PWScottIV

I totally agree... I was just seeing how many people who might blindly buy into my claim... Which is very likely not my actual speed, but more likely a glitch from decelerating very fast. It's easy to just blindly trust data from a graph, and many people do... It takes a lot more to actually make sure the data is accurate. That's why I'd like to compare data from at least two separate devices, like a GPS and a logging alti at the same time. Gravity Waits for No One.

No, but the wind is almost always coming from the same direction (approximately along the riverbed). Gravity Waits for No One.

So now are you going to apologize to us? Keep an open mind in this sport. You'll progress faster. Questioning things you don't understand is the best way to learn about them... They used to ridicule and even execute people for saying that the earth wasn't the center of the universe and that the earth isn't flat... Who wasn't open minded then?... The people who thought they already knew it all. I NEVER professed to know it all, I only questioned what some people had stated as being true without any science to back it up beyond "I once had a jump that showed such and such, but I don't have the data to support that claim anymore". How do you think things get discovered in this world? Your recommendation of keeping an open mind is a very good one... Because that is how science thrives. I honestly have yet to see any data that is good enough for me to fully make my mind up... I'd like to see a jump where someone has combined the data from GPS and Logging altimeter to determine if they closely support one another, or prove that there is significant error. I'm still very skeptical about the accuracy of logging altimeters. Due to the way they are measuring/calculating your decent rate while in freefall, it seems that it would be very easy to affect the reading by either placing it in high-velocity airflow or in burble. Does anyone have any such data that we could compare from a tracking jump? Gravity Waits for No One.

Yeah, if I track perpendicularly I end up going way over the airport, or the other way I end up going way past high-voltage powerlines, both of which are obstacles that I'd rather not play with. I can handle a landing and a potentially long hike on a sandy riverbed. I'll do the jumps tomorrow and see what my results are. Gravity Waits for No One.

Yeah, I'm honestly NOT trying to come off like I know it all, because I know I have a LOT to learn... Hopefully I will ALWAYS have a lot to learn. It's not the first time someone has complained that they thought I was arrogant or cocky, so it's not shocking or anything... Nor is it something I strive for, sometimes I just happen to come off that way. Sorry. As far as landing off, we have a riverbed that runs forever in each direction along our typical jumprun, so that is what I was planning to use to land on. I've tried tracking perpendicularly to the JR and I end up way too far away from the DZ when I do so, so that's why I'd like to do it the way I mentioned. Gravity Waits for No One.

There's some learning going on in this thread! Anyway, what the heck, here are a couple graphs to provide examples of the kind of tracks that people are talking about. The "j1368" one is a straight track. RW suit, no booties, skinny jumper. Even in the reduced air density at altitude, true vertical airspeeds are consistently in the 76 to 82 mph range. "j1544" is for another dive where I did a 180 turn which caused a spike in speed. It compares GPS output to Protrack data. (Raw protrack data reworked to provide a 3 second centered average rather than it's normal 6 second lagged average.) Although there is some confusion during the turn, the GPS seems to confirm that the Protrack is not totally out of whack during long, steady state flight. Of course I can't prove I didn't just spend all afternoon creating fake graphs. :) OK, thanks a lot for posting those. As you can see in the attachment above, I was apparently able to get pretty slow (~74mph) as well, with no suit. I just didn't think that was possible, so I had discredited those numbers. Gravity Waits for No One.

Ok, that's good to know because I frequently hear BS from people who know next to nothing about aerodynamics... I currently operate an engineering company and my dad was an aero engineer for Douglas and Boeing aircraft for 45 years. Don't get me wrong, as I'm not claiming to have any serious knowledge of aerodynamics and I've never worked on any such projects, but I'm not clueless either. Gravity Waits for No One.

Ok, I was staying out of it until now. Take this any which way, but for someone with a head as big as yours, you need to re-think certain things. I think instead of sounding like a badass, saying others dont track as well as you (with your jump numbers i seriously doubt you know what a good track even feels like), you should go back to square one and realize that tracking back up jump run is not safe. Seriously, humble down a bit before it's too late. There's NOTHING wrong with getting out last and then tracking UP jump run (not down), in the same direction the plane is travelling. And sorry to break it to ya, but I do have a good idea of what a good track feels like. Maybe not as much as the "experts" such as yourself, but good none the less. I don't think I'm a baddass. And anyway, how does tracking well make someone a baddass? Gravity Waits for No One.

I agree, you are wrong. There is no way in hell that someone is slowing down to 70/80mph without a wingsuit. Anyone who says so is either lying or fooling themselves. Digital logging altimeters show speeds that slow sometimes, but it's only due to fluctuations in air pressure caused by variable airflow and burble around the unit. Here you go. Here are some graphs from jumps during the recent sequential record in Z-hills. In 1923 there is 13 seconds between 78 and 91 where the sustained fall rate is in the mid 80s and you can see the speed bleeding off from 120 in the previous 17 seconds. In 1928 you can see the speed decreasing over 28 seconds to a minimum of 77.5mph. Unfortunately I don't have any data from World Team, where I was in the first group breaking off tracking for even longer, due to a problem with my Neptune which required it to go back to the facotry :-( I'm 5' 11" and weigh about 192 lbs with gear and lead. Ok, well I just didn't think it was possible to slow down to that speed... Here's a max track I did on jump 29. I was working on transitions from sit to belly to back flying during the jump and then I did my track at the end like i usually do. I apparently got down to 74mph... I have several other jumps where I got down to mid 70s too. Gravity Waits for No One.

Yes, when I'm in a good track my legs are tight together, legs locked straight, toes pointed, I'm fully de-arched and straight (except for bending at the waist to adjust my attitude), my chest is cupped as much as possible, my shoulders are hunched, and my arms are straight to my side with my palms facing down (I know some people swear by having their palms up, but I like the ability to use my hands to make small adjustments and it seems to work best with my hands cupped down). I know I'm not very experienced, but I know I don't suck at it. No, it doesn't seem like it takes a lot of physical effort to hold the position, but I'm on pretty decent shape too, so I'm not sure that I'd feel fatigued in any position if it only lasted for a minute or so. I'm gonna do a few jumps tomorrow where I get out at the end of the load and track up jump run to see how much distance I can get. I'll try to find references on the ground as I exit and deploy and check the distance on Google maps. I haven't done any tracking jumps where I just go in one direction for the whole jump because I usually cover a lot of ground very fast. I'm gonna track along a river bed we have, so if/when I land out, I'll have a safe place to land. I know. I'm still a total newb. Yep, I agree. I've been on a few tracking dives with others, but the other jumpers haven't been all that good at tracking compared to to me, so I'd definitely like to find someone to jump with who knows their shit... Nobody has sent me any protrack data... Just numbers that they remembered... But you're right, if they did there wouldn't really be any way of knowing if they were flying a wingsuit or not... Gravity Waits for No One.

Yes, but what's your frame of reference? If it's the jumper, then yes, it looks like you're developing a tremendous amount of "thrust" upwards, but if you look at the whole picture (i.e. you're primarily plummeting toward the ground), the picture doesn't look so great. I don't think you can use that as a comparison, as our velocity is WAY below the speed of sound, which is the region where I'm pretty sure that effect becomes functional. Correct me if I'm wrong, but I think the primary(possibly the sole) reason for the chines on the F-18 was for stability in high speed flight. It's also an air foil, which you've all ready conceded the human body does not excel at. Well I'm definitely not slowing my vertical decent rate down to anywhere near 70mph, but I do actually have a pretty decent track. To practice, I do a max track at the end of pretty much every jump, but on several tracking dives I've done, watching my horizontal speed relative to the ground, I'm definitely fucking booking. I've become pretty good at adjusting my attitude to optimize my glide. I can feel when I "stall" by flattening out too much, and I can feel when I'm diving too much and not preserving my altitude. I've never actually had a whole lot of interest with tracking, aside from it's ability to save my life, but I think I'm gonna work on getting some real data for myself to see what I can do. And the "magic" you've been experiencing might very well be the same "magic" that Throttle Body Spacers do to give you more hp in your car... Not saying that what you're claiming is definitely untrue, it just doesn't make sense to me. I'd like to see some REAL scientific data supporting the claim... Unfortunately all I've seen so far is several people "claiming" it is true, but don't have any REAL proof. (someone saying that they used to have the data, but it got corrupted, really isn't good enough) Not that it doesn't exist... I just haven't been presented with it yet. I'm really all ears though, so if someone has undeniable proof I'd be ecstatic. Gravity Waits for No One.

I thought typical decent rates for wingsuits were around 50-60mph... Someone cliamed they could get 70mph with just their body... I'd say that's "aproaching" wingsuit decent rates. As far as wreckage, imagine how relatively slow a big sheet of aluminum would fall relative to a person. Now imagine there's wind pushing that piece. It's not hard to imagine how far it could get pushed. Gravity Waits for No One.

Yep, that seems to be the same thing. Gravity Waits for No One.

How can you explain 102 seconds of freefall from 13,500 feet to 2,100 feet in an RW suit? How could I fool a Pro-Track into logging more free-fall time than actual time? How could I fool the exit or opening altitudes? That's why I wanted to see the data for myself. No offense, but I just don't believe that it's possible to slow your decent rate down near wingsuit speeds. It just does not make sense. Gravity Waits for No One.

How was their decent rate being measured/calculated? I just don't buy it... The human body sucks when it comes to acting as an airfoil. Is there concrete scientific proof or is this just information from some guy/s? I'm not arguing about the ability to fly horizontally that fast, just not slow their decent rate to that slow. That's aproaching wingsuit decent rates... Gravity Waits for No One.

I agree, you are wrong. There is no way in hell that someone is slowing down to 70/80mph without a wingsuit. Anyone who says so is either lying or fooling themselves. Digital logging altimeters show speeds that slow sometimes, but it's only due to fluctuations in air pressure caused by variable airflow and burble around the unit. Gravity Waits for No One.

Totally, I guess I should have specified that I was talking about armor piercing handgun rounds. They're what's illegal. I thought I even saw some of these "cop killer" bullets on a documentary, but I could be wrong. As I remember, the geometry seemed to be very simple and crude; just a straight taperd tip(maybe 90deg included angle) that was made from steel or a steel core. I imagine they were jacketed with somthing softer to minimize wear on the bore. Gravity Waits for No One.

How slow is "relatively slow"? Gravity Waits for No One.

Agreed... It would be *nice* to think we could generate a lot of lift with our bodies, but that's just not the case. Most of what's happening in a track is essentially thrust vectoring... Biasing the flow of relative wind off one side of your body or the other. There probably is a very small amount of aerodynamic lift created in a max track, but without a wingsuit, the effect is probbaly going to be relatively imperceivable. Gravity Waits for No One.

How sure are you that you can get your vertical velocity anywhere near that slow? I seriously doubt anyone can do that without a wingsuit. The physics you're proposing just don't make sense. Your body is not all that great of an airfoil with respect to creating a lot of lift. I know it's easy to fly fast horizontaly in a track, but that doesn't have a whole lot to do with "lift" like you see with an aircraft wing. It mostly has to do with the fact that the relative wind is glancing off your body at an angle. Gravity Waits for No One.

Umm, the ONLY way you're going to decend that slow is with a wingsuit. Just because you can move sideways, doesn't mean you're generating enough lift to slow your decent rate to sub-terminal (~120mph). Gravity Waits for No One.

Wouldn't a theoretical ratio of 1:1 mean you would actually achieve 60 mph horizontal and 60 mph vertical? Or am I confused Only if you were falling at 60mph... If you were falling at 120mph, and traversing at 120mph, that would be a 1:1 glide ratio. Your forward speed would be about 170mph. Gravity Waits for No One.

Kung fu gives exercise, mental discipline, and so forth. I would guess that given all the right conditions kung fu is very safe for young students. Given perfect conditions skydiving can still kill you dead. Apparently drinking too much water can kill you dead too. We should ban it... Especially for children. Gravity Waits for No One.

Unfortunately, mine too. Gravity Waits for No One.

"My other car is a limo." Gravity Waits for No One.