morten 0 #1 August 9, 2005 I fly a Sabre-2 at 1.4 lbs/sqft. I've been told that the lowest sink rate is obtained at maximum brakes - just prior to the stall. Does that assumption hold? Always? Quote Share this post Link to post Share on other sites
meatbomb 0 #2 August 9, 2005 The common perception round here is that deep brakes is the most effective on PD canopies, whereas rear risers are more effective on Icarus canopies...(probably the generally deeper toggle range on Icarus canopies has something to do with this...)--- Swoopert, CS-Aiiiiiii! Piccies Quote Share this post Link to post Share on other sites
ph8068 0 #3 August 9, 2005 QuoteI fly a Sabre-2 at 1.4 lbs/sqft. I've been told that the lowest sink rate is obtained at maximum brakes - just prior to the stall. Does that assumption hold? Always? On your canopy, you are never going to be far wrong by making that assumption. For steeply-trimmed canopies, however, it may be a little more complicated. Quote Share this post Link to post Share on other sites
Pendragon 1 #4 August 9, 2005 Min sink is always approaching the stall. Max glide is always slightly faster than min sink; how much depends on the level of head/tailwind. The greater the headwind, the faster at which max glide will be (e.g. strong winds could result in the canopy coming straight down, i.e. glide = 0. Pulling double-fronts to penetrate slightly therefore increases the glide ratio). Look at some polar curves; the website I would normally quote seems to be down, but try: http://www.phoenix-fly.com/articles%20stvari/PF_Wingsuit%20flying%20and%20Basic%20Aerodynamics_2.pdf, which has an example on the 2nd page. ..or ask a sailplane/hang/paraglider pilot -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites
fab777 0 #5 August 9, 2005 Understand the principle, but is a canopy generally trimmed for max glide, or not? Fabien BASE#944 Quote Share this post Link to post Share on other sites
aj4218 0 #6 August 9, 2005 QuoteThe greater the headwind, the faster at which max glide will be (e.g. strong winds could result in the canopy coming straight down, i.e. glide = 0. Pulling double-fronts to penetrate slightly therefore increases the glide ratio). reply] The glide angle through the AIR doesn't change with windspeed, only the glide angle relative to the ground. Just think of yourself as flying in a big 'box' of air; sometimes the box is stationery relative to the ground, sometimes it's moving i.e. there's wind. Either way, the way your canopy flies in the box stays the same. See Superstu's excellent post titled 'canopy resources' Quote Share this post Link to post Share on other sites Pendragon 1 #7 August 9, 2005 To be honest, I'm not exactly sure, but some canopies are trimmed to give a steep angle of descent (e.g. ZP.exe). Personally, I always thought max glide was closer to 1/2 brakes though, but I may be wrong! I wouldn't be surprised if opening characteristics are more of a concern here. Can anyone from Icarus/Aerodyne/PD comment? I would expect max glide to be improved more in a tail wind by pulling down on the rear risers slightly rather than toggles (which deforms the wing and makes it less efficient).-- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites fab777 0 #8 August 9, 2005 Quote I wouldn't be surprised if opening characteristics are more of a concern here. Can anyone from Icarus/Aerodyne/PD comment?(/reply] Well, I've got big concerns about my Crossfire 2 opening headings, but I think this is a different matter. I'm asking more in a ground launch point of view... QuoteI would expect max glide to be improved more in a tail wind by pulling down on the rear risers slightly rather than toggles (which deforms the wing and makes it less efficient). Well, that's what I had instinctively in mind. Anyway, thanx for the comment. Anybody from Icarus out there? Fabien BASE#944 Quote Share this post Link to post Share on other sites Pendragon 1 #9 August 9, 2005 QuoteWell, I've got big concerns about my Crossfire 2 opening headings, but I think this is a different matter. I'm asking more in a ground launch point of view... I'm not sure that it is a different matter; take the Katana for example. I haven't met anyone yet who has had a good word to say about the openings - but they all raved about the landings. I presume there is a balance to be had with how the canopy is trimmed in terms of opening characteristics at one extreme and HP landings at the other... but I'm not qualified to comment. Back to work... -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites PhreeZone 14 #10 August 9, 2005 I loved the Katana's openings. Camera, high hop and pops, Birdman... great openings every jump for the 2 weekends and about 18 jumps I had it. Canopies are not trimmed near max glide rate. In the case of certian canopies they are trimmed for more forward speed in full flight and longer recovery arcs, other canopies are trimmed flatter and fly differently.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites ph8068 0 #11 August 10, 2005 QuoteUnderstand the principle, but is a canopy generally trimmed for max glide, or not? No, just about every canopy is trimmed more steeply than the "max glide" setting. At max glide, the airspeed of the canopy is quite low which would mean a very weak flare so that landings would be horrible. To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon. This is very different from applying brakes. A small amount of brake will probably increase your glide ratio in zero winds(depending on the canopy design) but not as much as rear risers. In zero winds, deep brakes will never increase your glide ratio. Watch a first time student come in to land who flares at 50ft. Once their airspeed has been bled off during the flare, their descent is then way more vertical than when they were on full drive. Quote Share this post Link to post Share on other sites morten 0 #12 August 10, 2005 Thanks for the replies - I'll assume the rule holds. I'm referring to sustainable sink rate - obviously the sink rate at landing approaches zero ideally The reason for the post was my first experiences with the canopy: Last out of cessna - hop'n'pop at 5000 feet - first down although everybody else did at least 10-12 secs freefall. I'd like to be able to sort of park myself at a higher altitude to let the others land in the 'correct' order. Again thanks for the replies - I love dropzone.com Quote Share this post Link to post Share on other sites fab777 0 #13 August 10, 2005 Quote To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon Increasing angle of attack vs lowering the flaps, if you take it as an airplane... Fabien BASE#944 Quote Share this post Link to post Share on other sites Trae 1 #14 August 11, 2005 My K120 opens beautifully every time.... from the first hop and pop up till over 100 terminal openings ....no complaint...more like very impressed. VERY. Birdman---no worries including 2 nite jumps It is a bit sensitive during slower birdy openings but this was due to poor bag lift off from shortish bridle . You want an excessively well developed non-crossbraced canopy --get one you won't be dissapointed. Scouts honor. edited to include ..you want good openings pack it yourself...packers are jealous of Katana's Quote Share this post Link to post Share on other sites Pendragon 1 #15 August 11, 2005 Well, that's 2 guys now posted that say Katanas open great. Typical. Actually may well consider one after I get some more jumps in... I'll line it up against the Xfire2 and see what I think, sometime in the future. Not sure if I'd ever want to wingsuit with one though -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites hkf 0 #16 August 11, 2005 QuoteWell, that's 2 guys now posted that say Katanas open great. Typical. Make that 3!!! Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. 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Pendragon 1 #7 August 9, 2005 To be honest, I'm not exactly sure, but some canopies are trimmed to give a steep angle of descent (e.g. ZP.exe). Personally, I always thought max glide was closer to 1/2 brakes though, but I may be wrong! I wouldn't be surprised if opening characteristics are more of a concern here. Can anyone from Icarus/Aerodyne/PD comment? I would expect max glide to be improved more in a tail wind by pulling down on the rear risers slightly rather than toggles (which deforms the wing and makes it less efficient).-- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites
fab777 0 #8 August 9, 2005 Quote I wouldn't be surprised if opening characteristics are more of a concern here. Can anyone from Icarus/Aerodyne/PD comment?(/reply] Well, I've got big concerns about my Crossfire 2 opening headings, but I think this is a different matter. I'm asking more in a ground launch point of view... QuoteI would expect max glide to be improved more in a tail wind by pulling down on the rear risers slightly rather than toggles (which deforms the wing and makes it less efficient). Well, that's what I had instinctively in mind. Anyway, thanx for the comment. Anybody from Icarus out there? Fabien BASE#944 Quote Share this post Link to post Share on other sites Pendragon 1 #9 August 9, 2005 QuoteWell, I've got big concerns about my Crossfire 2 opening headings, but I think this is a different matter. I'm asking more in a ground launch point of view... I'm not sure that it is a different matter; take the Katana for example. I haven't met anyone yet who has had a good word to say about the openings - but they all raved about the landings. I presume there is a balance to be had with how the canopy is trimmed in terms of opening characteristics at one extreme and HP landings at the other... but I'm not qualified to comment. Back to work... -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites PhreeZone 14 #10 August 9, 2005 I loved the Katana's openings. Camera, high hop and pops, Birdman... great openings every jump for the 2 weekends and about 18 jumps I had it. Canopies are not trimmed near max glide rate. In the case of certian canopies they are trimmed for more forward speed in full flight and longer recovery arcs, other canopies are trimmed flatter and fly differently.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites ph8068 0 #11 August 10, 2005 QuoteUnderstand the principle, but is a canopy generally trimmed for max glide, or not? No, just about every canopy is trimmed more steeply than the "max glide" setting. At max glide, the airspeed of the canopy is quite low which would mean a very weak flare so that landings would be horrible. To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon. This is very different from applying brakes. A small amount of brake will probably increase your glide ratio in zero winds(depending on the canopy design) but not as much as rear risers. In zero winds, deep brakes will never increase your glide ratio. Watch a first time student come in to land who flares at 50ft. Once their airspeed has been bled off during the flare, their descent is then way more vertical than when they were on full drive. Quote Share this post Link to post Share on other sites morten 0 #12 August 10, 2005 Thanks for the replies - I'll assume the rule holds. I'm referring to sustainable sink rate - obviously the sink rate at landing approaches zero ideally The reason for the post was my first experiences with the canopy: Last out of cessna - hop'n'pop at 5000 feet - first down although everybody else did at least 10-12 secs freefall. I'd like to be able to sort of park myself at a higher altitude to let the others land in the 'correct' order. Again thanks for the replies - I love dropzone.com Quote Share this post Link to post Share on other sites fab777 0 #13 August 10, 2005 Quote To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon Increasing angle of attack vs lowering the flaps, if you take it as an airplane... Fabien BASE#944 Quote Share this post Link to post Share on other sites Trae 1 #14 August 11, 2005 My K120 opens beautifully every time.... from the first hop and pop up till over 100 terminal openings ....no complaint...more like very impressed. VERY. Birdman---no worries including 2 nite jumps It is a bit sensitive during slower birdy openings but this was due to poor bag lift off from shortish bridle . You want an excessively well developed non-crossbraced canopy --get one you won't be dissapointed. Scouts honor. edited to include ..you want good openings pack it yourself...packers are jealous of Katana's Quote Share this post Link to post Share on other sites Pendragon 1 #15 August 11, 2005 Well, that's 2 guys now posted that say Katanas open great. Typical. Actually may well consider one after I get some more jumps in... I'll line it up against the Xfire2 and see what I think, sometime in the future. Not sure if I'd ever want to wingsuit with one though -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites hkf 0 #16 August 11, 2005 QuoteWell, that's 2 guys now posted that say Katanas open great. Typical. Make that 3!!! Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0
Pendragon 1 #9 August 9, 2005 QuoteWell, I've got big concerns about my Crossfire 2 opening headings, but I think this is a different matter. I'm asking more in a ground launch point of view... I'm not sure that it is a different matter; take the Katana for example. I haven't met anyone yet who has had a good word to say about the openings - but they all raved about the landings. I presume there is a balance to be had with how the canopy is trimmed in terms of opening characteristics at one extreme and HP landings at the other... but I'm not qualified to comment. Back to work... -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites
PhreeZone 14 #10 August 9, 2005 I loved the Katana's openings. Camera, high hop and pops, Birdman... great openings every jump for the 2 weekends and about 18 jumps I had it. Canopies are not trimmed near max glide rate. In the case of certian canopies they are trimmed for more forward speed in full flight and longer recovery arcs, other canopies are trimmed flatter and fly differently.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
ph8068 0 #11 August 10, 2005 QuoteUnderstand the principle, but is a canopy generally trimmed for max glide, or not? No, just about every canopy is trimmed more steeply than the "max glide" setting. At max glide, the airspeed of the canopy is quite low which would mean a very weak flare so that landings would be horrible. To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon. This is very different from applying brakes. A small amount of brake will probably increase your glide ratio in zero winds(depending on the canopy design) but not as much as rear risers. In zero winds, deep brakes will never increase your glide ratio. Watch a first time student come in to land who flares at 50ft. Once their airspeed has been bled off during the flare, their descent is then way more vertical than when they were on full drive. Quote Share this post Link to post Share on other sites
morten 0 #12 August 10, 2005 Thanks for the replies - I'll assume the rule holds. I'm referring to sustainable sink rate - obviously the sink rate at landing approaches zero ideally The reason for the post was my first experiences with the canopy: Last out of cessna - hop'n'pop at 5000 feet - first down although everybody else did at least 10-12 secs freefall. I'd like to be able to sort of park myself at a higher altitude to let the others land in the 'correct' order. Again thanks for the replies - I love dropzone.com Quote Share this post Link to post Share on other sites
fab777 0 #13 August 10, 2005 Quote To achieve max glide, in zero winds, requires a certain rear riser input, which "flattens" the canopy relative to the horizon Increasing angle of attack vs lowering the flaps, if you take it as an airplane... Fabien BASE#944 Quote Share this post Link to post Share on other sites
Trae 1 #14 August 11, 2005 My K120 opens beautifully every time.... from the first hop and pop up till over 100 terminal openings ....no complaint...more like very impressed. VERY. Birdman---no worries including 2 nite jumps It is a bit sensitive during slower birdy openings but this was due to poor bag lift off from shortish bridle . You want an excessively well developed non-crossbraced canopy --get one you won't be dissapointed. Scouts honor. edited to include ..you want good openings pack it yourself...packers are jealous of Katana's Quote Share this post Link to post Share on other sites
Pendragon 1 #15 August 11, 2005 Well, that's 2 guys now posted that say Katanas open great. Typical. Actually may well consider one after I get some more jumps in... I'll line it up against the Xfire2 and see what I think, sometime in the future. Not sure if I'd ever want to wingsuit with one though -- BASE #1182 Muff #3573 PFI #52; UK WSI #13 Quote Share this post Link to post Share on other sites
hkf 0 #16 August 11, 2005 QuoteWell, that's 2 guys now posted that say Katanas open great. Typical. Make that 3!!! Quote Share this post Link to post Share on other sites
