Aces High Bulletin Board
General Forums => The O' Club => Topic started by: mechanic on February 12, 2016, 06:21:51 PM
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https://www.youtube.com/watch?v=VClAMnBLTQw
Sometimes life teaches you something while also granting you the luck not to be punished severely. Think I was about 12 inches from breaking both my legs on this one. This canopy flying game is a different world to just skydiving. It's taken over 400 jumps to get to this level, and I'm still such a rookie.
whew...
A brief explanation for those interested. The normal way to fly the canopy is with the steering toggles on a nice gentle straight in approach. These are long lines connected to the back of the canopy that you can use to alter the shape of the trailing edge. Just like elevators. They produce lift and also drag. These are the only wise option for recovering a low dive when you start learning to spiral down toward the ground and just miss.
A more dangerous and ultimately more awesome way of landing is to put the canopy into a diving turn calculating exactly the right altitude that the canopy will then level off again before you hit the ground. Along with this silly game comes the more advanced way of controlling the canopy, by pulling the rear or front risers. These are the 4 connections between your harness and the lines. The only lines not connected to the risers are the steering toggle lines. When you pull down on the front risers you change the angle of attack of the canopy and dive but without deforming the wing too much granting maximum aerodynamics for speed. Equally, when you pull down on the rear risers you decrease the canopies angle of attack, allowing you to level out of a shallow dive and swoop along the ground with minimum drag, scraping your feet through the grass and looking cool.
What happened to me was I tried to recover a low dive with the rear risers, realised that at that speed and angle I could not move them enough to swoop and then very nearly buried my ankles into the hard baked soil. Lesson learned. But man this game is so deliciously dangerous.
S!
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Wow. That last landing was dangerous.
That game has little margin for error. Is it really worth getting paralyzed over?
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Please don't end up as a Darwin Award winner.
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Wow. That last landing was dangerous.
That game has little margin for error. Is it really worth getting paralyzed over?
100% yes :D
https://www.youtube.com/watch?v=usreDL1BtNQ
Please don't end up as a Darwin Award winner.
I'll do my best, let's see what my genes are made of sir!
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You're a braver man than I.
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Does it put you back in the tower when you auger or do we start the Darwin award fund now?
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Woah!
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Start the fund now, I need a new canopy. I'll pay it back if I don't auger.
Bravery is overcoming fear. Proper training eliminates most of the fear. It's seriously fun!
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We call it "burning in" in the Army. :aok :salute
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Wisdom comes from experience.
Experience comes from mistakes.
Sometimes, there isn't room for mistakes and all you do is give someone else experience!
Careful out there.
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If you ever find yourself thinking, "Hey guys, check this out!", then STOP! Nothing good comes after that phrase.
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Dearly beloved, we are gathered here on this solemn occasion to pay tribute to Hamish, who flew over the Cliff of Adrenaline in search of something or other...
Be careful, dammit. :furious
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If you ever find yourself thinking, "Hey guys, check this out!", then STOP! Nothing good comes after that phrase.
"Hey guys, watch this. Here--hold my beer."
Lol
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I get it Bat. Some folks like to live in different ways, and if that's life for you, live it man! I'm glad you caught it and didn't get hurt, but I'm even more glad that you learned something from it to be a bit better and a bit safer next time!
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I get it. I roadraced motorcycles for 20 years. You don't dwell on the crashes but they start to add up and become a weighty burden. I quit on crash #47. Sooner or later you have to either decide you've gotten what you want from the sport and move on, or accept that the cumulative risk will finally bury you.
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Its not the death as much as the maiming.
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This game is just an extremely good way to give yourself a spinal cord injury. That's the least abrasive way to say it.
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live a little people, we were born warriors, it's just our easy life that makes us soft and scared.
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Common sense always tells me there's no perfectly good reason to jump out of a perfectly good airplane
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Ah yes, it's much more intelligent of us a species to use them to wage war on each other :D
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Ah yes, it's much more intelligent of us a species to use them to wage war on each other :D
:joystick:
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How about jumping out of a perfectly good airplane into war? :rock
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Hmm, that could be a possibility, I get to jump right?
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How about jumping out of a perfectly good airplane into war? :rock
Best of both worlds!!!
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Common sense always tells me there's no perfectly good reason to jump out of a perfectly good airplane
I'm an A&P Mechanic, I can tell you there's no such thing as a 'perfectly good airplane'.
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live a little people, we were born warriors, it's just our easy life that makes us soft and scared.
Oh don't get me wrong, I think it's awesome you do this, just do it carefully :)
Hell I turned 53 a few weeks back and I'm feeling, quite a lot, many motorcycle racing wrecks from when I was in my 20s. Wouldn't trade it for anything, might have wished one or two wouldn't have happened, but for the most part walked from them all :salute
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I'm an A&P Mechanic, I can tell you there's no such thing as a 'perfectly good airplane'.
I beg to differ. My Legacy is perfectly good. She never complains and rarely breaks. I wish I could marry her. :)
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I beg to differ. My Legacy is perfectly good. She never complains and rarely breaks. I wish I could marry her. :)
I beg to double differ, everyone knows the perfect is the enemy of the good so your airplane is oxymoronic or at the least hiding a deep dark secret. Marry her at your peril and woe betide you if you do!
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I beg to double differ, everyone knows the perfect is the enemy of the good so your airplane is oxymoronic or at the least hiding a deep dark secret. Marry her at your peril and woe betide you if you do!
:rofl
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I'm an A&P Mechanic, I can tell you there's no such thing as a 'perfectly good airplane'.
Thank god for ejection seats!
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Oh don't get me wrong, I think it's awesome you do this, just do it carefully :)
Hell I turned 53 a few weeks back and I'm feeling, quite a lot, many motorcycle racing wrecks from when I was in my 20s. Wouldn't trade it for anything, might have wished one or two wouldn't have happened, but for the most part walked from them all :salute
The chunks of titanium screwed into in my bones hurt more and more as years go by.
Just replacing the steering head bearing in my bike at the moment, too sore to ride anything but a big old bus that puts no weight on my wrists nowadays but nevertheless I am looking forward to slinging my leg over the old girl again once the icy roads quit!
Motorcycling should be illegal as it is almost 100% addictive after a single use and can be dangerous. Like two wheeled crystal meth!
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Duuude! You almost lost your perk points with this landing!
I won't comment on the swooping technique as I've never done it but I'd like to point an error (probably a typo) in what you said in your OP and I'd like to attract your attention on a possible cause of incident I wasn't aware of while skydiving and only learned about when I took up paragliding. Maybe you're already aware of this, but recent fatal incidents with experienced skydivers caused by wings collapsing near the ground (here (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4776886;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread) and here (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4779983;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread)) give me the impression that the info isn't common knowledge yet.
Equally, when you pull down on the rear risers you decrease the canopies angle of attack, allowing you to level out of a shallow dive and swoop along the ground with minimum drag, scraping your feet through the grass and looking cool.
Actually, pulling down on the rear risers will increase the AoA of your wing. And as the stall is only determined by the AoA, it is possible to stall your wing almost instantly with the rear risers, usually with a much smaller input than with the brakes. So kudos for keeping your wits and switching to the brakes instead of trying to dig yourself out of the corner by yanking on the rear risers, which would have probably ended much less nicely.
Now a bit of advice about flying a canopy with a decreased AoA in turbulent aerology: when you pull on the front risers (symetrically or not), you decrease the AoA of your wing (along the whole span or asymetrically). As you know, ram air canopies need pressurization (resulting from airspeed) to keep an efficient shape, and the cell openings are designed to maximize the pressurization when the airstream hits them at the standard AoA (when the risers aren't deformed).
So on one hand, you're gaining pressurization by the speed increase resulting from the dive initiated by the lower AoA, but on the other hand the airstream direction isn't entering the cell openings at the optimized angle so you're losing pressurization. The differential depends on the wing design but it is possible that, by diving with the front risers, your wing isn't as 'solid' (=pressurized) as in normal flight.
If a wing encounters at this moment a disturbance in the air mass (wind shear or turbulence) hitting the top part of the leading edge, it could be enough to cause a frontal collapse.
Now, paragliders are more prone to frontal collapses than skydiving canopies due to their lighter wing loading and essentially because they are flown more often in turbulent conditions (allowing them to gain altitude). Paraglider pilots are well aware of this phenomenon, and are taught to use the speed bar (allowing them to pull on the front risers to decrease the AoA) carefully when the air mass isn't calm.
However, a full or partial frontal collapse of a skydiving wing close to the ground leaves almost no room for recovery. Even if it is a rare event, the seriousness of the consequences shouldn't allow the swoopers to disregard it. The danger zone, IMO, is a landing area downind of obstacles.
Keep us posted, and try to become an old skydiver please ;)
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Live a little?
I jumped out of planes 20 years before you were born, Hamish. When real men used 2TU's and you had better have made the right decision when to exit because the wind decided your landing fate more than the blown out panels or girly, easy-mode square, ram air chutes or wings.
:)
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:D you win, Rolex, this round
Duuude! You almost lost your perk points with this landing!
I won't comment on the swooping technique as I've never done it but I'd like to point an error (probably a typo) in what you said in your OP and I'd like to attract your attention on a possible cause of incident I wasn't aware of while skydiving and only learned about when I took up paragliding. Maybe you're already aware of this, but recent fatal incidents with experienced skydivers caused by wings collapsing near the ground (here (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4776886;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread) and here (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4779983;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread)) give me the impression that the info isn't common knowledge yet.
Actually, pulling down on the rear risers will increase the AoA of your wing. And as the stall is only determined by the AoA, it is possible to stall your wing almost instantly with the rear risers, usually with a much smaller input than with the brakes. So kudos for keeping your wits and switching to the brakes instead of trying to dig yourself out of the corner by yanking on the rear risers, which would have probably ended much less nicely.
Now a bit of advice about flying a canopy with a decreased AoA in turbulent aerology: when you pull on the front risers (symetrically or not), you decrease the AoA of your wing (along the whole span or asymetrically). As you know, ram air canopies need pressurization (resulting from airspeed) to keep an efficient shape, and the cell openings are designed to maximize the pressurization when the airstream hits them at the standard AoA (when the risers aren't deformed).
So on one hand, you're gaining pressurization by the speed increase resulting from the dive initiated by the lower AoA, but on the other hand the airstream direction isn't entering the cell openings at the optimized angle so you're losing pressurization. The differential depends on the wing design but it is possible that, by diving with the front risers, your wing isn't as 'solid' (=pressurized) as in normal flight.
If a wing encounters at this moment a disturbance in the air mass (wind shear or turbulence) hitting the top part of the leading edge, it could be enough to cause a frontal collapse.
Now, paragliders are more prone to frontal collapses than skydiving canopies due to their lighter wing loading and essentially because they are flown more often in turbulent conditions (allowing them to gain altitude). Paraglider pilots are well aware of this phenomenon, and are taught to use the speed bar (allowing them to pull on the front risers to decrease the AoA) carefully when the air mass isn't calm.
However, a full or partial frontal collapse of a skydiving wing close to the ground leaves almost no room for recovery. Even if it is a rare event, the seriousness of the consequences shouldn't allow the swoopers to disregard it. The danger zone, IMO, is a landing area downind of obstacles.
Keep us posted, and try to become an old skydiver please ;)
You are right, about the opposite AoA. I was thinking upside down, considering more dive as more AoA with regards to the ground. The inflation of the cells is usually no problem with front riser dives. However, a strong headwind can cause difficulties with partial collapses as well as sometimes forcing the canopy to stay in a dive longer as the wind hit the top surface of the cells. Most canopies now have inflation in mind when being designed and it is difficult to empty a cell in normal conditions. Some even have valve systems inside the cell openings to prevent depressurisation.
I believe paragliders and speedwings are very different in design and much more prone to violent stalls.
Rear riser control on landing is standard for swooping, the main risk is that of yanking the risers down too violently and causing a stall. With this canopy, sabre2 135 loaded around 1.3, it is considered safe to use the risers if used properly. The main problem with using them to recover a low dive is that the pressure is multiplied so much with the speed that adequate control is much more difficult if not impossible.
For sure, I was lucky. But this was not a canopy or weather issue, this was my poor decision making followed, luckily, by very quick good decision making. Suffice to say, I am one step closer to being an old skydiver through learning this lesson without paying the price.
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I get the heebie jeebies reading this...lol
I jumped, once. With one of those old round chutes, posted the pic here a few times.
Been there done it, scared the crap out of me but I survived. All good. :bolt:
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:D you win, Rolex, this round
You are right, about the opposite AoA. I was thinking upside down, considering more dive as more AoA with regards to the ground. The inflation of the cells is usually no problem with front riser dives. However, a strong headwind can cause difficulties with partial collapses as well as sometimes forcing the canopy to stay in a dive longer as the wind hit the top surface of the cells. Most canopies now have inflation in mind when being designed and it is difficult to empty a cell in normal conditions. Some even have valve systems inside the cell openings to prevent depressurisation.
I believe paragliders and speedwings are very different in design and much more prone to violent stalls.
Rear riser control on landing is standard for swooping, the main risk is that of yanking the risers down too violently and causing a stall. With this canopy, sabre2 135 loaded around 1.3, it is considered safe to use the risers if used properly. The main problem with using them to recover a low dive is that the pressure is multiplied so much with the speed that adequate control is much more difficult if not impossible.
For sure, I was lucky. But this was not a canopy or weather issue, this was my poor decision making followed, luckily, by very quick good decision making. Suffice to say, I am one step closer to being an old skydiver through learning this lesson without paying the price.
Yeah Rolex, big :aok for jumping those jurassic-era rounds ;)
Mechanic, I should have said that there are indeed lots of positive things in your video: ok, you somewhat fubared your swoop (entry too low or rotation held for too long, i can't say) but you didn't take long to recognize the danger you got yourself in and you reacted super fast and adequately. And before all that, you had the wisdom to pick up a canopy size and type adapted to your skill level :aok
And I agree that your 'incident' had nothing to do with atmospheric conditions, I just wanted to share some knowledge that I missed during my skydiving days.
2 points I'd like to make:
1) I don't think that paragliders stall more violently than skydiving canopies, and I think it's the contrary for type A and B wings, designed for docility. The longer lines will store more pendular energy which will have to be dissipated by active piloting, and the higher aspect ratio of the planform will make them more prone to cravats and other niceties, but OTOH the bigger inertia will dampen the reactions. Speedflying wings are usually as small as swooping canopies and I won't comment about those as I have zero experience.
Here is a video of a 'big' skydiving canopy stalled intentionally with toggles: even with slow input, the reaction is brisk (especially the yaw)
https://www.youtube.com/watch?v=F3XmrH_9n6Q (https://www.youtube.com/watch?v=F3XmrH_9n6Q)
2) ref 'strong headwind': wind force and direction won't have the slightest influence on your canopy behaviour as long as they don't change drastically. When flying in a moving mass of air, only your ground path will be influenced. So your swoop will obviously be longer when flying downind than upwind, but your recovery arc and the height needed to flare will be exactly the same! :old: Or maybe I misunderstood you?
Here is a video of a swooping canopy held with a bit of fronts hitting the burble (wake turbulence) of a wingsuit... Yikes!
https://www.youtube.com/watch?v=oQ8WJBNh-qg&feature=youtu.be&t=58 (https://www.youtube.com/watch?v=oQ8WJBNh-qg&feature=youtu.be&t=58)
And for giggles, a vid of one of my flights during a SIV course (flight incidents simulation)... Or how to share the experience of the laundry in the tumble dryer....
https://vimeo.com/143241589 (https://vimeo.com/143241589)
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If you ever find yourself thinking, "Hey guys, check this out!", then STOP! Nothing good comes after that phrase.
Or...Hold my beer and watch this!
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The good ole days when I could walk through the airport metal detector without alerting Home Land Security.
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Yeah Rolex, big :aok for jumping those jurassic-era rounds ;)
Mechanic, I should have said that there are indeed lots of positive things in your video: ok, you somewhat fubared your swoop (entry too low or rotation held for too long, i can't say) but you didn't take long to recognize the danger you got yourself in and you reacted super fast and adequately. And before all that, you had the wisdom to pick up a canopy size and type adapted to your skill level :aok
And I agree that your 'incident' had nothing to do with atmospheric conditions, I just wanted to share some knowledge that I missed during my skydiving days.
2 points I'd like to make:
1) I don't think that paragliders stall more violently than skydiving canopies, and I think it's the contrary for type A and B wings, designed for docility. The longer lines will store more pendular energy which will have to be dissipated by active piloting, and the higher aspect ratio of the planform will make them more prone to cravats and other niceties, but OTOH the bigger inertia will dampen the reactions. Speedflying wings are usually as small as swooping canopies and I won't comment about those as I have zero experience.
Here is a video of a 'big' skydiving canopy stalled intentionally with toggles: even with slow input, the reaction is brisk (especially the yaw)
https://www.youtube.com/watch?v=F3XmrH_9n6Q (https://www.youtube.com/watch?v=F3XmrH_9n6Q)
2) ref 'strong headwind': wind force and direction won't have the slightest influence on your canopy behaviour as long as they don't change drastically. When flying in a moving mass of air, only your ground path will be influenced. So your swoop will obviously be longer when flying downind than upwind, but your recovery arc and the height needed to flare will be exactly the same! :old: Or maybe I misunderstood you?
Here is a video of a swooping canopy held with a bit of fronts hitting the burble (wake turbulence) of a wingsuit... Yikes!
https://www.youtube.com/watch?v=oQ8WJBNh-qg&feature=youtu.be&t=58 (https://www.youtube.com/watch?v=oQ8WJBNh-qg&feature=youtu.be&t=58)
And for giggles, a vid of one of my flights during a SIV course (flight incidents simulation)... Or how to share the experience of the laundry in the tumble dryer....
https://vimeo.com/143241589 (https://vimeo.com/143241589)
Man, that paragliding looks a lot of fun .But for sure it looks like the end cell stalls are far more violent and long lasting than a skydive canopy. Speedflying is a whole new kettle of fish, and seriously dangerous with instant and unpredictable stalls. The skydive wing at the size I'm currently flying by comparison is very easy to feel riding right up to and over the edge as far as input stalls are concerned. Turbulence stall not so easy, but learning to spot or predict the turbulence ahead of time is a good prevention.
Really nice recovery on your paraglider, I love the way when you get stable the cells just pop open one by one all down the wing.
I appreciate the advice and discussion, it all helps to keep me in one piece.
If you thought my mistake was dangerous, check out this lunatic on a speedwing...
https://www.youtube.com/watch?v=hl3iKGd4Yqo
truly beautiful and utterly insane.
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Oh and two points I forgot: A strong headwind can certainly prolong the recovery arc of your canopy, though for me it's is not a big issue at my amateur level. For the pro swoopers it can make a difference because the turn so steep that the wind is hitting nothing but the top of the canopy. Having spent some time here with competition level swoopers this is definitely true.
Also, the wingsuit burble hitting the canopy is far stronger than your average atmospheric turbulence. Having flown a wingsuit in another's burble I can confirm that the turbulence behind a wingsuit is horrific.
S!
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Now do it on a pony Ya rustler!!
Awesome Buddy, grinning for ya.. :D