (JP, not you necessarily.) I understand.

An important question is how much wider is is than the original Sabre slider. The sliders I have made for Sabres that have worked so well are 2 inches wider and 9 inches bigger front to back.