base698 1 #1 July 4, 2010 Are there any solid numbers on canopy speed at various wing loadings. A lot of people have GPS's now for wing suiting. As well as gadgets that calculate descent rate. I'm curious what a Sabre 120 at 1:1 versus a Sabre 170 at 1:1 is. I think the Sabre 120 would definitely be faster but with some interpolation you could get good predictions on what a downsize would do. Quote Share this post Link to post Share on other sites
Hellis 0 #2 July 4, 2010 The problem with using a GPS to find out the speed of a canopy is that it gives you your groundspeed, not airspeed. So unless the wind is exactly the same it can be the wind that makes the difference. How is the same person going to load a 170 at 1.1 and a 120 at 1.1? Got some magic diet? Quote Share this post Link to post Share on other sites
base698 1 #3 July 4, 2010 Weights. Low wind and take the average various headings. Quote Share this post Link to post Share on other sites
Jbag 0 #4 July 4, 2010 other issue is, some people are longer then others so it can cause drag :PIHYD Quote Share this post Link to post Share on other sites
sundevil777 93 #5 July 4, 2010 QuoteThe problem with using a GPS to find out the speed of a canopy is that it gives you your groundspeed, not airspeed. So unless the wind is exactly the same it can be the wind that makes the difference. How is the same person going to load a 170 at 1.1 and a 120 at 1.1? Got some magic diet? The data that a GPS unit can provide includes altitude, so it can be used as desired.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
timmyfitz 0 #6 July 4, 2010 QuoteHow is the same person going to load a 170 at 1.1 and a 120 at 1.1? Got some magic diet? He didn't say it would be the same person. QuoteI'm curious what a Sabre 120 at 1:1 versus a Sabre 170 at 1:1 is. Quote Share this post Link to post Share on other sites
Hellis 0 #7 July 4, 2010 QuoteQuoteThe problem with using a GPS to find out the speed of a canopy is that it gives you your groundspeed, not airspeed. So unless the wind is exactly the same it can be the wind that makes the difference. How is the same person going to load a 170 at 1.1 and a 120 at 1.1? Got some magic diet? The data that a GPS unit can provide includes altitude, so it can be used as desired. Yes? And why would we need the altitude? explain please, i dont understand QuoteQuoteHow is the same person going to load a 170 at 1.1 and a 120 at 1.1? Got some magic diet? He didn't say it would be the same person. QuoteI'm curious what a Sabre 120 at 1:1 versus a Sabre 170 at 1:1 is. Well, true. But he did say QuoteI think the Sabre 120 would definitely be faster but with some interpolation you could get good predictions on what a downsize would do. You dont normally talk about downsizing if its two persons. I read that as one person is going to downsize from 170 sqf to 120 sqf, and 170 pounds to 120 pounds. I might be wrong Quote Share this post Link to post Share on other sites
phoenixlpr 0 #8 July 4, 2010 QuoteAre there any solid numbers on canopy speed at various wing loadings. A lot of people have GPS's now for wing suiting. As well as gadgets that calculate descent rate. I'm curious what a Sabre 120 at 1:1 versus a Sabre 170 at 1:1 is. I think the Sabre 120 would definitely be faster but with some interpolation you could get good predictions on what a downsize would do. Your canopy scale, but your body don't. So bigger canopies have better glide on the same WL. Quote Share this post Link to post Share on other sites
base698 1 #9 July 4, 2010 Well the issue now that anyone that comes on DZ.com or asks anyone if they can safely downsize from say a 170 to 150. There are lots of pilot issues to take into account, based on their experience, however there is no concrete data on any of this stuff. You know a 150 at 1:1 is faster than a 170 at 1:1, but how much faster? 1%, 2%, or 20%? If someone had a graph with wingloading vs canopy speed for every size canopy as well as one for a given weight at many different canopy sizes vs size. You could say exactly that a 120 for Person A @ 200 lbs is X MPH, whereas their 150 they are currently jumping is X MPH. Everyone seems to have anecdotal evidence at best of a person they know at X wingloading getting hurt. I just think people could make more informed decisions about downsizing if they had this data. Quote Share this post Link to post Share on other sites
base698 1 #10 July 4, 2010 ^^ No kidding, but I want an actual number. I want an analytical analysis of it so you can say definitively a wingload of 1:1 on a 150 flies X fast and has a glide ratio of Y. Quote Share this post Link to post Share on other sites
antonija 0 #11 July 4, 2010 QuoteYes? And why would we need the altitude? explain please, i dont understand Canopies tend to lose altitude over time which contributes (about 1/3 IIRC; 90 degrees vector) to the total air speed. Ontopic: I don't think the biggest problem in downsizing is increased speed in full flight. From my (very limited) experience the higher sensitivity to inputs (and thus tendency for inexperienced pilots to oversteer their canopies), higher chance of violent spinner during funny openings, ... stuff that kills you, not just the stuff that makes flying more fun (speed).I understand the need for conformity. Without a concise set of rules to follow we would probably all have to resort to common sense. -David Thorne Quote Share this post Link to post Share on other sites
phoenixlpr 0 #12 July 5, 2010 Quote You know a 150 at 1:1 is faster than a 170 at 1:1, but how much faster? 1%, 2%, or 20%? People might be subjective. Can you tell if you fall %3 faster? Can you tell if you exit 50m lower? Quote Share this post Link to post Share on other sites
