RSL: Cause of entanglement.

[AndyMan 7]

I'm not trying to start any old debate.

However.

In this post http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=433474#433474, I asked Bill Booth what he thought of camera flyers and the Skyhook.

His answer was that previously, entaglements with the reserve bridle bouncing around was a big concern, and that concern was aleviated by the skyhook controlling the bridle.

This conflicted with my thoughts that most entaglements were caused by the departing main, not the departing freebag and bridle.

I consider it a very rare case where it's wise to disagree with Bill Booth.... Any thoughts?

_Am

__

You put the fun in "funnel" - craichead.

[garywainwright 0]

I agree that its a very rare case to disagree with Bill Booth.
The story that convinced me about not jumping rsl with camera is the one about the french guy whose reserve deployment back wedged against the helmet then the lines wrapped around it. I can't see that this would have been made any better by a skyhook. A cutaway sytem on his helmet may have given him a fighting chance.
It would be interesting to know if if the camera jumpers at deland who are RWS sponsored are using them.

http://www.garywainwright.co.uk

Instagram gary_wainwright_uk

[quade 4]

Andy --

I'm sure you're aware the two systems work totally differently. For people not sure, let's review a bit.

In the case of the RSL, the departing main is attached to a Reserve Static Lanyard, usually attached from one riser to the reserve ripcord near the reserve closing pin. Cutting away main, in theory, creates enough tension on the RSL that it pulls the reserve pin. That's all. After pulling the reserve pin, it does not actually remove the reserve from the container any faster than if you had simply pulled the reserve ripcord yourself.

In the case of the Skyhook RSL, there is an additional attachment to the reserve bridle that also pulls the reserve out of the container possibly saving some time that it would have taken for the reserve pilot chute to inflate and perform that function.

Since, by far, the largest danger of entanglement is due to an unstable deployment, the Skyhook's advantage would be that your reserve could be deploying before you could ever become unstable from the cutaway. At least, that's the theory.

That said, I doubt there is enough history and information available at this time to make an accurate assessment of the risks or benefits involved with adding this to your rig. Any time you add a new piece into a system, it's possible that it has consequences that were not imagined by the inventors. Only time will tell for sure.

quade -
The World's Most Boring Skydiver

[AggieDave 6]

I think Bill Booth said something to the effect that, the skyhook stopped spins and other sorts of unstableness due to the speed the reserve opened. Also, that you could have a life saving reserve (not necessarily a fully inflated reserve) over head in 1.5 seconds.

He (booth), seems to think that in a few years camera men/women will be thought of as "not understanding" if they're not jumping with a Skyhook. He sees it as a fix for those sorts of problems.

Can I tell you why? Nope, I'm not a camera guy, I can just tell you what he's mentioned.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[quade 4]

The key phrase there being "in a few years".

quade -
The World's Most Boring Skydiver

[murrays 0]

In the Skyhook Pictures thread in Gear and Rigging a couple of weeks ago I posted the following:
"My thinking on this scenario is that you may not _know_ you have a main/camera entanglement until you cutaway. The scenario that I am thinking of is if you have severe linetwists that come way down your risers and you can't move your head before chopping. You won't know if a riser is snagged until you cutaway. If it is, you would have to jettison your helmet and then deploy your reserve.

I really like the idea of the Skyhook but I think camera jumping requires some additional consideration due to the above scenario.

Jumping a more docile main that is less likely to spin up might be something to do if you wanted to jump camera and have the Skyhook installed on your container.
--
Murray


I think the Skyhook is a great idea but I do feel that camera jumpers have to be sure that they are free of any entanglement before they pull their reserve handle. In reponse to my above post Hookitt posted how he had chopped (while jumping camera) from under a spun up canopy that had his head pinned down. Had he had a Skyhook and an entanglement with a riser he might have had a bad situation....main attached to helmet, reserve container open and deploying....

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[motherhucker 0]

Quote

Jumping a more docile main that is less likely to spin up might be something to do if you wanted to jump camera and have the Skyhook installed on your container.

Then what's the point of flying camera?
I may as well get my tandem rating, then.

I like the idea of simplicity. I like the idea of being able to control when my reserve deploys after a cutaway. My set of emergency proceedures for jumping a camera include pulling higher. They also include practicing getting my helmet off in a single motion.
I don't like RSL's, and I ESPECIALLY don't like the idea of a skyhook for jumping camera. (Admittedly though, I'm not super familiar with the ins and outs of a skyhook, but I am with that of the cutaway sysem of a Sorcerer). A skyhook may prevent you from getting unstable after a cutaway, but what if you were unstable BEFORE/WHEN you cutaway?

[AggieDave 6]

Quote

A skyhook may prevent you from getting unstable after a cutaway, but what if you were unstable BEFORE/WHEN you cutaway?

Have you read the stuff that Bill Booth has written about this?

In his testing, the test jumers purposely set their heavily loaded PD Velocities to open spinning violently. In EVERY test the skyhook stopped the spin with their reserve and basically saved the jumpers a lot of precious altitude that would have been lost from trying to get stable after a cut-away or trying to fix a ton of linetwists from a RSL deployed reserve. What I mean by stopped the spin, I mean that they were damn near instantly stable under an open reserve (which didn't have line twists, etc).

You might want to do some more research before you give the Skyhook a death-blow.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[billbooth 10]

On a Skyhook equipped rig, if both your main risers are entangled with your camera helmet when you cutaway, your risers won't go anywhere, and your RSL won't open your reserve container. If only the RSL riser is entangled, the other riser will leave, but that won't open your reserve. If only the non-RSL riser is entangled, the RSL riser will leave and open your reserve container. The Skyhook will pull on the reserve bridle, throwing your pilot chute out into the windstream. The RSL riser will then stop traveling away from you, probably before the Skyhook pulls the reserve bag out of the container because of the long reserve bridle. The Skyhook will then release the reserve bridle, and hopefully allow the reserve pilot chute to deploy the reserve. I'm not saying this is a good scenario (no entangelment is), but it is not necessarily fatal. Guys, no device is perfect. The test is whether it saves more people than it kills. Only time will tell if the Skyhook is a good idea for camera jumpers. Any of you guys want to do test jumps for me under scenario # 3 above?

[Cajones 0]

Hmm... What does it pay?

Seriously, though... It's one of those things I hope is never necessary, but if it is - I sure hope it works like it's supposed to.

I'd rather see more of us putting cutaway systems on our helmets, than rushing out to get Skyhooks. I'm sure Bill would rather see both.

The laws of physics are strictly enforced.

[murrays 0]

Bill,
Thank-you for the analysis of the different possibilities in entanglement scenarios. There is only one scenario that results in the reserve being opened...out of three...so that's good to know.
In scenario three, if a helmet cutaway release was pulled immediately upon realization that there was an entanglement what would happen?
My thinking is that... If the Skyhook has released, you should fall away from your main and helmet and the reserve should have the opportunity to open normally.
If the Skyhook hasn't released, it should perform as it was designed to and result in a quick reserve deployment.
I have to admit that this allays my concerns considerably....but I would really love to see some tests of these scenarios.
Seeing that we are supposed to get 4-6 inches of SNOW tonight in a spring blizzard, I'll volunteer to do them if you'll fly me to Deland immediately!

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[billbooth 10]

In scenario #3, if the reserve bag is still in the container when the helmet release is activated, the reserve pilot chute, if it is free...or the combination of the reserve pilot chute and the malfunctioned main canopy (if they are entangled with each other), will deploy the reserve canopy just fine. You're only screwed if the reserve bag gets out of the container, AND wraps around the main, BEFORE you release your helmet. In other words, a whole lot of things have to go wrong, in a row, to actually kill you. I'd worry a lot more about getting run over by a drunk driver.

[diablopilot 2]

Quote

Andy --

I'm sure you're aware the two systems work totally differently.

Quote

Not so much. In fact in the instance of a main entanglement with the camera helmet post breakaway, the operation of the system must be considered the same.

Since, by far, the largest danger of entanglement with the reserve canopy is due to an unstable deployment, the Skyhook's advantage would be that your reserve could be deploying before you could ever become unstable from the cutaway. At least, that's the theory.

Quote

I think there are MANY possibilities you've not considered. RSL's and cameras used to be an easy discussion. People experienced enough to jump cameras could make such a decision. These days, mainstream skydiving is allowing knckeheads to get away with jumping cameras well before they should, and more lives would probably be saved by equiping those idiots with RSL's and hoping for the best in the long run.

----------------------------------------------
You're not as good as you think you are. Seriously.

• Quote

Share this post

---

Link to post

Share on other sites