madhatter 0 #1 March 6, 2008 I'm curious about the regulations for tandem skydiving. In THIS thread in Suggestions & Feedback, the following statement is made numerous times: " if lift do not exist in atmo , in which way is possible that the vertical speed when I do the atmo-tandem with out drogue , is around 180 km/h ( 110 miles/h ) ? …." I've gone on a few drogueless tandems as a passenger for trainee tandem instructors. What's the general rules when going drogueless with a 'non-skydiver' passenger, for something other than training purposes? How do the manufacturers of tandem equipment feel about this practice?A VERY MERRY UNBIRTHDAY TO YOU!!! D.S # 125 Quote Share this post Link to post Share on other sites
diablopilot 2 #2 March 6, 2008 AFAIK, Strong and UPT both forbid it, as well as the USPA.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
hackish 8 #3 March 7, 2008 I think the real issue would be exceeding the maximum deployment speed as specified in the TSO for the gear. I can't imagine it being a very pleasant deployment anyway? -Michael Quote Share this post Link to post Share on other sites
diablopilot 2 #4 March 7, 2008 In addition to the possibility of unplanned high speed deployment, there is the increased risk of instability, injury to the student, excessive wear/failure of the drogue and related components, and loss of altitude awareness.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
riggerrob 643 #5 March 7, 2008 Drogue-less tandems are a bad idea! Take it from someone who started with Vector I, before drogues were introduced. Openings are HARD! Hard on your shoulders, hard on risers and main canopies don't last very long. The greatest danger is that you will have to deploy a reserve and you might tear your reserve because you are going too fast. Remember that energy increases with the SQUARE of the velocity. If you still insist on doing drogueless tandems (GRRRR!) then plan on tossing the drogue above 7,000 feet and decelerating for 15 seconds before deploying your main. Quote Share this post Link to post Share on other sites
madhatter 0 #6 March 7, 2008 I'm not planning on trying it anytime soon. I can understand the use in having a tandem instructor experiencing it during training, just as we try to expose them to other negative scenarios they might encounter in their tandem career. The reason for my question was to determine the legality of Marco Tiezzi doing drogueless atmonauti tandems... They're even advertised on www.atmonauti.com @ Euro 160 a pop.A VERY MERRY UNBIRTHDAY TO YOU!!! D.S # 125 Quote Share this post Link to post Share on other sites
diablopilot 2 #7 March 7, 2008 Don't know what the regulations are in the country he's doing them, nor on the system he's using (Atom I think.) However it's a poor idea to be doing with wuffos.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
firstime 0 #8 March 9, 2008 I just saw a video today about tandems not deploying the drouge because a flat spin that happens so fast that it's beyond the TI's control. It was the most horrific video I seen in quite some time and it has given me a huge amount of respect (HUGE) for you that carry passengers. Sorry if this is not on topic but had to voice.. Still shaking my head...... I will to this day forward look at a TI with more admiration than ever. I love this sport with a passion, but to have a "full plate" everyday, every jump... WTF. Two thumbs up to you all Quote Share this post Link to post Share on other sites
riggerrob 643 #9 March 9, 2008 The last time I watched the side spin video (published by Strong Enterprises), I concluded that most of those people would still be alive if they had deployed their drogues 2 seconds after exit. Most of them were - briefly - stable exactly 2 seconds after exit. Quote Share this post Link to post Share on other sites
fcajump 164 #10 March 11, 2008 Quote AFAIK, Strong and UPT both forbid it, as well as the USPA. Its been a while since I have done Tandem, but am looking to reeducate myself and get back in the TI saddle this year... While I can see the wisdom of using the drogue (significantly) before deployment, and the assistance it gives in staying out of a side-spin, I do not see published where it is forbidden. Strong and USPA both reference no back-to-earth and no drogueless vertical orientations, but I don't see anything that forbids drogueless freefall... In fact, one of the required dives for Strong TI (when I went through it) was specifically a drogueless freefall with turns to point and track before setting the drogue. (passed it even though I lost my goggles on exit...) I would appreciate references that can bring me up to date on this if the policies have changed since I instructed last.... JWAlways remember that some clouds are harder than others... Quote Share this post Link to post Share on other sites
riggerrob 643 #11 March 11, 2008 This is a subtle point: even if drogueless head-down tandems are not banned in writing, they are still a bad idea. The only reason we ask new TIs to delay tossing a drogue on one of their training dives, is a confidence builder. Just because a TE asks you to do an exercise once, does not mean that it should become standard practice. Yes, back in the good old days, I did a bunch of drogueless tandem jumps (with a Vector I), but now I consider the practice foolish, because it vastly increases the risk of tearing a reserve canopy.. Quote Share this post Link to post Share on other sites
fcajump 164 #12 March 11, 2008 QuoteThis is a subtle point: even if drogueless head-down tandems are not banned in writing, they are still a bad idea. The only reason we ask new TIs to delay tossing a drogue on one of their training dives, is a confidence builder. Just because a TE asks you to do an exercise once, does not mean that it should become standard practice. Yes, back in the good old days, I did a bunch of drogueless tandem jumps (with a Vector I), but now I consider the practice foolish, because it vastly increases the risk of tearing a reserve canopy.. (Actually, head-down is specifically listed as forbidden...) I am not questioning the bennefits of the drogue, simple questioning the statement that (implied: "all") drogueless is forbidden by UPT, STRONG, USPA... Also: does anyone have handy the TSO limits for Strong of UTP tandem reserves? NOTE: I AM NOT suggesting that people do this, but I don't know of any rule "forbidding" drogueless freefall for the upper end of the dive. And if one were to do so, I am curious of the TSO speed ratings for the rigs... JWAlways remember that some clouds are harder than others... Quote Share this post Link to post Share on other sites
billbooth 10 #13 March 11, 2008 Back in 1983, I drop tested my (Relative Workshop...now UPT) 360 tandem reserve canopy (and rig) at 650 lbs. and 250 mph. (Tandem terminal is 170-180 mph.) After 25 years, we still use the same reserve canopy. I did a couple of hundred drogueless terminal deployments back then, but wouldn't do one again, unless I had to. I'm older and smarter than that now. Even going to tandem terminal, and then using the drogue to slow down before deployment is not a good idea, because it "tears" up the drogue pretty quickly.Quote Quote Share this post Link to post Share on other sites riggerrob 643 #14 April 10, 2008 I've gone on a few drogueless tandems as a passenger for trainee tandem instructors. What's the general rules when going drogueless with a 'non-skydiver' passenger, for something other than training purposes? How do the manufacturers of tandem equipment feel about this practice? Strong Enterprises says that drogueless tandems should only be done under the supervision of a Tandem Examiner. only with senior jumpers on the front and only when training TIs. The training objective is to teach new TIs that they can maintain control even at tandem terminal speeds. This helps reinforce the point that it is more important to get stable before tossing the drogue. New TIs usually do deliberately unstable exits during level 4 and level 5. After that, drogueless tandems may be done as part of spring refresher training, but only under the supervision of a TE and only with a licensed jumper on the front. Quote Share this post Link to post Share on other sites
riggerrob 643 #14 April 10, 2008 I've gone on a few drogueless tandems as a passenger for trainee tandem instructors. What's the general rules when going drogueless with a 'non-skydiver' passenger, for something other than training purposes? How do the manufacturers of tandem equipment feel about this practice? Strong Enterprises says that drogueless tandems should only be done under the supervision of a Tandem Examiner. only with senior jumpers on the front and only when training TIs. The training objective is to teach new TIs that they can maintain control even at tandem terminal speeds. This helps reinforce the point that it is more important to get stable before tossing the drogue. New TIs usually do deliberately unstable exits during level 4 and level 5. After that, drogueless tandems may be done as part of spring refresher training, but only under the supervision of a TE and only with a licensed jumper on the front. Quote Share this post Link to post Share on other sites
madhatter 0 #15 April 10, 2008 Thanks for that answer - that's how I understood our training (even though we're a Vector dz). Still seems there's no regulations prohibiting drogueless tandems except for the manufacturers'. Guess our atmo buddy's just being reckless, not illegal...A VERY MERRY UNBIRTHDAY TO YOU!!! D.S # 125 Quote Share this post Link to post Share on other sites
NickDG 23 #16 April 10, 2008 There's an inherent and natural reefing all canopies, round and square, exhibit in high speed environments. It's called squidding. And it means the canopy just can't overcome the power of the passing air molecules to spread until it slows the load down enough. It's the reason we could do terminal deployments on early squares before rings & ropes and the slider was invented. Squares of the day were way over built so I wouldn't do that today with a small light weight 9-cell, but there is a downside to modern reefing. If the system starts to slow you down, and then the reefing system fails, for whatever reason then you get a real slammer. My girlfriend, who's an engineer at JPL, was in on deigning the Rovers currently on Mars. When Vertigo (a bunch of eggheads who don't jump) where tasked with designing the parachutes for the Rovers their first few attempts in the wind tunnel got them a huge round with the apex pressurized and a closed skirt. These bozos labored over their sideways math and slide rules without a clue about what squidding was. B.A.S.E. jumpers are also counting on squidding without realizing it. We use mesh covered sliders on terminal delays not to control the opening so much but to control the lines. So find yourself a well preserved 1970s vintage Strato Cloud and you could bang out terminal no slider deployments all day long. But you couldn't because the current definition of a hard opening is something you felt . . . Oh, and that's how they actually did early tandem terminal jumps without a drogue. It wasn't so much the slider as it was squidding . . . NickD Quote Share this post Link to post Share on other sites
SPAWNmaster 0 #17 April 11, 2008 Quote There's an inherent and natural reefing all canopies, round and square, exhibit in high speed environments. It's called squidding. And it means the canopy just can't overcome the power of the passing air molecules to spread until it slows the load down enough. It's the reason we could do terminal deployments on early squares before rings & ropes and the slider was invented. Squares of the day were way over built so I wouldn't do that today with a small light weight 9-cell, but there is a downside to modern reefing. If the system starts to slow you down, and then the reefing system fails, for whatever reason then you get a real slammer. My girlfriend, who's an engineer at JPL, was in on deigning the Rovers currently on Mars. When Vertigo (a bunch of eggheads who don't jump) where tasked with designing the parachutes for the Rovers their first few attempts in the wind tunnel got them a huge round with the apex pressurized and a closed skirt. These bozos labored over their sideways math and slide rules without a clue about what squidding was. B.A.S.E. jumpers are also counting on squidding without realizing it. We use mesh covered sliders on terminal delays not to control the opening so much but to control the lines. So find yourself a well preserved 1970s vintage Strato Cloud and you could bang out terminal no slider deployments all day long. But you couldn't because the current definition of a hard opening is something you felt . . . Oh, and that's how they actually did early tandem terminal jumps without a drogue. It wasn't so much the slider as it was squidding . . . NickD Goddamn, Nick...every post I read of yours both from DZ.com and Basejumper.com I always learn something. Here's to helpful jumpers *beer* Quote Share this post Link to post Share on other sites
AdD 1 #18 April 14, 2008 What was the result of that droptest? Were the canopy or lines damaged? I would love to see some reserve droptest data for various manufacturers posted online.Life is ez On the dz Every jumper's dream 3 rigs and an airstream Quote Share this post Link to post Share on other sites
skydived19006 4 #19 April 14, 2008 QuoteWhat was the result of that droptest? Were the canopy or lines damaged? I would love to see some reserve droptest data for various manufacturers posted online. From: http://www.parachutesaustralia.com/s2/prod_icarus_tan.php We transferred the Icarus Tandem construction into the Precision TR375 tandem reserve and put it through the FAA TSO process. During the heavy drop testing we gradually increased the weight and speed and eventually dropped the canopy at 250MPH with 900lbs under it (400 KPH with 400 KG) the equivalent of 4 people doing double terminal. Measuring equipment on the dummy showed the total load on the canopy during the opening had been almost 10,000 lbs (4.5 tonne's). The canopy opened perfectly with no damage. (Exit height for these tests was 300ft)Experience is what you get when you thought you were going to get something else. AC DZ Quote Share this post Link to post Share on other sites
jurgencamps 0 #20 April 15, 2008 Quote... Guess our atmo buddy's just being reckless, not illegal... But only if his vertical speed is higher than the normal vertical speed with a drogue. So check this out and let us know if this is the case, before you make your statement. BTW You can say the same thing (being reckless) about backflip exits I guess. Quote Share this post Link to post Share on other sites
riggerrob 643 #21 April 15, 2008 Wow! That is more than a 10 G opening! You sure would not want to be awake for that opening! We had a similar experience in 1994, when we were drop testing P124A/Aviator (pilot emergency system) prototypes. After we completed enough heavy-weight (I lost count after 360 pounds) and high-speed drop (205 knots) tests to satisfy TSO C23D, George Galloway (head of Precision Aerodynamics) told us to continue upping the weight. We ran out of day light before we ran out of lead weights. The moral of the story is that we were not able to tear a P124A canopy made by Precision. Quote Share this post Link to post Share on other sites
skydived19006 4 #22 April 16, 2008 We had Mark "Shoobie" Knutson out to train us when we got our Eclipse ratings, and bought our first rig from him. It was interesting to talk with him about the certification testing. Like you said, after they'd passed they kept going adding weight and speed. He said the thing was landing so hard that the weight was burring itself in the ground. I'd like to be there just to see the Casa passing over at 300', 250 mph, and see the thing open and land. Most likely a short canopy "ride"!Experience is what you get when you thought you were going to get something else. AC DZ Quote Share this post Link to post Share on other sites
skydiverek 63 #23 April 16, 2008 Check the JumpShack "Test Jumps & Drop Tests" here: http://www.jumpshack.com/default.asp?CategoryID=Video%5FGallery Quote Share this post Link to post Share on other sites
AdD 1 #24 April 17, 2008 Cool, I had heard good things about precision reserves before, have also used one on a tandem subterminal. I liked it's flight characteristics and the opening was sweet. Those are pretty impressive parameters though. I would be particularly curious about Strong's Master test drop results.Life is ez On the dz Every jumper's dream 3 rigs and an airstream Quote Share this post Link to post Share on other sites
Radioshack 0 #25 April 19, 2008 Here is a video of a (mostly) drogueless tandem... mostly, because they do deploy it a little before they pull the main canopy... http://youtube.com/watch?v=5iV6DRD78k8 Quote Share this post Link to post Share on other sites
