static line jumps

[guest]

can anyone advise me of the "lower" limit for static lining a fox/reactor combo????Would 150' feet be on the unrealistic side or has that height been successfully jumped in the past?

[guest]

"as i'm sure others will that 150ft is even safe to put a first time freefaller off and still have plenty of time to fly ones canopy."

Why not 125 feet then they don't have to worry about all that extra canopy time....

[Dwain]

Most BASE accidents occur under a fully inflated canopy.
Therefore one could rationalize that by minimizing canopy time you minimize the time in which you are most likely to injure yourself. :)

[guest]

Experience, The object, the landing area, do you feel good about it. Late my brothers and sisters.

[guest]

[font size="1" color="#FF0000"]LAST EDITED ON Aug-28-00 AT 02:24 PM (PST)[/font][p]OK, it looks like everyone here just wants to jerk you around (don't take it personally--lots of people honestly ask for advice here and just get slammed). I'll try to help.

First, I would advise using a direct bag for a 150' deployment. Basically, anytime you are considering static lines, I believe (it's still a debated point) that a direct bag is a better option. The bag deploys the canopy with less deformation (i.e. it comes out how you packed it), which tends to give more consistent openings both in terms of heading and speed.

Second, if for some reason a direct bag deployment is impossible (i.e. no escape for the bag holder or no place for a bag holder to stand), I would say that a static line deployment is definitely possible at this altitude.

However, if you are going to use a static line (fixed, since if you had a friend to PCA you, you'd use the direct bag instead, right?), be very aware of your outs--you will likely have an off heading (and probably not have time to correct it, so you will be landing in some random direction). Static line deployments, which have (virtually) infinite snatch force, create maximum deformation (via center cell strippage) of the canopy during deployment. This translates to poor heading for static lines (this effect can be mitigated, but not eliminated, by a multi bridle attachment or a top gate).

So, if you're going from a 150' bridge over water, no problem. But if you're looking at a 150' building or guyed antenna (or, god forbid, something with an even smaller opening quadrant), I'd say you're looking at one of those "lucky to be alive, never do it again" kind of jumps.

One final consideration. The Fox's angle of attack (which gives it superb landings), may not make it the canopy best suited to low deployment. If you can lay your hands on a V-Tech equipped Fox (best option) or a Mojo (in my opinion better than a standard Fox), that would be better for a low deployment. A ZP top skin would also help inflation time, but would also make an offheading even more likely.

In summary--Yes, a static line is possible, No, I wouldn't recommend it. Consider a direct bag.

And do try to ignore the jokers who thought an honest question was just an opportunity to start heckling each other.

--Tom Aiello

[Dwain]

> Static line deployments, which
>have (virtually) infinite snatch force,
>create maximum deformation (via center
>cell strippage) of the canopy
>during deployment.

Center cell stripping does occur during canopy extraction on static line jumps, but it is not usually as bad (on extraction) as say during a 4 second delay with a 42" zp pilot chute. This is because the relative speed of extraction isn't as great.

However, the major deformation occurs when the pack job reaches line stretch. If the amount of force required to break the static line is too great (or if the PCA person holds holds onto the p/c too hard) then this can effect the opening of the canopy in regards to both heading and cell pressurization.
The type of static line used (or the person used to a PCA) is therefore critical to the opening.

If done correctly, PCA and static line jumps can have an extremely high on-heading rate. One reason for this is because the anchor point for extraction is fixed (versus an oscillating pilot chute).

[guest]

Cheers Dwain and Tom for putting this thread back on course,the info you have given will come in handy although for two buddies of mine (who shall remain nameless)it is a little too late....one has a broken fib and ankle from a fast impact and not much more than a top skin and the other is waiting to see what damage he has when his pot comes off in a week!!

To be honest...they can keep their 150' static line jumps,I like my bones and my freefall time too much!!Stay safe...

[guest]

right, let me tell the tale then.

the structure was a road bridge. rock drops were timed at a consistent 3.5+ seconds and visual guesstimates put the deck at about 150-160'. we went with a spare bridal fixed tight to the structure then four wraps of electrical tape to fix the canopy bridal and a 48" pilot chute. we did exit over water (barely) to allow for a wet out for off headings and had a gravelly/rocky beach as the primary landing area. my canopy (fox265, suspended weight 190 lbs) opened fast and on heading and i was straight on the toggles into half brakes to set up for landing. still, i came in so fast and hard, even with an ineffective flare and a plf, i'm sporting a cast until they can ascertain whether i have a hairline fracture or torn ligaments in the ankle. my mate wasn't so lucky, we'll have to study the video to work out what exactly went wrong but he basically only got bottom skin inflation and crashed in hard breaking his leg. i'll let him fill in the details in his own time. i wonder what we could have done differently for better results. the deployment bag would probably be a much better option from this height but i think it will be some time until i try something this low again, if ever! my personal advice to all (except dave johnson and 'not one of the others' who i encourage to f/f them) would be to leave these kinda heights alone or make the water your primary option.

stay safe!

airhugs

[Yuri]

Yo !

Tailwind ?

bsbd!

Yuri.

[guest]

VTEC FOX !!!!

[guest]

yuri: slight crosswind.

593: the v-tech certainly sounds like it would have been a better equipment choice.

a verbal explanation i have just received of inflation as opposed to pressurisation and the effects on control pretty well reflect how the canopy handled despite appearing flyable.

i hope this helps others to avoid this situation.

later

hugs

[guest]

Yo!

Well I'm the other crippled one and I've just got home after being released from hospital today. Additions include 1 x plate, 9 x pins, 1x cast so I'm out for a while.

Adrian has explained the points surrounding the jump. My Suunto Vector read 150 and the rock drops were 3.5 secs. From my point of view I exited, looked down and caught the most intense visual of my life, felt the tape go and looked up to see my canopy (Fox) just rippling away and I hit the deck with bottom skin inflation but no pressurisation at all. It seemed as if the front of all the cells had closed themselves off. I haven't seen the video yet but by all accounts it's pretty gruesome.

I had done some experimentation from a 220 ft object that I usually freefall with the same equipment and static line configuration as I used at the bridge and I got a couple of 20 second canopy rides so I didn't believe it was an outrageous jump allthough we both knew it was pretty full on without much margin for error.

I've now revised my low limit to 200 ft and I'm going to get a vtec mod while I'm on the ground.

Craig

Hi Tom

I disagree.

From a purely statistical view. I have done and witnessed hundreds and hundreds of jumps from my local 187 foot bridge with s/l. Allowing for extremely poor body position, I am yet to see an off heading greater than 30 degrees. I think that over 95% of the jumps have been within +/- 5 degrees.

Centre cell stripping -> The affect is much worse at higher air speeds (yeah, I know this is obvious)...

D-Bag

You have to rely on another person, human factor!!!! Lines out (twists????), holding the bag slightly uneven, letting go of the bag (unless you have the bag s/l as a backup), etc

All the d-bags I have seen have been %#^%#$%*U. But like anything it was primarily due to the people involved and not the technique.


Have you considered the WAD??? ;)

see http://tomarent.tripod.com/wad_exit.jpg