Forums: Skydiving: Safety and Training:
BOC vs Pull out

 


rendezvous  (C License)

Mar 25, 2002, 9:01 AM
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BOC vs Pull out Can't Post

What are the pros and cons of a BOC pilot chute vs a Pull Out pilot chute deployment mechanism.



axe96bam  (D 23380)

Mar 25, 2002, 9:27 AM
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Re: BOC vs Pull out [In reply to] Can't Post

I like the pull-out because I know that I am opening my container, plus it is harder to get a premature deployment. (at least this is my opinion)

Alex



Premier billvon  (D 16479)
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Mar 25, 2002, 9:50 AM
Post #3 of 16 (4225 views)
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Re: BOC vs Pull out [In reply to] Can't Post

Both are good systems. Historically this argument has devolved into "what kind of mal do you want to have?" If you prefer totals to PC-in-tows, then throwout is the system for you.

----------------
Pullout pros:

1. There is less "outside the rig" and therefore the deployment system is better protected from impact and the wind..

2. Non-inverted PC's allow for slightly faster deployments.

3. A PC-in-tow mal is _much_ less likely, even if you forget to cock your PC.

Pullout cons:

1. (and this is the big one) If the pud comes loose ("floating pud") you will be tempted to try to find it, because it's often possible. History has shown that many people have spent a little too long trying to find it.

2. Shorter bridle and non-inverted PC means minimal separation between your body and the PC when it launches. This may increase the chance of a PC hesitation.

3. A weak pull can result in a floating pud; generally, a weak pull on a throwout results in either a partially extracted PC or a deployment.

4. It is easier to pack a hard pull/total mal on a pullout.

5. The container must be slightly bigger to accomodate the bridle/PC.


-bill von


Kirils  (D License)

Mar 25, 2002, 10:47 AM
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Good analysis! I'll take the BOC

Skydiving is not a static excercise with discrete predictability...


TEB6363  (D 16363)

Mar 25, 2002, 10:49 AM
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Re: BOC vs Pull out [In reply to] Can't Post

As stated, both have good and bad. The throw out/BOC is the standard used by most jumpers. The people who use pull-out like that they "know" the container is open because the pin is pulled first. I use the BOC because I like to use a stock collapsible pilot chute.

:::OK, Canopy is Open, No Traffic Around, .. Why are these "Extra" Lines Draping Down??, Damn!


axe96bam  (D 23380)

Mar 25, 2002, 12:50 PM
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Re: BOC vs Pull out [In reply to] Can't Post

Hey Tom,

I don't really think that there is a difference between a BOC and a Pull-out P/C other than the handle. I might be wrong, but I have not seen any differences.

Alex



Premier billvon  (D 16479)
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Mar 25, 2002, 12:52 PM
Post #7 of 16 (4178 views)
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Re: BOC vs Pull out [In reply to] Can't Post

>I like the pull-out because I know that I am opening my container, plus it is harder to get a premature deployment.

Actually, I think the opposite is true, but that's a good thing. If the pin comes out of a throwout rig, a horseshoe is the likely result. If the pin comes out of a pullout rig, 99% of the time you just get a normal deployment, since you are not "out of sequence" (the pin is _supposed_ to come out first.) In most cases, a clean opening at 7000 feet is preferable to a horseshoe at 7000 feet.




-bill von


Premier billvon  (D 16479)
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Mar 25, 2002, 12:59 PM
Post #8 of 16 (4174 views)
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Re: BOC vs Pull out [In reply to] Can't Post

>I don't really think that there is a difference between a BOC and a Pull-out P/C other than the handle.

Differences:

A BOC has an external PC in a pouch with a handle on the apex. An external bridle leads to a curved pin, and then inside to the top of the bag. During deployment, a jumper throws the PC as far away from him as possible. Once he releases the PC, the PC "inverts", catches air, and pulls the pin, thereby opening the container and pulling the bag out. If the pin comes out prematurely, the PC generally stays in its pouch for a little while. leading to either an odd opening or a horseshoe.

A pullout has a handle attached via webbing to a straight pin that holds the container closed. It is also attached to the _bottom_ of the PC. The PC and the bridle are packed inside the main container. During deployment the jumper pulls the handle. This pulls the straight pin and opens the container. He keeps pulling until he pulls the PC into the air. Once it hits the air it inflates immediately and pulls itself out of the jumper's hand. It then pulls the bag out. Pulling the pin accidentally opens the container, and the PC flops around until it catches air, takes off and begins a normal opening.

They are two very different systems that require different PC's, bridles, pins and packing methods. Both can work well, but I know of at least 3 incidents (2 reserve rides, 1 fatality) that resulted from trying to pack a pullout like a throwout - so it pays to know the difference.

-bill von


axe96bam  (D 23380)

Mar 25, 2002, 1:07 PM
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Re: BOC vs Pull out [In reply to] Can't Post

Bill, I was referring to the P/C itself not to the systems. I know the difference in the systems. I jump a pull out and I used to have a BOC before so I am very familiar with the way they work, pack, and look. It was more in the sense that you can take a pull out P/C, saw a handle on in in the right place, put a pin on the bridle and it becomes BOC ready. Or is that not the case?

Alex




Premier billvon  (D 16479)
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Mar 25, 2002, 1:16 PM
Post #10 of 16 (4163 views)
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Re: BOC vs Pull out [In reply to] Can't Post

>It was more in the sense that you can take a pull out P/C, saw a handle on in in
>the right place, put a pin on the bridle and it becomes BOC ready. Or is that not
>the case?

Not exactly. A pullout PC has a grommet sewn onto the base to allow the pullout lanyard to slide through, thus reducing hard pulls. It also has a shorter bridle than a throwout, and no handle as you mentioned. To change it over you'd have to:

1. Add a hackey or whatever to the apex of the PC
2. Remove the lanyard, pin and pud
3. Remove the grommet (optional, but probably a good idea to prevent snags)
4. Extend the bridle to make it throwout length
5. Add a pin to the new, longer bridle


-bill von


rendezvous  (C License)

Mar 25, 2002, 2:49 PM
Post #11 of 16 (4143 views)
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Re: BOC vs Pull out [In reply to] Can't Post

So is it that, using a pull out PC rather than a throw out one will do away with the possibility of getting into a horseshoe or a PC in tow. If the only associated mal with the pull out seems to be a hard pull then doesn't that make a pull out much better than a throw out.



Premier PhreeZone  (D License)
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Mar 25, 2002, 3:17 PM
Post #12 of 16 (4128 views)
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Associated mals with a Pull out are Hard pulls and floating puds. Premature openings are also able to happen easier because once the pin is poped it opens instead of opening the flaps and possibly causeing a horseshoe mal like a BOC could.
My DZO had 3 reserve rides last year and 2 of the 3 were due to floating puds. Once it got kicked out by some one he was teaching to sit train, once by a funnel and it got knocked loose and a third time it was becasue the packer packed a impossible/near impossible pull becasue he had'nt packed a pull out in such a long time and for got the details. Needless to say... the DZO is jumping a BOC again......

I wish you would step back from that ledge my friend... ~3EB


Premier billvon  (D 16479)
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Mar 25, 2002, 3:22 PM
Post #13 of 16 (4124 views)
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Re: BOC vs Pull out [In reply to] Can't Post

>So is it that, using a pull out PC rather than a throw out one will do away with the possibility of getting into a horseshoe or a PC in tow.

That's the basic idea. It will reduce, but not eliminate, the odds of getting a PC in tow or a horseshoe.

-bill von


MrHixxx  (D 24144)

Mar 25, 2002, 3:35 PM
Post #14 of 16 (4116 views)
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Re: BOC vs Pull out [In reply to] Can't Post

Concerning items 1-3 and please do not take this as a caustic rebuttle of any kind, it is just why I changed.

When I used a BOC, I had several pilot chute hesitations doing hop-n-pops and CRW where the initial snatch didn't get the pin out until I started to accelerate more. This lead me to thinking on if it doesn't come out and I have a total what is the additional likely-hood of two out if I hit the silver handle when it finally releases. So I changed...

Concerning a floating handle, I have the non-inverted PC type
collapsible bridle my Wings. I pull the pud out into the airstream and the inflated PC pulls it out of my hand. So, I have good verification that the pin is out the PC has clean air. If I do have a situation where I have lost the handle without bringing it into the airstream, I can either trace the bottom of my right side flap and hook my thumb in the pud-bridle or hit my reserve knowing the main is secure in the container. I would probably only make one swipe at the handle before I used the reserve.

In sum, I am much more afraid of having two canopies out fighting each other (PD 143R and Xaos 98) and one or both are gonna lose,than I am afraid of a total and using the reserve. Further, I think we can all agree that there is a big pile of bones under the two balls of shit scenario...

Item #4 make sure the bridle is routed properly! the grommet the smaller bridle (with the pin) feeds through on the larger bridle should not be under anything other than one side flap. I created some hell-atious hardpulls for myself when I first transitioned and was packing this part of the bridle under the bottom and side flaps. However, this hasn't happened since I talked with someone who had 900 jumps on a Javelin pull out and showed me how he packed his...

Hope this is helpful, Hixxx

"Sous ma tub, Dr. Suess ma tub" Crazy


tlshealy  (D 8142)

Mar 25, 2002, 4:51 PM
Post #15 of 16 (4099 views)
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Re: BOC vs Pull out [In reply to] Can't Post

Either system if packed correctly and maintained properly will function well, I would like to know what the incident rate is for each system, hard pulls, hesitations, PC in tow, totals, etc. per jump. I would guess that many more jumps are made each day with a throw out , than a pull out, I myself have about 1200 or so throw out jumps without any problems. How about everyone else?
BSBD
Tad




billbooth  (D 3546)

Mar 25, 2002, 7:35 PM
Post #16 of 16 (4084 views)
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Re: BOC vs Pull out [In reply to] Can't Post

I have read this entire thread and must say that the pros and cons of this subject have been very well covered. However, perhaps I can add some insight. As the patent holder on both the pull out and throw out pilot chute systems, I have listened to customers jump stories about both for the past 25 years. Hand deploy pilot chutes had a lot of problems in the early days. But these problems have mostly disappeared as the result of design improvements like the Spandex pouch, the bottom of container (BOC) location (borrowed from the pull out), and covered bridle paths. However, the same old problems with the pullout, such as lost handles and no-pulls due to improper packing still remain. Plus, while the throw out allows you to actually throw the pilot chute into the clean air outside the burble, the pull out forces you to release the pilot chute inside the burble. To get hesitation free deployments, pull out jumpers have to momentarily alter their body position to break up the burble. On small, highly loaded ellipticals, this can cause line twists, which can become malfunctions. Perhaps this is why a good 95% of my customers, including me, jump throwouts.
I would say that the jumping public has already settled this debate. Both systems work when correctly maintained, packed, and deployed. However, people just seem to have fewer problems with today's manifestation of the throw out.




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