Basejumper.com - archive

It sounds like the main reason we pack in shallow brakes for slider up is that it pushes the slider down with more force and leads to more positive, consistent openings. If you're skydiving your BASE canopy, is there anything wrong with packing in deep brakes?

I'm thinking that in a skydiving environment, it's okay (probably even preferred) for the opening to take more altitude. I'm also wondering if it's possible to work on your custom deep brakes in a skydiving environment. I guess you'd want to account for the altitude difference, but if you're customizing them for somewhere like Moab (4000ft MSL) and you jump at a dropzone near sea level, then a normal hop and pop would put you in about the right place. You could still confirm your custom DBS off the Perrine before taking it off a solid object, but it could save a lot of time.

Its "ok" for skydiving but be aware of what might happen... In Slider up, Because you are now routing the control line through the keeper ring, you are deflecting the tail much more now than if you are slider down and the control lines are outside of the keeper ring. Because you are now deflecting the tail much more, the deeper your brake setting is the more the tail deflects...If you have a very deep custom setting this might lead to so much tail deflection that you might open with a full stall. But hey, Its skydiving.. just cut it away.

And its super hard to appropriately set your custom deep brakes while skydiving because you don't have a reference as to what your canopy is doing and how its performing while yarding on risers from the sky. You really need someone to be above the canopy while you are doing your drills to ensure the canopy is responding appropriately. Snake River Base Academy goes into detail about how to set your deep brakes and will help set them at the bridge, while also practicing your object avoidance drills. Highly recommended to all who want to "appropriately" set their custom settings.

Yeah, I know about the course and I'll probably do it at some point. For now I'm not trying to set my custom DBS so deep that routing the control lines through the rings would make the difference between stalling and not stalling. I just want to set it somewhere deeper than the factory setting, but a good distance from the stall point. There are plenty of people doing SD jumps with factory DBS and I'm pretty confident that I can do a better-than-nothing custom DBS by myself. You can't really tell how fast you're moving in the sky, but you can feel when the canopy starts to stall. It's just an idea I had. I may play with it in the sky a little and see how it works. When I want to dial my custom DBS in deeper, I'll probably look into the course.

It's a common misconception that setting your custom deep breaks is setting them to the point of stall...and that's wrong. It's actual quite opposite.

Good Lord man, just go jump it and see what happens. If it 'stalls' on you, which it won't, just release the toggles.

I've jumped several times in a BASE environment with a stall.
Stupid feeling actually, but no problem to correct it with toggle release. Nasty surge though

upd: The jumps were slider-down

Maybe your DBS are set too deep? Or too much of a tail wind?

Nah, it was due to line wear. Dacron stretches. A and B lines are the ones that get the highest load, thus they stretch the fastest. Which changes the wing profile closer to a stall. You can still jump without a reline for some time, just that your middle setting become deep settings.
Oh, and you can use this if you plan to open facing the wall

You also lose a lot of altitude, so on a low static line (or low pull), it can put you into the ground.

Yeah, very true, sinks like a round.

Regarding only the part of your question about DBS being safe in the skydiving environment, Sigma Tandem Reserves are designed and packed with the brakes set so deep that it is common for them to "Rock and Roll" as the canopy stalls during opening. As someone else said, you just release the brakes and go about your business.

im happy with my DBS in no wind conditions, without the worry of tailwind. i set them a bit too deep in twin, to where when jumping without a tailwind, i had just a hair of forwards speed, but with anything more than a few mph tailwind i begun opening into backsurging stalls. i lengthened them a bit after this, found the good forward speed sweet spot (in no/low wind conditions) and i will ONLY jump in my deep break settings off of solid, slider down objects. everything else, i pack in shallow brakes.

Why did you set your deep brakes to account for a tailwind? When do you plan to use custom deep brakeg with a tail wind? Or maybe I'm misunderstanding you.

With a tailwind of much strength and a near-stall-point setting on custom DBS, sometimes you can get what is called a "gust-induced stall" where the canopy tends to collapse because the airspeed of the tailwind blowing over the canopy is more than the forward speed of the canopy relative to it. I.e. no lift generated by wind over/under the canopy from nose to tail, thus the stall/backsurge.

I think samadhi understands that. I think his question was more asking what object with a tailwind would you jump with custom DBS? If you have a tailwind, you should just use factory deep to prevent a stall if you're jumping an antenna or something similar.

Someone much wiser than me informed me recently that density altitude has no effect on opening stall characteristics.

How often do you jump a solid object with a tail wind?

hmm this one is new to me. in my experience, while playing with brake settings, is the shallower the brakes the slower the openings (all slider up deployments.) even with our tandem canopies where i work. we have a 370 a2 that will take 2000 feet to open if you don't bury the brakes as deep as possible during deployment. and inversely a 350a2 that will snap open on you if you don't pop the brakes and let em go as soon as possible...deeper brakes opening both canopies faster.

yeah I get that. But anything with a tailwind and I'm in shallow brakes (antennaes) to prevent the stall surge like you say.

The tailwind negates the need for deep brake settings. The canopies forward movement is out stripped by the wind so even in the event of a 180 object strike is impossible.

i dont alan, thats my point. the ONLY time i will jump packed with my custom DBS setting is on a solid slider down object, most certainly with no tailwind at all. if im jumping an antenna or soemthing with a tailwind, i pack with my shallow settings.