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lineovers and hookknives

 

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alan  (D 17868)

Dec 16, 2003, 1:10 AM
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lineovers and hookknives Can't Post

Before you get too caught up in the idea of using a hook knife to cut lines on your reserve in the event of a lineover mal, take a few minutes to really think about it.

You are under your reserve, that means your are low. A serious lineover is a violent spinning mal and you are losing even more altitude rather quickly. You are already very excited. It takes time to find the knife. There is a good chance that due to the excitement and being tossed around by the mal, you will drop it.

Suppose you manage to hang on to it. You are still losing altitude. Where are you going to land? Well, maybe that isn't bothering you at this point. You have to figure out exactly which line is the cause of your problem. Ever try doing that? Try doing it under stress, while being spun around, and yes, don't drop the knife. How much altitude do you have left now? Worried about landing yet?

Best case, you manage to cut the correct line working from the inside out. By the way, a lineover is usually just that.......one line. And it is usually an outboard "D" line or a brakeline simply due to the nature of the mechanics involved in the mal. So much for cutting lines from the inside out.

You also need to try and cut just one line at a time. Cutting several on your reserve will just make a bad situation unrecoverable. Ever cut Spectra line with a knife while the lines are under heavy tension? They cut like a hot knife through butter. My bet is that in all of the excitement, you will slice though the entire group on a given riser (or possibly even the riser), except the brakeline. If it is a brake line that is causing the problem and you go for it, you may just get away with it.

A lineover can often be cleared by pulling the brake down on the offending side and "popping" it back up. This technique is often taught for clearing a similar problem on a main during the first jump course. It works, I've done it. Some lineovers can actually be landed. The spin can often be controlled by using the opposite brake or riser. PLF the lading. I've seen it done by a first jump student under a Manta.

In summary, with a lineover on your reserve I believe your time (altitude) is more wisely spent clearing/controlling the problem without attempting an emergency procedure you almost certainly have never practiced. If you do, it may even be steerable to some degree, depending on how many cells in the line is over. You could actually have some luck in steering to an open area and doing a good PLF.
Be wary of the advice given by some 100 jump wonder over the internet.

You should also realize that a lineover is virtually always the result of a packing error, so a serious one on a reserve would be very rare.........a competent rigger just should not make that kind of mistake.

If your DZ has an RD Trainer or can rig up something similar, you can practice your hook knife procedure. If you haven't seen one, an RD Trainer is a device that allows you to suspend from your rig and practice emergency procedures with substitute handles. It can be found in any recent Para Gear catalogue.

Take the blade out of your hook knife and have someone spin you around like you experienced on your lineover. You can even connect an old canopy to your rig and throw it over what ever the trainer is suspended from and have some one put one line out of place like a lineover. Now you can actually practice under simulated conditions.

Main canopy is out at 2500'. It takes 700' to open. You will lose about 45'per second with a line over or similar mal (normal rate of descent is about 15'/sec), so another 90' to 135' is gone before you realize it is not just a bad/off heading opening (most people burn another 300' to 400' trying to clear it before cutting the main away). The reserve takes about 250' to 300' to open (maybe less than 100' if you have the new Skyhook RSL system by RWS). Releasing the brakes takes another 90' to 135'. That also causes the the mal, now on the reserve, to spin faster and descend at about 60' per sec. You pump the brakes once or twice before deciding to go to the knife, that uses another 180' to 270'. Getting the knife out may take another 180' to 270'. Finding the right line to cut and making sure will take about 240' to 300', assuming you do it calmly and have practiced. About another 60' and hopefully you have it cut and got the right one and only the right one.

Do the math. Time yourself on the trainer and remember, you won't be as stressed and you have premade the decisions, so you should be faster on the trainer than in real life. You should very quickly see that it is a good idea to practice this if you incorporate it as an option in your plans. You should also realize why many people are choosing to open a little higher with todays newer canopies. 500' to 800' openings are very common.

Check the BASE forums for real info on lineovers. They use a release system for the brakes because they are the most common cuase of a lineover and it is much quicker and less damaging than a knife. Of course there are some very pratical reasons why that technology hasn't been adopted into our reserves, but it should give you some insight into the problem. Also, a lot of old time jumpers will tell you use the knife on your reserve.........becuase that is what they were told. A surprising number of jumpers will just accept what the old guys say and pass it along as fact, without taking the time to really think it through for themselves. I'm not advocating ignoring the old guys, they really are the best source of information, but do what you are doing. Get information, think it through, really think it through, and do what is best for you. Things change. That is what the old guys will tell you. They are right.


andy2

Dec 16, 2003, 6:16 AM
Post #2 of 35 (2281 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

Quote:
Check the BASE forums for real info on lineovers. They use a release system for the brakes because they are the most common cuase of a lineover and it is much quicker and less damaging than a knife.

(edit - no you didn't just didn't catch it the first time) You forgot to mention that slider up parachutes for the most part do not exhibit true line overs. Theyre packed that way. The new mods for BASE are primarily for slider down jumps. Same as the tailgate, etc.

My plan for a line over on my reserve would be to attempt to clear it first, then stabilize it with opposite riser, then see if cutting it would be an option at that point.

The last time I pulled my reserve I was under canopy at 2.7k


(This post was edited by andy2 on Dec 16, 2003, 6:20 AM)


skymedic  (C 33561)

Dec 16, 2003, 6:37 AM
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Re: [andy2] lineovers and hookknives [In reply to] Can't Post

Quote:
The new mods for BASE are primarily for slider down jumps.

Uhhh...NO...


Hooknswoop  (D License)

Dec 16, 2003, 7:01 AM
Post #4 of 35 (2256 views)
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Re: [andy2] lineovers and hookknives [In reply to] Can't Post

Quote:
You forgot to mention that slider up parachutes for the most part do not exhibit true line overs. Theyre packed that way.

What do you mean, "true line-overs"?

Quote:
The new mods for BASE are primarily for slider down jumps. Same as the tailgate, etc.

The y have been experimenting with slider-up tail gates and the new slider-up advances are the super and WLO toggles, designed to release the steering line in the event of a slider-up line-over in a similar manner as the line-over mod for a slider down/off jump.

Derek


councilman24  (D 8631)

Dec 16, 2003, 7:07 AM
Post #5 of 35 (2251 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

In reply to:
If your DZ has an RD Trainer or can rig up something similar, you can practice your hook knife procedure. If you haven't seen one, an RD Trainer is a device that allows you to suspend from your rig and practice emergency procedures with substitute handles. It can be found in any recent Para Gear catalogue.

You can also make one for about $30 bucks in parts, a little sewing, and a little drilling just by looking at the picture.


davelepka  (D 21448)

Dec 16, 2003, 7:46 AM
Post #6 of 35 (2231 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

Quote:
Check the BASE forums for real info on lineovers.

---------------------------------------------------

Check the BASE forum and you can watch a video of the moderator using a hook knife to clear a line over after a jump from a cliff. Nuff' said.


(This post was edited by davelepka on Dec 16, 2003, 7:48 AM)


andy2

Dec 16, 2003, 10:16 AM
Post #7 of 35 (2186 views)
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Re: [skymedic] lineovers and hookknives [In reply to] Can't Post

Quote:
Uhhh...NO...

Care to elaborate on that instead of just wasting bandwidth? So youre saying that you're more likely to get a line over on a slider up jump than a slider down jump? Notice I said primarily, as most reefing technology in BASE it appears is originally invented for slider down/off jumps. The slider acts as an awesome reefing device when jumping slider up.

I'll be interested to read your comments about this, sky medic.


Paige

Dec 16, 2003, 10:31 AM
Post #8 of 35 (2176 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

Thank you, I found this to be most informative! Appreciate the postSmile


alan  (D 17868)

Dec 16, 2003, 10:55 AM
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Re: [davelepka] lineovers and hookknives [In reply to] Can't Post

Quote:
--------------------------------------------------------------------------------
Quote
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Check the BASE forums for real info on lineovers.
---------------------------------------------------
Check the BASE forum and you can watch a video of the moderator using a hook knife to clear a line over after a jump from a cliff. Nuff' said.

That reply is a little cavalier. Tom is a very experienced jumper, that should be taken into consideration. There is no discussion on how he may or may not have prepared himself to deal with such a situation. That should aslo be taken into consideration. Tom also was using a large and very docile canopy in comparison to the typical sport parachute and reserve, which should also be a consideration. I would certainly think that Tom's thoughts on the subject would be worthwhile.

Lineovers seem to be a problem common in the BASE community just as with sport skydiving. A difference that I can see is that in BASE it is far more serious since a reserve canopy is far less common. It has to be dealt with. Do they incorporate cutting steering lines into their training?
Also, do they have more incidents than we do with our reserves? Seems to be a more appropriate comparison.

Does anyone have any firsthand knowledge of a skydiver actually experiencing a lineover on a reserve and successfully using a hook knife to clear it?

Dave, this is not an attack on you. I believe these are legitimate concerns and should be considered by anyone trying to make an informed choice.


Premier Remster  (C License)

Dec 16, 2003, 12:06 PM
Post #10 of 35 (2153 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

Quote:
Does anyone have any firsthand knowledge of a skydiver actually experiencing a lineover on a reserve and successfully using a hook knife to clear it?

Alan,

I'm not sure if you were still reading posts at that time, but Dereck did a test with an intentionally lineovered canopy and he couldnt identify which line to cut (even having put it there himslef when packing), let alone cut it. I'm too lazy to search for the thread, but I'm sure its either in G&R or S&T.


yoink

Dec 16, 2003, 12:18 PM
Post #11 of 35 (2142 views)
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Re: [Remster] lineovers and hookknives [In reply to] Can't Post

I thought that a lineover, especially on a highly loaded wing, could acutally slice the canopy fabric - not something that inspires happy thoughts at 500ft...
Is this true or not?

Thanks

Will


alan  (D 17868)

Dec 16, 2003, 12:30 PM
Post #12 of 35 (2140 views)
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Re: [Remster] lineovers and hookknives [In reply to] Can't Post

Quote:
I'm not sure if you were still reading posts at that time, but Dereck did a test with an intentionally lineovered canopy and he couldnt identify which line to cut (even having put it there himslef when packing), let alone cut it. I'm too lazy to search for the thread, but I'm sure its either in G&R or S&T.

Thanks, I remeber reading it but not the details. I have experienced two lineovers and was able to clear them both. Once "popping" it off with the brake line and once using the riser. The time with the brake line, I was still pretty inexperienced and just went to my FJC traing for partial/low speed mal. Just guessed it was a lineover until the DZO said he saw it as well. I was pretty excited at the time and going off reflex more than thinking.

The second one was much later in my career and involved a HP elliptical canopy. No way could I tell what line was the problem and "popping" the brake did not fix it, so I decided on one try with the whole riser. It worked. Very wild ride. FWIW, I knew something was wrong before I released the brakes, it was already not looking right and starting to spin during inflation. Releasing the brakes rally made it take off! Maybe should have tried to clear before releasing brakes?


Premier Remster  (C License)

Dec 16, 2003, 1:14 PM
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Re: [yoink] lineovers and hookknives [In reply to] Can't Post

I'm not sure about slicing, but friction burns on the fabric are not uncommun.


relyon  (D 18973)

Dec 16, 2003, 1:25 PM
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

In reply to:
Does anyone have any firsthand knowledge of a skydiver actually experiencing a lineover on a reserve and successfully using a hook knife to clear it?

Numerous CRWdogs have successfully used hook knives to clear malfunctions far worse than reserve lineovers (eg. cutting up someone else's main that is entangled with their reserve while hanging upside down - yes, it's on video). Not an everyday occurrence, but it does happen.

Bob


PhillyKev

Dec 16, 2003, 3:18 PM
Post #15 of 35 (2083 views)
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Re: [relyon] lineovers and hookknives [In reply to] Can't Post

Quote:
Numerous CRWdogs have successfully used hook knives to clear malfunctions far worse than reserve lineovers (eg. cutting up someone else's main that is entangled with their reserve while hanging upside down - yes, it's on video). Not an everyday occurrence, but it does happen.

Yeah, but that's not as delicate a procedure as cutting a single line on your last 'chute.


Premier TomAiello  (D 22400)
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Dec 16, 2003, 3:46 PM
Post #16 of 35 (2077 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

Disclaimer: You're mostly talking about skydiving gear here. My knowledge of skydiving gear is fairly limited, and experiences do not translate directly between the two sports. I think you're far better off to look at actual skydiving examples (like HooknSwoops test jump) for guidance on this issue.

In reply to:
I would certainly think that Tom's thoughts on the subject would be worthwhile.

My general feeling is that your first priority is to establish control over the canopy. If you feel that your canopy is controllable and landable, then the return from a decision to cut lines is quite low (and possibly negative).

In the particular case referenced above (my line over in October 2002), here are a few things that effected my decision:

1) I had cycled the offending toggle twice without noticeable result.
2) I had a clear view of which line was effected, and could easily cut that (steering) line without endangering any of the suspension lines.
3) I had a previously injured, weakened ankle, and was concerned that landing the line over might re-injure it, especially as I would have very little ability to flare when landing the line over.

Under these circumstances, I decided to cut the line. If I had been fully healthy, I probably would have just tried to land it in the big grassy landing area. If I could not determine which line was over the canopy, or if I couldn't be sure that I could get that line alone (probably the case on any non-steering line), I would also probably just decide to land the line over.

You might also find it interesting to read Dwain's thoughts on this from BLiNC (emphasis mine):

Quote:
Regardless of whether you have a line over or tension knot you should still release the brakes and cycle the offending line (yank down hard repeatedly on the line). This can cause the line over or the tension knot to clear.

However the main priority should always be to stop the canopy from turning. Turning chews up a lot of altitude and decreases your time to deal with the problem. Toggles should generally be used first and if this results in a stall then hard front riser input can be used to try to stop the turn. Finally if that is insufficient then as a last resort try a combination of front and rear riser. It is usually a very fine line between stopping the turn and stalling the canopy (if it is at all possible). Slow the turn as much as you can without stalling the canopy.

One hand should be working to clear the line over or tension knot (via cycling) and the other should be working to stop the turn. If you are low or close to the wall, stopping (or slowing) the turn has a much higher priority than clearing the problem.

Some other thoughts:

If it is a steering line that has lined over, you can use the guide ring as a cutting guide, to keep the knife away from the suspension lines.

The behavior of a 280 square foot BASE canopy with dacron lines, and the behavior of a 150 (or less) square foot skydiving reserve (with some kind of micro lines) will probably be radically different.


Premier TomAiello  (D 22400)
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Dec 16, 2003, 3:56 PM
Post #17 of 35 (2074 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

In reply to:
...BASE...It has to be dealt with. Do they incorporate cutting steering lines into their training?

As far as I know, none of the formalized training programs (virtually all of which are intended for first timers only--i.e. we have no intermediate or advanced training at present) include line cutting training. I suspect that Vertigo may include some information on using their WLO (slider up line release) toggles in their FJC, but I don't know that for certain either.

In reply to:
Also, do they have more incidents than we do with our reserves?

I suspect that the incidence of line over on BASE gear is probably lower (due to less time packed before deployment primarily). However, the BASE system (attached bridle) is probably more prone to line over than a skydiving reserve (freebag) deployment system.

Unfortunately, there isn't very much good data available on the subject. We've probably seen more BASE line overs than skydiving reserve line overs in recent years simply because we've reached the point where there are more slider up BASE deployments than skydiving reserve deployments worldwide in any given time span.


relyon  (D 18973)

Dec 16, 2003, 10:23 PM
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Re: [PhillyKev] lineovers and hookknives [In reply to] Can't Post

In reply to:
Yeah, but that's not as delicate a procedure as cutting a single line on your last 'chute.

Huh? How is cutting a single line on a reserve more complicated than cutting multiple lines of another person's main (they've already cutaway) that is entangled with both your reserve and your foot (causing you to hang upside down), without damaging your reserve while the whole mess is spinning and the ground is coming up fast? Do you understand just how complicated of a predicament that is?

Bob

PS - the reserve slider did get hooked in the process and needed replaced.


alan  (D 17868)

Dec 17, 2003, 10:47 AM
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Re: [relyon] lineovers and hookknives [In reply to] Can't Post

Very true and no debate on that from me. But, it does not address the issue I was didcussing. What altitude do most of these CRW entanglements occura at? What altitude to most reserve deployments occur at? Is there a diffeence in the time involved to allow for cutting? Why do CRW dogs carry 2 or more knives? Is it because they know accessability and dropping one or more are real issues?

Don't get me wrong, I think we should use knives, I'm just questioning the conventional wisdom with respect to reserve mals.


Premier faulknerwn  (D 17441)
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Dec 17, 2003, 1:22 PM
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Re: [relyon] lineovers and hookknives [In reply to] Can't Post

And don't forget - what most impressed me was when we got all the canopies back to the tent and started untangling them, about 10-15 lines were cut on the other person's canopy - not a single line was cut on any of his gear. Now that's nice knife work!


relyon  (D 18973)

Dec 17, 2003, 2:17 PM
Post #21 of 35 (1959 views)
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In reply to:
But, it does not address the issue I was didcussing. What altitude do most of these CRW entanglements occura at? What altitude to most reserve deployments occur at?

The example I brought up was a main/reserve entanglement that required a hook knife and was finally cleared at a very low altitude. I'll defer to Wendy for a guess as to the actual altitude, but it looked under 1000'.

Bob


Premier faulknerwn  (D 17441)
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Dec 17, 2003, 2:48 PM
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Re: [relyon] lineovers and hookknives [In reply to] Can't Post

The wrap started at around 8k I would guess. By the time the first cutaway went, it was probably 7k, then the 2 main entanglement started. He fought that for a good while, and I think after cutting away didn't work, he probably dumped his reserve around 3, caught the freebag, tried to throw it into clean air, and was unsuccessful.
That's when he had the main/main/reserve entanglement. He slowed down after some of his reserve came out shortly after that, mostly inflated, but was still spinning like a top. Then he started hacking lines since he was still hanging upside down. He probably got clear of those ~1k. The video is on the Rantoul '02 tape.

W


alan  (D 17868)

Dec 17, 2003, 10:53 PM
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Re: [relyon] lineovers and hookknives [In reply to] Can't Post

Not quite the same as a lineover or tension knot on a reserve, considering there were 3 canopies up there including a mostly inflated reserve. In your example the reserve was deployed at 3000' and cleared at ~1000'. Most non-CRW jumps, the main isn't even deployed at 3000'. I know that there are exceptions to that and that is good. But the SIM has 1800' as decision altitude and reserve deployment by 1600'. With 100' to 300' for reserve opening that means my sport jumper will be down around 1200' or 1500' feet before he can even know he has a mal and will be down around 1000' before releasing the brakes, making an initial attempt to control/fix it. Your guy used 1000'+ to cut lines not on his reserve risers. Can you see how I might think my sport jumper might run out of altitude? And then that still leaves the issue of finding a place to land and flaring.

One good recent trend I have been observing is jumpers tend to be opening a little higher. However, that is at least partially offset by the longer opening distances of the newer canopies.

Consider the test done by Derek. A very experienced jumper with more than a few cutaways, an experienced rigger that packed the offending line, and he knew the mal was coming. He still was not able to identify the offending line in a reasonable time.

I think CRW is a good time to have 2 or even up to 4 knives. I just don't think that the experiences in CRW necessarily translate into legitimate arguements for using a knife on a reserve mal on a non-CRW jump. I would not just rule them out, but my plan is more like Tom described. Kind of a last resort thing and only on a clearly identified steering line if altitude allowed.


pilotdave  (D License)

Dec 18, 2003, 6:10 AM
Post #24 of 35 (1890 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

This is why I don't jump with a hook knife. I doubt I'd have any clue what to do with it even if I needed it. Ok, I realize you aren't telling us not to bother with hook knives, and I'm actually getting one with my new container in a few more months (hey arlo, HAS IT BEEN 14 WEEKS YET???). It's just not something I've ever thought of as required or very important equipment for the jumping I do.

Dave


relyon  (D 18973)

Dec 18, 2003, 10:17 AM
Post #25 of 35 (1870 views)
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Re: [alan] lineovers and hookknives [In reply to] Can't Post

In reply to:
Not quite the same as a lineover or tension knot on a reserve, considering there were 3 canopies up there including a mostly inflated reserve.

I trust you've never been in a really serious entanglement or wrap involving cutaway main canopies. More canopies is not a good thing. I would take a lineover or a tension knot on a single reserve canopy at any altitude to some of the stuff I've seen people have to ride in.

In reply to:
I just don't think that the experiences in CRW necessarily translate into legitimate arguements for using a knife on a reserve mal on a non-CRW jump.

I think you're mistaken on this point, but I'm certainly not arguing for hook knife use at all. I've had plenty experience with malfunctioning canopies and trust that experience will be in my favor should I find myself in the unfortunate circumstance to need it. I've not used a hook knife to date and hope it stays that way, though I carry two on every jump and have no reservations about using one.

Bob


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