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I'm really confused. Why would anyone want to not use a PC for a static line? - especially from a height of 150'+ where it's still possible for full inflation? i mean.. if you're jumping <100' over land, and you're screwed either way, ...

are we going to have some fatalities soon from heights people freefall (170'+) because someone took their PC off and there was a premature breakage??

if i'm missing something/not understanding something... fill me in. it just seems like a horrible idea.

i thought this was going to be a poll you pussy.

I agree,

but nate, man, 100' is still possible to free fall and live. even at 80 SLs take a pc. make it a big one.

Shortish (150') building jumps with a fence (or light pole, rubbish, tall elephants, etc) to clear might be one example.

The question is: Is there a way to make it as safe as possible?

There's a reason for that. It all depends when the break happens. The only premature break I'm aware of, the canopy was just being extracted when the break cord busted. The Pilot chute took over and saved the day.

there was (is ???) video on sdmovies of a SL antenna jump where the SL breaks (no idea how it was rigged) right after exit - and the PC extracts the canopy (i *think* it was a jump in S. America). I don't see how that would of been survivable without the PC.

I know of one case in which a similar premature break (with no PC) was survived, very early on. I believe that the jumper actually flailed enough to elbow the canopy out (either that or he flopped around enough that it fell out to one side--depends on if you believed the jumper or the others watching), got partial inflation, and survived the impact.

ok... for our FJC leaders out there,
when teaching PC-less 150' Static line jumps where you need to clear a fence and trees by a small amount, remember to tell students to be ready to flail around as soon as they exit, it could save their life.

I've always taught them to FJC students with the PC attached, as a backup.

What you decide to teach to students, and what you decide to do for yourself are two very different things. When you're teaching, someone else is trusting you with their safety, so you generally teach the most conservative techniques possible. When you are jumping for yourself, you set your own level of risk, and use whatever techniques fit that level.


edit because I forgot that Lonnie also taught static line in his FJC

im just being sarcastic with all of this...

if i ever teach SLs (and i wouldnt, i see no point in jumping something you cant freefall) the PC will be ATTATCHED. period.

but, if some see the need, or they are geographicaly limited for exits, then go for it, short bridal no PC SLs, or SL on bridal/canopy connection.

but i STILL SAY DO A FREAKING DBAG.

but this is a free sport. and it should remain that way.

Pc's sometimes get in the way of video.

very true..
see mike.. that's all ya had to say.
*that* is a valid reason.

i should have known that. oh well.. i'm still learning...

 

Calvin, I very much respect your innovation and creativeness with all sports you do... thanks again for the rope jumps. But, why put down the idea of pushing the limits safely with SL jumps? This is starting to sound like another.... What is a real BASE jump thread.

I actually enjoy the funk (some of the big afro kind) SL jumps that require some creative rigging, clearing some funky objects, or just plane smiling for the fiance from the top. It's a wonderful way for me to take my rigging knowledge from Big Wall climbing to BASE.

if your alone or the last one off, you cant do a Direct-Bag, (dbag),

i have thought of ways you could do it, but i dont want to test them.

your not ignorant, i should have specified direct bag, not dbag.

if you object is cliff, of abandind A, or bridge, or even building, i would say just leave the dbag there, and retreive it afterward. or have GC do the dbag, and then rap down, etc.

I hope no one will freefall what you are SLing!

again, if the no pc method works for you, i have no problem with it.

the original post was asking for other jumper input, i gave mine.

so, in my personal little jumping world, that is very different from a lot of other peoples, i would never do it. 9' or longer bridal, with a PC sized correctly. actualy, PCAs and SLs are only in desperation, and i would prefer a dbag. I also agree that i like the way my blackjack flys without a bridal.

i like the way my blackjack flys without a bridal

All canopies fly better without extra things
attached to top of them. Most pro swoopers
actually REMOVE their sliders, d-bags, and
pilot chutes for less drag & more speed.

When ground launching with my Dagger 266
of course I removed my shrivel flap & pc.

I once was about to exit off a lowish A with wind at ~45 degrees. A gust caused my PC and carrywith to "take off", sliding down the railing to stretch. I grabbed my bridle at the last second to keep it from possibly opening my container. Sure did wish I didn't have a PC on that one.

Solutions:
-have it tied off somewhere it can't slide (and possibly snag/loose your carrywith)
-have PC in hand and toss clear on exit.
-stand on your PC
-don't use a PC

When it's windy it's a pain in the ass on SL jumps, but i'll always keep it, just in case

Solo d-bag, no problem just use some jeans!

Maybe Spacey Tracy will throw in his two cents re solo D-bagging waaay back in the day in tejas. He would use an old pair of jeans as the D-bag, attaching the rubber bands to the belt lops for line stowage and packing the canopy into the ass-trunk of the jeans. I think he would sew across the bottom of the legs to make the d-bag proper closed, but would leave the blue jean legs attached so that he could tie them around something on the little towers he was lopping off solo somewhere in S. texas at the time.

He had some HILARIOUS stories about these episodes and some related epics, the details of which I forget, maybe he'll chime in here, nevertheless, he claimed it to be a solid technique that he used for years. It makes sense.

DT

Freefalling over hard earth at 100'??? What is your definition of "live"? FOr that matter, what did you mean by possible?

Freefall chart:

Freefall Time (sec) Speed (mph) Distance Fallen (ft)
1 10 16
2 31 62
3 51 138
4 70 242

P.S. Always use a pilot chute. And never trust someone to PCA you without the PC!!!

what do you think my definition of 'possible' is?

im not going to do it, but with a small canopy, 46"pc, 9' bridal, a -PIN- rig, i think one would live. and by live i mean you will live.

ps- i doubt vents would matter at that point. but they wouldnt hurt, well, maybe they would make the canopy heavier...

PPS- im not going to do it. and havent

weak.
... shovels!

your the flatlander with something around 100 SLs... you should do it.

so this thread hasn't really made any progress.

i'm seriously wondering why people want to not use a pc on s/l.

Oh... someone said that they needed to clear a fencem and thats why you were trying to get rid of PC for SL jumps...

solution- buy a blackjack with zp

The only real answer is "because they want to."


When I first met Dwain Weston, he was talking about throwing aerials from under 200'. I asked him "why would you want to do that?" and he looked at me kind of funny and said "why would you want to BASE jump?" Same answer: just because I/you/they want to.

ahh!!!!

dont get mad at me... i think you should do what you want.

im just saying that if you dont have to clear a tree or fence or whatever, then there is no point and its not worth the risk(to me) to do a SL without a PC.

in those few situations were you need to clear something... double that shit up and do it right...

and have a blast.

sorry, i was not bashing it... just answering the questions in other thread. . . .


dont go in.

fair enough tom. point made.

i'm with calvin too. no bashing, just curious.

have fun. don't die.

I love confused young men.

cincy sucks huh? i qoute...

"This is a bit out of my realm of comfortability"
-M.G.
haha, remember that on the twin?

last time you were here was my first weekend jumping.
ever plan on coming back??

Yes I do and if we go SL off anything, I'll leave my PC on. I can read all about people having done SL's without them but I still haven't been presented with any ideas that would make jump without one.

But then again, I met my woman in an emergency room after she slipped on her own sweat on a strip club's stage and fractured her elbow. Bless her heart, she has no dancing skill, but she can sew a sweater quicker than a cat can catch it's tail and is a hell of a good cook. Fat as she is, she still the one.

PC off Static Line Jumps

Maybe this thread was started because I have talked to Hydoguy recently about removing my PC for curtain jumps and have all SL’ed so jumped recently without one.

Firstly let me start by saying my PC (usually my 48zp) goes on about 90% of my SL jumps. It goes on every jump unless I believe it will cause me more problems then it will solves.

I fully understand all the arguments for leaving a PC on and trashing PC’s (I also have an old, repaired 48 kept for SL only) is acceptable to me if it is not going to course me an additional problem.

I have had an Electrical Tape SL break early. I got a 3sec canopy ride from 240ft. I had a 46ZP PC on and was very thankful for it. I changed to break cord after that jump.

I have also very recently had an unexplained low opening on a 173ft E SL. I again had a large PC (48zp) on. The friend at the top said it looked from the top like it went right, but to me it felt like I freefell it and I only got a 4sec canopy ride (less than when I freefall). Again maybe my PC saved my life. I was using 2 pieces of break cord.

I do not do many none PC SL’s but the jumps where I have removed my PC are where the need for forward speed / flight performance / glide ratio of my canopy out ways the risk of jumping with no PC. You all know from skydiving the difference a collapsible PC makes to your glide. I am working on that for BASE but do not have a reliable system I like yet.

Examples of PC off SL jumps:

150ft B, a construction site with nasty stuff under the exit point and a spiky fence that NEEDS it be cleared. I didn’t believe I could clear the fence with a large PC on and not clearing it was unacceptable. I jumped it with no PC, I flared and lifted my feet to clear the fence. Fun Jump!

Small E, with a long rocky hillside to out fly. I didn’t believe I would clear the whole talus with a PC on. I have now out flown it with no PC, so next time I will SL it with my 36 f111 and if that works I will jump it with my next size up and so on. I would like my PC on but not out flying it would put you into big rocks and power wires.

I am paranoid when I jump SL with no PC, but in certain circumstances it makes a jump do-able where refusing to jump without a PC would mean not jumping. The good thing about BASE is it is a free sport and we all jump as we wish, to the level we wish. You might not all like it and I RECOMMEND IT TO NO-ONE but these jumps were very worth it to me.

My SL set up with and with out my PC is the same and more than likely the same as most of the rest of you.

I use the break cord APEX BASE sells (80lbs). I’m sure you can get it from other places but it is real convenient for me to get it from them.

I always tie in with 2 loops.

If I have the option I tie in tight to 2 separate loops on my bridle
(see APEX SUPERBOWL set up)

If not I tie in one tight and one loose.

I adjust my bridle length depending on my jump.

I use ‘carry with you SL’s on illegal jumps, unless I feel it would snag

I tie in as short as possible to lower the snatch forces on my break cord

I undo my pin and riser covers

I prime my pins again to lower the snatch forces
(I want my container to open and my pack job to lift with minimum force possible, thereby giving the break cord the best chance to stay intact)

On legal jumps or places I will be returning to the exit point I set up a stay behind anchor and retrieve it later.

I am paranoid about mine and my buddies bridle routing.
(Arms, feet, snag points catching your bridle or PC are all bad)
(sometimes the best way is to get the last jumper to lightly hold the bridles / PCs, of the other jumpers clear, extra safety is never a bad thing)

I push off just enough to clear the object to minimise the pendulum effect
A light push off here is better than dropping straight down as a canopy always drives forward a little. Adjust this to the jump, under hung / large ledges might mean a running exit is needed (scary on a SL jump be very very paranoid about bridle routing)

You are static lining so chances are you are lower than normal, when you release your brakes let them up slowly to minimise the canopy dive. If you practice this you will see you will fly further from the object on all jumps if you let them up slow. If it is low 130f and below consider a shallow break setting and not releasing the brakes. Land on rear risers. If it is real low 100ft or below adopt the PLF position (you did learn how? Right) as you step off the exit and leave the brakes and risers alone. At this height nothing you do will help just let the canopy do its thing.

Lowest by me so far: 90ft (SL attachment point height) onto concrete.
A Fox 243, ZP, V-Tec, Multi

It landed hard!

I have also jumped 98ft onto grass on my MOJO
(I don’t know if this was a lucky jump or repeatable, I was still using electrical tape and thought it was higher)

120ft onto concrete was done by 3 of use a few weeks back
2 vented canopies and on not, all were acceptable rear riser landings but the vented canopies defiantly had better pressurisation on landing.

Gald to see you chimed in!

Not sure what exactly happened on that low 'E' jump, but I would go as far to say the PC did help out. As for the 120' over concrete, we all PLF'd but could of stood up (Two vented canopies fully pressurized, unvented had closed end cells). Double break cord setups tied very short to the pins, carabiner clipped to Toyota. Great jump!

DW!!!!!!

I remember the umpteenth time I met DW.

TB:"Bridge there, you haven't jumped it. No gear. Bad luck. You miss out".
DW: "You've got some crap in your car, I know it".
TB: "All I've got is a shitty water rig with no spare pilot chute".
DW: "Just make sure you hang onto that bridle - I trust you ".

As he steps off I call out, "shit, I've dropped it".

He appreciated my sense of humour.

I've BA another person off a building.

Don't know about you, but I would not trust ANYBODY without a P/C as a minimum.

Consequence: nil deployment.
Reward: I can't think of any. Maybe you won't damage a pilot chute or you are testing the trust and/or skill level of your mate?????

But I'm just a flacid appendage I guess....

p.s. BA is a bridle assist.

I agree completely, If I can have a friend at the top and can't SL it I would D-Bag it. I see no reason to PCA with no PC. That would just put a huge amount of necessary pressure / responsibility on the PCA'ing friend. Imagine how he / she would feel if they dropped it an you went in.

SL'ing with no PC is all my fault, I have control

PCA'ing with no PC is still all your own fault (you jumped) but your friend has full control.

Scary


Greeny

quote]what do you think my definition of 'possible' is?
Since when did this forum become www.BASEJumping.psychologist.com???

I was asking your definition of live? Quadraplegic? Full functionality?

When you say possible, under what circumstances (conditions, configurations, etc)?

r.e. the vents, they either help or not. Your thoughts? Why?

Since when did this forum become www.BASEJumping.psychologist.com???

I was asking your definition of live? Quadraplegic? Full functionality?

When you say possible, under what circumstances (conditions, configurations, etc)?

r.e. the vents, they either help or not. Your thoughts? Why?
live meaning your not dead. and by possible i would say that a jumper with 200^' f111 vented canopy(pin rig you hosers) and 46"pc packed slider off with no primary stow, nose wraped around plackjob, no tailgate or other reefing, jumper exit and fall in feet down position with thrown up PC would walk away 50% of the time. thats just a guess.

vents add a little weight to parachute (extraction-line stretch time), no matter what size. but if they are there, the canopy is not just pressurised faster, (even with vents, it would not be flying at 100' FF) it is a larger (if slightly) projected area, as in the first stage of open slider down canopy, its essentialy a round. so i dont know about vents/no vents.

Calvin,

Give me vents, ZP top skin, 48zp unvented PC
Let me preinflate my PC on a 4ft bridle
and I'm in, you will survive

but I don't want to just survive I want to walk away

so I am going to be chicken and ask for an extra 20ft

120ft should be repeatable!

but i still need to work down to it 160ft is my lowest FF and I only have 3 jumps off it so far.

Greeny

my lowest is 180'

dagger 222, 42" unvented, warlock (pin) rig, plenty of time. well, if 4 seconds is plenty of time.

------------4' BRIDAL!!!!!?????????????????

dude, no, 9'. 9.

even in feet down position, your wake will effect a PC.

Why do you say that? What is the purpose of the 9' bridle? How does it fulfill this purpose on a go and throw?



How long is the burble at time zero (which is when you pitch at those kind of altitudes)?

you sleep as much as me obviously.

a burble starts if an object is moving. period. i agree it will be much much less at zero airspeed, but the risk is not worth 5' in my opinion.

the length of the burble? i dont know.

the burble is zero at time zero, but that does not matter. from zero time on the jump to line stretch on the canopy is at least a second. the PC wont stay at exit altitude.

i would guess that a 4' bridal and 9' bridal would produce very different pull forces in the first 30' of a jump. no matter the jumper postion.

this along with the no PC SL scare me.

i never thought of myself as a conservative jumper when it comes to rigging. (packing in 15 min? my good one might be 20mn) but hey, gear risk for a jump like that does not make me wet.

In my opinion;

The real danger on an ultra low freefall (I'm thinking sub 200' freefall, here) is pilot chute hesitation. Hesitations, by their nature, are somewhat random.

Predictability ought to be the main goal of an ultra low freefall system.

Decreasing the length of the bridle, and preinflating the PC removes the unpredictable element of pilot chute hesitation. Done properly, you ought to be able to leave the exit point with a PC that is already inflated, at bridle stretch, and pulling.

I'm not saying this is a good technique for everyone, or for standard use. But Greeny is interested in pushing the limits, and he has specific gear custom tailored to these type of jumps. His canopy is unique, his techniques are good, and he's tailored the entire system (and his procedures) for ultra low deployments. He's doing relatively large amounts of repeated practice jumps in a relatively short time, and dialing in the system.

Given his circumstances? I think he can find useful techniques and gear modifications that simply don't make sense for any other application, but that will work for him.

Calvin speaks of theory.
greeny sounds like he is building experience.

that is the point of science experiments; collect data to confirm or refute theory.

greeny: good luck!
Calvin: sew up a 4 ft bridle. attach a pilot chute. secure it to your back. preinflate the pilot chute. get pulled on a skateboard, jump into a pool, etc. and video the results!

already planned the tests man. i was thinking more doing my rope jumps (i have a computer-linked load cell), so i can measure pull force and stuff.

and totaly theory.

greeny man, if your really doing that stuff that low, thats sweet. i really want to see footy of that and get your results. i dont want to do it, it just fascinates me.

i kinda dissagree.

im weird and i dont really believe that PC hesitations are random. i think they are only caused by the jumpers wake(burble)

a 4' bridal, (in my opinion) would make these 'random' hesitaions a lot more frequent.

we should be testing this stuff on a rope jump...

Negative. I've tested PC's with a 9' bridle and a very small weight at the end, which ought to have virtually zero burble, and still seen occasional hesitations. I'm very convinced that there is more than that going on in a PC hesitation.

Busy today will try to post video ect tonight / tomorow

Greeny

hesitation as in the PC does not inflate right away?

or it does not have ful drag right away but is fully inflated.

It does not inflate immediately.

ahh... well then.

i withdraw my disagreement.

thats why 4ft bridals,special pc tecniqes and exit possisions can be made to make it more safe

you dont even need to shorten your bridel to do that but in the low envioment you rather want the 5 extra feet below you than on top of you..

greeny has dream gear for jumping in the low envioment,most others wouldnt fine tune their gear like that,but then again they wouldnt go that low..

i still think that 4' bridals are a bad idea.

the burble comes into effect. it has to.

i will test it at potato this summer. rope huck style.

the thing is that you place your pc outside the burble as you exit in a way that it already is inflated as you start faling away,then it only need to build up the force that you have adjusted your pins to pop at..

I do agree that used in a wrong way its bad juju

I have a hard time with discussion of a burble in zero to low airpeed conditions. The burble created, if any, in these low jumps is so close to the jumpers back that a PC released at arm stretch would have a very hard time getting "caught".

I think what is often referred to as burble effect is more times than not an actual bridle/pin/velcro hang up. This clears as the airspeed increases and looks like a PC caught in the burble of a terminal freefall.

now if you got over your aversion to s/l...
exit an antenna s/l. wind at your back. you can see the tied off pilot chute inflated already.

now have a tail wind exiting from the ironwork of a bridge, holding a shortened bridle with a pre-inflated pc. where is the burble? in front of you! it is a tailwind!

if you customize your gear to have very light closing forces, you will likely drop away from the pc and NOT tow it very far. by the time you build up enough speed to have a significant burble above you, the pc is long gone.

o.k.
it is just more theory. (but I trust greeny's experience...)

 

The above are keys to doing lower margin of error activities more safely! Consistency, and minimal variability.

Now imagine this conversation regarding a 100ft freefall??????

p.s. regarding the technique of pre-inflating by waving the p/c around: be very wary and careful of bridle / pilot chute / hand entanglement. It does happen. Especially when the conditions are a little windy as this will add a third dimension of possible error inducement.

R.e the underarm throw, be very wary of bridle routing.

I am sure you are considering these anyway.

Regarding object turbulence, it starts as soon as a mass starts moving through the air. By definition, when the mass moves through the air, it displaces air particles and they have to go somewhere and do something. At lower air speeds little swirling eddies begin to be created because the particles are pushed rapidly to the side of the mass. They then want to fill the void (vacuum) that is created behind the mass as it moves through the air. This is the reason why p/c get stuck behind people's backs.

At lower airspeed the strength of these air movements is less than at higher air speeds and they cover less area (i.e. the body induced burble increases its volume as the mass increases its descent rate). But the affect is still there.

Watch a p/c as in inflates using the techniques you are discussing. There are two main reasons why it does not anchor better/quicker/more symmetrically than it does: one is the lack of initial tension and pressurisation, and the other is localised turbulence induced by air movements around BOTH the exiting body (which are caused by the body moving through the air) and the object (which are caused by air moving around the object).
The first reason can be caused by technique issues (unsymmetrical throw, offset throws, improper location and placement of bridle and p/c materials during the throw, etc), and equipment issues (manufacturing quality, wear and tear of gear, etc).


If you consider EVERY single variable and take the right corrective action, your ability to safely perform low freefalls increases.

Thanks for posting the info and your experimentation.

I think I remember watching that canopy surging backward on opening when you were jumping during the "Yuri Incident."

Did you ever sort that issue out?

My canopy was built as a specialist low freefall canopy; it was never intended to go past 1 sec delays. When you saw it being jumped there it was also set in excessively deep brakes, which have since been adjusted.

Vents on most canopies have been sized to give you a balance between pressurisation on all delays and not driving backwards excessively on any. Mine was designed around a 0-1sec delay only.

Before Todd built the canopy for me he told me if I took it past a 1 sec delay it would back up on opening. This backing up is caused because so much air enters the canopy through the enlarged vents that once the canopy is full pressurised the extra air still coming in has no where to go but out of the nose. This air rushing out of the nose is what drives the canopy backwards.


Sub 200ft freefall (instant delay) & Static line the canopy is working great, it is both pressurising and transitioning from open to flying very fast.

Greeny

LOOK WHAT YOU GUYS DID TO A SUPER LOW JUMP NEWBIE/MORON!!!!!

email to me-


i set him straight, i told him that you have be at least at 600' for this to be a good idea, and heading performance is nil. so he will be ok.