gus 1 #1 October 4, 2006 One for the GPS BASE boys? I'm trying to do some rough glide ratio calculations from places where I know (a) the exit altitude (b) my opening altitude and (c) the horizontal distance covered. What's a good estimate for the amount of altitude used up before you're flying 'properly'? Let's say before you're flying at 75% of your final glide. 500 ft? I'm thinking about this: if a big wall is 4000 ft vertical and 5500 ft horizontal to the landing area and it takes 500 ft to get flying then a 2:1 glide would have you pitching over the landing area at 750 ft. A 2:5:1 would have you pitching at 1300 ft. But I don't know how realistic that 500 ft is. Thanks! GusOutpatientsOnline.com Quote Share this post Link to post Share on other sites
yuri_base 1 #2 October 4, 2006 QuoteWhat's a good estimate for the amount of altitude used up before you're flying 'properly'? That altitude is very individual. It depends not only on skill, but on wingloading, too. Wingloading makes a huge difference on when you start to fly. Since vertical speed during initial 2-3-4 seconds is about the same regardless of weight (it's linearly increasing with time: V=g*t), the horizontal acceleration (and hence, horizontal speed and distance) is inversely proportional to windloading factor. (F ~ surface area; a = F/m ~ (surface area)/m = 1/windloading) So, for example, if we have two jumpers of the same size and skill, but with difference in weight 50% (140 and 210lbs), the lighter jumper will travel 50% more in the first few seconds. If you're preparing for a "do it or die" jump using L/D calculations, the only data you can use is your own GPS data from previous flights. YuriAndroid+Wear/iOS/Windows apps: L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP iOS only: L/D Magic Windows only: WS Studio Quote Share this post Link to post Share on other sites
LukeH 0 #3 October 4, 2006 Hey Gus, Whatever about the bullshit, and equations and theories, my opinion for what it's worth, it that a decent pilot with a decent exit can get a V2 type suit flying in 400 - 500 feet. I haven't measured it, it is just a guess based on observations of a few WS exits. I think 500ft is a good ballpark figure to use. I doubt it's dramatically more or less. -Luke Quote Share this post Link to post Share on other sites
robibird 3 #4 October 4, 2006 150 m for exit, 150 m for opening. this is more or less what we deduct in calculations when considering the WS flight from some wall. 300m minus from total useable altitude. Of course, 150m is not enough to start some times nor recommended altitude for start too....Robert Pecnik robert@phoenix-fly.com www.phoenix-fly.com Quote Share this post Link to post Share on other sites
Calvin19 0 #5 October 4, 2006 150m for opening? weak. -SPACE- Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #6 October 4, 2006 Quote150m for opening? weak. Did you just call RobiBird weak????? Man I just spit up on the screen! Quote Share this post Link to post Share on other sites
robibird 3 #7 October 4, 2006 Of course this is my opinion. BTW, the opening is just the end of rush we have after long or close flying so no need to push ( always ) at the pull time Robert Pecnik robert@phoenix-fly.com www.phoenix-fly.com Quote Share this post Link to post Share on other sites
TomAiello 26 #8 October 4, 2006 QuoteQuote150m for opening? weak. Did you just call RobiBird weak????? Man I just spit up on the screen! Me too. Hecker, I'm sure you didn't mean that. Have you jumped with Robi? 'Cause he sure as hell ain't "weak."-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
Mikki_ZH 0 #9 October 4, 2006 Quote150m for opening? weak. Check out this video...Michi (#1068) hsbc/gba/sba www.swissbaseassociation.ch www.michibase.ch Quote Share this post Link to post Share on other sites
GeordieSkydiver 0 #10 October 4, 2006 Quoteso no need to push ( always ) at the pull time I like the way you never push the envelope Robi. Keep not pushing it. .Lee _______________________________ In a world full of people, only some want to fly, is that not crazy? http://www.ukskydiver.co.uk Quote Share this post Link to post Share on other sites
RJmoney 0 #11 October 4, 2006 geeez matt use your smiley faces or nobody on the internet will ever know what you are saying.word to your mother, RJ$$ BASE 1117 Quote Share this post Link to post Share on other sites
KrisFlyZ 0 #12 October 4, 2006 I feel like I am taking off when I exit. The GPS says(error in the bowl) that my glide for the first 20 secs is almost 5 to 1 (see attached..exit altitude is 1438 m) . Anyway, next time I'll jump with the barometric alti GPS and that should sort this problem out. For me, if the exit is good, there is no perceptible 'fall' so to speak it just takes time to build up speed. Even this is only about 8-10 secs. Kris. Quote Share this post Link to post Share on other sites
