BASE Canopies

[TomAiello 25]

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It is pretty much uncontested that the multi has never been known to cause problems.

See: Lukas and Per in the BLiNC technical archives.

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From detailed analysis of video, we can see on alot of Team Bautasten's jumps that the multi seems to work poorly in crosswind conditions. Even with what seems like totally reasonable body position and acceptable pilotchute movement, the mutli is causing asymmetrical loading on the canopy resulting in very bizarre 180's.

I'm pretty sure the Swedes ended up removing their Multi's altogether.

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Tom is very, very, very much in the minority that venting is not for beginning jumpers.

This may be a matter of perspective. As a PDX guy, you're probably exposed to more BR thoughts on the matter. In general, the CR thinking is opposite. I don't think it's fair to characterize me as "very, very, very much in the minority". I can think of at least six jumpers with more than 400 jumps (including a major gear manufacturer) who are also in my "minority."

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You'd be beyond reckless to take a new rig out and jump non-custom brake settings

I could not agree more. It scares me that so many people are doing this, and that some manufacturers don't tell people to customize their deep brake settings.

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ALL gear manufacturers INSIST that jumpers must customize their brakes.

Not true. BR has removed all suggestions for DBS customization from their documentation and gear. When I inquired as to the reason, they responded that the bottom skin vents created "weirdness" with deep settings, so they had removed their factory "deep" setting, and were shipping all canopies with the "shallow" setting only. What scares me is that they didn't even tell people this, they just started shipping shallow braked canopies to new jumpers--with no notes on customizing DBS, and no instruction to do so. Worse, CR followed suit, and now ships Blackjacks with only the one "shallow" brake setting, rather than a "best guess" custom DBS they used before (fortunately, CR does include a note on DBS).

I believe that this statement, in the BR owner's manual, reflects their view on jumpers installing their own (gasp!) customized deep brake setting:

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Modifications

Do not make and/or do not allow anyone to make modifications or “improvements” to this equipment. We recommend returning any equipment for repairs or service to Basic Research.

This thread has another good illustration of BR's "no DBS" policy, and it's impact on new jumpers (this guy didn't customize his brakes because it would have been "against the manufacturer's recommendations" to do so).

I don't know about Vertigo, but the only manufacturer that I know tries to customize DBS based on body weight is Morpheus.

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if you set brakes too deep on both and jump, the results are going to be equally bad.

If you set the brakes for minimal forward on a canopy, then cut vents in the same canopy, and jump it, it will backsurge on opening. With vents, you can be faced with a choice between surging forward (what BR chooses to do with their canopies) and surging backward. While I feel that, for me, the riser responsiveness gains of secondary inlets overcome this problem (I can often pre-empt the surge by applying early riser input and getting a response), I do feel that a beginner should have a little more time to grab the risers. It's a bit like jumping into an already moving car, and trying to avoid the crash it's headed for. With an unvented canopy, you're driving a big truck, and it's going 5 mph. With a vented canopy, you're driving a highly responsive sports car, but it's going 20 mph. I'd rather see a beginner driver in the slow truck.

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a vented canopy still pressurizes with brakes too deep, while an unvented one just turns into a big jellyfish over your head.

A vented canopy with overly deep brakes backsurges on opening. I'd rather see a beginner "jellyfishing" straight down than backsurging into an object.

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There are many experienced jumpers who have sold off all of their unvented canopies and now jump only vented canopies.

And I am one of them. But there are many experienced skydivers who have sold off all their F-111 PD 9 cells--does that mean that students should be jumping VX's?

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Recommending unvented canopies to new BASE jumpers is like recommending a car without seatbelts to new drivers.

I tend to think it's like recommending a big truck, rather than a racy sports car. The sports car is cool (like a hot swooping canopy), and everybody wants one eventually, but you're probably safer to start in a big slow, simple truck (like student skydiving gear).

Hey Doug, do you feel like we've rehearsed this show, and are now giving it as a performance for the benefit of the skydivers at DZ.com?

[humorous aside]

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If you jump gear without custom brakes, you are rolling the dice on objects where an off-heading could result in object strike.

"They just used to open facing the cliff--and we all just accepted it! We just though, oh yeah, that happens, you just have to be on it."[/humorous aside]

Edited to illustrate that BR is giving a "no DBS" recommendation.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[TomAiello 25]

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I'm not sure I want a fast flying canopy for a first BASE canopy

Sorry, now I'm just thinking aloud.

If a canopy can fly both faster and slower, and glide both steeper and shallower, what is the downside?

It's not too hard to grab your toggles and hold the canopy back. In fact, it's standard practice on all BASE approaches (with any canopy) anyway. If you're going to be flying in half brakes anyway (and you should be), what is the negative of having more control range available on both the top and bottom end?

I guess the downside might be that you would mis-use the greater range of the canopy--same reason you don't give a student a Stiletto. Let me think about that a bit.

Hmmm. This is starting to sound like a conversation that Doug and I had in Amsterdam a while back. Maybe the Flying Dutchman will pop in here on a bicycle in a minute...

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Faber 0]

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You are also correct that going deep slider down can blow toggles (I use a custom pin setup with the toggles in part to alleviate this problem).

Do you have a pic? i cant se this for me..

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Many of us believe that it is possible to get a better landing using one riser and one toggle, versus throwing away the second toggle altogether and landing both rear risers

What did you do Tom?Know there were a slider,but did you cut both?

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Remember, we set our brakes custom so that, when we open, the canopy is (ideally) stalling, falling straight down. Why? So that, if we get a 180, we can turn away from the object (without releasing brakes) using rear risers, rather than having lots of forward speed on opening (brakes too shallow) and, on a 180, flying into the object even before we can do anything to turn away.

Can you tell how you do this?Is it good enouf yhat i feel good or does i need one more to watch?

Thanks for this info.It helps me alot.

Stay safe
Stefan Faber

[TomAiello 25]

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Many of us believe that it is possible to get a better landing using one riser and one toggle, versus throwing away the second toggle altogether and landing both rear risers

What did you do Tom?Know there were a slider,but did you cut both?

I kept the right toggle in my hand, but flare on both the rear risers. This was the technique I learned when I first started jumping, and I haven't re-visited it in a while, but it seemed to work out ok for me.

In general, the people I have heard referring to "keeping the toggle" were referring to this technique.

Doug, have you practiced landing with an actual toggle stroke on the other side? I tried that one weekend, ate it about three times, and gave it up. I'd be curious for tips on how you manage it.

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Remember, we set our brakes custom so that, when we open, the canopy is (ideally) stalling, falling straight down.

Can you tell how you do this?Is it good enouf yhat i feel good or does i need one more to watch?

Case in point. Many people are BASE jumping without customizing their DBS. BASE manufacturers need to start (or resume) including DBS instructions with their gear.

Read this from the BLiNC Technical Archives.

About halfway down I've posted a common method for finding DBS on a non-vented canopies. Note that following this method for a vented canopy will likely yield a DBS that creates opening backsurge. Read the rest of the thread, too. Dwain is perhaps the world's best BASE jumper, and his strike avoidance technique is the best one I've seen.

The best way I've found for identifying good DBS on vented canopies involves sewing in multiple brake settings, and making a bunch of jumps off a friendly span while switching between them.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[favaks 0]

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Not true. BR has removed all suggestions for DBS customization from their documentation and gear. When I inquired as to the reason, they responded that the bottom skin vents created "weirdness" with deep settings, so they had removed their factory "deep" setting, and were shipping all canopies with the "shallow" setting only. What scares me is that they didn't even tell people this, they just started shipping shallow braked canopies to new jumpers--with no notes on customizing DBS, and no instruction to do so. Worse, CR followed suit, and now ships Blackjacks with only the one "shallow" brake setting, rather than a "best guess" custom DBS they used before (fortunately, CR does include a note on DBS).

If this is the case, what they're doing is just "WRONG". When I got my Fox VTEC, I was told the manufacturer DBS is customized optimally for the given wingloading and canopy size. Because of this, I didn't customize my own DBS. I guess I have been living on borrowed time.

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If you set the brakes for minimal forward on a canopy, then cut vents in the same canopy, and jump it, it will backsurge on opening. With vents, you can be faced with a choice between surging forward (what BR chooses to do with their canopies) and surging backward

How much of a forward and backward surge are we talking about here? Are these proven phenomenons or just mere speculations?

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The best way I've found for identifying good DBS on vented canopies involves sewing in multiple brake settings, and making a bunch of jumps off a friendly span while switching between them.

Where do you recommend i sew additional settings from the current one? I'm thinking of 2 additional ones. one is 3 inches below, and the other is 5 inches below the factory installed one. What do you think?

I'm so pissed!

favaks

[TomAiello 25]

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I was told the manufacturer DBS is customized optimally for the given wingloading and canopy size. Because of this, I didn't customize my own DBS.

Deep Brake Settings need to be customized for every jumper. The brake setting for a particular canopy needs to be adjusted based on the suspended weight. (Minor differrences in CG can also have some effect on brake settings).

It is impossible to set a standard brake setting based solely on canopy size.

BR sets the brakes on their canopies based on their "ideal" wingloading. In general, I've found that the single brake setting (the shallow setting) that they ship canopies with is set for slider down openings with a wingloading around .7. Obviously, if you use this brake setting with a higher wingloading, you will see opening surge. If you use it with a lower wingloading, you can experience deployment stall (and opening backsurge with a vented canopy).

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How much of a forward and backward surge are we talking about here?

That totally depends on where the brakes are set. My experience has been that my best setting for an unvented canopy creates a backsurge of approximately one half canopy length when used for a vented canopy.

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Are these proven phenomenons or just mere speculations?

Proven phenomenon. I have very good video of backsurge on both a Blackjack and a Vtec FOX.

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Where do you recommend i sew additional settings from the current one? I'm thinking of 2 additional ones. one is 3 inches below, and the other is 5 inches below the factory installed one. What do you think?

I started out by setting mine at plus and minus 3 and 6 inches (so, five total settings) from the factory settings. It's probably not necessary to put the lighter settings in, but I'd try setting them about at three inch intervals.

Are you familiar with the effects of tail (and head) winds on deployment stall? It can become important with deeply set brakes, mostly if you are doing low, wind-through objects with a tailwind.

A few other places to look for information on DBS:

Brake Settings thread from BLiNC Technical Archives. In particular look at the comment from Adam Filipino which includes the following:

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What this all means with respect to your questions is that unless the deep brake setting was custom placed for you by either the manufacturer, or at your request after experimentation, it may have no relevance to the actual deployment brake setting you need.

Another comment from Adam is in this thread.

Customizing your own DBS is mandatory for slider down BASE.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[favaks 0]

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BR sets the brakes on their canopies based on their "ideal" wingloading. In general, I've found that the single brake setting (the shallow setting) that they ship canopies with is set for slider down openings with a wingloading around .7. Obviously, if you use this brake setting with a higher wingloading, you will see opening surge. If you use it with a lower wingloading, you can experience deployment stall (and opening backsurge with a vented canopy).

I weight 140 naked. My exit weight is about 170. I own a Fox VTEC 245, so I'm loading it at .7. Since this is the "ideal" wingloading according to BR, should I attempt to customize it further? Maybe this is a question for BR. Still, is this the "ideal" brake setting for slider up or off? I guess the best way to find out is try it out myself.

The ultimate question is, with VTEC, is there a way to set the brakes so that there is minimal or no back surge, relative to non-VTEC. If there is none, then the penalty for jumping VTEC is with very deep brake setting, you'll get a back surge, and with shallow settings, you get a forward surge. The best one can do is compromise? All of a sudden VTEC just doesn't sound very appealing anymore.

I'm not very familiar with the effect of tail/head wind. I only jump when there is little or no wind, so far.

Thanks,
favaks

[TomAiello 25]

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I'm loading it at .7. Since this is the "ideal" wingloading according to BR, should I attempt to customize it further?

That's not the ideal wingloading according to BR. It's my personal feel for the brake settings on the BR canopies I have experience with.

You should always customize the brake settings on any BASE canopy. It is particularly important for slider down non-span jumps (where you will have less separation from the object).

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...is this the "ideal" brake setting for slider up or off?

The "new" standard brake setting on Vtec FOXes is identical to the "old" shallow setting on standard FOXes. BR used to recommend using this brake setting for slider up, and a deeper one (factory set 4 inches deeper on all FOXes, regardless of size) for slider down. Now, they recommend using the "old" shallower setting for all jumps. You're going to have to draw your own conclusions.

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I'm not very familiar with the effect of tail/head wind. I only jump when there is little or no wind, so far.

OK, that probably ought to be a different thread. This one has already diverged from canopies to deep brake settings, which is more than enough topics for one thread (maybe I'll try to split this up). If I find the time, I'll try to start it. If not, feel free to start a "what is the effect of winds on openings" thread yourself.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[TomAiello 25]

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The ultimate question is, with VTEC, is there a way to set the brakes so that there is minimal or no back surge, relative to non-VTEC. If there is none, then the penalty for jumping VTEC is with very deep brake setting, you'll get a back surge, and with shallow settings, you get a forward surge. The best one can do is compromise? All of a sudden VTEC just doesn't sound very appealing anymore.

I believe this is the achilles heel of vented canopies. I also think that several people know this, and aren't saying anything about it. Their reasons for not discussing it are their own--I understand that one of them "refuses to discuss the research of this shop with our customers."

Don't get me wrong, I do think that secondary inlets are a major advance in BASE technology. I just don't think that they are the magic solution that so many people seem to think they are (and that they are sometimes marketed as). There is a lot of work that still needs to be done here, and saying that we've solved all the problems seems counterproductive.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Dd0g 0]

Yes, ok, wow. Lots of different items popping up in this thread, most of which I'm really not qualified to comment on. Of course, that won't stop me from commenting. . .

1. Backsurge: while Tom states that this a proven phenomenon based on video analysis (and I'm sure if he says he's seen it, then he has), I think the magnitude of the movement here is trivial. According to Tom, he's seeing around 1/2 a canopy depth movement which he attributes to bottomskin venting. Again, assuming this is accurate, this is trivial.

There are very few jumpers who have ever opened so close to an object that a "backsurge" of approximately four feet would have resulted in an object strike and/or injury with an on-heading opening. Tom is one; I'm another, as are some of my jumping mates.

Seriously, though, we really shouldn't be opening so close to an object that 4 feet of backwards movement is substantive. Too, even an incredibly small wind can cause a canopy to move four feet in any given direction on opening, no problem.

Net net, no jumper has ever been injured or killed due to "backsurge." It may be an interesting technical phenomenon, but I don't see it as being relevant to actual gear choices. DW, who first posited the existence of backsurge (and who first explored the ideas of bottomskin venting in BASE) and I discussed this, and he concurs.


2. The moniker of "Deep Brake Settings" (DBS) is a misnomer. No brake setting is inherently "deep" or "shallow;" just because a canopy has two different brake settings on it's lines does NOT make one "deep" and one "shallow," save (trivially) in reference to each other.

It is quite common to see jumpers using their deeper (which I prefer to "deep" since both may in fact be too shallow) brake setting on slider down jumps and their shallower setting on slider up. However, it is equally common to see that BOTH the deeper and the shallower settings are way, way too shallow for safe use with hard objects behind a jumper. Being too shallow, remember, simply means that on opening the canopy is moving forward with some speed, versus sinking straight down.

There's good video of a jumper in Malaysia suffering the consequences of too-shallow brake settings on a legal building jump. With helmet cam footage, the sound of him repeatedly impacting the building while his canopy surges forward into it is. . . sobering. Too-shallow brakes can kill you.

Conversely, if a canopy ships with one brake setting only, this setting is neither "deep" or "shallow." It just. . . is (kinda Zen-like). It might be too deep (unlikely with most gear manfacturers), or too shallow for safe jumping. In any case, it likely needs to be customized for a given jumper.

Tom's advice both on why to customize brakes and HOW to customize brakes is terribly important. BASE jumpers today die from object strike, for the most part. Too-shallow brake settings are a major - if not the major - cause of object strike injuries or fatalities (this is my opinion, but even if it isn't the #1 reason, bad brake settings always make a bad situation even worse).

Tom is also right that I'm skewed by my locale, perhaps. In Portland, we jump lots of low and often underhung objects, and have been known to do this with "non-optimal" winds. Consequently, we take proper brake settings as a given; I've been jumping a new canopy with brakes too shallow for a few months now on and off, and every jump I am aware of the impact this oversight will have and plan accordingly. To simply not know that improper brake settings are a huge issue is hard for me to understand, but I think it is more common than I imagine given my Portland-jumping roots.


3. In terms of venting for new jumpers, I think Tom and I have as much a difference in perspective as we have a difference of opinion. Again, in my home area there simply aren't any "safe" objects for beginners. So my concept of "beginning" BASE is skewed, certainly. However, in other places in the world I guess folks can flop off easy stuff for years during their BASE career and wouldn't ever really need venting.

Frankly, I'd say this however: if a beginning jumper is poor enough with BASE canopy management that bottom-skin venting is a "complexity" that is hard for them to manage, they aren't anywhere near good enough to be jumping "real" BASE objects. Now that I'm sliding into "Pacific NW BASE snobbery," I'll just stop typing before I get any deeper. . .


4. Landing with one rear riser and one toggle is not too bad. I've done it three times slider down, due to blown brake lines. Never done it slider up, so I can't comment on that. I learned to do it after I blew a brake line jumping in South Africa - a 500 foot to impact cliff with a 2000+ foot canopy flight to landing. So I had lots of time to play with the riser/toggle "flare" before setting up for landing. Once I'd found the sweet spot, I got a MUCH better flare than both rear risers - important on that jump as I was landing on pavement with a slight tailwind.

I'm not sure toggle/riser is "better" than riser/riser, but once I learned both I was able to get a better landing with the toggle/riser setup. Not sure why, maybe that only applies to fat-assed, horny Dogs.


5. Final metaphor (or is it a simile?): vented canopies are cars with anti-lock brakes, unvented are without. Non-ABS is "less complex" and "simpler," but one wouldn't recommend that a new driver avoid the "complexity" of ABS, right? Vented canopies behave like unvented ones, but with a bigger envelope of responsiveness and more options for off-heading correction.


6. I'd much rather see a student of mine have "backsurge" of a few feet on opening with a vented canopy than a snivelly, jellyfish opening on an unvented one (brake settings held constant for both). Why? Simple: jellyfish openings are much more likely to evolve into full-on off-headings; a bit of backstall isn't going to cause anything worse than a strange visual from above, and the need to pop the toggles off quick to get the canopy flying forward.

In general, I look at every tech element mostly in terms of how it will affect off-heading percentages, and how it will help or hinder the correction of off-headings after the fact. This is, again, because the majority of jumpers have died from off-heading openings, plain and simple. They are the true "black death" element of BASE, and the more we plan for and understand them, the longer we'll live.

From another angle, we can control almost all other BASE risk factors - but not off-headings. We can minimize them, but we don't fully understand them and they happen to ALL jumpers sooner or later. They are the one great "Russian roulette" element of BASE - many of us have done jumps where an off-heading would have been fatal, no question. Aiguille du Midi in 20+ mph winds


7. Tom knows more about BASE than I do, so listen to him and not me! I'm just a fat-assed BASE canine from the land of dodgy objects and rainy weather


Good thread, Tom. I hope folks appreciate the time and energy (and knowledge) you are investing here. What's up, too sunburned down there to get out and jump?

Peace and happy holidays,

D-d0g
[email protected]
www.wrinko.com

ps: "I am sorry, that is not possible."
Tom: "but we're FLYYYYYYYING down. . . (flaps arms to demonstrate)
Dog: "I have a Norwegian friend. . . "
Dog: "That jump is only safe if you pull the slider down. . . "

+~+~+~+~
But this, surely, was the glory that no spirits, canine or human, had ever clearly seen, the light that never was on land or sea, and yet is glimpsed by the quickened mind everywhere.

[TomAiello 25]

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Net net, no jumper has ever been injured or killed due to "backsurge."

I'm pretty sure this is not correct. I believe there was a wall strike resulting in injury due to canopy backsurge during inflation. If memory serves, it happened in the pre-BASE canopy days, on an old skydiving canopy. While that may have no bearing on the vented/unvented discussion, it does illustrate that backsurge can be a dangerous phenomenon, and has injured jumpers in the past.

I'll dig around and try to locate more details on the incident.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com