JohnRich 4 #26 December 30, 2006 QuoteIt's my best guess as to why reserves are cheaper. Be sure to note my choice of words such as "Reserves probably aren't" or "It might degrade" If your best answer is just a guess, then it's probably better to keep your mouth shut and just listen to others who actually know. At your experience level, you should be listening to, and absorbing, technical advice, not giving it. QuoteAnd based on my first post and all the posts after, looks like I was fairly close. You can tell by the comments when people know what they're talking about. Several people here do, and they're comments directly contradict what you've said. QuoteSince obviously your post clearly states that jump numbers = experience. How the hell do you know I don't have a degree in Aerospace Engineering or manufacturing? You provided nothing to specify your expertise for such technical knowledge of parachutes, so all we have to go by is your profile info. Even if you had an aerospace engineering degree, it wouldn't mean you know anything about parachute construction. And if you do have an aerospace engineering degree, why are you working in information technology (per your profile)? But hey, if there is something about your life experiences that gives you such expertise on reserve parachute construciton, then now is the time to state it, to lend credence to your statements. QuoteI'm totally sure that someone on here will read my post and buy a reserve as a main and go jump it without a second glance. Riiiiight! In matters of life and death, which this sport is, one shouldn't give advice unless they're sure it's correct. QuoteMaybe I'll change my profile to say I have 4100 jumps, people on here will do as I say then right? One should also not lie about their experience in order to appear more knowledgeable than they actually are. I may have over 4,000 jumps, but I don't know the answers to the question in this thread, and that's why I'm just listening and absorbing from the experts, instead of giving advice that I don't know anything about. I suggest you do the same. Pardon my bluntness. The general warning about advice in thess forums applies here. Quote Share this post Link to post Share on other sites
Chris-Ottawa 0 #27 December 30, 2006 You put way more effort into your reply then I ever would have. I have no need to post further in this thread, your post is irrelevant and you overreacted. I'll send you a quick PM though. Chris"When once you have tasted flight..." Quote Share this post Link to post Share on other sites
moth 0 #28 December 30, 2006 i agree with chris as you are fat!!! Quote Share this post Link to post Share on other sites
BIGUN 1,397 #29 December 31, 2006 QuotePD reserves must be sent in for inspection after 25 uses or 40 pack jobs Thanks for the correction, Drew. As for the older Ravens, none of them caused me concern either (as long as they were properly W/L).Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites
nate_1979 9 #30 December 31, 2006 QuoteAccording to the PD article, the PD Reserve was approved in 1989 and has been on sale since. So thats 17 years of sales. The R&D costs should have been covered by now so they just need to recoup costs of manufacture. Main canopies have a shorter market life, the Sabre was replaced by the Sabre 2 etc... so the R&D costs need to be covered in a shorter time frame. I have heard that the PD Reserve has been the same all 17 years, however I recently heard that there may be differences between the older ones (like mine which is about 15 years old) and newer ones, ... Newer ones easier to pack / less pack volume? Any riggers (or others) have any experience with the older PD-Rs vs. the newer ones and have any input to this? As a side note, regardless, I do intend to replace my reserve with a new one this year assuming that I have the money to do so. FGF #??? I miss the sky... There are 10 types of people in the world... those who understand binary and those who don't. Quote Share this post Link to post Share on other sites
riggerrob 643 #31 January 1, 2007 You are close. PD has not changed the design of their reserves in the last 17 years. However, over the last couple of years, PD has been experimenting with a lighter, thinner fabric than F-111. We expect PD to introduce a new line of lighter weight/smaller pack volume reserves in 2007. Quote Share this post Link to post Share on other sites
JohnRich 4 #33 January 2, 2007 Quoteyou are fat!!! I have the integrity and guts to be known for what I say. You, on the other hand, hurl childish insults while hiding behind a blank profile. Quote Share this post Link to post Share on other sites
billvon 3,059 #34 January 2, 2007 >And I wondered if you could use a reserve for a main. Yes. My first rig was a Swift; they were originally sold as a set (i.e. swift container, main and reserve.) The idea was you could jump the main for say 1000 jumps, then get rid of the main, move the reserve to the main container, and get a new reserve. One selling point of all this was that your reserve flew exactly the same as your main did, so there was no re-learning involved. This turned out to be not the best slogan, since they had some problems with mals on the Swifts. Many people have used Ravens as mains. They have main attachement points and can be used as mains or reserves. There is some debate over the legality of their use as reserves after they have been used as mains, but some manufacturers explicitly allow the user to make one "familiarization" jump on the reserve. Quote Share this post Link to post Share on other sites
mark 107 #35 January 2, 2007 QuoteSwift: they were originally sold as a set (i.e. swift container, main and reserve.) The idea was you could jump the main for say 1000 jumps, then get rid of the main, move the reserve to the main container, and get a new reserve. One selling point of all this was that your reserve flew exactly the same as your main did, so there was no re-learning involved. Your rig might have had a Swift reserve installed as the main, but that was not Para-Flite's intention. From Poynter, Vol2: The Swift main was about 200 square feet, the reserve was about 180 and designed to be more docile than the main. You might be thinking of Precision's original Ravens. Those were equipped with pilot chute attachment points for use as mains, and they were also TSOd for use as free-bagged reserves. Mark Quote Share this post Link to post Share on other sites
billvon 3,059 #36 January 2, 2007 >Your rig might have had a Swift reserve installed as the main, but >that was not Para-Flite's intention. Actually the rig I had was a Swift container with a Pursuit 215 and a very old Swift (not Swift Plus) reserve; it was quickly replaced by a PD reserve. The thing about the same canopy being used for main and reserve was explained to me by the rig's former owner. Quote Share this post Link to post Share on other sites
porterhouse 0 #37 January 2, 2007 Another reason for using F-111 on the reserves is because when Zero-P fails, it usually fails catastrophically. Zero-P is much less porous. Therefore, if there is a rip in the canopy, all the energy in the air from the opening will be channeled directly to the tear, and therefore cause the tear to become much larger. F-111 breathes more, so if there is a tear in the fabric, the air doesn't tend to rush to the spot and make the tear larger (which is a very desirable trait when you're talking about your last chance to ever have sex again). Quote Share this post Link to post Share on other sites
mark 107 #38 January 2, 2007 Quote Another reason for using F-111 on the reserves is because when Zero-P fails, it usually fails catastrophically. Reserves must pass drop tests regardless of materials, design, or construction method. Elegance of failure mode is not one of the criteria. Precision stopped using ZP fabric in reserves because riggers (rightly) complained and there wasn't enough of performance difference to warrant continuing. Thousands of jumps on thousands of ZP main canopies are a testament to the structural sufficiency of ZP fabrics. QuoteZero-P is much less porous. Therefore, if there is a rip in the canopy, all the energy in the air from the opening will be channeled directly to the tear, and therefore cause the tear to become much larger. F-111 breathes more, so if there is a tear in the fabric, the air doesn't tend to rush to the spot and make the tear larger... Maybe. But the lower tear strength of ZP also shows in pull tests on the ground, where differential air pressure is absent. The lower tear strength is a consequence of the coating that makes the fabric zero porosity. Mark Quote Share this post Link to post Share on other sites
DrewEckhardt 0 #39 January 2, 2007 QuoteQuote Another reason for using F-111 on the reserves is because when Zero-P fails, it usually fails catastrophically. Reserves must pass drop tests regardless of materials, design, or construction method. Elegance of failure mode is not one of the criteria. Opening speeds beyond reserves' placarded limits are likely in a number of situations - prematures freeflying, low reserve deployments following loss of altitude awareness while freeflying, prematures on exit from high-altitude high-speed jump runs on big way attempts, and AAD activations while unconscious. When I become my reserve's test pilot in one of those situations I want more strength than that required to satisfy the FAA minimums . Enough to avoid a failure would be i deal, followed by enough for an injury free landing, and enough for a survivable landing. Quote Share this post Link to post Share on other sites
mark 107 #40 January 2, 2007 QuoteWhen I become my reserve's test pilot in one of those situations I want more strength than that required to satisfy the FAA minimums . Enough to avoid a failure would be ideal, followed by enough for an injury free landing, and enough for a survivable landing. That's my ideal world, too!ZP is strong enough and durable enough. That's why we can use it for mains. Testing does not necessarily reveal failure modes beyond the test limits. You might want a partial fabric failure if that means survivable opening shock. I have 825# Spectra lines on my PD reserves because when I bought them I didn't know any better. I'm going to get Dacron lines next time, because even though the Dacron lines are rated for a lower weight, they'll make the openings more comfortable in those test pilot situations. Mark Quote Share this post Link to post Share on other sites
JoeG 0 #41 January 2, 2007 QuoteThe lower tear strength is a consequence of the coating that makes the fabric zero porosity Can you expound on this? Is it a mechanical or a chemical bond? How does it affect the fabric?_________________________________________ "Knowledge is Power!" Quote Share this post Link to post Share on other sites
mark 107 #42 January 2, 2007 Mechanical: it affects the deformability of the fabric. With a woven fabric, fibers at the end of a tear can move and slide a little bit. That distributes the stress and makes it harder to continue the tear. In a non-woven fabric (like paper), the fibers cannot move, so continuing a tear is easier. The ZP coating reduces the ability of the fibers to move, so moves the fabric a little bit toward the non-woven end of the scale. [Thanks, Dan Poynter!] Mark Quote Share this post Link to post Share on other sites
JoeG 0 #43 January 3, 2007 Ahh that makes perfect sense. Thanks!_________________________________________ "Knowledge is Power!" Quote Share this post Link to post Share on other sites
JohanW 0 #44 January 10, 2007 QuoteQuote Another reason for using F-111 on the reserves is because when Zero-P fails, it usually fails catastrophically.Reserves must pass drop tests regardless of materials, design, or construction method. Elegance of failure mode is not one of the criteria.It may not be a certification criterion, but AFAIK it is a design criterion. I definitely recall having read that somewhere, but I can't immediately find a reference in Poynter's or on Google.Johan. I am. I think. Quote Share this post Link to post Share on other sites
