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If you could build the ultimate low freefall pilot chute how would it be built?

For low freefall only so disregard longevity, or use in any other application.

Load tapes: how many? mesh only or also on topskin?

Bias vs Block built

size: 48 or 52? Bigger?

Other considerations worth mentioning?

Thanks

Solid object?

What do you consider to be "Low" free fall?

Under 200' or as low as possible. Not that I'll be jumping that low. But if you were to jump the lowest object physically possible and could build a PC however you wanted how would you build it.

Solid objects or not but I guess I was thinking E or A

I guess I'd go 6 tapes, small mesh ring vent for stability while still having zp at the apex. I might even name it something like "nuclear" because it would kind of look like a toxic waste symbol ;)

I'd go for a 46 in size, maybe 48. Seems to be about the size where unless you're able to sprint and pre-inflate, you start to reach the point of diminishing returns for pc inflation time/ distance to enough snatch force to do what you want.

Zp non vented might be a tad faster, but off of low solid objects I'd start worrying about heading performance.

I'm the attached picture, the seams on the ring vent are on block. Most pilot chutes are a single piece of material, so it's hard to say it's really built on block of bias as there are likely more than 4 tapes. I'm not sure that on that small of a piece of material with as many tapes as are present that there is a huge amount of difference in each panel (gore) like on a big round. Someone smarter than me probably has a better answer about that though.

Solid Object versus Tail Wind might affect
one's decision to use a vent, so far I have
seen four different types of vents . . .

Options for Type of Material changes when
you add the caveat of ONLY ONE JUMP . . .

As for Size, I could do a dissertation on the
topic, but the four variables I would want
to know before I answered is the jumper's
exit weight, canopy details, field elevation,
and yes even the expected temperature.

As in the perfect PC for Jesse Hall to freefall
a 150 foot antenna in Tallahassee in Winter
is different than the ideal PC for Tree to
freefall a low cliff in Moab in Summer...

Thank you, I appreciate the response. So basically your saying it already exists and a toxic is the tool for the job. I was just wondering if anyone has any crazy ideas on how to improve on it.

Ok so I definitely wasn't specific enough with my original question

How about 65F at sea level, 150lb jumper with a 225 OSP, running exit off Antenna in zero wind conditions.

48'' F111 works for 43m :) https://youtu.be/gIbBSgBzIwM?t=126

It's weird, almost everything in base has a lot of brand loyalty, but lots of people jumping non asylum gear still love toxics. I think they're fantastic. With your gear, free falling 200 ft and even down to 180 shouldn't be an issue with most standard apex vented pilot chutes. I used a standard 46 for most of my low freefalls.

That PCA 180 looked like it hurt lol nice landing area too

Good to know and thanks for the advice. I have a 42" toxic and love it. so say we change the scenario slightly and now I'm stepping off with an underhand toss PC S folded all the way. would I then benefit from a 48" with my weight and gear or do you think I would still be better off with a 46"?

Also have people pretty much decided that 52" is not beneficial anymore? after reading DW ultra low freefall writeup many times it seems like it may really depend on your setup whether it will help or hurt your opening height.

Sounds like a pretty fucking dumb idea

Its just a scenario but thanks for your input. also are you suggesting people don't jump freestanding antennas in low to no wind conditions? cause I imagine it happens quite frequently...

Also just to clarify once again I have no specific jump in mind. I'm just looking for positive suggestions as to what could be done to build the ultimate low freefall PC. if you have ideas crazy, far-fetched, or whatever I would like to hear them.

All depends what 65F means

ok sorry 65F is 65 degrees Fahrenheit... it has nothing to do with the height of the object lol I was responding to GreenMachine and he asked for specifics on the scenario regarding Jumper, gear, ASL, Temperature. I thought 65F was pretty clear. As far as I believe to FF 65 feet you wouldn't need a PC or any other gear for that matter because it wouldn't help...

If you're only using it once, you could just use a rocket deployment system, maybe with some kind of ballistic spreader for the canopy.

I think the rocket deployment system that Peter Gambs had cost something around $1000 per deployment, but I saw video of him getting full inflation from things that were probably low enough to survive (landing on solid ground) without a parachute.

hahahaha now this is what I am talking about

Any video of this anywhere? I seen that picture a while back. looks like a cool idea but how did it work in reality?

It's not my pics. I would like to see video too.

Yeah I thought he meant feet

Handsome dude.

Extremely handsome!

I have seen guys free falling 200ft with old school 42 inch designs, I've repeatedly done 170 with a Troll 285 and a standard old Apex 48. And I have lost count of the amount of sub 200ft free falls I have seen on old school gear like Mojo's and shit with PCs that were just as old. The Toxic's are definitely a step up in performance due to being constructed on the block. So the gear available is already functional for lower jumps.
That being said, to answer your original question, I would consider a PC built with 6-8 tapes that takes the block into consideration, no handle or cap. If using the pre-inflation technique I would consider using a larger 50-52 inch. I'm not sold on venting large PCs for Go'N'Throws as I don't feel there is enough airspeed to warrant it.
Something I have always been curious about is the pulled down apex of rounds. I do not have a complete understanding of how the centre line measurement affects inflation times but I think this is an area that could potentially be "optimised".
Also worth considering, and something the frog guy touched on, is what other aspects could influence the PCs efforts. Or what aspects would influence opening times and therefore dictate necessary PC performance. Some examples:
1) Canopy weight: For sure size and weight of construction will affect PC performance.
2) Wind Conditions: Strong Tail winds help "pre-inflate" the PC and can lead to higher openings. Not necessarily a good thing on a low free fall where you will probably end up landing down wind.
3) Line Lengths: Shorter lines obviously mean you don't fall as far before line stretch. I believe Greeny optimized his line trims to increase inflation times too.
4) Bridle Length: Obvious.

Personally, on real low, say sub 100ft PCA/SL) I much prefer a headwind.
A reasonable headwind increases the opening height/pressurization significantly and slows things down a lot quicker. I see no reason for this to change just becasue of FF rather than SL/PCA. .

I agree (assuming a non-solid object, generally, although at a certain altitude that almost stops mattering).

I can definitely see Fledgling's point on pre-inflation and tailwind, too. I'll have to play around with that. My preference for pre-inflation has always been zero wind so that the PC doesn't do anything unexpected.

i'd add that i have a lot of gear from a lot of companies... but a few years back Marty built me a really nice regular non vented 48" PC with a single attachment point that i absolutely love for low freefall or go and throws in general. thing works wonderfully.

Just thought I'd post this for people who haven't seen it yet. Lots of interesting pilot chute related stuff.

http://base-book.com/...action-and-inflation

Thank you for your excellent input. I think the centerline measurement is something I am going to further research.

Yes I think there is a lot that can be done to the canopy itself to make it better for low freefall as well. Ive read most of Greeny's ideas on how he has had his custom low freefall canopy built. very interesting stuff no doubt.

yes ive been experimenting with different length bridles on both overhand and underhand throws and having a friend laser topskin from above. (forgiving objects)

Before I start getting low I want to learn as much as I can about all parts of the deployment. Figured I would start with the PC as its arguably the most important and first in the chain. Thanks everyone for their responses, I now have places I can take this info and learn further

Be CAREFUL with that. Shortening the center line too much can turn a good PC into a death trap, because you end up with a "self-collapsing" shape.

All the major manufacturers build in a healthy margin for error, and in theory you could shorten the center line to speed inflation, but personally I'm not willing to play that game because of the potential for catastrophic error if you go too far.

Thanks for the warning. wasn't planning on modifying any myself. just learning more about pulled down apex of rounds and how it applies to the PC's we use. just trying to gain a real understanding of the physics involved.

As Tom said. Be careful with any modifications. A center line that is too long will also delay inflation of the PC. Even if you never mod your PC your research will give you a better understanding of your components.

How will you test it if you're not jumping it? Just wondering, cus it would be interesting to see the effects it causes and it should be something one could do on a worn PC not in use.

yea I am not at the point of understanding to want to modify any of my pilot chutes. currently my goal is what you stated, to better understand the components.

maybe haul a weight up to some dayblazers equivalent to the relative force a pc would have pulling back on it in low to no airspeed conditions and send it off. see what happens with a very long centerline and a very short centerline to better understand?

A shorter center line will reduce the volume inside the PC and thus create a working canopy sooner. Too short and the PC will spill too much air to do its job. How short is too short? In skydiving I insist that people replace their kill line when it has shrunk to the point that it is shorter than the PC center line. But I have seen PCs still working even when the apex had been pulled down level with the skirt which in theory shouldn't work (this was skydiving at terminal).
A longer center line obviously has the opposite effect requiring more volume to fill the PC. I suspect it will also cause distortion of the PC shape as it gets stretched out and result in a smaller effective surface area.
I'm sure there is a standard rule of thumb that is being used here. They have been building rounds for 50 years after all. Something along the lines of "the center line should equal x amount of the radius.
Is a flightsight a possible tool here? I have never even seen one but it seems that swoopers and wingsuiters get all sorts of info from them. Maybe build a package with some weight and a flysight and start throwing it off shit with different PCs.
Also something else you could try to dig up, something I briefly came across years ago but never really looked into. Essentially it said that while the air would fill a round from underneath the passage of air over the outside of a round also had a vital role to play in its inflation. Or in other words the relative wind passing over the outer skin would help pull the canopy open from the outside. Though I suspect this to only really be relevant for the very long rounds back in the day.

Has anyone ever reinforced load tapes on top skin of pc to spring into a maintained shape?

I helped design the system. The initial set up cost per deployment was minimal. Just charging up the gas bottle with a pressure regulator monitoring to get to the required PSI. Having horizontal speed sped up the deployment and reduced the altitude needed for the deployment. In heading tests with H-speed 4 meters was sufficient for full deployment.
About the Ultimate low freefall PC, One often overlooked factor is the weight of the PC. They could be built using much lighter materials.
Face it. It wouldn´t be designed to be a workhorse.
Take care,
space

I have seen PCs in ejector seats that basically looked like an umbrella that you had to compress and lay on its side as you packed it into the rig. It essentially functioned like a spiral spring PC.
I think that the added weight of any "Spring" type configuration would reduce any benefits gained. Pre-inflation before exit would have to be more effective here for hand held deployments.

Sorry I'm late to the party!!! What I like to use for low stuff is a ( 48, Non Vented, ZP, Block Constructed, Lightweight Tape, no hat/handle PC ) Branden from BadSeed Base made mine. Best 48 I ever had......

I was thinking plastic memory shapes.. Not a spring. Something to make sure it doesn't drag before inversion

Yes I understood your intent. I still think pre-inflation would be better than what you are suggesting.

A long time ago I saw a PC that had delrin rods sewn into the load tapes on the top skin to make it "spring" open.

It was a half baked concept and the implementation wasn't particularly good, but I'd be curious to see if someone could develop it further. It's pretty specialized, though.

I made a no mesh PC for faster inflation.
I do not jump enough low object to have a real feedback on it.
Of what I saw it works very good but I have to work on the traction power (apex and size).
To much ideas and not enough time to do everything and jump.

Correct inflation from pre inflation isnt predictable. I've seen a few of my throws roll.
All this would do is help reduce one variable in the extraction process

I like this idea. would be difficult to produce I think but its definitely something worth looking into I believe.

very interesting as well. seems like using something to maintain the shape of the pc is becoming a common idea here. granted it would have to also be a very light material that does the reinforcing.

hmm this is a very interesting idea. overall weight of pc would be lowered dramatically and zero restriction to air inflating pc. I imagine there would be considerable downsides to not having any mesh though. still something to look into for sure.

Balloon tubes for the shape. Of course there are Pros and cons....
Take care,
space

I was just talking to someone about this idea actually...deserves more research for sure.

I dare someone to tie their bridle to the handle of a large, sturdy umbrella and use it as a pre-inflated handheld PC.

haha if this happens please get outside video....fuck

How about this?

Risk is that is the wind catch it by the top the handle could go around by the inside and make the PC almost inefficient.
My design can only be used hand helded and with the mushroom packing or it would not be safe. That's why it cannot be sold, some advantages but not enough safe in case of an use out the recommended conditions.