Brake Setting For Ultra Low

[JaapSuter 0]

Hi,

some people have a third brake setting for ultra-low jumps where they need glide faster than what their DBS would give them.

This brake setting is between your DBS and the shallow brake setting, correct? If your current brake-settings are close together, there might not be a lot of room in between, do you just overlap the bartacks?

Time to talk to a rigger...

[JaapSuter 0]

And while were at it, what do people consider ultra-low in this context? E.g. in what context do you use this third setting?

I recently noticed that my DBS worked great from a 500fter and in LRM skydives, but worked less than ideal from a 180ft PCA. Hence my asking. Admittedly, my opinions are not based on a statistically relevant sampling.

[Faber 0]

As im not jumping slider ups i cant say if my shallow(more shallow than dbs)is the same as for slider up.

I found the more shallow brake more handy at spots were you for some reasson might dont have time to pop your toogles,or at least if im "rusty" so im not sure im fast enough...

Ived freefalled 180ft by my dbs and still landed nicely by toogles,however it were in the end of a sesson were i were really familiar to my canopy and how it flyes.
If i should freefall 180ft tomo i probaly use the more shallow setting as i havnt freefalled that low for some time now,that way i know i can set my canopy down by rearrisser if needed.

The thing is that IF you land on rearriser you want some forward speed=shallow brakes.

IF you want to land by toogles make sure you know how to pop your toogles correct so you
1 dont Hook/surge into the ground as you pop your toogles
2 your sure they get off easily so you dont make a untential turn into the ground as 813 did...

Stay safe
Stefan Faber

[crwper 7]

Hey Jaap!

I've done s/l jumps as low as 111 feet and freefalls as low as 210 feet. I'm sure "ultra-low" is a fairly subjective thing, but for me it starts at about 130 feet for s/l and maybe 180 feet for freefall (just guessing on that one). In my experience, that's where very good technique becomes not just really helpful, but absolutely necessary. Not that I'd recommend doing jumps higher than this without good technique. But you already knew that.

On all my slider-down jumps, I've used pretty well the same brake settings, so I'd be kind of surprised if it was very helpful to change them for the "ultra-low" environment. In fact, I think it might be more helpful to stick with settings you have the most experience with, as this will help you judge your toggle release more accurately.

I think it's really critical on lower jumps that you release your toggles just right. In my opinion, what you want to aim for is to pull your toggles down quickly just to the point where the line is pulled free from the white loop. Then you want to let them up in a very controlled way. Too slow, and you won't reach full-flight as fast as you can. Too fast, and you give your canopy extra speed at exactly the same time as it surges forward from opening. I've seen one jumper cover 165 feet in a surprisingly short time because of this kind of oscillation. If you let the toggles up at just the right speed, you'll be able to control the canopy's opening surge.

When you say that the brake setting was "less than ideal" for the 180-foot PCA, what exactly do you mean?

Michael

p.s. Dave knows what I'm talking about with the toggles, and maybe can give you a bit more info tomorrow.

[JaapSuter 0]

Thanks for the information Faber and Crwper. I also got some very helpfull PMs, thanks guys!

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When you say that the brake setting was "less than ideal" for the 180-foot PCA, what exactly do you mean?

I had a significant backsurge on opening. It wasn't he accordeon style ripple going through the canopy, but I was actually flying backwards for at least two feet, maybe more. Following that I popped my toggles gently (like you're talking about), and I had an unussually steep flight.

My other 4 base-jumps with this canopy and brake-setting were one second hand-held jumps, and the brake-setting was great, with a minimal amount of forward speed but no stall. I also had a great glide angle and glide-range.

The only thing different on the PCA that I can think of, are that the opening speed is different, and that I was in a more head-high position. The pull-direction compared to a pilotchute was not significantly different. I think my DBS was just too deep for this kind of jump, but that's guessing at this point.

Then again, I only jumped this particular 180 footer once, so it doesn't make a good sample. I'll be going back to it soon, and hope to get some better video footage to see what is happening.

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p.s. Dave knows what I'm talking about with the toggles, and maybe can give you a bit more info tomorrow.

I think I know what you are talking about. You basically want to avoid swinging underneath your canopy like on a swinging-chair. Thanks for bringing this up, because it's not something I often think about consciously, but more something I do natural. I'll discuss it with Dave too.

I think it's better to err on the slower side of letting up the toggles. That will avoid creating the forward surge you mention. That way, in the worst case scenario, you'll get a sinked-in landing with a less-than-powerful flare. Not ideal, but something any accuracy jumper should be more than comfortable with.

Thanks!

Jaap

[crwper 7]

Hey Jaap,

I think I know what you're talking about with the back-surge... I had a couple of jumps off a cliff where I noticed myself sinking back toward the face a bit on opening. Not a good feeling when there's a ledge below you.

Anyway, I've never fine-tuned my brake settings, so the solution in this case was for me to go to the shallower setting (Fox 245 vtec). This seems to work well, but I'm guessing my brake setting is not as deep as it could be for longer delays. It may well be that the reason I haven't had to use a different setting on the short stuff is because I'm compromising on the higher stuff.

Have fun!

Michael

[TomAiello 25]

Was there a tailwind on the PCA?

Wind effects on deploying canopies work in a (rough--not linear) relation to the airspeed of the deployment. So less wind at PCA speed will have more effects (if that makes sense).

A tailwind effectively "deepens" your brake settings, and the PCA makes you more susceptible to it. I wonder if this might have had something to do with the different opening experiences you had.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[JaapSuter 0]

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Was there a tailwind on the PCA?

If anything there was a slight headwind.

We did it again yesterday, now in a noticable headwind. The backsurge was even stronger now. People on top of the S where guessing that I flew backwards close to twenty feet, and saying that my canopy halfway dissappeared underneath the S. This was on a one inch shallower brake setting than the one I previously used, but I'm guessing the stronger headwind pushed me back more than before.

We didn't get footage on this jump, but we're considering to go back soon and get some video solely to analyse the opening. I will use my shallowest setting on the next try though.

I'm a clueless, because my longer-delay openings have been great, on deeper DBSses. I can't imagine the airspeed and wind having that much more of an effect on opening, compared to my other jumps.

Right now though, there's no chance of doing a PCA from a solid object, because a perfect onheading opening would smash me backwards into the object. Not that I should be doing those anyway...

I'll follow-up once I have video that I can analyse.

[JaapSuter 0]

For what it's worth, on a very recent 270ft static-line jump, I had perfect bang-on opening. This was using the same brake-settings as on my most recent 180ft PCA, but there was significantly less wind (zero vs a strong headwind).

We have this opening on video, and there was zero backsurge, and I might even go as far as to say it was a perfect opening with a minimal amount of forward speed, yet no stall.

Maybe I'm making a mountain of a mole-hill, but until I get some video of my PCA jumps, I guess we'll have to wait for a real explanation.

[JaapSuter 0]

Okay, we have a theory that is related to the PCA technique. We'll be trying this out shortly and I'll report back here.

I'd also like to point out that in no way is this backsurge phenomenon related to the fact that I'm jumping a Rock Dragon. I've seen PCA's on Rockdragons that worked brilliantly, and all my other non PCA jumps had great openings. If anything, this is related to the PCA technique, and we'll be testing this out shortly.

Cheers,

Jaap

[jalisco 0]

I'm so confused.

If my dbs is set so that I have almost no forward speed, and I jump in a head-wind, shouldn't I expect to back up, just by virtue of being blown by the head-wind?
Might I also expect that the deploying canopy might be blown backwards more than me prior to full inflation, leading to some rock-back and maybe a little back-surge during the rock-back?

[JaapSuter 0]

Those are all valid points you bring up, and perhaps I'm just over-analyzing. The reason I am a little confused is because the canopy behaviour was so dramatically different on my two PCAs compared to my other slider-down jumps.

I'll jump more, talk less, and then come back...