Hard Opening?

[Rottenmilk 0]

Hello all,
Had a really hard opening yesterday that knocked the wind out of me!
I threw out the pilot chute and for a moment nothing happened. I started to say to myself, "ok.....?" - then BANG!, I was under canopy. Immediately after regaining my composure I checked for canopy damage, however, none was visible.
Upon repacking I found that my reserve risers had been slightly pulled out and the reserve pilot chute was visible, thus requiring a repack. (I have a Wings container, by the way)

One of the packers thought that it probably was due to a "line dump" - lines not stowed efficiently resulting in all lines releasing at once. He thought that this might also explain the sudden deployment that I experienced.

Anyone else have ideas? Possibly a packing error that I might avoid?

Thanx for your time everyone!
J.

[AggieDave 6]

A very hard opening could be caused by a number of things, including the speed in which you dumped, although an opening as hard as you described is probably from a packing error (unless you dumped in a headdown or something).

How big are the bites you stow, are you using small rubberbands, how many were broken after this deployment? If the bites were very small or became dislodged while putting the bag in the container, that can cause a hard opening. This is especially true of the two locking stows, those are very vital. As a rule of thumb, you want your bites to be about as big as the space between the grommets on your d-bag (that's a general rule of thumb and there ARE exceptions). Also, did you remember to uncollapse your slider when you packed. Was the slider all the way againste the slider stops? Was the canopy packed evenly (slider stops lined up semetrically)? If they were uneven to one side, that can cause a hard opening. How old is the canopy/lineset, a canopy that is badly out of trim can open hard, due to semitry during deployment.

With all of that said, it sounds like you did have line dump, since you didn't feel anything at first. This is because the d-bag/canopy has to extend the length of the lines before you feel any resistance (if you really pay attention, you can actually feel the stows coming undone during deployment).

Also, were you using tube stows and are the fairly worn? The main thing to look at here is the line stows/rubber bands.

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

[darkwing 5]

I second everything said above, but I'll add that sometimes it just happens, without there being an "error" that caused it.

-- Jeff
My Skydiving History

[skycop 0]

Are you using a 4 grommet D-bag? I blew up a canopy a couple of years ago. All indications were line dump/bag strip. I switched from a 2 to a 4 grommet bag and paid extra attention while packing. So far no more problems with hard openings.

"Just 'cause I'm simple, don't mean I'm stewpid!"

[Pablito 0]

Go to the PD Website they have an interesting article in how to prevent hard opennings, they apply to all the canopies I've packed.
Hope it helps
Cielos Azules
Pablo

"If you don't overcome your fears they will overcome you first"
Shady Monkey/6Segundos Rodriguez/AKA Pablito

[Hooknswoop 19]

Since the delay between throwing out and getting opening shock took longer than normal, I think you can discount "line dump". If the lines had fallen out of their stows, and that would have to include the locking stows, the time from throw-out to opening shock would be a lot less. Without having to pull the lines out of the stows anymore, the canopy would have come out of the bag and you would have experienced opening shock in the length of time it take to fall the length of your lines.

Depoending on how far apart the final two stows are on the D-bag, it is very difficult to actually get line dump. Both stows would have to break or the weight of the lines between the locking stows would have to be greater than the weight of the line outside the locking stows. If the locking stows are 4 inches apart and you make 2 inch line bites, then there is 4 inches outside of EACH stow and only 4 inches btween the stows. 8 inches total outside the stows and 4 inches inside the stows. Even with loose stows (not recommended) weight alone should keep the lines inside the rubber bands. Take a look at reserve free-bags. The entire line set could "dump" out of the stowage pouch (on most designs), because the only line stows are the two locking stows. As long as they hold, no line dump. How often do you hear of people blaming "line dump" for a hard reserve opening? Fall rate, body position, keeping the slider against the stops while packing, canopy design, and pilot chute size all play a larger role in hard openings.

I posted a request for anyone w/ video of line dump. I think I got 2 responses, one for old gear and the other couldn't produce the video. With all the deployments on video, where are all the videos of line dump?

Hook

[AggieDave 6]

I think Pablo may have a video that could qualify. His Spectre opened in 2 frames! (It wasn't packed by him or me).

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

[Hooknswoop 19]

I've had canopies open hard. I have video of a couple of Sabre opeings that were downright brutal, but in none of those could the hard opening be attributed to "line dump". On the video of the Sabre openings, you can see the lines un-stow normally, then WHAM! I have seen video of a rubber band breaking (I was the TDM-I and Pablo was shooting the video), but it wasn't a locking stow and the opening was normal and we wouldn't have even known the rubber band broke unless there had been video.

I woud really like to see, out of the thousands + (guessing here) of video'd deployments, canopy coming out of the bag and inflating w/ slack lines from the lines, including the locking stows, "line dumping".

I just don't believe in "line dump", except in extreme cases, very wide bag, very wide locking stows, big PC, loose stows, small stows, and heavy lines.

Hook

[Rottenmilk 0]

Thanx everyone...
It's funny, but I had actually taken my time to pack for this particular jump. Previously in the day, I 'trashed-packed' in a hurry to catch a load, but the deployment was smooth.

Anyway, the slider was properly packed. However, I believe that my concern lies within the stows. Generally, I try to keep my stows, overall, the width of the bag (is this known as "bites" referred to in the forum?). I had been told that excessive stow length might catch causing a malfunction (any truth to this?). Still, longer is better than shorter.

Ultimately, my deployment was smooth and stable. But hot-damn, it hurt!