0
fcajump

Pilot-chute In Tow (its just the PITs)

Recommended Posts

In thinking how bad PIT's can be, I'd like to start a discussion on how to avoid them...

So, if you've had one and know the cause, please list it here... preferably with the solution you, packer, rigger, mfg or other's came up with to avoid that in the future.
-------------------------------------------------------

Gear
- Vector II-V9 (good condition),
- Spectre-230 (newish - right-sized for the container),
- Cazer ZP collapsable pilot chute (3rd jump)

Jump
- lowish alt demo (3,500')
- planned 5 sec delay

Determined cause
- Bottom Line: Incompatible parts
- PC was too small for my canopy. At the time Cazer didn't tag the PC's as to sizing. I was new to ZP PC's and didn't know there was a difference, nor that my local supplier only had the smaller ones on the shelf.

Resolution
- Cazer replaced (no charge) the PC for a larger model by the next weekend and from then on all of the Cazer PC's I saw for sale had sizing tags/instructions in the bag.

The rest of the story
I decided on cut-away/reserve (as I had been taught). As soon as I got both handles grasped the pin popped and the main slammed me. Good news, instant main... bad news, the opening was hard enough that my left hand dislodged the reserve handle and I had 2 out. Bottom line, after careful consideration, I chose to chop the main. Landed within sight of the audience (with USA flag deployed... but with everything else, they forgot to play the anthem :-).
------------------

Ok... whose next to teach us how not to f-up??

JW
Always remember that some clouds are harder than others...

Share this post


Link to post
Share on other sites
I've never heard of anyone having PCIT with Pull-out. Get one = problem solved. Maybe not what you were looking for, but it works!
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

Share this post


Link to post
Share on other sites
Deyan

I've never heard of anyone having PCIT with Pull-out. Get one = problem solved. Maybe not what you were looking for, but it works!



True, but pull-outs do have their own issues.
In general a floating handle on a throw-out doesn't have to be found... (for better or worse ;-) It is possible to route the handle/bridle such that you can't pull it, and just try to find someone at most DZ's that can properly pin check you (or maybe even pack it).

I've jumped both (thugh admittedly only a few on the pullout), and both are good in their own way.

JW
Always remember that some clouds are harder than others...

Share this post


Link to post
Share on other sites
All of what you've said is true!
However, you asked how the PCIT can be solved. On top of that floating handle is way better than PCIT. Of course that's only my opinion which in most cases is not worth 2 cents.
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

Share this post


Link to post
Share on other sites
skydiverek

How many inches was the PC?


Good question... I don't have the "too small one" anymore, and don't see the "just right one" currently (its in a box... somewhere...)

I did find an old reference that said he made 24" and 28"dia PC's... so lacking any other information, I'd have to say that the too small was one of the 24". Recollection was that the sizing card that appeared after my PIT said that the small one was good for main canopies up to 170SqFt

JW
Always remember that some clouds are harder than others...

Share this post


Link to post
Share on other sites
Pilot chute drag is very important. Depending on design and materials, the drag to two identically sized pilot chutes can be very different. This is one reason why buying any component after-market can be risky. You must communicate to the seller exactly what you will be using the component for, so that you get a truly comparable part.

A correctly sized pilot chute should get you canopy to line stretch 0.5 to 0.7 seconds at terminal. (A bit slower on a hop and pop, of course.) Too big can cause line dump, and too small can cause a bag lock from lines blowing over the bag. What size rubber bands or tube stows you use, and whether you use a full-stow or semi-stowless bag can also alter your deployment time. But when you put all those considerations together, 0.5 to 0.7 seconds is what you should aim for.

A pull out probably would not have made any difference in your situation, because I suspect your pilot chute, even though too small, pulled the curved pin (which should only take around 5 lbs. of force) opening the container. Your PC just didn't have enough oomph to pull the bag out of the container because of your low airspeed.

Pilot chute hesitations, reserve pulls, and fatalities because of pull outs were numerous in the 70's when a lot of people first tried them. That's why hand deploys became the dominant system. When all is said and done, hand deployed systems simply have far fewer problems in actual usage.

Share this post


Link to post
Share on other sites
"Pilot chute hesitations, reserve pulls, and fatalities because of pull outs were numerous in the 70's when a lot of people first tried them. That's why hand deploys became the dominant system. When all is said and done, hand deployed systems simply have far fewer problems in actual usage. "

I can't even imagine going back to a pullout. I remember the last person I knew who had one. Her husband and I were in the C180 getting out on the next pass and we watched her in freefall with the pud in her hand and the bag getting line stretch in a huge horseshoe. We never did figure out how she actually got canopy but she finally switched to throwout after that one.

Share this post


Link to post
Share on other sites
Deyan

I've never heard of anyone having PCIT with Pull-out. Get one = problem solved. Maybe not what you were looking for, but it works!

. I'm here to tell you it can happen. Been there done that got the tshirt.
i have on occasion been accused of pulling low . My response. Naw I wasn't low I'm just such a big guy I look closer than I really am .


Share this post


Link to post
Share on other sites
billbooth

... A correctly sized pilot chute ... Too big can cause line dump...



Well, Bill, hopefully we won't have a number of people seeing what you wrote and then going around saying that "Bill Booth says that if you have a big pilot chute that you will get line dump."

We know that "line dump" is possible under certain conditions, but line dump is not common, otherwise there would be many videos of it and a number of seriously injured jumpers.

I asked a while back for anyone to come up with an image of line dump and it took a long time to ever see one. (One of the two I ever saw was on a tandem rig.)

Line dump caused by issues with "stowless" bags is of course another topic altogether!

The reason I am commenting on this is because I have heard so many people over the years mention line dump when they have simply had a moderately hard opening, and then they go messing around with smaller pilot chutes instead of figuring out what the real problem is.

P.S. Here is a data point. I have been using a 34 inch zero porosity pilot chute to deploy my Stiletto 150 for many years. All nice openings using moderately tight rubber bands, not double stowed.

Share this post


Link to post
Share on other sites
Gary;

Perhaps you're right. I used the term "Line Dump" (it is a rare beast, but something more easily understood by most jumpers) rather loosely to cover the litany of problems that come from high separation velocity at line stretch, such as high snatch force and the general disorganization of the pack job it produces. I just know from conversations with legendary canopy designer Theo Knacke and decades of observation, that nothing good comes from separation velocities over 50 fps, which equates to line stretch times of about 0.5 seconds for average sized sport canopies deployed at terminal.

As I have written here before, it is rather easy for a jumper to determine line stretch time by simply having someone video one of their deployments. Just count frames from container opening to line stretch.

Share this post


Link to post
Share on other sites
jumpsracer

Really, you couldn't figure out why she had a horseshoe? Pulling the pud on a pull-out opens the container exposing the bag to the airstream, eventually it'll work its way out. Key, dont hold on to the pud!!



Yup, 'zactly. Out of sequence deployment on each and every jump.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

Share this post


Link to post
Share on other sites
jumpsracer

Really, you couldn't figure out why she had a horseshoe? Pulling the pud on a pull-out opens the container exposing the bag to the airstream, eventually it'll work its way out. Key, dont hold on to the pud!!



That's not what he said.
My computer beat me at chess, It was no match for me at kickboxing....

Share this post


Link to post
Share on other sites
Deyan

I've never heard of anyone having PCIT with Pull-out. Get one = problem solved. Maybe not what you were looking for, but it works!

. I figured someone would be curious but whatever ;)
i have on occasion been accused of pulling low . My response. Naw I wasn't low I'm just such a big guy I look closer than I really am .


Share this post


Link to post
Share on other sites
Hi Ken,

Quote

Out of sequence deployment on each and every jump.



Pretty strong statement when there are so many variables.

Many years ago, on a pull-out ( my own rig ), I spent a good 6-7 seconds with the pud in my hand. I wanted to see what would happen.

The pull of the p/c stood me straight up; the bag never left the container until I let go of the pud.

Jerry Baumchen

Share this post


Link to post
Share on other sites
keithbar

***I've never heard of anyone having PCIT with Pull-out. Get one = problem solved. Maybe not what you were looking for, but it works!

. I figured someone would be curious but whatever ;)

I'd love to hear that story ;)
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

Share this post


Link to post
Share on other sites
gowlerk

***Really, you couldn't figure out why she had a horseshoe? Pulling the pud on a pull-out opens the container exposing the bag to the airstream, eventually it'll work its way out. Key, dont hold on to the pud!!



Yup, 'zactly. Out of sequence deployment on each and every jump.

So pulling the pin before you get the PC out is considered "out of sequence deployment"?
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

Share this post


Link to post
Share on other sites
Back in about 1975 or 1976, Jay Hilden and Mike Cerosoli showed up in Athens, Mi. to form the first 29 way round. They had the first throw outs that came from the Wonderhog shop. Wonderful concept. Pull outs came later and so did curved pins for the throw outs. The first curved pin came from a hardware store door latch that we bent. At that time, Sandy Reid and I mounted the pilot chute on the bottom of the container. Thus, the first BOC. There were a few different designs for the pull out. With the pud on the bottom of pc and a container that just burst open upon pin removal was quickly seen as a bad deal. With a few changes, the pull out configuration became more reliable to us than other systems. That is why a few of us used a pull out on our reserves.This presents another problem. AAD on pull out? Did not matter back then. That would take at least another weekend of pondering. Right now for the general public, the marketed throw out is the best thing going that they can buy. D-3411

Share this post


Link to post
Share on other sites
Deyan

******Really, you couldn't figure out why she had a horseshoe? Pulling the pud on a pull-out opens the container exposing the bag to the airstream, eventually it'll work its way out. Key, dont hold on to the pud!!



Yup, 'zactly. Out of sequence deployment on each and every jump.

So pulling the pin before you get the PC out is considered "out of sequence deployment"?


In my mind, yes. The bridle should load up before the pin is extracted. Unless you’re using a spring loaded p/c.

Share this post


Link to post
Share on other sites
Deyan

So pulling the pin before you get the PC out is considered "out of sequence deployment"?



In a way it is, especially if you compare it with a throw-out system. But with a pull-out system, this is how it is designed. (It is also expected that the jumper will quickly let go of the pilot chute once the pin is pulled.)

This is why it is important for the main bag to be wedged into the main container in a way that requires pilot chute extraction, and doesn't just fall out, or be blown out from the wind.

Share this post


Link to post
Share on other sites
Quote


The bridle should load up before the pin is extracted. Unless you’re using a spring loaded p/c.



Hmm, I was just about to say, all those reserve deployments would be considered out of sequence.... unless you somehow artificially exclude them because of a spring loaded PC, maybe because it "it is out of sequence but isn't out of sequence for that long so I won't count it because I want to say that pull-outs are bad, without saying that all our reserves are bad too".

So I'm in the camp saying that a pull out isn't 'out of sequence' -- but whether a pull out or a reserve, one can debate how well the staging of the deployment is protected from becoming out of sequence in less than ideal circumstances.

Most reserve deployments just have the bag sitting there waiting to fall out, except for any pocketing going on by the container, while the PC extracts and the bridle stretches out.

Exceptions being a few early 1980's rigs with hesitator/staging loops, and the appreciable number of Vectors and Sigmas and Icons for example adding them back in again in the last decade or so.

(I won't count MARDs; that gets messy, as they do restrain the bridle somewhat but don't stop the bag from tumbling out.)

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