Will a bag lock slow you down or increase your speed?

[ZigZagMarquis 9]

Bob Celaya taught me years ago, "Never try to stand-up a bag-lock."

[hackish 8]

From a simple EP point of view a baglock to me just means that I might have a little more trouble finding it.

I asked someone with considerably more experience and know-how than most mortals. He directed me to a video:
http://www.youtube.com/watch?v=vSd_EbVUNAg

Around 4:30 you see an intentionally baglocked configuration on a test jumper. The PC fully inflates and pulls the bag up but you don't see an appreciable increase in descent rate. I'm surprised that the jumper wasn't pulled upright.

I know it's only one example but maybe this means that standing up during a baglock is an avoidable condition initiated by the jumper's expectation of an opening shock and inflating main.

-Michael

[diablopilot 2]

Next time you have a bag lock, figure out the speeds for us, will ya?


Me, I'm gonna get rid of that shit quickfast.

A high speed mall is just that, high speed.

Edit to add.

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maybe this means that standing up during a baglock is an avoidable condition initiated by the jumper's expectation of an opening shock and inflating main.

Ever consider the possibility that being pulled into an upright position is an advantage in handling a bag lock malfunction as it facilitates the clearing of the three ring assembly?

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

[airtwardo 7]

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From a simple EP point of view a baglock to me just means that I might have a little more trouble finding it.

I asked someone with considerably more experience and know-how than most mortals. He directed me to a video:
http://www.youtube.com/watch?v=vSd_EbVUNAg

Around 4:30 you see an intentionally baglocked configuration on a test jumper. The PC fully inflates and pulls the bag up but you don't see an appreciable increase in descent rate. I'm surprised that the jumper wasn't pulled upright.

I know it's only one example but maybe this means that standing up during a baglock is an avoidable condition initiated by the jumper's expectation of an opening shock and inflating main.

-Michael

You're serious right?

~ If you choke a Smurf, what color does it turn? ~

[Booster_MPS 0]

Hackish - I would lean on your instructors of course but those with much more experience here have noted specifically that a bag lock could clearly stand you up. Don't try to rationalize this too much. If nothing else, please consider where your risers connect to your harness and how a force at this point relative to your cg will induce a moment (force/torque) and potentially put you on your feet.

EP's!

Observe and act.

[billvon 2,989]

>The PC fully inflates and pulls the bag up but you don't see an
>appreciable increase in descent rate.

I saw a video once where the guy opened his parachute and went up!

If you get stood up and it's a low-drag baglock you'll probably go faster. If it's a high-drag baglock (i.e. a tandem) or you don't get stood up (i.e. a collapsed PC, lines everywhere) you might not. And it doesn't really matter either way.

>I know it's only one example but maybe this means that standing up
>during a baglock is an avoidable condition initiated by the jumper's
>expectation of an opening shock and inflating main.

Perhaps. From now on, try to go a bit head down to anticipate the "standing up" effect of the baglock, just in case. You'll get a lot of slammers - and may just _cause_ a mal - but at least you'll be able to have no effect on a rare sort of malfunction that you will likely never have.

[pchapman 279]

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but maybe this means that standing up during a baglock is an avoidable condition initiated by the jumper's expectation of an opening shock and inflating main.

That wording does sort of make it sound like you are putting blame on the jumper...

But yes it does seem to me that a jumper's position under a draggier baglock can depend partially on the jumper's actions. A jumper might initially be pulled shoulders-high under a baglock, or into a stand.

Whatever the percentage chances, if it is only to a shoulders-high position, if the jumper then rotates their legs forwards (whether expecting opening shock or to get a better look or whatever) they may end up more in a sit or stand position, presenting less drag area and accelerating to a higher speed.

If one is in a standing type position, it may be prudent not to admire the view for too long even if altitude is sufficient.

Airtwardo mentioned being able to slow down for reserve opening because he didn't have an RSL. And on DZ.com I've heard of a baglock clearing itself, in a messy manner, after the jumper was stood up for some time. A very hard opening resulted.

[peckerhead 0]

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I have split this off the Spaceland fatality thread as best as I can. There are some ophan posts in here that I could not leave but this is the best that the software would let me with out getting super messy.

In terms of the bacglock, I've got video somewhere of a tandem having a baglock that slightly tilts them head high but they quickly are returning to tandem terminal, not maintinaing their same speed. All malfunctions are different, larger pilotchutes and drogues may tilt you more head high and have you presenting less surface area to the relative wind and that may have you speeding up, other times the drag may be small enough that it does not alter your body position and you end up still at belly speeds.

I can't figure out why you would move my posts to this thread. I was in no way commenting on this subject but you have made it look as though I was.

Whats up with that?

I can understand moving entire threads from one forum to another but when you copy and paste individual posts from thread to thread then comments can easily be taken out of context.

I really don't care if a baglock speeds you up or slows you down, it is a high speed malfunction and should be dealt with accordingly.

In the incidents thread I was discussing the possibility that it was not a bag lock at all but rather a two out situation where the main was released before the canopy came out of the bag, thus giving the appearance of a bag lock.

[gemini 0]

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I was discussing the possibility that it was not a bag lock at all but rather a two out situation where the main was released before the canopy came out of the bag, thus giving the appearance of a bag lock.

Although it is conceivable that the main could be released during deployment prior to the main coming out the bag, it would be highly unusual. This would also indicate that the reserve was deployed at at nearly the same time, but since the Cypres fired I suspect the reserve was deployed subsequent to the main and the baglock. The Cypres data may help with this question.


From the S&TA:

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Scott, the Cutaway handle, the free bag, and the main (Still bag locked) were all found within a 20yd radius.

Blue skies,

Jim

[hackish 8]

My interest in this subject is about a baglock and if it really makes you fall faster. The EPs are very clear - cut it away and break that nice little red sealing thread... That's why I note the only thing I see about a baglock is that finding the main will be a little harder 'cause if I have one it's gonna be gone before you can say oh shit.

People keep saying ask my instructors. None of my instructors have ever had a baglock and most aren't concerned with what it does or doesn't do - just to get rid of it and execute the EP's correctly.

The point of this thread is in understanding the dynamics of the situation. If you are unavoidably stood up or if people stand up as a reaction to feeling the snatch force. I assume billvon is joking when he suggests that one should stay a little head-down in case you have a baglock - that's silly and beside the point.

Clearly it's not something that has ever researched and presented or discussed. It probably has little or not impact on the EPs - just my desire to understand the technical details as fully as I can.

-Michael

[dragon2 2]

Well I saw a recent video of a baglocked tandem... Boy did they accelerate! Camera guy (also a TM) was so amazed he almost forgot to pull A few stows came undone then it went messy. The tandem pair was real lucky the TM pulled as high as he did (5k if memory serves), we counted it took 8 secs from attempt-at-main-deployment to a reserve over their heads and by then they were in cypres territory. The reserve is only just visible in the video as the camera guy pulls, so far below were they. Of course tandems are different from sports rigs but they accelerated like mad

ciel bleu,
Saskia

[DSE 5]

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Clearly it's not something that has ever researched and presented or discussed. It probably has little or not impact on the EPs - just my desire to understand the technical details as fully as I can.

-Michael

yes, it HAS been researched, presented, and discussed. Check out the Skydiving Survival Series DVD and watch it for yourself.
I see every reason that a baglock could seriously increase fall rate and little reason to believe it would slow the fall rate by any meaningful value.

[mouth 0]

Like I said earlier...I have had a container lock (only PC was out...pin dislocated from bridle). My pro track showed that my bottom end speed increased dramatically before I was under canopy at around to 1000 feet. I waved at 3, threw at 2.5 or a bit above, reached back to try and clear then cut away and went to reserve. My video even shows 4 seconds from wave to cutaway.

Figure that anyway you like but it was impossible for me to get flat again. I was basically knees down fighting to arch.

Like I said in the other thread...get a plan, practice it and stick to it. Be aware.

--
Hot Mama
At least you know where you stand even if it is in a pile of shit.

[pilotdave 0]

I don't know the answer for sure, but I'm guessing it can go either way.

If a jumper is flat and stable at pull time, at terminal velocity, his drag is equal to his weight. Assume he throws out his pilot chute and is instantly stood up. For a split second (at least), his drag will be out of equilibrium with his weight. The drag from his body will most likely be reduced, but he'll have additional drag from the pilot chute (and dbag). If the new total drag (drag from the pilot chute plus the drag from his body) is less than his weight, he'll speed up to a new, higher terminal velocity. Otherwise he'll slow down to a new terminal velocity.

So does the drag from his body decrease more than the drag caused by the pilot chute? Maybe it depends on what he's wearing, how much he bends his knees, how big his pilot chute is, or whether or not he's wearing his clown shoes that day.

I still don't see how it would ever matter...

Dave

[VideoFly 0]

I watched another jumper open with a bag lock. Considering his life was over, he chose not to complete emergency procedures. He was pulled upright, spun around with tight 360s throughout the descent, and appeared to accelerate slightly. His Cypres fired and after his reserve opened at about 450 feet, the locked bag dropped to his side. As the reserve carried him across the landing area, his main slowly dropped from the D-bag and then deployed into his reserve. At about 300 feet, the two canopies began to twist up and he went into a rapid spin while traveling across the runway at 25 feet and smashed into the ground. I ran to him to find him laying still and face down. Upon speaking to him, he stood up, brushed himself off, and walked back to the packing area.

[peckerhead 0]

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Although it is conceivable that the main could be released during deployment prior to the main coming out the bag, it would be highly unusual. This would also indicate that the reserve was deployed at at nearly the same time, but since the Cypres fired I suspect the reserve was deployed subsequent to the main and the baglock. The Cypres data may help with this question.

Highly unusual yes.

But not impossible. In fact it has happened before.
That is why it was being discussed as a possibility.

[Rdutch 0]

I did a couple intentional Baglock jumps to test the skyhook, and to be honest, it never stood me up, I was a little more than head high. That with a 30 inch pc and a 170 main with dacron lines, so there was some drag. The videographer had no problem staying with me for the entire thing as I pulled the main at 5000 and deployed the reserve at 2500. The video used to be available on the RWS web site.

Edited: after watching the video quickly, It looks like the drag on my legs kept me belly to earth.

Ray
Small and fast what every girl dreams of!

[Andrewwhyte 1]

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Edited: after watching the video quickly, It looks like the drag on my legs kept me belly to earth.

I wonder if the going faster under a baglock thing would be negated if the jumper kept arching. If you are going that fast, and were in an arch, it seems to me the tendency would be to return to belly down. I can see where people would stop arching after the initial pull of the baglock stood them up a bit.
For the record, my bag lock did not stand me up either.

[hackish 8]

Yes, this is one point I was thinking about. I know some people disagree with that evaluation and some even made fun of my suggestion that people were standing up because they felt the snatch force and broke the arch in anticipation of an opening. Now about that $1000 challenge that a baglock couldn't make me fall slower... If I had a lot more experience and a rigger-b I'd consider doing up a rig to test it out...

-Michael

[DSE 5]

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...and some even made fun of my suggestion that people were standing up because they felt the snatch force and broke the arch in anticipation of an opening....
-Michael

Which post makes fun of you?

In this vid the baglock stands him up.
So does this one.

More importantly, does it matter? I'd sure hate for the last thing to go through your mind to be "The folks on DZ.com were right/wrong!"

[champu 1]

If you'd like another example of body position trumping other sources of drag, take a look at freeflying with a large freefly tube. Those things generate a fair amount of drag and it's really not that difficult to maintain head-down speeds while holding one in a head-up position.

[mark 107]

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More importantly, does it matter?

It matters to me, because I'm curious and I'd like to know. Just to know.

Besides Jump Shack's 20-year-old pictures (available where?) and anecdotes (remembering that the plural of "anecdote" is not "data") are there any controlled studies which looked at the effects of, say, pilot chute size, initial freefall speed, and body position?

Mark

[AFFI 0]

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More importantly, does it matter?

It matters to me, because I'm curious and I'd like to know. Just to know.

Besides Jump Shack's 20-year-old pictures (available where?) and anecdotes (remembering that the plural of "anecdote" is not "data") are there any controlled studies which looked at the effects of, say, pilot chute size, initial freefall speed, and body position?

Mark

Look. high speed partial - whatcha gonna do?

Mykel AFF-I10
Skydiving Priorities: 1) Open Canopy. 2) Land Safely. 3) Don’t hurt anyone. 4) Repeat…

[mark 107]

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Look. high speed partial - whatcha gonna do?

I have had three or four high-speed partial malfunctions in my career. I know what I'm going to do.

The title of this thread was "Does a bag lock slow you down or speed you up?" I'd like to know the answer to that question, based on something other than anecdotes or personal experience. Do not patronize me by answering a different question.

Mark

[airtwardo 7]

. . .are there any controlled studies which looked at the effects of, say, pilot chute size, initial freefall speed, and body position?

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I've never heard of any in-depth study of the type you describe.

The cost / benefit equation wouldn't make such a study very practical.

The number of possible variables to test would get ya a Gold Wing for intentional cutaways...and then someone would say "How about if your shoe laces were double knotted making less drag."

'Anecdotes' & personal experience are a valuable tool for learning if not for scientific evaluation.

I still stand by my personal experience, and the pro-track data confirming that I sped up following the pull as well as watching another jumper go past me under one.

I agree with the posters that say it could possibly do either, and I'll add if you guys want to fund the study...I'll get out my intentional cutaway rig & clear my calendar.

~ If you choke a Smurf, what color does it turn? ~