labrys 0 #26 September 11, 2007 QuoteWould you say that a ram-air canopy, since it is unpowered and constantly descending, does not develop lift ? Yes, I suppose it does.Owned by Remi #? Quote Share this post Link to post Share on other sites
AFFI 0 #27 September 11, 2007 QuoteHow would you describe your tracking position? A Canadian Instructor I admire would compare it to the long ski jump body position - even though there are differences I think this is a good analogy.Mykel AFF-I10 Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat… Quote Share this post Link to post Share on other sites
wildcard451 0 #28 September 11, 2007 As someone else said... Go to Cross Keys. Find a member of CK1 (Yonatan, Will, Jimmy). Get tracking coaching/theory discussion. Leave your friends behind. Those guys are some of the best trackers I have seen, and readily available to you. Take advantage of it. Quote Share this post Link to post Share on other sites
pchapman 279 #29 September 11, 2007 Just to clarify the terminology, as used in aerospace engineering and aviation: Lift is the force perpendicular to the direction the flight vehicle is moving. Drag is the force opposite to that movement. Together, lift and drag combine to perfectly oppose weight, if the vehicle is in steady motion and not accelerating. See diagram. L=lift, W=weight, D=drag, V= velocity So a tracking jumper creates lift. Lift is contributing to keeping the jumper from falling faster, even if that lift is not from Bernoulli style flow, moving smoothly along the object's surface like on an airplane wing. In a sense the lift from a tracking jumper will be like that of drag, just a force from having a rough, non-aerodynamic, blunt object forced through the air. Since that blunt object is at an angle to the air, the force created ends up angled away from the direction the object is moving. We then represent that single overall force by the forces at right angles to each other, which we define as Lift and Drag. A 180 lb jumper in a steady track will have lift and drag combine to a 180 lb upwards force, no matter how good or bad the track is. (Indeed, it will be the same when the jumper is under canopy.) Thinking about lift and drag for skydivers is a little messier than for airplanes. For planes the angle of attack is so small that for a first approximation, one can think of drag as "towards the tail" and lift "up" relative to the airplane flying level. But for a skydiver at maybe a 0.5 glide ratio in a track, with lets guess a body angle 10 degrees head down from level, that's an angle of attack of 53 degrees. So Lift and Drag directions are not "straight up away from your back" and "towards your feet", nor "vertical" and "horizontal". No big deal, but it makes thinking about lift and drag less intuitive. In the end, when it comes to tracking: As the combination of lift and drag stays the same, the issue becomes how to achieve that combination with a lot of forward speed, or a high glide ratio, depending on your goals. A lot of drag and a lot of lift are both helpful in achieving those goals. Quote Share this post Link to post Share on other sites
Myrka 0 #30 September 11, 2007 QuoteQuoteslow fallrate is just by-product of going horizontally really fast.... You left off the "and generating some lift" part. If you can find a body position that will allow a tracker to generate lift, you'll be a popular guy. Since we dont have engines and can't generate lift, we have to reduce fall rate to a minimum so that we have more time on the way to pull altitude to get maximum horizontal separation. Hey guys: It is in my understanding that during tracking you simply attempt to convert your body to an airfoil shape. When do, it behaves similarly to the wing of the airplane, or even the canopy, but the principle is generally the same, and yes, it generates lift and drag, and creates a glide ratio (distance traveled::horizontal speed over height lost::vertical speed). Factors that shape the human airfoil of course are arms, shoulder position and shape of the rig, etc.. There was a study done in 1969 if you’re interested (http://www.usaarl.army.mil/TechReports/69-9.PDF) Quote Share this post Link to post Share on other sites
pilotdave 0 #31 September 11, 2007 QuoteA 180 lb jumper in a steady track will have lift and drag combine to a 180 lb upwards force, no matter how good or bad the track is. This assumes there's no acceleration (or deceleration if you prefer). The jumper's fall rate wouldn't change if he produced only his weight in lift. We're apparently able to create slightly more lift (and drag) than our weight, which causes our fallrate to decrease. Eventually a steady-state is reached when our fallrate decreases enough to reduce the amount of lift being produced, and we maintain a constant fallrate. Dave Quote Share this post Link to post Share on other sites
hackish 8 #32 September 11, 2007 I'm working on my tracking as well. Does anyone have a good photo that shows a really good tracking position? A few people have showed me (dirt diving) how they track and everyone seems to be a little different. -Michael Quote Share this post Link to post Share on other sites
Myrka 0 #33 September 11, 2007 Dave: I'm still a n00b and have no idea what i'm doing, but i recorded one of my dives this weekend on AltiTrack, and i did slow down when I tracked. I did 2 tracks separated by 180 turn about 25 seconds in the dive, and speed graph is attached. Quote Share this post Link to post Share on other sites
darkwing 5 #34 September 11, 2007 It is absolutely NOT the case that slow fall necessarily = good track. However, a good track is not a fast fall rate. Other than that I agree with most of the advice. -- Jeff My Skydiving History Quote Share this post Link to post Share on other sites
pilotdave 0 #35 September 11, 2007 You're probably better off getting a picture of your own track than a perfect one. Chances are you'll be able to see what you're doing wrong by looking at yourself. I film all the coach jumps I do... Really helps the students see that they aren't doing what they were taught. They think they have their legs out and are dearched, but the video almost always proves them wrong. Dave Quote Share this post Link to post Share on other sites
AUSkyguy 0 #36 September 11, 2007 Here's a couple of pics both back tracking and belly tracking...-Chris Martin Quote Share this post Link to post Share on other sites
AFFI 0 #37 September 11, 2007 Elephant tracking trajectory... Quote Share this post Link to post Share on other sites
Myrka 0 #38 September 11, 2007 Quote Elephant tracking trajectory... is that good or bad? Quote Share this post Link to post Share on other sites
Remster 30 #39 September 11, 2007 QuoteHere's a couple of pics both back tracking and belly tracking... Thats why I dont think group tracking jumps are necessarally good tracking practices. These tracking positions are awfull.Remster Quote Share this post Link to post Share on other sites
Fast 0 #40 September 11, 2007 QuoteQuoteHere's a couple of pics both back tracking and belly tracking... Thats why I dont think group tracking jumps are necessarally good tracking practices. These tracking positions are awfull. I agree. The tracking position shown in the "belly down" tracking picture is pretty bad. For all the jumpers in it. That would be more of a delta, not a track. The idea that I teach is to get the belly side of yoru body to form into the shape that the top of an otter wing makes. You never really quite get that, but the idea works pretty well. Make sure you are rolling your shoulders up to your ears and once you're comfortable you should be brining your arms in and legs together for even more speed.~D Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me. Swooping is taking one last poke at the bear before escaping it's cave - davelepka Quote Share this post Link to post Share on other sites
AUSkyguy 0 #41 September 11, 2007 I know they aren't great pics for learning but come on guys... Post some of your own pics, The only reason i posted those is because no one else was posting any pictures -Chris Martin Quote Share this post Link to post Share on other sites
pilotdave 0 #42 September 11, 2007 Best I could find of my own pics. The Guy on the left gets right into his max track position very early in his track. He starts in a "superman" position with his hands out front, then suddenly throws his arms under him into a flat tracking position. Dave Quote Share this post Link to post Share on other sites
Butters 0 #43 September 11, 2007 QuoteQuoteHere's a couple of pics both back tracking and belly tracking... Thats why I dont think group tracking jumps are necessarally good tracking practices. These tracking positions are awfull. Question, do you believe these are awful tracking positions or awful max tracking positions? The reason I ask is that I am really into tracking ... almost all of my jumps are tracking jumps. I want to become a really good belly and back tracker and eventually be able to dock and form formations (if I can find other people to track with me)."That looks dangerous." Leopold Stotch Quote Share this post Link to post Share on other sites
kallend 2,026 #44 September 11, 2007 QuoteQuoteQuoteHere's a couple of pics both back tracking and belly tracking... Thats why I dont think group tracking jumps are necessarally good tracking practices. These tracking positions are awfull. Question, do you believe these are awful tracking positions or awful max tracking positions? The reason I ask is that I am really into tracking ... almost all of my jumps are tracking jumps. I want to become a really good belly and back tracker and eventually be able to dock and form formations (if I can find other people to track with me). If you are tracking in a formation you have to go at the speed of the worst tracker in the group, or you won't stay in formation. That's why tracking dives are not good practice for max tracking.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
kallend 2,026 #45 September 11, 2007 QuoteBest I could find of my own pics. The Guy on the left gets right into his max track position very early in his track. He starts in a "superman" position with his hands out front, then suddenly throws his arms under him into a flat tracking position. Dave There are a bunch of tracking pictures in this thread, with some narrative: www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1435381#1435381... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
Butters 0 #46 September 11, 2007 Quote Quote Quote Quote Here's a couple of pics both back tracking and belly tracking... Thats why I dont think group tracking jumps are necessarally good tracking practices. These tracking positions are awfull. Question, do you believe these are awful tracking positions or awful max tracking positions? The reason I ask is that I am really into tracking ... almost all of my jumps are tracking jumps. I want to become a really good belly and back tracker and eventually be able to dock and form formations (if I can find other people to track with me). If you are tracking in a formation you have to go at the speed of the worst tracker in the group, or you won't stay in formation. That's why tracking dives are not good practice for max tracking. Thanks. That is what I thought. PS: I went on a tracking jump last week with three other people where point had never been point and was one of the most skilled trackers ... right away the point went into a max track, needless to say the group began to separate both horizontally and vertically and never came close to forming a diamond. My head was on a swivel ... The next tracking jump was with two other people where point was one of the least skilled trackers. We formed a close proximity triangle, it was awesome! Sorry, I had to share, I just love tracking ... "That looks dangerous." Leopold Stotch Quote Share this post Link to post Share on other sites
kelpdiver 2 #47 September 12, 2007 Quote If you are tracking in a formation you have to go at the speed of the worst tracker in the group, or you won't stay in formation. That's why tracking dives are not good practice for max tracking. might be ok for those going from unknown tracking to half decent, though I stayed away from those large groups out of concern for the zoo factor at pull time. It only took a couple practice jumps and ground talk in a small group lead by John Hamilton at Elsinore to get substantially better than I was prior. (thought thanks to the shoulder injury, I'm probably starting back over again) Quote Share this post Link to post Share on other sites
Fast 0 #48 September 12, 2007 Quote I know they aren't great pics for learning but come on guys... Post some of your own pics, The only reason i posted those is because no one else was posting any pictures Sorry, I don't have any great pictures. The one dave posted does show a decent tracking position. The guy in yellow is.. uh "Guy" ~D Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me. Swooping is taking one last poke at the bear before escaping it's cave - davelepka Quote Share this post Link to post Share on other sites
pirana 0 #49 September 12, 2007 QuoteThe explanation that seems most reasonable is that the track position provides a lot of drag to slow the descent and an angle that deflects a massive amount of air to the rear, giving forward speed. This one gets my vote. Tracking is achieved primarily by changing the angle of attack." . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley Quote Share this post Link to post Share on other sites
