sdctlc 0 #1 May 2, 2003 http://www.freeflytim.com/movies/Dustdevil.rm Tony Ross posted this over on rec.skydiving. Worth taking a look at. I dont know who it is or what DZ it is so I cant give any credit other than to Tony for posting it. Makes you think that its not over till its over regarding canopy flight and landing. Scott C."He who Hesitates Shall Inherit the Earth!" Quote Share this post Link to post Share on other sites
billvon 2,990 #2 May 2, 2003 That's Perris, and where he landed is a primo area for dust devil formation. I watched one form there and sit stationary for a good 60 seconds shortly after I landed one day. One of the reasons I really like the grass area is that dust devils seem to avoid it (at least they don't seem to form there.) Quote Share this post Link to post Share on other sites
Guest #3 May 2, 2003 I saw Tony's post on the wreck and was about to put it here. Thanks for taking the initiative. Was that Tony under the canopy? "The mouse does not know life until it is in the mouth of the cat." Quote Share this post Link to post Share on other sites
SkydiveMonkey 0 #4 May 2, 2003 Dude, that's some freaky stuff. . What's the main cause of them? Just rising heat from the ground, or other factors as well? ____________________ Say no to subliminal messages Quote Share this post Link to post Share on other sites
dreamsville 0 #5 May 2, 2003 I can remember about a month ago when we started to see dust devils at about 1-2pm on Saturday. It began right about the time Deguello was landing from a practice jump; we could see a pretty tall DD about 80-100 yards beyond the grass landing area in back of their landings. Philip and the rest of us stopped jumping as it was gusting up a bit as well. Someone else told me that she caught the edge of one a few weeks ago in the landing area, but fortunately slid off to the side and stopped safely after being carried along a bit by it near the ground.| I don't drink during the day, so I don't know what it is about this airline. I keep falling out the door of the plane. Harry, FB #4143 Quote Share this post Link to post Share on other sites
riker 0 #6 May 2, 2003 What do you use to view a .rm file? Quote Share this post Link to post Share on other sites
SkydiveMonkey 0 #7 May 2, 2003 Real player from HERE____________________ Say no to subliminal messages Quote Share this post Link to post Share on other sites
sdctlc 0 #8 May 2, 2003 I just copied the link that Tony put up, I made no decision of the format One thing to look at when the jumper gets up it looks like there are a bunch of broken lines on the ground. Not sure though if they are from the canopy. i looked at it and I did not recognize it as Peris but hell, I've only been there a few times so what can I say. It did not really look like it but I guess it could be. I will look again. The second word on the runway seemed to be longer then Perris but I also could not make it out from the vid clip.... Scott C. "He who Hesitates Shall Inherit the Earth!" Quote Share this post Link to post Share on other sites
bch7773 0 #9 May 2, 2003 that looked like it hurt. I'm glad I jump where there are no dust devils... doing a backwards slam and skid doesn't seem like fun to me. Quote One of the reasons I really like the grass area is that dust devils seem to avoid it (at least they don't seem to form there.) Or is it that just as many dust devils are in the grass area, but that you can't see them because there isn't any dirt for them to pick up? This is just idle speculation on my part, im not questioning the all-powerful admin MB 3528, RB 1182 Quote Share this post Link to post Share on other sites
mikkey 0 #10 May 3, 2003 "One thing to look at when the jumper gets up it looks like there are a bunch of broken lines on the ground. Not sure though if they are from the canopy. " Thats not broken lines, thats from his collapsible slider (the small lines you pull to collapse it).--------------------------------------------------------- When people look like ants - pull. When ants look like people - pray. Quote Share this post Link to post Share on other sites
mikkey 0 #11 May 3, 2003 It is definitely thermal. As far as I know (and pls correct me if not) - when the heat from the sun reflects on "ground" that reflects heat well, the reflecting heat creates a lot of thermal "wind". So the bare dusty ground reflects the heat well, whilst the grass area does not. That is why a grass area is more save in regard to the thermals. The following is pure speculation: I think that the bare dusty ground is very "uneven" in its heat reflection, thus causing these circular small dust tornados - the hot dust from the ground probably does contribute to this. Where I jump it gets very hot in summer - well into the 40's Celsius, which is probably about 105-110 F as a top and consistenly above 90 F. When you jump in these conditions on a sunny day over a dusty field its like a mini roller-coaster ride. Really need to fly the canopy carefully....--------------------------------------------------------- When people look like ants - pull. When ants look like people - pray. Quote Share this post Link to post Share on other sites
itllclear 1 #12 May 3, 2003 To quote from the FAA's "Aviation Weather"... "Dust devils occuir under sunny skiues over sandy or dusty, dry surfaces...thermals are strong and turbulent..." Perris seems to famous for them during the summer, when all the wind socks and tetrahedron are pointing straight out in different direction. Once they start, they can move across the DZ, even the grass. Only problem is when they're over the grass, there's no dust for them to pick up so you can't see them I actually prefer going for the plowed dirt because 1) there's dust so you CAN see them, and 2) the plowed dirt is softer than the grass just in case your canopy does collpase. There have been at least two fatalities in Southern California in the last 15 years from these devils. Maybe best to head for the bar once they start! Blue Skies! HarryQuote"Harry, why did you land all the way out there? Nobody else landed out there." "Your statement answered your question." Quote Share this post Link to post Share on other sites sdctlc 0 #13 May 3, 2003 OK, after watching right from the begining I can see its Perris. My bad before but I see it now, the vid turns away after showing about 1-2 sec of the loading/packing/partying area. Regarding what I thought was broken lines, it actually looks to be more scrub of some sort and not broken lines. I did not think it was the kill line for the slider as that is very apparant. The scrub I wondered about looked a little like a coiled line. the vid was jumpy at that point. I guess the lesson learned is that Dust Devils are bad. I was caught is one at about 100 feet one time years ago. I had about 100 jumps at the time and I was very lucky to walk away unscathd. I was told it looked like my canopy was colapsed by an invisible hand that came down from the top and then tossed me about 50 yards to the side. My canopy inflated again at about 30-40 feet and I landed in a wheat field that was luckley pretty tall and soft at the time so the landing was soft and I did not get a sctarch. Scott c. "He who Hesitates Shall Inherit the Earth!" Quote Share this post Link to post Share on other sites billvon 2,990 #14 May 3, 2003 >Or is it that just as many dust devils are in the grass area, but that you > can't see them because there isn't any dirt for them to pick up? They definitely pass over the grass, but I don't think they form there as readily since they water the grass (and thus it's cooler there.) On the minus side you can't see them when they're over the grass, so it's much harder to avoid them. (They still pick up loose grass and twigs but not nearly as much as when they're over dirt.) Quote Share this post Link to post Share on other sites riggerrob 643 #15 May 3, 2003 Dust devils need hot (90 degrees fahrenheit), desert soil and a bit of horizontal wind to form. Thermal lifting is not enough to form a dust devil. They need a bit or horizontal wind to start them spinning. Once they start spinning they are nasty. The worst dust devils are the ones that start on hard pan, because you cannot see them. Quote Share this post Link to post Share on other sites apoil 0 #16 May 6, 2003 QuoteDust devils need hot (90 degrees fahrenheit), desert soil and a bit of horizontal wind to form. Thermal lifting is not enough to form a dust devil. They need a bit or horizontal wind to start them spinning. Once they start spinning they are nasty. The worst dust devils are the ones that start on hard pan, because you cannot see them. Thermal lifting can create feeder drafts from below that start it spinning. They can occur in Florida as well, just not quite with the same regularity, and they wont be visible if there's no dust/debris on the ground. But the ones in the South west are fearsome to behold, easily rising up a thousand feet or more. Quote Share this post Link to post Share on other sites SAMPLEKSample 0 #17 May 9, 2003 I could be off, but dust devils do go over grass, but they are obviously more difficult to see. Elsinore had one starting in the grass...5 freak landings in a row, we figured out what it was Its not the dust that gets them going, the dust is what we see... Quote Quote Share this post Link to post Share on other sites itllclear 1 #18 May 12, 2003 Rob- I wish the temps had to be over 90F to start them. It never got up to 80F yesterday at Perris but someone had to cut away on the grass when his canopy got in one. Yes, they're more common, and more powerful, when it's hot, but they can get going in lower temps. "Better to be on the ground wishing you were in the air, than in the air wishing you were on the ground!" Blue Skies! Harry"Harry, why did you land all the way out there? Nobody else landed out there." "Your statement answered your question." Quote Share this post Link to post Share on other sites pchapman 279 #19 May 13, 2003 Quote I wish the temps had to be over 90F to start them. It never got up to 80F yesterday at Perris but someone had to cut away on the grass when his canopy got in one. Agreed. One can't just write dust devils off as something that only happens off in California, or in the middle of summer. A week ago my planeload saw one in southern Ontario Canada on a nice spring day that can't have been above 75 F. We were climbing out when we saw it a few fields away, showing a tight core on a ploughed field, with dust extending above our 1000' altitude. Dust devils do exist here in warmer and thermally months, but they're still rare enough that nobody thinks about them as a drop zone hazard. Peter Chapman Toronto, Canada Quote Share this post Link to post Share on other sites skyjumpenfool 2 #20 December 16, 2009 Wow! That is a bit scary. I did a jump shortly after a tornado came thru... that didn't go so well. Squirrelly winds can be dangerous. This video did not show the landing. How did it turn out??Birdshit & Fools Productions "Son, only two things fall from the sky." Quote Share this post Link to post Share on other sites lethargic8 0 #21 December 24, 2009 I flew into one at Elsinore just over a year ago while on my final approach. It had started over the dirt in the student landing area but by the time I flew into it the dust devil was over the grass main landing area, I had no idea. My canopy collapsed twice and snapped back open at what I believe to be 15-20 feet above the ground. Resulted in a hard landing that I PLF'ed the shit out of, but no injuries. I was the first one down, everyone else on the load saw my canopy doing its wild dance and landed down wind. -derek 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. 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sdctlc 0 #13 May 3, 2003 OK, after watching right from the begining I can see its Perris. My bad before but I see it now, the vid turns away after showing about 1-2 sec of the loading/packing/partying area. Regarding what I thought was broken lines, it actually looks to be more scrub of some sort and not broken lines. I did not think it was the kill line for the slider as that is very apparant. The scrub I wondered about looked a little like a coiled line. the vid was jumpy at that point. I guess the lesson learned is that Dust Devils are bad. I was caught is one at about 100 feet one time years ago. I had about 100 jumps at the time and I was very lucky to walk away unscathd. I was told it looked like my canopy was colapsed by an invisible hand that came down from the top and then tossed me about 50 yards to the side. My canopy inflated again at about 30-40 feet and I landed in a wheat field that was luckley pretty tall and soft at the time so the landing was soft and I did not get a sctarch. Scott c. "He who Hesitates Shall Inherit the Earth!" Quote Share this post Link to post Share on other sites
billvon 2,990 #14 May 3, 2003 >Or is it that just as many dust devils are in the grass area, but that you > can't see them because there isn't any dirt for them to pick up? They definitely pass over the grass, but I don't think they form there as readily since they water the grass (and thus it's cooler there.) On the minus side you can't see them when they're over the grass, so it's much harder to avoid them. (They still pick up loose grass and twigs but not nearly as much as when they're over dirt.) Quote Share this post Link to post Share on other sites
riggerrob 643 #15 May 3, 2003 Dust devils need hot (90 degrees fahrenheit), desert soil and a bit of horizontal wind to form. Thermal lifting is not enough to form a dust devil. They need a bit or horizontal wind to start them spinning. Once they start spinning they are nasty. The worst dust devils are the ones that start on hard pan, because you cannot see them. Quote Share this post Link to post Share on other sites
apoil 0 #16 May 6, 2003 QuoteDust devils need hot (90 degrees fahrenheit), desert soil and a bit of horizontal wind to form. Thermal lifting is not enough to form a dust devil. They need a bit or horizontal wind to start them spinning. Once they start spinning they are nasty. The worst dust devils are the ones that start on hard pan, because you cannot see them. Thermal lifting can create feeder drafts from below that start it spinning. They can occur in Florida as well, just not quite with the same regularity, and they wont be visible if there's no dust/debris on the ground. But the ones in the South west are fearsome to behold, easily rising up a thousand feet or more. Quote Share this post Link to post Share on other sites
SAMPLEKSample 0 #17 May 9, 2003 I could be off, but dust devils do go over grass, but they are obviously more difficult to see. Elsinore had one starting in the grass...5 freak landings in a row, we figured out what it was Its not the dust that gets them going, the dust is what we see... Quote Quote Share this post Link to post Share on other sites
itllclear 1 #18 May 12, 2003 Rob- I wish the temps had to be over 90F to start them. It never got up to 80F yesterday at Perris but someone had to cut away on the grass when his canopy got in one. Yes, they're more common, and more powerful, when it's hot, but they can get going in lower temps. "Better to be on the ground wishing you were in the air, than in the air wishing you were on the ground!" Blue Skies! Harry"Harry, why did you land all the way out there? Nobody else landed out there." "Your statement answered your question." Quote Share this post Link to post Share on other sites
pchapman 279 #19 May 13, 2003 Quote I wish the temps had to be over 90F to start them. It never got up to 80F yesterday at Perris but someone had to cut away on the grass when his canopy got in one. Agreed. One can't just write dust devils off as something that only happens off in California, or in the middle of summer. A week ago my planeload saw one in southern Ontario Canada on a nice spring day that can't have been above 75 F. We were climbing out when we saw it a few fields away, showing a tight core on a ploughed field, with dust extending above our 1000' altitude. Dust devils do exist here in warmer and thermally months, but they're still rare enough that nobody thinks about them as a drop zone hazard. Peter Chapman Toronto, Canada Quote Share this post Link to post Share on other sites
skyjumpenfool 2 #20 December 16, 2009 Wow! That is a bit scary. I did a jump shortly after a tornado came thru... that didn't go so well. Squirrelly winds can be dangerous. This video did not show the landing. How did it turn out??Birdshit & Fools Productions "Son, only two things fall from the sky." Quote Share this post Link to post Share on other sites
lethargic8 0 #21 December 24, 2009 I flew into one at Elsinore just over a year ago while on my final approach. It had started over the dirt in the student landing area but by the time I flew into it the dust devil was over the grass main landing area, I had no idea. My canopy collapsed twice and snapped back open at what I believe to be 15-20 feet above the ground. Resulted in a hard landing that I PLF'ed the shit out of, but no injuries. I was the first one down, everyone else on the load saw my canopy doing its wild dance and landed down wind. -derek Quote Share this post Link to post Share on other sites
