Sail Sliders

[imported_Tom Aiello]

I've never used a sail slider on a BASE jump. However, I find myself in a situation where I anticipate wanting to soften some terminal openings for a little while.

Does anyone have any tips on jumping a sail slider?

I'd appreciate it. Thanks.

--Tom Aiello
tbaiello@mac.com

[guest]

I think if you need to soften the opening just hold a sail slider out of the car as you drive.

[BASE_689]

I always use a F-111 sail slider when jumping our terminal wall. 2 rubber band wraps as direct control, and I use indirect control as well. Never had a hesitation. Never had a problem with sail slider. Still, I get quite brisk openings with my packings!!! But, as you know, our terminal wall is quite high, and becomes higher if you do a good track. So, unless you pull incredibly low, the difference in height consumed in opening between sail and mesh is a non-issue.
I use(d) ZP sail slider when skydiving my Fox: ZP sail slider seems to give (slightly) softer openings compared to F-111 sail slider.
For your information: I always use mesh slider when jumping our sub-terminal wall (5÷7 s)!!! 1 rubber band wrap as direct control and indirect control as well is used.
Stay safe out there
Blue Skies and Soft Walls
BASE #689

[guest]

I found my Mojo was just great with a sail slider for the first 50 jumps at terminal, then it started to get a bit too soft for my liking.

Now I have a dinner plate size hole in the slider, which is covered with mesh. I haven't tested it yet as we are not allowed to skydive our Mojo's from aeroplanes, but it should be about right. I'll use it on a terminal tracking jump in a few weeks.

For wingsuiting I always use a mesh slider and 36" ZP pilot chute. I always use direct slider control now, as I believe my hardest openings were slider dump related.

I can't imagine ever taking a ZP or partially ZP canopy to terminal track without a sail slider.

/Lukas

[guest]

Tom,

Theres so much variability in deployment that id say theres nothing you can do to gaurantee a soft opening every time. If you are in a 'delicate' situation then think about that. Even with the best methods, you will get whacked bad eventually.

Take it easy...

[guest]

Yea Tom. Take some time to heal first. I like you bro and I'd hate for you to get worse.

Your body has been traumatized 3 times in 20 months with one of them being as close as one can get to the brink of death without going over.

Take it easy for awhile and let them bones heal.

[guest]

I jump a Mojo and I've tried most things: low cliffs, tall cliffs, mesh slider, sail slider, no slider, big pilots, small pilots. With my Mojo I've ended up with nothing but sail slider when I need a slider. For anything more than 5-6 seconds to terminal jumps I have sail and 32" ZP pilot chute. Openings at these delays are always fast and snappy. For less I have a bigger pilot and for 1-2 (3) sec delay I have no slider. I have stopped jumping with mesh slider alltogether. Don't need it, don't want it.

Cheers

[guest]

Tom,

From 287 terminal and sub terminal jumps I have found the following from my own experience in terms of sliders. Openings from softest to hardest:

ZP sail - way too slow for BASE

F111 sail - still too lsow for BASE for my liking

F111 sail with coffee can size hole in the middle - Good for BASE if a slightly higher opening is planned.

Small hole mesh - the best for 8 seconds delay to terminal BASE jumps if you are in good health and are landing just above your opening area. Best choice for terminal BASE!!!

Large hole mesh - good for sub termainal less than 7 seconds. Too unpredictible for comfortable opeings.

Bikini or spider sliders - good for crew, but haven't tried it for BASE - although I would like to...Subterminal of course

I always double stow my mesh sliders and single stow my sails. Rarely do I use the under-the-tail pocket indirect stow - it's redundant if you control the slider...

For you, I would recommend F111 sail - although you should plan on opening higher and anticipate more off headning openings.

Coming over to Norway Tom???

JJ
:-)

[imported_Tom Aiello]

>Coming over to Norway Tom???

Yep. I've got an F111 slider and I plan to make some test jumps off our local tower as soon as my spine doctor gives the ok (probably around the end of this month, when I see him next). I should arrive in Europe around the middle of next month, with Norway as my first stop.

Tell Feral to save me some smack!


--Tom Aiello
tbaiello@mac.com

[imported_Tom Aiello]

I'm going to post this here because it was a thoughtful (and knowledgeable) answer I got via private email from an experienced but controversial jumper. I am intrigued by his logic, and would like to see if anyone has any response to it.

...

I use a sail slider on slider jumps for a very simple reason:

The sail acts on the wind in direct proportion to the windspeed.

If I'm at the low-speed end of a slider-appropriate jump, there is little wind slowing the slider's descent toward the links, so it doesn't take any longer to go down.

If I'm at the high-speed end of a slider-appropriate jump, the sail comes down like it does on a terminal airplane jump -- faster, but still doing a better job reefing the opening than a mesh slider.

Bottom line in my experience: All pluses, no minuses because if you're low enough for the possible difference in slider-down-to-the-links speed to matter, then you should probably be going slider off anyway.

...

This reasoning sounds pretty solid to me. So solid that I'm going to try some test drops (and maybe jumps, later) to compare opening rates with sail and mesh sliders.

I'm glad there are still knowledgeable jumpers questioning the received wisdom (and sharing their thoughts). That's how this sport progresses.

Any thoughts, anyone?


--Tom Aiello
tbaiello@mac.com

[guest]

It sounds logical, but I just don't see or feel that way in practice. I have jumped sail sliders on as short as 5 sec delays from towers and have opened high, but experienced very soft openings. I am frightened as hell to take a mesh slider to terminal. Team Bautasten laugh at me for that, but then they all walk around with stiff necks :-)

So the theory seems simple enough, but my jump experience doesn't back it up. Body position is so important for openings, and really hard smack type openings produce the funkiest body positions. I am considering testing my dinner plate hole sail slider for wingsuit jumps just to avoid that gnarly body swing that one can get while cruising along on a wingsuit.

Tom, if you are healing or broken, which you seem to be, try the hole in a sail slider.

/Lukas

[BASE_689]

I would like to add the following.
In my above post I said what I do with my rig/canopy. And it works well.
What I forgot to mention is that my 2 canopies have got < 90 jumps (BASE + skydives) between them two, so they are quite new. So the above configuration (sail or mesh) works for me for those delays and for the conditions of my Fox's.
A jumping mate of mine, jumping earlier with used Fox ( > 150 BASE jumps at the moment of purchasing), was using a mesh slider happily. Same canopy size as myself (245), more or less same suspended weight, same packing technique. He was jumping with a mesh and I was (am) jumping with a sail happily.
When my jumping fellow bought another used Fox 245 (but with only 10 BASE jumps on), tried his first jump off our terminal wall with his "new" canopy using a mesh: he was slammed on opening. He immediately switched to sail slider for jumping our terminal wall.
So, what I said above is just my personal choice, and it works very well for my packing technique, my suspended weight and my canopy's age. It is not and it cannot be valid in absolute terms. A very big role is played by canopy's age (=jumps).
It's simply an indication that under certain conditions it (=sail slider) works very well indeed.
But I shall keep a very careful eye to my openings as time (and jumps!) pass by my canopy, being ready to switch from sail to mesh as soon as I decide my sail openings are becoming too slow for jumping our terminal wall.
For sure, for jumping anything different from a terminal wall (=subterminal jump), I will always use a mesh slider!!!
Stay safe out there
Blue Skies and Soft Walls
BASE #689 :D

P.S.:
> If I'm at the low-speed end of a slider-appropriate jump, there is little wind slowing the slider's descent toward the links, so it doesn't take any longer to go down.

I do not agree with this: after "only" 3 s of freefall, you are exactly at half (50%) of your terminal velocity and 24% of terminal pressure/force (exerted by air on sail slider), so you cannot say: "...there is little wind...". After 4 s of freefall, you are at 63% of your terminal velocity and 38% of terminal pressure/force; after 5 s of freefall, you are at 72% of your terminal velocity and 51% of terminal pressure/force; after 6 s of freefall, you are at 80% of your terminal velocity and 63% of terminal pressure/force; after 7 s of freefall, you are at 85% of your terminal velocity and 73% of terminal pressure/force.
As you can see, after only 3 s of freefall (when you are still going (but that being the limit) slider off), there is quite a lot of wind (= 50% of terminal velocity and 24% of terminal pressure/force). A lot of wind that is definitely going to refrain your sail slider from coming down "immediately". A mesh slider, having no solid cloth between its grommets, cannot be refrained in any way by any wind speed.
So, only when doing terminal jumps and under the right conditions (packing technique, suspended weight and canopy's age), is possible to use successfully a sail slider. Anything different from that, subterminal jumps included, I would not use anything different from a mesh slider.
Just my 0.02 €.

[guest]

...Frightened to take a mesh slider to terminal? How can you go low with a sail? Come on...harden up, man...Mesh is just fine for terminal... Go low or go home... }>

[guest]

Regarding Tom's post where a friend of his stated "The sail acts on the wind in direct proportion to the windspeed."

If you ask me, knowing little, the arguments seems to be a tad thin and based on personal thoughts and thinking. The physics is never that simple.

Here is my very qualitative analysis of the subject.

Considering the first case with a low end slider-appropriate jump. The "inflation forces" subjected to the canopy should be more or less the same using either sail or mesh slider. The "inflation force" should also be somewhat small.

If considering high end slider-appropriate jumps(guess that would be terminal ones). Again, at a sertain airspeed the "inflation forces" should be the same either using sail or mesh and the force should be greater then in low air speed. But here the constraint of a sail slider will be greater compared to a mesh one, thus preventing hard openings.

The difference in opening speed should therefore be controlled by the design of slider. If using a sail slider the constraint will be higher than using a mesh slider. Thus providing a slower opening.

The apparent difference in opening velocity is a matter of physics. A slider, when sliding, will reach its maximum velocity when the "inflation force" pressing the slider down, equals the resistance force origin from the air retarding the slider. When the "inflation force" is low there is more time for the air to move around the sail, in higher air speeds the resistance for this to ocurr is greater. Thus very apperant and results in slower openings.

The gist of my arguments is that there will always be differences in opening velocity. Even in the case of low end kind of jumps when comparing different configuration i.e. mesh vs. slider. Similarities in opening characteristics is a matter of inlinearities of the physics behind the opening characteristics and maybe mostly about personal thoughts, thinkings and likings.....

Then the question whether the differences in opening characteristics is neglible rises!?......Which always is a question for the individual using a sertain configuration.

My personal experience with terminal jumps is limited to mesh only, in a Vtec fox. The openings were quite distinct but nothing to worry about if you don't suffer back probs.... if you prefer softer openings....well I'm just not the one to ask for advice....sorry.

All this is of course just a reflection of my own personal thougths. And should probably be ignored due my own inexperience in the sport.

take care

// percy....:P

[crwper]

The sail slider has a much greater effect on the air which it passes through... This needs to be taken into consideration not just because of the force which the air puts on the slider, but also I think because of the burble which will be created behind the slider (and hence directly in the path of the opening canopy). I would think this will give rise to greater variation in openings... Not just heading, but also opening times.

But, this is all theoretical for me. I've never done a BASE jump with a longer delay than 4 seconds, and only a few slider-up jumps from a popular 480-foot span.

Michael