mdrejhon

Don't thank me...thank yourself and your instructor! But appreciated! AND congratulations for being back in the air. Now get back up there and keep jumping. (Within financial reason) Be safe, and never let your guard up at landing. I'm still super focussed on my landings 600 jumps later.

Fixed it for ya. There's no problem trying to make the landing so safe that you are able to do pillow-soft stands most of the time, but safety is the priority that comes before trying to stand up a harder-than-usual landing.

No, but I could feel the vibrations of the arcade machine, especially when I was eating blue ghosts.

What's that waka-waka-waka-waka sound coming from the next cubicle?

I have often wanted to get a job in the United States when I was offered a good one or a good contract. I even had the opportunity to do so last year, despite the recession, but was stuck in Canada between jobs part of the time. I have actually done this pre-9/11, before moving back to Canada. It's much tougher now. Unfortunately, I do not have a university/college degree. Therefore, I do not qualify for a H1-B at all! Which means I have to go through much more complex visa routes (i.e. TN-1 visa) and even so, it's extremely difficult. Yet household income is 6 figures, and we'd benefit the U.S. economy quite a bit if it ever ended up being a permanent relocation. There's a way for people to sorta 'buy' (er, 'invest') their way into the states. If I quit skydiving, it'd be much easier to save up an $X amount (I think it was $250,000 when I did my research years ago, before it went up) to 'buy' my way into USA (Basically starting a business in U.S.) -- I am incorporated as a consulting business and could theoretically invest in running a U.S. business just by moving my business over. That is a potential loophole (from needing a university degree) available to me, if I had that money, but I don't even have a significant fraction of a million dollars available to me. I would have to get an equivalency degree from a reputable university using the skills I already have, and back it up with some recurrency studies (which may still take me a year or two). At this time it's not practical, and there is plenty of work in Canada that's almost as good paying, to the point where it is not worth the time and effort for me to go retroactively back to university. The U.S. does not easily allow Bill Gates style immigration. (Although Bill Gates, did, indeed, later get a degree retroactively) During last year's recession to fix my cashflow problem while staying in Canada, I let myself become flexible (accept any job from Ottawa-Toronto-Montreal, major cities all within 5 hour drive of each other). Nortel's bankruptcy really hurt Ottawa at the time, but Toronto and Montreal have massive job markets. Instead of considering America, me and my spouse are relocating to Toronto as of June. We have some great opportunities we're starting next month, that will almost double our combined average household income (becoming DINK's), although offset somewhat by Toronto's higher cost of living. U.S. remains a fun vacation destination that will receive a lot of tourist dollars from me, and skydiving dollars (and the occasional business trip I get sent on in my lifetime), but from an immigration perspective, I fall through the cracks even though I would have more net-benefit to U.S. than most immigrants... That's my "stay in my own country and build the best life possible" option.

For those unfamiliar, there's a well-known downturn in Mark's life -- which may or may not have played a role. This is a condolences thread so I think people rather not discuss this subject mattrer in this thread. (Search term 'Slyde' in dz.com forums) For those not familiar who Mark is, www.MarkSchlatterSkydiving.com

The ASUS one is great looking too - nVidia would blow the 3D performance of the other one away. For office apps, I think both laptops would have similiar performance. Just hope you don't get a defective unit. My Acer has been rock stable. Even standbys/hibernates very fast (1-2 second standby, 15 second hibernate)

virgin-burner, Here are good clickies. Do not use quotation marks when doing the google search, for this type of search term. When people put google search keywords, usually you don't copy and paste the quote marks. The model number is sufficiently context enough. Clicky: 'Acer Aspire 1810T' Clicky: 'Acer Timeline 1810T' Clicky: Amazon 4.5 star average rating by users! Clicky: Future Shop 4 star average rating by users Be warned, some of these places are clearing these laptops out for the summer release of the 1830T which is the Core i3 version. (A netbook sized Core i3 machine!). But that means you may be able to get a 1810T at a good price too, as some places sold that one for $750 before...

An excellent ultraportable to consider is the Acer Timeline 1810T, or the upcoming 1830T (which uses the Core i3 instead). These 'netbook' like ultraportables use real CPU's rather than Atoms. I have one of those, and love it. 11.6" screen, Core2 Duo dual-core, 1080p video capable (external BluRay drive works), HDMI output, gigabit Ethernet, latest 11n WiFi, Bluetooth 2.1, 4 gigs RAM, 320 gigs HDD, Windows 7 Professional, and 8 hour battery (6 hour real-world) ...all in a 3 pound netbook form factor! (I paid $649 for it.)

That is a legitimate question, and is which is why scientific testing is needed to really prove those out. There is numerous anecdotes from dummy drop tests by parachute manufacturers and riggers, including two postings made in the last few days in a different thread. (There are dozens others that come up time and again, including in the Incidents forum, too.) . JerryBaumchen: Every square reserve that I have ever drop tested with a dummy has turned down-wind; bar none. JerryBaumchen . captain1976: Myth. Fact. There are probably exceptions, but since I hang out, fly the airplanes and help at a parachute testing facility, I would put the figures in the high 90% range for an unassisted square with or without brakes to assume down wind flight. ______________________________________ Although Mythbusters isn't that scientific, it could make one kick-ass Mythbusters special. One Quick Way to Disprove Naysayers If one doesn't care about anecdotes, just throw a paper airplane crosswind through the air stream of a fan. Paper airplane nose tilts towards downwind as the leading edge of the plane hits the faster moving cross wind. This even still happens halfway across a room from the fan if you're flying a very light slow-moving paper airplane with large wings. Note, This is Just ONE test case Yes, there are more kinds of wind-speed boundaries in the atmosphere, but you've still just instantly personally disproved the naysayers by the above experiment. But, this single test case is very repeatable and reliable, and is ALL we need to prove that, at least in ONE cases, there EXISTS a way for a wind to point a wing towards the downwind direction. Some wind-speed boundaries, are similiar, at a grander scale, with smaller turns to downwind resulting (that eventually builds up). There's all kinds. Horizontal pressure bounaries. Vertical pressure boundaries. Eddies. Vortices. You name it. But we've definitely proven, personally, without a doubt, that at least when a wingform goes through at least one kind of wind speed boundary, there's a definite, reliable, repeatable downwind shift. (try it yourself! All you need is a fan and a paper airplane.) More advanced paper airplane test: Another, experimental test (using the real outdoors rather than a fan), is throwing paper airplanes crosswind in an intermittent breeze. Repeat throw many times. The noses of paper airplanes tend to rotate towards downwind more often than upwind, when you throw paper airplanes crosswind in an intermittent breeze. Count each occurance (X times turned upwind, X times turned downwind, X times no change). Consistent winds won't do much, so you need intermittency or turbulence during the flight of the paper airplane, like a gusty day, or throwing behind an obstacle that injects turbulence into the wind. This is easier with a 10 minute parachute flight than a 5 second paper airplane flight, since winds don't always vary much over a 5 second period, so bear this in mind when testing. Also easier with lighter paper airplanes with big wings will also, be more affected, than sleek fast-flying paper airplanes, so test with lighter ones that otherwise glide in a straight line in a dead-still room. (good to calibrate the paper airplane's flight path reliability first, and throw crosswind in both directions (left-of-upwind and right-of-upwind) to eliminate chance that a built-in turn in the paper airplane, is distorting the experimental data. _______________________________ In closing, this is a legitimate question that requires more scientific tests, and is which is why scientific testing is needed to really prove these out. This may be a useful topic for a university student to take upon, or a parachute manufacturer's dummy drop test, to include additional sensor tests into their dummy to record data.

I wonder if my first exposure to skydiving as a spectator, in 1988 as a kid, was watching one of Mark's demo jumps. I will never know, because I don't even remember exactly where it was except it was an hour outside Northhampton during the summer. Regardless of what happened to Mark I have a lot of respect for the demo jumpers and just only hope the family is not too traumatized, seeing Mom and Dad outlives Mark. Given the circumstances it probably was a sad death but I hope he is at peace now, and I know he had his 'Good Days'... Just a token toast to the demo jumper 'up there' now

Added Note to above post: Wind direction measurements would need to be known too (i.e. meterological data). But for improved accuracy, another sensor may need to be added to the dummy to determine forward airspeed (pitot type sensor). This would be subtracted from the GPS track so that the leftover GPS track determine the direction and magnitude of wind. A new wind vector could in theory be be calculated every few feet of altitude. This would be much more accurate than the day's meterological data for wind direction. If no airspeed sensor is available to help improve accuracy of these calculations, then known glideslope data for the parachute could also be used instead (unless brake stops and planeforms was being changed from jump to jump), to deduce wind direction from a GPS track, while using meterological data as verification for these calculations. It can be done mathematically, and we might only need rough accuracy (+/- 30 degree wind direction granularity). Ideally, I'd prefer to include an airspeed sensor to maximize accuracy of wind direction calculations from GPS data.

And quoting Jerry, who said that all his test dummy drops, all turned downwind: What is your definition of 'scientific testing?' Just curious really; so please do not take this in a negative sense. JerryBaumchen Tough one; defining scientific testing: Do we use the outdoors as a testing lab? Or do we reproduce the variable winds in a wind tunnel? For the former, we cannot control the winds. For the latter, we won't be able to produce all kinds of the same turbulence conditions and wind transition layers in a scientific wind tunnel. Thus, I think dummy drop tests probably would have to be one of the most scientific, but a lot more data should be collected for future dummy drops (by any parachute manufacturer), and recording all the data. -> Altitude, Canopy, Canopy size, Wingloading, etc (determine co-relation of these variables versus tendancy of preferred heading) Weatherstation-style telemetry should be recorded from the dummy (compass heading, GPS position, dynamic G-forces caused by turbulence. The technology is simple nowadays -- even iPhones have GPS/accelerometer/compass capabilities already!) -> Determine coorelation of heading changes that correspond with sudden changes in speed or turbulence (increased random G forces detected by accelerometer), etc. -> Post-analysis can determine a bias towards a preferred heading. GPS tracking determines wind direction, and computer compass determines heading. -> Determine whether more turbulence/more variable winds, causes more frequent tendancy towards preferred heading (i.e. downwind) -> Determine how much 'heading hunting' occurs after the heading points downwind: Is there less heading changes during a downwind-pointing heading, than upwind-pointing heading? Telemetry analsys and a graph would show a pattern like a beacon, once enough data was collected in many test drops... There's more data to record (for a proper scientific plan), but the above examples will likely be sufficient "to get started" making conclusions... Test drop. Record data. Rinse and repeat. Enough times. Various sets of drops in different kinds of wind conditions. (How many? That is up for debate. 10? 100? 500 times? Enough dummy drops to get ironclad data that's not coincidence.) Graphs can then, thus be generated out of all the record data. The data would be scatter plotted or many different lines from many different test drops. -> One example graph is parachute altitude (as it drifts down) along horizontal axis, and parachute heading "degrees off wind axis" along vertical axis ... This would in theory show a pattern whether it stabilized to a downwind heading as altitude decreased, showing all the data converging into compact data along the "0 degree" level. -> Another example graph is.... Along one axis is "degrees off wind axis at landing" .... Along the other axis is data such as altitude or canopy size or variability level of winds that day, amount of turbulence (detect turbulence by using accelerometer data analysis). Scatter-plot the recorded data. Bam. See convincing pattern that co-relates with a specific variable (if any). -> Many different kinds of graphs could be experimented with to gain easy-to-visualize insight to the recorded data. For generating the graphs, an Excel macro or quick-and-dirty one-day .NET app could even be used to do this, as a programmer time cost-saving measure. In *theory*, if the precision of the iPhone sensors are sufficient enough (to be determined) then a custom iPhone app, with only 5 to 10 days of good programmer time ($2500 to $5000 at a generous $500 per diem programmer time, and just use a quick-and-dirty Excel macro to generate the graphs), and a sacrifical iPhone can be embedded into the dummy, in an off-the-shelf waterproof Otterbox case surrounded by additional shock-absorbing foam. The iPhone must be more-or-less horizontal for the digital compass in the iPhone to work properly, and to maximize the quality of the accelerometer data (for post-analysis to detect turbulence conditions, with accurately-enough distinctive G-force telemetry from swinging harness versus wind changes versus turbulence.). The iPhone could even be used as a backup method to assist in recovery of a dummy becoming lost, because an iPhone can be remotely GPS-tracked too, either through additional off-the-shelf software, or as a feature built-in into the custom private iPhone app. (the special private "black box recorder" iPhone app would not be put into the app store, for competitive reasons) Or upon the parachute manufacturer's option, part of the algorithm could be open sourced to gain maximum trust in the scientific technique and to make sure data wasn't being fudged by anyone.... Ideally, instead of an iPhone, a more precision lab computer instrument would be better, but such telemetry recorders that support recording in-depth GPS/compass/accelerometer data might be expensive. Whereas an iPhone is an expendable $500 instrument and the custom software can be reloaded onto it. Parachute manufacturers doing dummy drops might have a limited budget to "slipstream" or "embed" scientific tests like these, into their regular normal parachute testing regimen. (hint, hint Aerodyne, PD, etc -- if you are reading this -- please feel free to steal my ideas from this thread) Heck, I'd do it (both the iPhone and ground analysis software) if I got two custom-made (Both with my Rainbow-circle-logo on underside) parachutes for free out of it -- or bribe a different skydiver to program this telemetry recorder app for a mass market GPS/compass/accelerometer equipped pocket device such as iPhone. Note: Down-headingness is expected to happen more often with stable squares that have quick recovery characteristics (i.e. reserves), than ellipticals. So down-heading tendancy likely varies from canopy to canopy. Therefore, I recommend my enhanced telemetry-recorder idea be implemented next time one of the parachute manufacturers are testing a new reserve, since we are more interested in down-headingness in situations where it's likely to happen (i.e. reserves) since if a skydiver is ever unconscious under parachute, it's likely happening under a reserve. Once a parachute manufacturer does this, how useful is the data? Hard to say, but it could lead to a study of survivability of downwind landings, and recommended reserve wingloading for survivability of an unconscious skydiver, etc. (especially if the dummy is equipped with G-force shock meters, as in a crash test dummy). Or optimization of brake stow position for maximum downwind survivability (tradeoff horizontal versus vertical speed etc). Or if co-relation of downheadingness is proven by the testing, then more accurate searching patterns for tracking a lost skydiver if we now know we should begin the searching downwind of the drop. Or other unexpected 'useful' uses of this data might occur.

I have decided to split off a much-better worded post to this more-relevant thread: This would not happen if wind was 100% laminar flow, no turbulence, with no wind layers. However, even in fractional mph differences have a tendancy to shift some uncontrolled light-weight aircraft (gliders, parachutes, paper airplanes, something with sufficiently low momentum that can't resist the micro turbulence) gradually towards the downwind direction where they tend to approximately linger. Also if you fly through turbulence, while keeping your brakes stowed, there tends to be bigger turns off your present heading if you're flying upwind than if you're flying downwind. (I even notice tihs -- remember I still fly a Sabre 170 after 500 jumps so I notice turbulence more than most of you skydivers do.) Someone explained there is turns in one direction when wind speed changes in one direction, and a turn in opposite direction when wind speed changes in opposite direction. It should cancel out!? NAH! In reality, higher-speed air typically has more instability/turbulence than slower-speed air. As a result, transition from slowspeed to unstabe highspeed air will cause a turn of a different degree, than the identical mirror reverse transition from the same unstable highspeed air to the same slowspeed air. Rinse and repeat several times. Eventually, the difference leads to a downwind heading. Still argue it shouldn't matter? HAH! There's something else too: Even if the micoturbulences are exactly the same for both cases, remember planeforms aren't the same shape from the front as from the rear. Sudden pressure changes in front of the wing behave differently from sudden pressure changes behind the wing. Pushes and pulls from changes in pressure (wind boundary layers) will have different effects from behind than from the front. Wind tunnel tests prove that. Only a Frisbee can fly forward and backwards with the same effect. Wings cannot. Blow a paper airplane from behind (sudden gust/turbulence from behind), the airplane behaves differently than if you blow the paper airplane from front (sudden gust/turbulence from front). THEREFORE, due to the reasons above, wings turn a different angle when transitioning from a highspeed to slowspeed wind, THAN when transitioning from slowspeed to highspeed. And you know, the atmosphere is full of wind layers and turbulence, the atmosphere is not laminar flow. One says they are an airplane pilot and don't notice? It's not a meaningful factor: Don't worry -- metal bird pilots typically don't notice this because their plane has a lot of mass and inertia. Our wing needs to be low wingload, like paper airplanes and parachutes, and are more easily affected by the above. Keep reading. Eventually, all the forces average out to a preferred downwind direction for many kinds of planeforms/wingprofiles as it is the flightline of maximum stability for many planeforms in turbulent air. Just toss a paper airplane into slight breezes, the paper airplane has a tendancy to turn downwind as it hits the transition layer of the breeze. Same damn thing with parachutes (though it takes time for the forces to build up as the turns are tinier with micro-tubulence and slow wind speed changes in wind layers, etc). We're never parachuting in laminar flow air (zero eddies, zero microturbulence, identical wind speed for the whole altitude, that never happens for the whole skydive), so our parachute will definitely turn as a result of the wind speed changes. Turns are noticed. But turn where? Well, apparently, it seems to be downwind on average. Pilots flying metal birds won't notice, as the wingloading of these aren't usually often enough to turn dramatically. (And any dramatic uncommanded turns are often followed by a startled pilot correcting heading. Dramatic uncommanded turns in certain metal birds also tend to dive the airplane a little, which just increases the panic factor of the pilot.) Takes much longer for the forces to build. Most pilots aren't willing to let planes glide themselves uncommanded long enough with no autopilot keeping compass heading. Therefore, scientific data from airplane pilots are less valid than parachute dummy drops and paper airplane tests, in the perspective of the "unconscious skydiver" uncommanded parachute flight. Comment about overshoot tendancies: During the turns caused by going through transition layers, it is presumed that some parachutes/planeforms will 'hunt' heading more than others as it goes through random transition layers. Especially if the weather is very very stable and/or there isn't much altitude, so the downwind heading with tend to 'hunt' a little off (i.e. 20 degrees left off downwind, 30 degrees right off downwind), overshooting back and fourth past the downwind heading. Yes, the planeform's apparently tendancy to randomly hunt for a heading might sometimes massively outweigh its tendancy to point downwind. Yes, the planeform can have a built-in left turn or right turn that overcomes the weak desire to turn downwind. Yes that happens. Yes, there's been at least one unconscious skydiver that didn't land downwind, because of all the above factors. But in all the cases, there's always a preferred heading of maximum stability (point of maximum resistance to turning when going through transition layers) that goes into the equation, and that's almost always downwind. To maximize likelihood of downwind heading, you would appear to need: (1) low intertia, bigness, like a big parachute, (2) maximum time under parachute wihch means sufficient altitude (3) more wind-speed boundaries will accelerate the tendancy (4) totally uncommanded with no body shifts or arm/leg movements to cause mico-harness-turns (5) stable planeform that automatically returns to level flight that (6) nearly no built-in turn. No planeform is perfect, but built-in turn tendancy should be easily overcome by the turning forced by the wind-speed boundaries. Most well-trimmed well-maintained not-too-old student parachute seem to fall in this category. (7) more immune to other shifts like moving body, engine vibrations, that might distort other turn tendancies. (8) and you have a wing that does have a clear noticable have a tendancy to turn when it hits turbulence; NOTE: You can get away with just having 'most' of the above factors, but the fewer bullets that match the criteria, the downwind tendancy gets weaker, and the wing's desire to 'drift' or 'hunt' for a heading becomes greater. So it makes sense that many wings tend to turn downwind -- especialy confirmed to happen in dummy drops (this thread), confirmed to happen with unconscious skydivers (numerous other threads), and confirmed to happen with paper airplanes in a drafty/breezy room (try it yourself). And yes, I've gotten 90%+ marks in Physics, Math and Chemistry classes back in my day, and it still makes sense. It'd be nice to see proper scientific testing on this, though.

Very, very minor two-word correction to an error I notice in my writing I meant, "Most pilots flying metal birds won't notice, as the wingloading of these aren't often light enough".

That's correct. Many better skydivers could not make the event because they couldn't afford it, or wasn't at enough big ways with the same organizers, to be invited to the 400. That said, the organizers did their damndest best to choose the best skydivers that they were able to choose. It's a mind bogglingly difficult job to determine which applicants get the cut. Also.... I probably rank highly enough now to be in the next RW big way world record, but not highly enough to be on an over-subscribed 200-way yet. (i.e. probably more than 400 applicants applying for a 200way, I'll have a harder time competing) So I might (if I continue to maintain excellent big way currency) easily be accepted into the World Team now, while not easily accepted into a 200-way sequential. Being in the same big way event as key organizers help a lot too in up-ranking me a little. I've been to nine Perris big way events (50ways, 100ways, and Men's World Record)! And it seems I was the low timer at Kaledioscope 2009 sequenjtial 100-ways -- I don't think anyone had less jumps than I, at that one.

Tough one; defining scientific testing: Do we use the outdoors as a testing lab? Or do we reproduce the variable winds in a wind tunnel? For the former, we cannot control the winds. For the latter, we won't be able to produce all kinds of the same turbulence conditions and wind transition layers in a scientific wind tunnel. Thus, I think dummy drop tests probably would have to be one of the most scientific, but a lot more data should be collected for future dummy drops (by any parachute manufacturer), and recording all the data. -> Altitude, Canopy, Canopy size, Wingloading, etc (determine co-relation of these variables versus tendancy of preferred heading) Weatherstation-style telemetry should be recorded from the dummy (compass heading, GPS position, dynamic G-forces caused by turbulence. The technology is simple nowadays -- even iPhones have GPS/accelerometer/compass capabilities already!) -> Determine coorelation of heading changes that correspond with sudden changes in speed or turbulence (increased random G forces detected by accelerometer), etc. -> Post-analysis can determine a bias towards a preferred heading. GPS tracking determines wind direction, and computer compass determines heading. -> Determine whether more turbulence/more variable winds, causes more frequent tendancy towards preferred heading (i.e. downwind) -> Determine how much 'heading hunting' occurs after the heading points downwind: Is there less heading changes during a downwind-pointing heading, than upwind-pointing heading? Telemetry analsys and a graph would show a pattern like a beacon, once enough data was collected in many test drops... There's more data to record (for a proper scientific plan), but the above examples will likely be sufficient "to get started" making conclusions... Test drop. Record data. Rinse and repeat. Enough times. Various sets of drops in different kinds of wind conditions. (How many? That is up for debate. 10? 100? 500 times? Enough dummy drops to get ironclad data that's not coincidence.) Graphs can then, thus be generated out of all the record data. The data would be scatter plotted or many different lines from many different test drops. -> One example graph is parachute altitude (as it drifts down) along horizontal axis, and parachute heading "degrees off wind axis" along vertical axis ... This would in theory show a pattern whether it stabilized to a downwind heading as altitude decreased, showing all the data converging into compact data along the "0 degree" level. -> Another example graph is.... Along one axis is "degrees off wind axis at landing" .... Along the other axis is data such as altitude or canopy size or variability level of winds that day, amount of turbulence (detect turbulence by using accelerometer data analysis). Scatter-plot the recorded data. Bam. See convincing pattern that co-relates with a specific variable (if any). -> Many different kinds of graphs could be experimented with to gain easy-to-visualize insight to the recorded data. For generating the graphs, an Excel macro or quick-and-dirty one-day .NET app could even be used to do this, as a programmer time cost-saving measure. In *theory*, if the precision of the iPhone sensors are sufficient enough (to be determined) then a custom iPhone app, with only 5 to 10 days of good programmer time ($2500 to $5000 at a generous $500 per diem programmer time, and just use a quick-and-dirty Excel macro to generate the graphs), and a sacrifical iPhone can be embedded into the dummy, in an off-the-shelf waterproof Otterbox case surrounded by additional shock-absorbing foam. The iPhone must be more-or-less horizontal for the digital compass in the iPhone to work properly, and to maximize the quality of the accelerometer data (for post-analysis to detect turbulence conditions, with accurately-enough distinctive G-force telemetry from swinging harness versus wind changes versus turbulence.). The iPhone could even be used as a backup method to assist in recovery of a dummy becoming lost, because an iPhone can be remotely GPS-tracked too, either through additional off-the-shelf software, or as a feature built-in into the custom private iPhone app. (the special private "black box recorder" iPhone app would not be put into the app store, for competitive reasons) Or upon the parachute manufacturer's option, part of the algorithm could be open sourced to gain maximum trust in the scientific technique and to make sure data wasn't being fudged by anyone.... Ideally, instead of an iPhone, a more precision lab computer instrument would be better, but such telemetry recorders that support recording in-depth GPS/compass/accelerometer data might be expensive. Whereas an iPhone is an expendable $500 instrument and the custom software can be reloaded onto it. Parachute manufacturers doing dummy drops might have a limited budget to "slipstream" or "embed" scientific tests like these, into their regular normal parachute testing regimen. (hint, hint Aerodyne, PD, etc -- if you are reading this -- please feel free to steal my ideas from this thread) Heck, I'd do it (both the iPhone and ground analysis software) if I got two custom-made (Both with my Rainbow-circle-logo on underside) parachutes for free out of it -- or bribe a different skydiver to program this telemetry recorder app for a mass market GPS/compass/accelerometer equipped pocket device such as iPhone. Note: Down-headingness is expected to happen more often with stable squares that have quick recovery characteristics (i.e. reserves), than ellipticals. So down-heading tendancy likely varies from canopy to canopy. Therefore, I recommend my enhanced telemetry-recorder idea be implemented next time one of the parachute manufacturers are testing a new reserve, since we are more interested in down-headingness in situations where it's likely to happen (i.e. reserves) since if a skydiver is ever unconscious under parachute, it's likely happening under a reserve. Once a parachute manufacturer does this, how useful is the data? Hard to say, but it could lead to a study of survivability of downwind landings, and recommended reserve wingloading for survivability of an unconscious skydiver, etc. (especially if the dummy is equipped with G-force shock meters, as in a crash test dummy). Or optimization of brake stow position for maximum downwind survivability (tradeoff horizontal versus vertical speed etc). Or if co-relation of downheadingness is proven by the testing, then more accurate searching patterns for tracking a lost skydiver if we now know we should begin the searching downwind of the drop. Or other unexpected 'useful' uses of this data might occur.

A PLF landing can be just as soft as a stand up landing,.... I agree. Sometimes a PLF landing is a lot softer on you than a standup would have been. True. On some of the Perris jumps the infernal, damned spot and my long floaty tracks away from the big ways formation, I kept landing in rough bush that was 2 to 3 foot tall, and I had to roll nearly every damned landing that day. (Bigway organizer Josh hurt his shoulder, near where I landed, and grounded himself for a while)

I didnt notice it until you pointed it out.... Same. I never noticed the typo in the thread until now. It's ALLLLLLL Bender's fault. ALLLLLL!

This would not happen if wind was 100% laminar flow, no turbulence, with no wind layers. However, even in fractional mph differences have a tendancy to shift some uncontrolled light-weight aircraft (gliders, parachutes, paper airplanes, something with sufficiently low momentum that can't resist the micro turbulence) gradually towards the downwind direction where they tend to approximately linger. Also if you fly through turbulence, while keeping your brakes stowed, there tends to be bigger turns off your present heading if you're flying upwind than if you're flying downwind. (I even notice tihs -- remember I still fly a Sabre 170 after 500 jumps so I notice turbulence more than most of you skydivers do.) Someone explained there is turns in one direction when wind speed changes in one direction, and a turn in opposite direction when wind speed changes in opposite direction. It should cancel out!? NAH! In reality, higher-speed air typically has more instability/turbulence than slower-speed air. As a result, transition from slowspeed to unstabe highspeed air will cause a turn of a different degree, than the identical mirror reverse transition from the same unstable highspeed air to the same slowspeed air. Rinse and repeat several times. Eventually, the difference leads to a downwind heading. Still argue it shouldn't matter? HAH! There's something else too: Even if the micoturbulences are exactly the same for both cases, remember planeforms aren't the same shape from the front as from the rear. Sudden pressure changes in front of the wing behave differently from sudden pressure changes behind the wing. Pushes and pulls from changes in pressure (wind boundary layers) will have different effects from behind than from the front. Wind tunnel tests prove that. Only a Frisbee can fly forward and backwards with the same effect. Wings cannot. Blow a paper airplane from behind (sudden gust/turbulence from behind), the airplane behaves differently than if you blow the paper airplane from front (sudden gust/turbulence from front). THEREFORE, due to the reasons above, wings turn a different angle when transitioning from a highspeed to slowspeed wind, THAN when transitioning from slowspeed to highspeed. And you know, the atmosphere is full of wind layers and turbulence, the atmosphere is not laminar flow. One says they are an airplane pilot and don't notice? It's not a meaningful factor: Don't worry -- metal bird pilots typically don't notice this because their plane has a lot of mass and inertia. Our wing needs to be low wingload, like paper airplanes and parachutes, and are more easily affected by the above. Keep reading. Eventually, all the forces average out to a preferred downwind direction for many kinds of planeforms/wingprofiles as it is the flightline of maximum stability for many planeforms in turbulent air. Just toss a paper airplane into slight breezes, the paper airplane has a tendancy to turn downwind as it hits the transition layer of the breeze. Same damn thing with parachutes (though it takes time for the forces to build up as the turns are tinier with micro-tubulence and slow wind speed changes in wind layers, etc). We're never parachuting in laminar flow air (zero eddies, zero microturbulence, identical wind speed for the whole altitude, that never happens for the whole skydive), so our parachute will definitely turn as a result of the wind speed changes. Turns are noticed. But turn where? Well, apparently, it seems to be downwind on average. Pilots flying metal birds won't notice, as the wingloading of these aren't usually often enough to turn dramatically. (And any dramatic uncommanded turns are often followed by a startled pilot correcting heading. Dramatic uncommanded turns in certain metal birds also tend to dive the airplane a little, which just increases the panic factor of the pilot.) Takes much longer for the forces to build. Most pilots aren't willing to let planes glide themselves uncommanded long enough with no autopilot keeping compass heading. Therefore, scientific data from airplane pilots are less valid than parachute dummy drops and paper airplane tests, in the perspective of the "unconscious skydiver" uncommanded parachute flight. Comment about overshoot tendancies: During the turns caused by going through transition layers, it is presumed that some parachutes/planeforms will 'hunt' heading more than others as it goes through random transition layers. Especially if the weather is very very stable and/or there isn't much altitude, so the downwind heading with tend to 'hunt' a little off (i.e. 20 degrees left off downwind, 30 degrees right off downwind), overshooting back and fourth past the downwind heading. Yes, the planeform's apparently tendancy to randomly hunt for a heading might sometimes massively outweigh its tendancy to point downwind. Yes, the planeform can have a built-in left turn or right turn that overcomes the weak desire to turn downwind. Yes that happens. Yes, there's been at least one unconscious skydiver that didn't land downwind, because of all the above factors. But in all the cases, there's always a preferred heading of maximum stability (point of maximum resistance to turning when going through transition layers) that goes into the equation, and that's almost always downwind. To maximize likelihood of downwind heading, you would appear to need: (1) low intertia, bigness, like a big parachute, (2) maximum time under parachute wihch means sufficient altitude (3) more wind-speed boundaries will accelerate the tendancy (4) totally uncommanded with no body shifts or arm/leg movements to cause mico-harness-turns (5) stable planeform that automatically returns to level flight that (6) nearly no built-in turn. No planeform is perfect, but built-in turn tendancy should be easily overcome by the turning forced by the wind-speed boundaries. Most well-trimmed well-maintained not-too-old student parachute seem to fall in this category. (7) more immune to other shifts like moving body, engine vibrations, that might distort other turn tendancies. (8) and you have a wing that does have a clear noticable have a tendancy to turn when it hits turbulence; NOTE: You can get away with just having 'most' of the above factors, but the fewer bullets that match the criteria, the downwind tendancy gets weaker, and the wing's desire to 'drift' or 'hunt' for a heading becomes greater. So it makes sense that many wings tend to turn downwind -- especialy confirmed to happen in dummy drops (this thread), confirmed to happen with unconscious skydivers (numerous other threads), and confirmed to happen with paper airplanes in a drafty/breezy room (try it yourself). And yes, I've gotten 90%+ marks in Physics, Math and Chemistry classes back in my day, and it still makes sense. It'd be nice to see proper scientific testing on this, though.

Student parachutes have a lot less horizontal velocity. So even the reduced vertical speed is much more noticeable, and draws your attention more because you're not turf and surfing much.

Yep. As long as the hard disk is not malfunctioning. All modern Windows (Windows7/Vista/XP) supports FAT32 on external hard disk drives. In fact, you can even manage read the data off a 20-year-old IDE hard disk drive that's in good old MS-DOS FAT format. If the drive is lucky enough to still spin-up properly, and the computer BIOS supports configuring for it too. Should work fine with any adaptor that supports PATA (parallel ATA -- like good old IDE -- in variants that frequently include UDMA 33/66/100/133). The connector on most of these 2.5 inch drives is a miniaturized 40 pin IDE connector (small version of desktop ribbon cable). Most late 90's era and early 00's laptops are PATA hard disk drives. Both desktop and laptop connectors are already built into the adaptor in the last link I posted. So the adaptor is pretty much universal for almost any IDE/EIDA/UDMA/ATA/SATA hard disk ever made, both desktop and laptop form factors. For laptops, depending on model, 10-year-old laptops MAY be harder to open - meaning hard disks somewhat more difficult to remove (i.e. need to remove a few more screws), but the hard disk should work perfectly like an external drive, with that thingy. I own one of them too and it always come in handy. My oldest laptop of the bunch is a 2003 Dell and it is still designed for easy HDD removal (one screw), so it's 7 years old. For old laptop, google for your laptop's manual and download it, preferably if you can also download the Service Technician Maual or Repair Manual or whatever they call it (Dell provides them, for example) that gives you step-by-step disassembly for things like hard disk removal. Short story: With the adaptor, any old hard disk drives 'magically' behaves like a thumbdrive. Once the cables are connected -- bam -- drive letter just shows up (if the hard disk is not defective). File copying becomes pleasant child's play.

John has a great reputation, including among whuffos.

Wow. You're more wordy than I can be -- I've been known, in my day, to write massive amounts of text. (Back five years ago in 2005, berryfaq.com was one sprawling example.) Anyway, I agree with the "listen to your instructors" advice. My stance is always knees and feet together, slightly bent, even in good looking landings. That way, I am always prepared to "PLF" or "roll out" a really bad landing. Never reach out to the ground with my legs. Then if the parachute planes out successfully -- vertical velocity becomes zero and I am gliding horizontally above the ground -- then that's my cue that I can start preparing to run out the landing. As long as I don't reach my legs to the ground. Keep flying the parachute, keep flaring even when your feet contacts the ground. Resist the temptation to stretch your legs to reach the ground. Let the ground reach your feet instead. Keep your knees ever so slightly bent so you more easily automatically buckle into a PLF in unexpectedly bad landings that do not fully zero your vertical velocity. And if you plane out, keeping flying/flaring while you touch down or even perfect stand up landings, helps keep your balance better and also leads to less injuries too, and leads to a good habit for future landings. I stand up nearly all my landings (also including all but one of my student jumps, but bear in mind I was wingloaded at 0.65 at first!). You already know most of this from your instructor of course, depending on the training techniques they use, and what type of parachute they put you under, but it's good to put this in perspective about always being prepared to PLF and how to always be prepared. Of course, any advice you hear on dz.com including from me, don't try independently, although you can bring it up with your instructor (who might, if he's a good instructor, explain exactly why a specific good or bad advice was given)

Did you know laptop hard drives are often much easier to remove than desktop hard disk drives? They are usually popped out by a single screw, due to design for easy upgrade. No need to open up the laptop or casing, like you have to for desktop computers. (Unless it's an Apple laptop, or certain subnotebooks such as Sony Vaio P series) Most modern laptops (made in the last 5 to 7 years) have very easy-to-remove hard disks, that can be instantly removed by a single easily-accessible external screw. It may not even void your laptop warranty if it was designed for easy upgrade. Google for your laptop's manual to double check. Turn your laptop upsidedown. One rectangular panel is covered by a single screw, or a pull-out hard disk drive at the edge of the laptop, is held in by a single screw. Check your laptop manual to determine which panel you need to remove to easily pop-out the hard disk. (Lost manual? No problem! Download the manual. They've all been converted to PDF.) I used an adaptor I got from a computer store to temporarily plug my laptop hard disk drive to a USB port in my computer... It appeared as an "F:\" drive, which I could browse normally, copy files off, etc. Then I put the laptop hard disk back into the laptop, reinserted the single screw, and the laptop was back exactly the way it was... Also, once you've rescued your files, do an XP recovery to reinstall XP on top of XP. That usually resurrects a corrupt registry, although you might have to probably reinstall some (not all) of your software. Example of "quick and dirty" USB cable for laptop hard disk drives: http://www.cooldrives.com/seatatousb20.html (SATA only) http://www.newertech.com/products/usb2_adaptv2.php (PATA and SATA) Cost is about $35 I recommend an adaptor similiar to the latter, as they support nearly all laptop hard disk drives made in the last 10 years. Perfect tool to keep in your chest, whenever a hard disk goes inaccessible due to operating system corrupion, or that you need a fast way to copy an old computer's hard disk, etc. I have also outside external bootable operating systems, rescue CD's, but I found that removing the hard disk and this gadget was at least 20 times faster to get things done. In one case, I was done in only 5 minutes and I was copying an important file a minute later...