Deuce 1 #1 September 30, 2002 On final I'm in front risers and it suddenly feels like I cutaway. I drop about 20 feet, it feels like, and I actually hear the crowd watching gasp(it was our boogie, so we had some spectators). My canopy reinflates about 10 feet up and I flare and step out no problem. Dust devil or something. It banged into the hagar right after it flew through me. It was not visible. Some skydivers tell me good job, that I was completely collapsed and then reinflated right before I bit it. I never looked up at the canopy so I don't know how bad it looked. Several people called me a dead man walking. I'm grateful for my training, and my Spectre. But mostly I'm glad I was lucky. Quote Share this post Link to post Share on other sites
jtval 0 #2 September 30, 2002 scary stuff. was that your FIRST deflate? lol glad youre wlaking, even if you are a dead man ! hahaMy photos My Videos Quote Share this post Link to post Share on other sites
moodyskydiver 0 #3 September 30, 2002 Man! I'm glad everything turned out good in the end. "...just an earthbound misfit, I." Quote Share this post Link to post Share on other sites
Viking 0 #4 September 30, 2002 wow somebody flashed god for extra life!! glad your ok man!I swear you must have footprints on the back of your helmet - chicagoskydiver My God has a bigger dick than your god -George Carlin Quote Share this post Link to post Share on other sites
nws01 0 #5 September 30, 2002 Got to love those Spectres. Glad you are ok you crazy man. Quote Share this post Link to post Share on other sites
TEB6363 0 #6 September 30, 2002 Deuce, Dude, glad you're alright!!!! I didn't know it was that hot in Byron yesterday, but I'm glad you're fine. Once the plane takes off, you're gonna have to land - Might as well jump out!! Quote Share this post Link to post Share on other sites
quade 4 #7 September 30, 2002 QuoteIt banged into the hagar right after it flew through me. How close were you flying to the building? When this happened, were you upwind or downwind of the building? Are there other buildings in the area? Could this have been building induced turbulence.quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
Jumperpaula 0 #8 September 30, 2002 Quote I almost got killed yesterday Please don't do that. Glad your ok. Quote Share this post Link to post Share on other sites
billvon 2,989 #9 September 30, 2002 >My canopy reinflates about 10 feet up and I flare and step out >no problem. Yep, it can happen anywhere (although it's much more likely in certain places.) Quote Share this post Link to post Share on other sites
christoofar 0 #10 September 30, 2002 QuotePlease don't do that. Just what I was thinking! ____________________________________________________________ I'm RICK JAMES! Fo shizzle. Quote Share this post Link to post Share on other sites
franck102 0 #11 September 30, 2002 You may want to think again about how safe it is to come in pulling on both front risers in anything but steady wind with no turbulence. Your may be flying your canopy close to the smallest angle of attack it will accept without collapsing, and a sudden change in the relative wind can take you over the line. BTW the same applies to coming in in deep brakes just above stall speed. Franck Quote Share this post Link to post Share on other sites
jtval 0 #12 October 1, 2002 Quote Yep, it can happen anywhere (although it's much more likely in certain places.) i get alot of turbulance over the landing area in vegas. well my pattern thus far has taken me over the highway around 1000-500 ft and even though im under a bus(210sabre) i can feel the thermals kicking me aroundMy photos My Videos Quote Share this post Link to post Share on other sites
dropdeded 0 #13 October 1, 2002 Dude,VERY glad to read this in the Talk Back catagory instead of........ dropdeded------------------------------------------ The Dude Abides. - Quote Share this post Link to post Share on other sites
bbarnhouse 0 #14 October 1, 2002 Deuce honey be careful out there.......who else is gonna call me the Rock-N-Roll Ballerina? xoxoxox B^2 Quote Share this post Link to post Share on other sites
Iflyme 0 #15 October 1, 2002 Hmmm .. did you sign up recently for the Alien Skydiver thingy on SETI@Home??? Maybe THEY found YOU!!! Quote Share this post Link to post Share on other sites
ECVZZ 0 #16 October 1, 2002 That gives me butterflies just thinking about it. Glad you're o.k.!!! Greg Quote Share this post Link to post Share on other sites
pilotdave 0 #17 October 1, 2002 QuoteYou may want to think again about how safe it is to come in pulling on both front risers in anything but steady wind with no turbulence. Your may be flying your canopy close to the smallest angle of attack it will accept without collapsing, and a sudden change in the relative wind can take you over the line. BTW the same applies to coming in in deep brakes just above stall speed. Can you (or someone else) explain this? Canopies are likely to collapse at low angles of attack? How about deep brakes? That would be a high angle of attack. I'd imagine flying slowly at a high angle of attack would lower the pressure inside the canopy so it would be less rigid. What's the problem at low angles of attack? Is it that the nose could fold over if the angle of attack goes negative from a gust or something? Dave Quote Share this post Link to post Share on other sites
riddler 0 #18 October 1, 2002 I know everyone's got their own opinions, but I really do believe in air-lock canopies. I'm not saying they definitely would have prevented this, but from the sound of it, they probably would have.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites
franck102 0 #19 October 1, 2002 As a pilot you can forget about pressure in the cells, the canopy designer has (or should have -) ) taken care of making sure the canopy remains in shape across the range of useful angles of attack (AOA). If you get a perfectly airlocked canopy it will never collapse but it will kill you all the same if you allow the angle of attack to get our of control - so as a pilot it is more productive to think in terms of AOA. >What's the problem at low angles of attack?Your canopy is an airfoil that needs a positive angle of attack to generate lift (the force that keeps you in the air). If the AOA becomes too small, the canopy stops generating lift. It may collapse, or surge forward, one way or the other it will leave you at the mercy of gravity. >How about deep brakes? That would be a high angle of attack. I'd imagine flying slowly at a high angle of attack would lower the pressure inside the canopy so it would be less rigid Maybe but this isn't the problem. You're right, flying in deep brakes creates a high angle of attack. The problem is that airfoils don't like too high an angle of attack. At normal AOAs the air flies smoothly around your canopy (it is laminar and more or less follows the contour of the section), but if the AOA becomes too high (the wind starts hitting the canopy at a right angle) the flow suddenly becomes mostly turbulent - that's a stall. Again pressure in the cells has nothing to do with the problem, airplanes stall just the same as canopies do. Your canopy collapses because it stalled, not the opposite. Now how does turbulence affect youy cnaopy? The AOA is the angle between your canopy (its chord - the line between the tail and the leading edge) and the relative wind. Turbulence (or variations in the wind strength for that matter) can suddenly affect the direction and the strength of the relative wind, and thus play havoc with your angle of attack. Imagine you are flying in no wind with a glide ratio of 1/1, going 10 mph down and 10 mph forward. In a 10 mph gust from behind you are suddenly flying vertically at 10 mph down relatively to the air around you and your canopy's angle of attack is suddenly about 90 degrees ( not good -) ). A 10 mph vertical downward gust (unlikely) would leave you with just 10 mph forward speed relatively to the air around you, and your canopy at an AOA close to 0. It will stop generating lift and you will also fall from the sky. Note that only relative changes matter - a 5 mph wind that suddenly turns 180 degree will not affect you more that a 25 mph wind that suddenly drops to 15 mph without changing direction - and the latter is quite common on gusty days. Franck Quote Share this post Link to post Share on other sites
franck102 0 #20 October 1, 2002 QuoteI know everyone's got their own opinions, but I really do believe in air-lock canopies. I'm not saying they definitely would have prevented this, but from the sound of it, they probably would have. Probably not, see my other post. Unless there is a fundamental flaw with the canopy, it collapsed because it was out of its flying range, and an airlocked canopy while it would have reacted differently would not have helped. In fact I suspect that it may have made the problem worse by surging forward and causing a pendulum effect - but that's just a hunch. I have flown airlocked canopies in turbulence and I felt less safe that with a canopy that collapses but stays over your head. Franck Quote Share this post Link to post Share on other sites
Deuce 1 #21 October 1, 2002 QuoteIt banged into the hagar right after it flew through me. -------------------------------------------------------------------------------- How close were you flying to the building? "Hagar". I fly better than I type. Really. Q, the wind was blowing from the northwest, so it was coming over open ground, and the airport and buildings were behind me on final. There's one shed out in the field that's about 8' X 8' by 6' tall. I don't think it was a contributing factor. I wasn't hot yesterday, either. Maybe describing the turbulence as a dust devil is innacurate. As I think about it, the term clear air turbulence comes to mind, but that's not a phenomenon I know enough about to use it to describe what happened. I have had my canopy deflate once before that I was aware of, but it was at 1000' where our turbulence layer usually is. Shifty ground winds are nothing new at Byron, they can 180 while you are setting up your pattern. When things get sketchy near the ground I say in my mind at about the speed of light "fly the landing, keep flying, fly the landing out..." This time when the canopy reinflated right near the ground I had a pretty high sideways speed and I flat-turned into the wind just in time to get a decent flare. I'm pretty cynical, so when I first heard people saying "nice landing" I thought they were dogging me about my 7-cell. The old, "that looked like a swoop, only smaller" kind of thing. But several told me I'd just beat the reaper, and I thought I'd share it with the group. Quote Share this post Link to post Share on other sites
riddler 0 #22 October 1, 2002 Yeah - if it was an AOA problem, then it's obviously not flying, so there is a definite drop. But I think you are forgetting about valuable "re-inflate" time. If it was an AOA problem, it certainly recovered quickly for him, but I'm sure he lost a lot more altitude than an air-lock would have to make the canopy re-inflate. If he was 10 feet lower, there would have definitely been an unfortunate collision with the ground (however serious), whereas (I believe) an airlock would probably have not dropped him that much. Of course, airlocks do NOT prevent line-slack, so if something hit him from the side, he would have likely been in some sort of turn whilst making previously mentioned unfortunate collision with ground.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites
Sebazz1 2 #23 October 1, 2002 JP dammit!! You're supposed to avoid those invisible dust devils. Don't tell your wife. And I am happy you're ok So someone forgot to shut the fans off on the hill this weekend Quote Share this post Link to post Share on other sites
Chief 0 #24 October 1, 2002 Glad you are okay. I had that happen once. Canopy did not fully re-inflate. Very hard PLF. Quote Share this post Link to post Share on other sites
quade 4 #25 October 1, 2002 Is it possible that you flew through somebody else's wake?quade - The World's Most Boring Skydiver Quote Share this post Link to post Share on other sites
