SkydiverNigel

Naah, not even close. The quality of jumper training today, mostly AFF, is head and shoulders above the highly variable S/L FJCs of yore. Your last sentence makes me wonder about your familiarity with todays FJCs, by any method....

Any plans to bring back @dropzone.com email? I miss my short simple old email address

+1

1) Reference cited is highly technical = good. Relates to round canopies = likely completely irrelevant. 2) You have the famous PD ad? I'll believe it when I see it. 3) As others (mrk, pchapman) have explained better than me, softer openings don't have to mean longer (time or distance) openings. Why is this so difficult to understand?

@mxk and pchapman: Thanks for explaining what I meant better than I could have done. @masterrigger1: Why do you say a PDO '...probably won't open in 750ft'? Extraordinary statements require extraordinary evidence, which I'm just not seeing. And the recent PIA report on reserves didn't show a propensity for any reserve to open in line-twists - the other odd statement in your post. I need to check. ...I'll do what I should have done in the first place and ask the manufacturer (in one of the earlier replies John Leblanc is quoted saying they take the same time to open. I think I believe him).

I did not and have never said that. Erhh...and I never said you did ;-))

Here's what Mark Procos from UPT had to say on the topic: BPA Skydive the Expo 2015 - Equipment Compatibility with Mark Procos Softer openings was one of the design goals for the OPT. That means covering longer distance, which may make it less safe than a PDR under specific circumstances (where many other variables and decisions come into play). On the other hand, it may be safer than a PDR at higher speeds or in situations where canopy size is a factor. I have not seen sufficient evidence to conclude that the OPT is inherently less safe than the PDR, but I do have my Vigil set to 1,250 ft to account for the longer snivel. Nice. That is by far the most realistic and sensible thing I've seen written about this subject. Design is compromise, and PD did not get something for nothing when they built in a short snivel. Interesting presentation, but a bit short on actual data, and sometimes Mark P contradicts himself. Around 22:00 says '....softer openings doesn't necessarily mean longer openings...' which makes sense to me: can just mean the opening is spread more evenly over time, rather than mostly happening in one big jolt. Earlier he had said '3 secs, 300' ' was a myth, though later he comments that it's the de facto unofficial standard reserve manufacturers aim for, and meet. Without showing any data, he then states PDOs may take more than 2.0-2.5 secs to open, but certainly less than 3 secs. I took that to mean PDRs and other reserves are closer to 2.5 than 3 secs. What I did learn was reserve openings are complex with plenty of nuances: 'dynamic corners', the burble, pilot chute design and placement, cutter placement, weight and body position. Different AADs are also different in the the ways they arm and fire. But I still see no data to make me believe PDOs are less safe than PDRs. I can certainly believe there are Youtube videos showing atypical behavior, but as I said earlier, these are not under controlled conditions and I wouldn't change my practice based on an n=1 event. That's just me, though. Other posters can believe and do whatever they like. I aim to pull at 3000', certainly not lower than 2500'. And like another poster, I've set my Cypres's to fire at 1250'.

No, sir you do not. Here is a five minute query on YouTube that resulted in two somewhat similar types of malfunctions.The PDR one is spinning a little less, but the OPT is traveling at a higher speed also. One is with a PDR without a Skyhook. https://www.youtube.com/watch?v=T2ekBNYCk_s The other is with a Skyhook and a OPT. https://www.youtube.com/watch?v=ctim2aDfQJs View them and let me know if they open at the same speed or not. Better yet, get a stopwatch and some popcorn and watch a few videos.They are out there if you look for them. MEL PDR + Skyhook vs PDO - Skyhook is hardly an apples to apples comparison. And Youtube videos are anecdotal; I prefer the controlled engineering test data collected for certification to some random dude's 'Shit there I was...' story. Bottom line, I'm not seeing any credible evidence to show that PDOs are less safe than PDRs.

......................................................................... If I hear the word "legal" one more time, I am going to vomit all over your shoes! You guys are sounding like lawyers. I fear lawyers because of the misery they have dragged me through over the past eight years ..... with no end in sight. GRRRRRR!!!!! Lawyers argue subtle wordings while ignoring the bigger engineering issues. Yes, the harness must be stronger than the opening shock, so that it does not tear. Since low-speed canopies and hard-opening canopies have disappearred from the skydiving scene, that side of the debate is irrelevant. As for modern Mirage harnesses not being strong enough to meet TSO C23B standard category opening shock ... I say "poppy cocks!" My 1985-vintage Mirage was as strong as a Vector or Racer harness .... similar materials, similar hardware, similar thread and similar stitch patterns. Twenty years later, Mike Johnson (sp?) designer of the modern Mirage G3 and G4 harnesses showed me a stack of drop-test data. I vaguely remember him saying that the drops were done on PD's drop test tower. He concluded that modern Mirage harnesses (doubled Type 8 MLW) were slightly stronger than older Mirage harnesses because Type 8 stretches slightly more than Type 7. That additional stretch allows webbing to absorb opening shock slower. The Mirage factory did not apply (to the FAA) to update their certification because repeating all the drop-tests to TSO C23D standard was cost-prohibitive. The FAA has long allowed parachute factories to continue manufacturing "aircraft accessories) under older TSOs provided they keep the fatality rate low. In the end, you guys sound like a mob of "barracks lawyers" when you argue over subtle differences in wording while ignoring engineering data. Why so angry? Seriously, I was looking for an answer to what I thought was a reasonable and straightforward question...

So I'm seeing some good debate on harness vs canopy opening forces strength, and potential to use an under-rated harness with some reserves. But I'm not seeing any significant differences in opening times ( 3 secs or less) or altitude needed for full infation. Have I got that right at least?

Hoping someone here can definitively close out this post from another forum. In an apples to apples comparison, I find it hard to believe Optimums (TSO-23d) take longer or more height to open than PDRs (TSO version unspecified). Anyone here know the answer? Re: [masterrigger1] Fatality, Russia, 05AUG16, video (ends just before impact) [In reply to] Edit | Delete | Quote | Reply masterrigger1 wrote: Optimum reserves take longer to open than regular PDRs? What is the source or evidence for this statement? Yep. It was part of PD's advertising when they first came out.I am sure someone has access the earlier ads. MEL PDRs meet TSOs (Canopy characteristics doc on PD website is non-specific as to which revision). Optimums meet TSO-23d Either canopy should open in 250-300 ft max. The openings on PDOs may feel softer than on PDRs, but I can't see anything that says PDOs take more time or altitude to open.... Maybe someone from PD or an experienced rigger can chime in here? Nigel

SkydiverNigel here. I've just seen this - very odd. I don't think Quagmirian and I have aver used the same PC....except, come to think of it. A couple of times I've used a hotel business center PC and noticed a previous user has been on dz.com. Maybe that's it?

Yes the guy did an awesome job lying to the public, good enough for jail. I don't think many of us knew what his job description was though until now. In honor of the good job he did, the USPA can adopt a new logo: https://imgflip.com/i/19641b Nice misdirection but people can also not renew or not join. Obviously. You have intermittent literacy. That's why I helped you answer the questions you missed. http://www.uspa.org/News-Events/News/Article/1864/USPA-Acts-to-Ensure-Proper-Tandem-Instructor-Certification QED. Satisfied now dude?

Very sorry for your loss AuntCathy. Condolences to you and her family. And probably best to ignore the unthoughtful and insensitve speculation that is rife on these forums. BSBD

Again: How exactly is a group member DZ *held* to a higher standard? Way too many people think the GM program is anything more than sending a check and signing some pledge. If Lodi sent in its check and sighed the pledge, they would be group members. Ron: for starters, USPA has freely available standards. I've yet to see the Lodi SIM. And BTW FWIT etc etc I do have a jump or two in the 39 years it will be since I started on 28 Aug 1977. Blue skies dude😎