morris

So far so good, agreed... Don´t agree at all! While you need to pitch the nose up by swinging forward of the center to start climbing, you don´t need to swing back aft the center to start descending. Lift is a function of stuff like (to name just some) profilcurvature (which can be changed by the pilots as well by applying more or less brakeinput), angle of attack (your fault in my opinion is that you are only thinking about this one) and airspeed (the most important one you´re missing). Imagine someone is climbing by swinging forward and pitching up the nose. Now he would float up there forever if he wouldn´t swing back AFT the center to pitch down the nose??? No, even if he would stay where he is - forward of the center - or swing back to any other point forward of the center (but closer to the center) or swing back exactly "into" the center - but NOT AFT the center - he would start descending/sinking as soon as the airspeed goes down!!! Once you climbed you can only maintain level flight (while the airspeed goes down/is decreasing)) by a) applying an even higher angle of attack by pitching the nose even further up (which is difficult to do because you already swung forward, now swinging even further while flying at an already lower airspeed could only be achieved for a short moment by applying a serious amount of rear- or brakeinput, not the best choice) or b) by gradually changing the profilecurvature by appling more and more brakeinput. You will however soon run out of too much airspeed (and controlrange) to keep on playing this "level-flight-game" (if you keep on playing it nevertheless, you gonna stall the canopy) and gonna start descending - even if your body is still forward of the center or in the center but not after the center! I agree however partly with what you are saying. I think the perfect pop-up is a swing forward of the center in the beginning, than a - the slower the better - move back of your body closer to the center - BUT STILL IN FRONT OF IT - followed by a second little swing forward during the very last moment of the flight, the moment your applying this very little something of toggleinput that you might have left for just before touchdown.

Yes, it is. But the more headwind you have, the less sense makes a (high) pop-up. This is because the price you pay - a loss in (air- and) groundspeed - is (in a headwindscenario from a certain strengh/windspeed on, depending on how high you pop-up, which should be less in headwind, blah blah blah) too high for what you get - an increase in airtime. While the price in airspeed doesn´t change with the wind, the price you pay in groundspeed (the one that counts for distance) is less in a tailwind. So a really high pop-up makes the most sense in a downwindscenario - and I for sure don´t wanna try to stand up one of those. Even an ultrafast sprinter/runner would take a very high risk of injury.

I´m with you, raymod2. This results in a 2:1 lead for the "non-divers"...

In case someone doesn´t know, those landings are way softer than they might look like - if well executed. But this was not what I´ve been talking about, I had to bring it down BEFORE all the speed was gone...

I forgot to mention that an extra long cheststrap is also a nice option to have if you are serious about somersault-freestyle.

Absolutely! And by the way, I recommend using an rds (not necessarily full, but at least a removable slider) for any kind of somersault landings, no matter whether forward or backward. The risers should be as far apart from each other as possible - this makes passing through the center A-lines with your legs easier!

To avoid popping up you can use the energy for a) carving, b) going for a forward somersault or c) a blindman followed by a backward somersault.

I absolutely agree - and I even agree more since last weekend! I also would like to mention that "never head towards an obstacle" holds even more true/is even more important if you are popping up to go for ultimate distance. If you are up there in the first or second floor, 20ft from the ground, floating at high speed, you can´t just put your feet on the ground and stall the canopy or initiate an extrem carve to kill energy and distance. The only thing you can do (to my best knowledge) is to release a little bit of brake input to make the canopy start descent (that´s what I did) - but this will result in a touchdown (actually it felt more like an impact) while still traveling at a high forward speed and, way worse, with a pretty high rate of descent. I´ve been lucky, impact resulted in a forward somersault - stupid but unhurt...

The more I´m trying speed myself, the more I´m impressed by those numbers! Your topspeed of 325mph+ is...!!! ...and the need to be that fast at the bottom end for "just" a ~420km/h average... Now I´d really like to know what topspeeds have been reached/flown during male-worldrecordruns where the averages have been in the range of your personal topspeed. Any idea? Any numbers?

Hi everyone, as the forum of speedskydiving.com is almost inactive I´m looking for advice here. Any tipps regarding bodyposition? Thanks for any kind of input!

No doubt about it, you are absolutely right, I never had the intention to say "things are this way and no other", like somekind of "law" for all canopies, all I wanted to give was a "rule of thumb", not more. And to mention that there are windsituations that make frontriser are reasonable input. How strong that headwind needs to be and how much frontriserinput would be the best choice in those scenarios is differnt for any design, loading and so on... sorry if I didn´t point tht out clearly. Always a good idea.

We are not talking about moderate but serious headwinds here, or did I misunderstand the first question? The testing involved (so far) more than a dozen different canopytypes, -sizes and loadings, ranging from a tandem all the way to a Katana 97 (loaded 2.1), resulting in very different numbers, but the "basic message" was always the same... For canopies of about 150sqft and a loading of about 1.4 the distance over the ground, flying into a headwind, was about equal for fullflight and a certain degree of frontriser input if the headwind was about 8 knots. Flying into a headwind any stronger (10knots or more) resulted in "frontriservictories"... correct/agreed

No doubt about it! I´m not saying that the real wind doesn´t need to be considered, of course it affects your ground track, big time. I´m only saying that the real wind is not affecting the flight path in relation to the surrounding air. If the real wind would have no "impact" on your ground track the statement "you´ll always end up shorter applying frontrisers" would be true. But as the real wind is affecting our true glide there are scenarios where our true glide will be changed to the better by frontrisersinputs - eventhough frontriserputs will always make our relativ glide worse...

Don´t mix true (in relation to the ground) and relativ (in relation to the air) glide! In nowindconditions both are the same, and in nowind you are right that frontriserinput will never let you fly further, you´ll end up shorter. But with wind it´s a whole different story. In my example the relativ glide for full flight was 3meters forward for ever meter down, the relativ glide for frontrisers was 2.66meters forward for every meter down, resulting in less distance covered - in nowind. In a headwind as strong as in my example the true glide for fullflight is down to 0.5meters forward for ever meter down while the true glide for fronts is 1meter forward for ever meter down, resulting in twice the distance. You are saying that by pulling down the fronts you would increase the drag as there would be more topskin presented to the headwind. Sorry, but that´s just not true. The canopy always flies in relation to nothing but the surrounding air, the relative wind will hit the canopy always from the exact same direction if the same input is applied, winds are not affecting relativ glide at all, they are only affecting true glide. Your canopy is flying in relation to the surrounding air always as if in nowind (as long as we don´t take/bring turbulences into the picture, but that´s another story/aspect, don´t let us mix those two).

If you are interested how this looks like you can scroll through this document: http://www.metatag.de/webs/dfv/downloads/1_-_KATE-Projekt_im_Detail_mit_ersten_Ergebnissen.pdf I know it´s in german language and you´ll likely don´t understand the details but it will give you an impression what it is all about. They are even monitoring turnrates... Once again it doesn´t take a headwind that strong that "he" is killing all of your groundspeed to cover more distance with frontrisers. Do the math (not by guessing, we got the data) or just give it a try....

I have to say I´m very sorry, but the delta is not a guess. A whole lot of testjumps has been done in Germany over the last two years likely collecting the most detailed data ever of parachute flight. (Maybe with the exception of the X-38 http://en.wikipedia.org/wiki/NASA_X-38 but one of the jumpers has been part of the X-38 program). They are working with a company that is specialized in collecting all kinds of flightdata. There systems are not only using GPS and airpressuredata but combining those with INS. http://en.wikipedia.org/wiki/Inertial_navigation_system In addition they are even monitoring the toggleinputs (how long - inches and time - the input is and what forces are necessary to apply those inputs).

Yes, 3:1 is good enough, and yes, 2.66 is as if there would be only one kind of fronriserinput and only an one and off. My example had the only purpose to explain and underline my "message"....

If the headwind is that strong that you aren´t covering any ground anymore in full flight, it is obvious that you´ll be able to fly further by applying frontriser input. Way more interesting is the question how strong the headwind needs to be to make frontrisers the input of choice. Here´s an example: (sorry that I´m using meters not feet, if you wanna have the numbers in feet multiply the meters by/with three, take the result and add another 10%...) Full flight: Opening altitude: 720m Rate of descent: 4m/s Forward speed: 12m/s Glide ratio: 3:1 Headwind: 10m/s (not that much that you aren´t covering ground in full flight) Groundspeed: 2m/s Time under canopy: 180 seconds Distance flown till touchdown: 360m Frontriserinput: Opening altitude: 720m Headwind: 10m/s Rate of descent: 6m/s (+50%) Forward speed: 16m/s (+33%) Glide ration: ~2.5/1 (2.66 to be exact) Time under canopy: 120 seconds Groundspeed: 6m/s Distance flown till touchdown: 720m Twice the distance! You could argue that 10m/s (=20knots) of headwind is still quite a lot for a canopy of average loading and seize and I would have to agree to this objection. But if you do the calculations for any strenght/speed of headwind you´ll figure out that you´d travel the same distance no matter whether your choosing full flight or frontrisers if the headwind is 4m/s. In other words: If the headwind is any stronger than 4m/s you´d be better off using frontrisers. If the windspeed on the ground is 2-3m/s (4-6knots), you´ll have a reasonable chance that the winds at opening altitude are exceeding 8 knots - making frontrisers the weapon of choice to fight a headwind. The headwindspeed that is asking the pilot for frontriserinput is way lower than most people would expect. If you need to fly far in a headwind or if you have to clear an obstacle - don´t let the high rate of descent fool you - apply serious frontriserinput!

I think you are right, this is how it looked like from my perspective, being the lower guy.

:-) Always been there, but thanks anyways! We are located in Germany and will get input from one of the very best german CReWjumpers ten days from now. I´m coming to the states on a regular basis for jumping for about a decade now but this was always just for RWteamtraining and CanopyPilotingCompetitions, never for doing CRW with the exception of a single jump doing outsidevideo for a 4way sequential team from Florida at Eloy. Next time I´ll come over will likely be for the US CP-nationals. Any CRW events in August/September I should try to pass by? We feel already quite ok flying the stairstep and the docks aren´t that scary either, just don´t wanna figure out anthing by trial and error... Thanks for your input!

This helps a lot, thanks very much! We are using Storms loaded about 1.6 Let me first point out that we are very(!) happy with the chutes! We´ve chosen the regularversion, not the "full" CF-Version. Instead we went for the CF-option with the rings on top for the retractable POD and PC. This option comes with continous center A-lines and we´ve chosen dacron 600 for the lines. This CF-option for casual CF however does not include continous outside A-lines. Now we are going to install continous outside A-lines asap as it looks like we like CRW way too much to do it just on a casual basis. As the linetrims for the regular Storm and the CF-version are different ones, we need to know the length for those lines. For this reason I´ve contacted PD this very morning (on a Friday) by email, asking for help. They´ve been answering within minutes and gonna get the needed information for us from the engineering-department. THIS IS WHAT I CALL OUTSTANDING CUSTOMERSERVICE!

Why do you wanna remove it at all? An additional cheststrapextension isn´t that bulky...

What do you mean? Remove it completely?? Please clarify!

Can someone please explain how you have to "entangle" your legs for downplanes? The way we do it is for sure not the best one as we aren´t able to fly it for as long as we want to. With our "engineering" we can´t keep it together for very long, the tension just gets to strong...

Experts please confirm whether this is correct or not! Outside frontinput will not only get tension "into the system" - which might be a good thing - but will also make the undocked side fly even faster...?? This could be a bad thing...?