Line Release Modification

[JaapSuter 0]

This one is a little contest. I can't offer much more than eternal fame for prizes, but hopefully that should motivate some to answer.

What is the most important component in a line release modification?

[base736 0]

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What is the most important component in a line release modification?

The jumper?

[SkyDaemon 0]

The line would be an obvious answer.

-=Raistlin

find / -name jumpers -print; cat jumpers $USER > manifest; cd /dev/airplane; more altitude; make jump; cd /pub; more beer;

[pBASEtobe 0]

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What is the most important component in a line release modification?

I would say the white loop, three different components interact with it. It goes through the line and then the ring and then the toggle goes through it.

Edit to add: Is this too obvious of a component to be the right answer?

[cygnusbase 0]

It was just recently pointed out to me on my triple risers on my Javelin that I was stowing my breaks like the good ole days with the white loop through the line and then through the ring which was how I was taught intitally with my Skydive Rig and my BASE Gear. However, the argument was that this placed a tremendous amount of the opening force on the stiching holding the white loop as opposed to the riser taking that force. the correction was to place the white loop and the line through the ring and then secure the toggle through the two placing the opening pressure onto the riser. Again I took my BASE course Years ago in Perris and I am not sure if that has already been a discussion here but the question seems timely to this post. Any thoughts?

[NickDG 23]

From a failure standpoint the weakest link has always been the control line releasing when needed while not flying off on its own during a normal deployment. Originally called the Line Over Modification (LOM) it was indeed just a slight modification of a normal skydiving setup. It used the same soft toggle the only difference being the control line isn't passed through the small keeper ring on the riser.

This setup worked and saved many an early BASE jumper. However, one problem cropped up from time to time. Under the increased load of line-over on the control line the toggle could jam and no amount of pulling would release it. In fact a jumper pulling very hard on the toggle in this situation would only makes things worse by pulling the entire riser down thereby increasing the rate of turn. A smaller side issue is a jumper releasing and letting the good side go and having the bad side jam. This would dramatically increase the turn and decent rate.

It may be interesting to also note (off the top of my head) that I believe no BASE jumper has ever died from landing with a full blown line over and many have done so including Mark, Troy, Jesse, and others. In that respect simple line twists have proved more dangerous and figure into more fatalities.

To cure the jamming problem we tried all kinds of things like not setting the toggle so deep, but this caused premature releases. One jumper even promoted coating your toggles in beeswax but that never caught on. Also around this time some jumpers are saying they didn’t like the differences in control stroke between control lines that are routed through keeper rings and those that are free flying. One jumper came up with a large ring, about two inches across that a released toggle would pass through when let go. This allowed the geometry of the control stroke to remain normal and still release a line-over when needed. That one didn’t catch on either. On the other hand most jumpers saw this as a none problem and liked the increased measure of control free flying control lines provided. Todd hit it on the head when he said, "Now, you can use English on your steering inputs."

In order to cure the jamming problem we went back to an older type of toggle used on the drop zone. These are the "pin" type toggles originally called Zoo Toggles. Again, like almost everything else in BASE, it solved the initial problem and created new ones. At first premature release is rampant. The problem is the pins themselves are too short. However, there aren't longer ones available anywhere. One BASE manufacturer had some existing pins lengthened at a local machine shop and this seemed to work and be more secure. The next problem is early designs dictated pulling the toggle away from the riser rather than straight down. This caused a rash of what jumpers described as "stuck" toggles. Moe Viletto more correctly called these "misses." We all had misses in those days, including Moe. Some jumpers also complained about the inability to let go of the toggle without losing it, but I never understood that as a problem.

For a while it seemed like there is a new toggle configuration coming out every month each with its good and bad points. Finally the gear industry turned their attention to preventing line-overs in the first place. We started with going back to an old Para-Flite trick of using rubber bands to stow the brake lines directly to the center of the canopy's trailing edge. This later morphed into direct line control and the modern day tailgate.

We also paid more attention to what causes line-overs in the first place. No one ever totally figured that out but we did realize strong crosswinds on short delays can cause them. Another factor is this is a time when PRO packing is first becoming popular outside the rigging community. There is suddenly a rash of line-overs at the drop zone and soon it became apparent people learning to PRO pack are inducing them by not clearing the control lines or allowing them to run down between the stabilizers. Since we do know slider up line overs are very rare I know most line overs at the drop zone are still caused by this problem. Today skydivers are way too quick to call any distortion of the canopy or any lower surface line entanglement a line-over. I always smile and take a dash salt when I hear a skydiver breathlessly describing their "line-over"

Fast forward to modern times and we can see a few new factors coming into play. Our pack jobs are light-years ahead of the early days and this has gone a long way in preventing line-overs. We are also jumping larger canopies. The canopy size of choice 20 years ago centered around 220 Sq Ft. Today that has grown to 265 and higher. This makes surviving a line over landing that much probable. Also we are doing more slider up jumps than ever before and that also knocks down the line-over rate. Early in BASE jumping, before the advent of the mesh slider, any slider up jump is considered risky. There is that unknown factor and a slider hang up would leave a BASE jumper with a single canopy system no where to go. Fortunately it turned out slider hang-ups weren't as prevalent as we thought they would be.

Nowadays, we have gotten so good at preventing line-overs some are now saying the LOM isn't even needed anymore. I'm not in that camp . . .

Hey Jaap, did I hit on it anywhere in the above?

NickD BASE 194

[JaapSuter 0]

Thanks everybody. All offered great contributions, and certainly Nick outdid himself with another excellent post. The answer closest to the one I am looking for came from base736.

This is not aimed at anybody in particular, but more as a general observation.

Why the hell are you using the LRM if you have never landed on rear-risers before?

Imagine you are trying to cross the ocean on a boat. For emergency situations, the boat has a helipad with a helicopter on it. During a heavy storm, the boat starts sinking and you have to evacuate the ship. Quickly you jump into the helicopter....

...and realize you have never flown a helicopter before!

There's an analogy for ya...

[JaapSuter 0]

In no way does this post reduce your right to call me on my own dangerous behaviour. I do plenty of stupid things myself. I'm not bitter, just surprised.

[kleggo 138]

Why the hell are you using the LRM if you have never landed on rear-risers before?

probably because by doing so one puts themself in the position where an injury is relatively likely during the course of this training exercise.
there is a very real possibility of flaring too high or too deeply and slamming onto your ass / back / neck / skull.

the only time i've landed on rr was many years ago when a lower control line connection failed, ( on a skydiving canopy ). It was a Pegasus so i was able to get away with a very low, shallow flare that i PLFd away from.
I would not espouse the theory that people should intentionally land on rr alone.

Do some no contact CReW with someone and do rr flares. You'll probably learn enough canopy dynamics to understand what's required when forced to land this way.

in the LRMod situation i would recommend tossing the good toggle away so you're not tempted to land with one rr and one toggle.......... OUCH.

be safe

kleggo

[JaapSuter 0]

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probably because by doing so one puts themself in the position where an injury is relatively likely during the course of this training exercise.
there is a very real possibility of flaring too high or too deeply and slamming onto your ass / back / neck / skull.

With proper training (which one should get as with every other aspect of BASE), landing on rear risers is no more dangerous than landing on toggles. I've done plenty rear riser landings on my Sabre 170, and on my BASE canopy I would even argue that my rear riser landings are softer than on toggles.

I don't think that injury is relatively likely with rear riser landings.

And even if it would be, would you really want to put yourself in training mode when you're already in a high-stress situation because you just accidentally lost a toggle on a non-friendly object?

Isn't it much better to ask an experienced jumper (preferably even on your dropzone when you're skydiving your BASE canopy) for advice and practice in a safe environment?

I don't think it has anything to do with people being afraid of rear riser landings. It has everything to do with people having to much fun dicking around and not enough fun learning safety skills. This is skydiving all over, where amazing freeflyers can't even put a canopy down safely because all they ever learned was freefall skills. It's AFF versus static-line courses. It's going to be the age of the Potato jumpers.

For the record, I'm a very poor canopy pilot whose idea of an advanced BASE landing site is a fifty acre grass field. I factor this into my object selection (except that one time that I landed in a tree). So I'll shut up now.

[base736 0]

It's interesting to me that people are so divided on this one.

On a CRW training jump, a teammate of mine (a guy with a peg leg) lost a toggle and was forced to land on rear risers on a Lightning. The guy got to the ground and told the other three of us that, on our next jump, we were landing rear risers. If a cripple could do it, he reasoned, we were damn well going to. On that next jump, I had one of the softest landings I've had on that canopy, flaring on rear risers.

I've heard the same story from a lot of people -- feather-soft landings on rear risers, on both BASE and skydiving canopies. While it's certainly possible to bust yourself up landing on rear risers, it's also straightforward not to. Flaring on rear risers is not "sport death".

I'm with Jaap 100% on this one. If you're worried that you'll screw it up, do it at the Potato Bridge and land over the water. No-contact CRW will teach you little that you couldn't have picked up just trying out your rear risers on a solo flight -- which is to say, it won't teach you to land the thing on 'em.

[NickDG 23]

Okay, this is something I don't understand. Have we progressed (or regressed) to the point where landing a large docile BASE canopy using the rear risers is so hard? I'll agree you have to be careful if the toggles are fired and gone, but it still happens in slow motion. Wearing your helmet and body armor along with realizing a little riser equals a lot of toggle and using your best PLF is always easier than riding in a spinner . . .

NickD BASE 194

[Treejumps 0]

Hi Japp,

I think the part you are missing is that landing on the rears is easy, when the control lines are still pulling the tail down. Pack your Sabre with the line mod and then toss your toggles and I will bet you that your rr landing is far from soft. Without the control lines pulling the tail down it will pretty much "flip up" when you flare with the rears (too hard). You have to be oh so gentle to do it and not have the tail flip up. When the tail does flip up it instantly, and I mean instantly, puts you flat on your back.

The rr stroke with your toggles trailing can be described as tightly gripping the the risers, and rolling your hand forward, essentially just bending your wrist about 90 degrees. You have to do it quite low for the obvious reason that if you over input (easy to do in these situations) you land flat on your back. Not a good idea from say 10'.

I have one landing this way. I set it down on the little beach at potatoland, flat on my back from about 3'. Got right up and wasn't even bruised, but would hat to have landed on rocks like that.

I am a slacker and still have not built my idea of a line mod riser that allows you to reel your control line back in after you clear youy line over.

[JaapSuter 0]

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I think the part you are missing is that landing on the rears is easy, when the control lines are still pulling the tail down. Pack your Sabre with the line mod and then toss your toggles and I will bet you that your rr landing is far from soft.

Done this, on both my Sabre 170 and my BASE canopies. Not a problem. I've packed my Sabre 170 with the line-mod in skydives. I regularly drop my toggles at the Perrine for shitz and giggles because every time somebody will yell: "Don't flare too high!"

I agree that over-flaring is the issue. But that's a difference between operating a canopy and flying a canopy. People that operate their canopy don't feel what they're doing and they just transform theory into fixed control strokes. People that fly their canopy transform theory into feedback loops where every input into the canopy affects their current theory. This is the difference between just yanking on your risers and dropping out of the sky or pulling slightly on your risers and feeling how it affects your glide angle.

Flying versus operating. If you ever spot a bad driver, look at how they are driving. You will notice they are operating their car, instead of driving it as an extension of their body. Once you recognize it, it becomes obvious to the point where you can just spot the little manual in their head that tells them step by step what motions to go through.

For anybody that is really worried about first time rear-riser landings, wear your helmet, knee-pads and body-armour (you have body armour, right?) and error on the side of flaring not at all.

I actually intend to drop my toggles soon and not flare risers either. Maybe I'll do this into the water first, and then take it to the land. I'm trying to figure out how bad of a landing one makes under an uncontrolled large BASE canopy. It's not really a useful skill, but I'm satisfying a curiousity how hard one would hit the ground if one is unconscious under a large canopy. Of course, if one is really unsconscious, you'd also hit the object a bunch of times and be unable to PLF, but hey I can only take the simulation so far, right?

I wonder if I'm going to be the first person on the list that died because he was experimenting with intentional malfunctions. Sorry guys...

Edited to add: this post should not be read as a direct reply to Treejump. I'm pretty sure he's a much better canopy pilot than I am anyway.

[blitzkrieg 0]

just knock yourself out under canopy by huffing a can of ether. then let the people on the ground tell you how hard you hit.

[greeny 0]

JaapSuter,

Which would you rather learn in the heat of the moment?

Landing on rear risers

or

Landing that line over

I'll take rear risers any time....................

Greeny

[JaapSuter 0]

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Which would you rather learn in the heat of the moment?

Landing on rear risers or landing that line over?

I thought about this argument, and there is some truth to it. It's like saying that having the helicopter and a manual is still better than having no helicopter at all, since you might be able to read the manual and learn how to fly before the ship sinks.

It is also better to jump from a building wearing a parachute than without one, even when you've never flown a parachute before. That doesn't make it a good idea necessarily.

I agree with you; in a way the LRM has use even if you'e never learned how to land on rear risers. At that point it is the lesser of two evils.

Nonetheless, I still don't understand why some people have never given a rear riser landing a try in a safe environment. A recent broken back in Moab could have been avoided this way.

[greeny 0]

That part I totaly agree to..............

[TomAiello 25]

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I still don't understand why some people have never given a rear riser landing a try in a safe environment.

Agreed. I think that doing the first couple into water is a really good idea.

I've landed a clapped out canopy downwind on rear risers (toggles completely gone, I had aborted a cutaway after releasing the toggles), on railroad tracks, without incident. In my opinion, rear riser landings ought to be considered a mandatory BASE skill.

I honestly don't think that landing on rear risers is all that hard. Just try real hard to set up into the wind, flare late, and PLF well. I've had to make around 10 rear riser landings in anger (i.e. not for practice). Most of these were aborted cutaways, though, so I knew from the outset that rear riser landing was a possibility.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Treejumps 0]

Hi Jaap,

I may or may not be a better canopy pilot, but I definitly don't have your youth or light wingloading to intentionally chuck my toggles. In fact, its been some years since I even used the line mod.

All that being said what you are doing is very valuable training that may one day keep you out of the ER. As Cypress Hill once said, "When the shit goes down, you better be ready". You seem ready to me, maybe even anxious for it.