Forums: Skydiving Disciplines: Canopy Relative Work:
How big (how many persons) do you build stacks?

 


morris

Oct 2, 2011, 2:29 PM
Post #1 of 18 (1750 views)
Shortcut
How big (how many persons) do you build stacks? Can't Post

Can you/do you build stacks with as many persons as you have jumpers available? Or do you usually "switch" to planes once the formation starts getting bigger?

Additional question:
Lets say you are flying a 5way-stack. What inputs should be given? Half brakes at the very top? A little bit of brakes by number 2? A bit of frontrisering by the lowest person to create some tension? What to take care about while flying it?

Thanks for any kind of information and/or input!


StefB

Oct 7, 2011, 4:35 PM
Post #2 of 18 (1587 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

Morris, you are from Germany, right? Then the Frstenberg Fallschirm Team might be a good source for information about stack formations. http://www.ff-team.de/


(This post was edited by StefB on Oct 7, 2011, 4:36 PM)


morris

Oct 8, 2011, 7:30 AM
Post #3 of 18 (1572 views)
Shortcut
Re: [StefB] How big (how many persons) do you build stacks? [In reply to] Can't Post

Ive already been checking their website before even posting here and couldnt find the information Im looking for. There is a video of a 10way on the site, but they are flying it as a plane, not a stack...


CaTo  (D 81811)

Oct 8, 2011, 9:08 AM
Post #4 of 18 (1570 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

I once saw a 12 -way stack being build (i was the cameraman) by a group of english crw-nuts Wink it was partly build as using a planed formation, partly stack. The biggist problem was that it was swinging at the low-end, making it VERY hard to dock. Eventually the succeeded the full formation (uk record as i remenber)
I should have the video somewhere..... If i find them i will post them

edit: picture found and attached


(This post was edited by CaTo on Oct 8, 2011, 10:33 AM)
Attachments: 12-12way.jpg (39.0 KB)


morris

Oct 9, 2011, 1:14 AM
Post #5 of 18 (1545 views)
Shortcut
Re: [CaTo] How big (how many persons) do you build stacks? [In reply to] Can't Post

"...it was swinging at the low-end..."
this is why Im asking, without any planes in the formation at all, just "pure" stacks, we experienced a 5way that didnt fly very nice at all, but maybe thats just us...?


BillyVance  (D 18895)

Oct 11, 2011, 7:48 AM
Post #6 of 18 (1502 views)
Shortcut
Re: [CaTo] How big (how many persons) do you build stacks? [In reply to] Can't Post

There's a pic on the wall at West Tennessee Skydiving (Mullin's home DZ) of a stack that I think is the state record. I don't remember exactly how many were in it, but it was around 15. It was set a long while ago.

My largest is a 10 stack, which is the Alabama state record. I was next to last on the bottom. I found it harder to dock there than higher up in the stack due to the increased sink rate.


G.G

Oct 12, 2011, 3:31 AM
Post #7 of 18 (1474 views)
Shortcut
Re: [BillyVance] How big (how many persons) do you build stacks? [In reply to] Can't Post

I was one of the crazy brits in the pic, however the largest planned stack is 24 built in England in 1986


morris

Oct 13, 2011, 8:56 AM
Post #8 of 18 (1434 views)
Shortcut
Re: [G.G] How big (how many persons) do you build stacks? [In reply to] Can't Post

planned stack?


Andrelr  (D 270)

Oct 14, 2011, 2:44 AM
Post #9 of 18 (1410 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

Hi Morris
You plane the stack for stability. Unplaned stacks tend to sway as they are longer and pivot around the ankle/line grips on the centre cell.
Planed stacks are shorter and far more stable.
We built an 18-way planed stack in South Africa in 1988, and even that had quite a sway at the bottom.
Cheers
Andre


morris

Oct 15, 2011, 2:30 AM
Post #10 of 18 (1373 views)
Shortcut
Re: [Andrelr] How big (how many persons) do you build stacks? [In reply to] Can't Post

Now we are finally "closing in" on what I want to know...
I understand that planed stacks are far more stable than unplaned ones. This was exactly what Ive been asking for.
My question was:
a) Do you plane the stacks - from a certain number of persons on - for stabilitiy reasons (I know the answer is yes)?
and b)
What I dont know is:
What is that number???
With how many persons can you build UNPLANED stacks??
Or do you always plane em as soon as possible?
lets add c)
What is the largest UNPLANED stack on record?
lets add d)
What to take care about flying em?
Ive seen pictures of 5ways that flew very nice.
I have not been looking/searching for pics of larger ones yet, I thought itd be better to ask you guys as words will tell me more than any pic.
Weve tried to build an unplaned 5way stack with regular Storms (not CF-Storms but with the CF-option and dacronlines) of various sizes and loadings ranging from ~1.5 to 1.6.
After the final jumper docked (myself) the formation became very "nervous" very fast. This was not caused by the dock! After the final dock it flew very nice - but just for some moments...


CFPasi  (D 3067)

Oct 15, 2011, 8:02 AM
Post #11 of 18 (1365 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

"What is the largest UNPLANED stack on record? "
- I belive that it is 12-stack made in USA in 1979

You will find more info from:
http://www.skydivehame.com/cf/biggest.php


morris

Oct 16, 2011, 11:06 AM
Post #12 of 18 (1330 views)
Shortcut
Re: [CFPasi] How big (how many persons) do you build stacks? [In reply to] Can't Post

What to take care about flying unplaned stacks?
Quite a lot of brakes at the very top?
A little bit of brakes right below the very top/towards the middle?
Or would you recommend building planes if were exceeding four persons because unplanned stacks of 5 or more persons are too difficult to fly especially at higher loadings?


crotalus01  (B 28932)

Oct 16, 2011, 8:34 PM
Post #13 of 18 (1310 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

There is a picture in the hanger of my home DZ of the TN state record, a 13 stack. Of the 13 only one of the canopies is planed - the rest are stacked.


CFPasi  (D 3067)

Oct 17, 2011, 9:20 AM
Post #14 of 18 (1288 views)
Shortcut
Re: [crotalus01] How big (how many persons) do you build stacks? [In reply to] Can't Post

Hope to get more info about that 13-stack - date and place of the jump and ...

All info are wellcome!


CaTo  (D 81811)

Oct 20, 2011, 11:55 AM
Post #15 of 18 (1229 views)
Shortcut
Re: [CaTo] How big (how many persons) do you build stacks? [In reply to] Can't Post

In reply to:
I once saw a 12 -way stack being build (i was the cameraman) by a group of english crw-nuts Wink it was partly build as using a planed formation, partly stack. The biggist problem was that it was swinging at the low-end, making it VERY hard to dock. Eventually the succeeded the full formation (uk record as i remenber)
I should have the video somewhere..... If i find them i will post them

found some footage, look between 8:56 and 9:21 and you see some clips that show the setup of the 12 way. And yes, no stack but almost all in plane....
http://www.youtube.com/watch?v=yo1xXtZrsuc

(by the way, I grew some muscles keeping track of the stack going down... :-)


Madison  (D 25271)

Oct 20, 2011, 12:25 PM
Post #16 of 18 (1225 views)
Shortcut
Re: [G.G] How big (how many persons) do you build stacks? [In reply to] Can't Post

In reply to:
the largest planned stack is 24 built in England in 1986

The 24 stack was built with the jumpers exiting from a helicopter along side the stack as it built.

Just saying...


morris

Oct 23, 2011, 8:16 AM
Post #17 of 18 (1177 views)
Shortcut
Re: [Madison] How big (how many persons) do you build stacks? [In reply to] Can't Post

Quite a lot about planed stacks coming in, but I still wanna know about unplaned stacks, what to take care about...?


TVPB  (F 666)

Oct 31, 2011, 5:28 AM
Post #18 of 18 (1080 views)
Shortcut
Re: [morris] How big (how many persons) do you build stacks? [In reply to] Can't Post

To be technical, a "planed stack" is an oxymoron. A plane is where feet are at risers, a stack is where feet are at bottom skin. Planes are more stable because the canopy is supported by the lines of the canopy above, whereas on a stack the canopy can pivot around the feet.



Forums : Skydiving Disciplines : Canopy Relative Work

 


Search for (options)