0
Babi

Hard openings

Recommended Posts

I am sure a lot was written about this subject. But, in short, can anyone tell why this happens and how to avoid it?
I've had a couple really bad ones and I started to fear if it gets worse.
I pack my own canopy, a 280 student canopy, Skymaster, which is pretty hard to get into the bag and into the rig. It is always inspected by someone skilled at the DZ. I seem to pack the same and the openings are different.

Share this post


Link to post
Share on other sites
The article Gus included is a geat one, and as Ken mentioned, many times it is the lines stows.

PD's article says: Replace Tube Stoes or rubber bands that appear worn. Do not wait until they break!

I replace all of the rubber bands on my D-bag about every 25 jumps or so. Also be sure that you are using the correct sized rubber bands....This might sound obvious but on my first rig (5 years ago) I got slammed several times...to the point of accidentally biting through my lip and coming down with a lot of blood on my face.

I even had up-jumpers watch me pack. I finally realized on my own that I needed microline rubber bands for the microlines of the canopy (a PD210) instead of the larger bands I was using for the student gear with dacron lines.

Keep in mind, hard openings can lead to malfunctions. Good Luck!!
Rigger, Skydiver, BASE Jumper, Retired TM

Share this post


Link to post
Share on other sites
The tightness of line stows has very little to do with how hard a canopy opens. The critical thing to watch out for with line stows is that the locking stows do not release before the lines are under tension (line stretch).
----------------------------------------------
You're not as good as you think you are. Seriously.

Share this post


Link to post
Share on other sites
I agree, line dump prior to line tension is bad news --- however, I believe that having all of the line stows snug helps make for a nice, orderly, and staged deployment, which usually means a softer opening.

Plus I don't think any of us should tell a new packer to pay attention to only the first two stows and feel free to slop the rest ;)
Rigger, Skydiver, BASE Jumper, Retired TM

Share this post


Link to post
Share on other sites
Thank you for your replies. I have a rented Skymaster with rubber bands (stows??) to attach the lines to the bag. They are pretty difficult to handle, especially the first two. I tested them once on the ground by pulling the canopy out and they performed O.K.

I think, reading the article, the reason for may hard opening was in how the canopy was bagged. I did a good job of folding the canopy (was inspected) but when packing it into the bag it got slightly disarranged. I still find bagging the canopy very difficult. But at least now I know what I did wrong.

I have the rig home with me till Saturday when I go jumping again, so I can practice on it.

I remember that it took quite a wile (longer than ususal) to feel the pull of the canopy and once I did feel it the canopy opened with a bang, almost as if it exploded.

Thank you once again.

Share this post


Link to post
Share on other sites
Quote

and staged deployment,



Staging the deployment has very little to do with how a canopy opens. It refers to the sequence of deployment.

Metering the deployment, i.e. reefing, can have a large affect on how a canopy opens

How can tight or loose stows effect how the canopy opens if the canopy is still in the bag. If the locking stows remain closed until line stretch the rest of the stows are just for neatness.
My idea of a fair fight is clubbing baby seals

Share this post


Link to post
Share on other sites
>>>How can tight or loose stows effect how the canopy opens if the canopy is still in the bag?



This is mostly my own theory so I could be totally wrong...you have about 1,200 more jumps than me so Babi should probably listen to you...

I've never had one myself, but 'bag lock' is when the pull force created by the drag of the pilot chute does NOT exceed the restriction created by the rubber band (of course a knot around the bight can do it also). Now I have had a few slammer openings using regular rubber bands with a single wrap on microlines. (yeah, I know, dumb but I asked every skygod on the DZ then and none of them caught it either). The first stows are usually fatter than many of the others, to the point that some people use regular rubber bands there and microline bands everywhere else (especially Aerodynes).

So what I am getting to is that the force required to deploy 8 bights of line has some marginal affect on the velocity of the jumper consequently slowing them down ever so slightly before the locking stows give way and the canopy is released.

While my theory might be plausible I agree that the net affect is small, however, instructing newbie packers to take care with ALL of their line stows will probably help them avoid other problems.
Rigger, Skydiver, BASE Jumper, Retired TM

Share this post


Link to post
Share on other sites
Quote

the canopy opened with a bang, almost as if it exploded.



All of the line stowing tips have been correct and are important. Make sure they are not coming out until they are pulled, especially the ones that lock the bag closed.

You may want to try rolling the nose of the canopy. This is commonly used to slow down an opening, and I'm sure you can find a packer at your DZ to explain it to you.

Kevin
_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

Share this post


Link to post
Share on other sites
I do roll the nose, especially since I was told that this slows down the opening and makes it softer.
Tomorrow is a jumping day and I hope all goes well. I have a different rig this time, same type. I hope all goes well this time.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0