billvon 2,476 #26 December 15, 2003 >Typically, most canopies are trimmed slightly nose down from best glide. Agreed. Adding some rear riser may improve your glide ratio, but your forward speed will still drop. Adding rear riser will never speed your canopy up. Quote Share this post Link to post Share on other sites
alan 1 #27 December 15, 2003 QuoteOK its still not going to speed up if you lessen the angle of attack of the wing. My post did not take issue with that. It simply corrected this statement. "Once I reach my best glide (Which BTW is what a canopy is lined at)"alan Quote Share this post Link to post Share on other sites
alan 1 #28 December 15, 2003 QuoteAgreed. Then why the reply to my post with the addition of these comments? QuoteAdding some rear riser may improve your glide ratio, but your forward speed will still drop. Adding rear riser will never speed your canopy up. Is there anything at all in the exchange below that even remotely suggests that I was addressing the issue of adding a riser to speed your canopy up? Quote -------------------------------------------------------------------------------- Once I reach my best glide (Which BTW is what a canopy is lined at) -------------------------------------------------------------------------------- All manufacturers do not trim all canopies the same and mfgr's trim some models differently. Typically, most canopies are trimmed slightly nose down from best glide. They do this for a variety of reasons, including but not limited to, attaining desired opening characteristics, higher pressurization, and stability. Some canopies are trimmed closer to best glide than others.alan Quote Share this post Link to post Share on other sites
billvon 2,476 #29 December 15, 2003 >Is there anything at all in the exchange below that even remotely > suggests that I was addressing the issue of adding a riser to speed > your canopy up? No, which is why I agreed with you. I also pointed out that going to rear risers slows you down, since an earlier poster on this thread mentioned that going to rear risers can cause you to speed up. Quote Share this post Link to post Share on other sites
alan 1 #30 December 15, 2003 QuoteNo, which is why I agreed with you. I also pointed out that going to rear risers slows you down, since an earlier poster on this thread mentioned that going to rear risers can cause you to speed up. Well, you see, the thing is, that by tagging your reply and the additional comments to my post, it might leave the impression that I was saying/implying that going to rear risers can cause you to speed up.alan Quote Share this post Link to post Share on other sites
billvon 2,476 #31 December 15, 2003 > it might leave the impression that I was saying/implying that going > to rear risers can cause you to speed up. Sorry, didn't mean to imply that. Quote Share this post Link to post Share on other sites
Dougjumper 0 #32 December 16, 2003 Yes, This should help flatten your Glide out a bit while your downwind and help you make it back to your intentional landing area. Remember all Parachutes react different. Depending on the Wing and Load. This is a practice I learned from a more Experienced Jumper flying a High Performance Wing similar to mine. It seems to work for me. Quote Share this post Link to post Share on other sites
BlindBrick 0 #33 December 16, 2003 QuoteWhat options do you have? This one is not directly related to your question, but it's still related and often overlooked. Never forget you can always run downwind. If there's even a chance that you might back into a unsafe landing area look downwind and see if you can find a large open area there. Better a hike of a few miles than taking the chance of backing into something nasty liek a powerline, building, fence. Besides, I never seen anyone have trouble hitching a ride back after an off-field landing. -Blind"If you end up in an alligator's jaws, naked, you probably did something to deserve it." Quote Share this post Link to post Share on other sites
kallend 1,683 #34 December 16, 2003 Quote QuoteAgreed. Then why the reply to my post with the addition of these comments? QuoteAdding some rear riser may improve your glide ratio, but your forward speed will still drop. Adding rear riser will never speed your canopy up. Is there anything at all in the exchange below that even remotely suggests that I was addressing the issue of adding a riser to speed your canopy up? Quote -------------------------------------------------------------------------------- Once I reach my best glide (Which BTW is what a canopy is lined at) -------------------------------------------------------------------------------- All manufacturers do not trim all canopies the same and mfgr's trim some models differently. Typically, most canopies are trimmed slightly nose down from best glide. They do this for a variety of reasons, including but not limited to, attaining desired opening characteristics, higher pressurization, and stability. Some canopies are trimmed closer to best glide than others. Season's greetings Alan: Some are trimmed a whole lot faster than best glide speed. Do you know of any modern canopies that are trimmed at or below best glide speed? (OK, angle of attack before you jump all over me).... 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 1,683 #35 December 16, 2003 You know, we get a lot of discussions like this in this forum and the Canopy Control forum, and it often ends up with someone (like me) ASSUMING certain canopy characteristics and then doing an analysis. Wouldn't it be nice if we could get some actual data on a real canopy (like L/D vs alpha)? Maybe PD has such data they'd be willing to share. I'm fairly sure they measure this stuff during their testing, and I think they use CFD during the design stage.... 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
alan 1 #36 December 16, 2003 QuoteSome are trimmed a whole lot faster than best glide speed. Do you know of any modern canopies that are trimmed at or below best glide speed? (OK, angle of attack before you jump all over me). Hi John! I still have a pie waiting for you, would you prefer it frozen or thawed? I do not "know" of any canopies that are trimmed below best glide, but lighter front riser pressure usually indicates a canopy that is closer to that. Stiletto and Cobalt come to mind. If any are trimmed below best glide, my guess is that they might be reserves or accuracy canopies and maybe even CReW canopies, although stability and pressurization would have to accounted for. Mfgr's don't routinely publish specific angles of incidence and aoa, although PPM gives some generalities. I would think that if one had the time, facilities, and canopies, they could be layed out and measured. I suspect that some mfgr's do this with competitors canopies to stay abreast of what the other guy is doing. Chris Martin, are you out there? Can/would you give us a little run down on canopy trim?alan Quote Share this post Link to post Share on other sites
