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hwjl

Stalling the canopy to remove a line over?

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So in my personal opinion, the moment I see I have a line over, or feel the canopy just isn’t as it should be, I would immediately cut it. Perhaps if it was a high pull and felt like the canopy was temporarily stable enough to try this manoeuvre I would try it. But realistically I’m no test jumper, so doubt I would be bold enough to put myself in a potentially more dangerous position.

That also being said, I’ve also heard that this manoeuvre could also damage the canopy fabric so perhaps not…

Anyway, is there ANY footage of this event or is it just a theoretical idea. I would LOVE to see proof this is possible. Has anyone out here actually done this? What was the outcome? I guess this wouldn’t really work with bow tie line overs.

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I had this happen to me when I was 1st learning to pack. I packed a steering line line-over on a 1:1 wingloading canopy. After it deployed, I saw what it was, flared the canopy, and when I let the toggles back up the line-over cleared.

We looked it over after I landed for burns, but the canopy was fine.

 

 

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Most of the time when people think they have a line over they actually have a tension knot. It's very difficult to look up and correctly diagnose the distorted canopy. Stalling the canopy and re-inflating it will generally clear a tension knot. It is far less like to clear a line over. If you do get a line over on a loaded canopy you will have line burn on you the top skin. If you don't have line burn it is unlikely that you had a line over.

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Stall or collapse? They are not the same thing.

Collapse: Occurs when the canopy loses sufficient inflation either from significant distortion or turbulence. The canopy folds in on itself and drops out of flight entirely. The pilot goes back into freefall.

Stall: Occurs when the canopy exceeds the critical angle of attack of the wing and loses sufficient lift to remain in proper flight. Most commonly, this occurs after a full flare.

So I think you're talking about a collapse. In that case, I have always wondered the same thing. I think it's possible it could clear the lineover if it's toward the ends. I dont think it would help if the lineover is in the center. The issue is when you collapse the canopy, when it reopens the reopening is typically a bit violent and the canopy surges forward during reinflation. If you already have a lineover this could in theory make the situation even worse by possibly causing the lineover to move in a position that now forces the canopy to spiral down. Instead of chopping a stable canopy you're now chopping one that's spinning. Of course this is theoretical. What would actually happen is anyone's guess I think.

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I have used deep stall to clear a few tension knots on tandems and one line-over on a solo canopy.

the technique requires pulling the canopy into a deep stall, straight ahead. When you let the goggles up rapidly, the canopy dives forward and - for a brief few seconds - there is hardly any tension on the suspension lines. This allows tension knots to untie themselves and - on rare ocassions - MIGHT allow a line-over to clear itself. MIGHT!

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A former coworker of mine used to trash pack pretty bad and got line overs fairly routinely on his Raider. He cleared them by climbing a riser - front most often - nearest the point of the line over until the line slipped off. Of course this was done with a loading of 1.3 +/- on a square F-111 canopy. Not sure I would try it on a heavily loaded HP canopy.

With all that said, I have always been an advocate of just getting rid of anything that doesn't fly right, and doing it quickly. I have seen docile malfunctions turn into vicious, high G ones in the blink of an eye. I have also lost friends because the mals they had were so violent that they were rendered unable to properly perform EP's.

If it looks bad and flies bad, it's bad. We will never know how many jumpers have died because they jacked around with a mal that went south in a big way. Don't add yourself to the list. 

And on that subject, this is timely.... https://parachutistonline.com/p/Article/dont-delay-cut-awaythe-link-between-spinning-malfunctions-and-difficult-cutaways 

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(edited)

This is taught in paragliding, where "line overs" (or as they are called, "cravats") result from large collapses with some frequency (unlike skydiving where they happen almost never) and must be cleared during SIV (canopy course).  You have to stall out the part of the wing that the line is over for it to slide down, and in general, a full stall is a "reset button" for your paraglider.

 

It will work just as well with a parachute to clear the lineover, but realize that paragliders are MUCH better behaved wings with regards to stall recovery and maneuverability in an impeded state (i.e. the "canopy course" you take as a PG pilot will have you intentionally collapse 50% of your wing by pulling on front risers, and then fly controlled - straight, make turn one direction, turn opposite direction... you just can't do that with a skydiving wing very well...), so unless you are comfortable recovering your wing from a stall and have done it a bunch of times, a line over is not the time to experiment because poor stall recovery can make everything much worse very quickly in all kinds of creative ways.

Edited by lyosha

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Not necessarily recommending this but I will tell a tale :-)  I had probably 5000 jumps at the time and was open about 4500.  On a Sabre 120 I believe loaded at 1.3ish.  Opened and started to turn with a line over on the outermost left cell I believe.  Immediately the first thing I do is stop by yanking opposite riser.  I pull on the riser and stop the spin so that gives me time to contemplate - if you can't stop the spin chop immediately.  But by pulling heavy on a riser I could get the canopy flying straight and it gave me time to evaluate the situation.  

I tried rear riser stalls and toggle stalls a bunch of times to no avail.  I then decided to cut away around 3kish.  I let go of my risers and grabbed my handles but started to spin really fast because I was no longer stopping the spin.  I had a brand new rig with really good velcro on my cutaway handle.  I yanked it and couldn't pull it at first, but having taught a thousand FJC's by now I knew I just needed o peel the velcro.  But I was spinning really hard so I let go of my reserve handle and yanked down my rear riser and stopped my spin while I peeled the velcro.  I peeled the velcro and looked down to verify that it was off because I knew that when I let go of the opposite riser I would start spiraling again and needed to grab my reserve handle quickly.

But when I looked up after holding just the opposite left rear while peeling my cutaway handle my lineover was clear and I had a good canopy.  I was like huh. look at that, as I calmly placed my cutaway handle right back on the velcro.  

So in my case somehow just holding down the one side cleared mine when dual-sided stalls did nothing.  Can't explain it but can definitely say if I had had a rig with less strong velcro I would have had one more cutaway than I do.  

 

 

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On 7/11/2019 at 10:56 AM, Hooknswoop said:

I wouldn’t try this on a main canopy, I definitely would try this on a reserve canopy.

 

Derek V

That's what the military taught us in freefall school.  Reserve line-over = "pump it for the rest of your life."  (The toggles/risers)

-JD-

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(edited)
On 8/2/2019 at 1:34 PM, skyfox2007 said:

That's what the military taught us in freefall school.  Reserve line-over = "pump it for the rest of your life."  (The toggles/risers)

-JD-

Or you could just cut the line, which would be my preference. Better than dealing with a potential canopy collapse or have the canopy reopen and spin you up and into the ground. A good thing to consider is which line caused the lineover. If it's a brake line or a C/D line, then I'd probably cut it You can land on the rears if needed and the C/D lines tend to be less critical. The A/B lines, and especially the A's, form the shape of the nose and so cutting those is a lot more risky, as the canopy might have trouble holding it's shape.

Edited by 20kN

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14 hours ago, 20kN said:

Or you could just cut the line, which would be my preference. Better than dealing with a potential canopy collapse or have the canopy reopen and spin you up and into the ground. A good thing to consider is which line caused the lineover. If it's a brake line or a C/D line, then I'd probably cut it You can land on the rears if needed and the C/D lines tend to be less critical. The A/B lines, and especially the A's, form the shape of the nose and so cutting those is a lot more risky, as the canopy might have trouble holding it's shape.

All the more reason to carry a hook knife...  

The only trouble with this option would be the diligence required in locating the right line and under a chute that is unstable and bucking you every which way.  Line overs create canopy asymmetry - unless it's right down the center of the middle cell - and make for a wild ride, don't they?

-JD-

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I tried cutting a line over.  On a jump where I knew I would have a line over.  On a PD-170.  From 13,500 feet.  Couldn’t do it.  Cutting a line over is not a good plan.  Better than doing nothing, but your odds of finding the correct line and then cutting it are not good.

 

Derek V

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