big pilot chutes = faster openings?

[guest]

couple basic questions, (and i'm trying to use this new board)
right now i think i'm using a 46 inch pilot chute.
If i am doing some lower than usual jumps above water. how much benefit such as, how much faster will my canopy open utilizing a 50 inch pilot chute with all conditions being the same. slider down, raven 4, velcro rig, etc. How big is big or too big? Like 55 inches. I just want it to open as fast as possible, but I don't want a static line deployment, or D - bag.
any input would be highly apprieciated.

[guest]

I'm using a 42" pilot chute, i thought it was 46", yes, i know, "should have measured before i posted" anyway, please apply my previous post in regards to moving from a 42" pilot chute to lets say 50" or bigger. Will i save 20 to 30 feet in opening altitude??

[guest]

Dude, I don't mean to blast you but this is not a sport that lends itself to guesswork! You "think" you are using a 46" pilot chute? I "think" that the canopy "might" open with "about" 150 feet of available altitude......"maybe"?

Also, if you're over water at an "unusually low" altitude, forget the rig and land feet first with your hands tightly against your sides, eyes closed! More info. on site speciffics would yeild a better reply. Good Luck1

Dave

[Nick]

<center><font size="1" color="#ff0000">LAST EDITED ON Sep-30-99 AT 10:34&nbsp;AM (EST)</font></center>

Generally you can say a larger size pilot chute will provide more pulling power than a smaller one. However, that depends on how it's built. A pilot chute has a trim setting that determines it's pulling power and this has to do with how much you pull the apex down. (Controlled by the centerline tapes). This is set during the manufacturing process, so two pilot chutes the same size could vary from manufacturer to manufacturer.

As for deployment time, that's a tough one. There may not be that much of difference unless we're talking really small pilot chutes Vs really big ones. Across the span of the most popular BASE sizes (42"-48") there may not be much of a measurable difference in time of deployment.

At one time 52 inch pilot chutes were used for almost all BASE jumps. These were big and heavy and if thrown hard enough on a short delay they would angle your deployment out in the same direction. (The most popular ones are called Hank 52's for the rigger who built them. These were originally designed and sold to the military to retard the fall of bombs).

Over time BASE jumpers realized 52 inches is a bit of overkill. And some other problems were starting to surface. The drag retarded the flight of the open canopy. Folks who are still BASE jumping with nine cell canopies are getting bow-tie type openings, and since retired skydiving canopies are what most are jumping we started to see bridle attachment points begin to fail.

If you are planning a BASE jump where you are counting on a certain size pilot chute to provide a faster opening you are cutting things too fine.

It's like when Jump Shack advertises the speed of their reserve deployment being faster than other rigs that have the reserve pilot chute inside the container, well, they are counting on many things going right for that to be true.

When thinking about available altitude and how best to use it always factor in room for a line over and a pilot chute hesitation and you will never die.

Unless it's your time . . .

Nick-BR

[guest]

I read an article in Skydiving Magazine some while ago about using a too big pilot chute for a specific delay and that "the bigger the better" would not always yield.

I remember it was something like that if the pc is too big it pulls too hard on the center cell and therefore stretches it too much in the vertical direction. Because the center cell gets pulled out of shape the opening with such a huge pilot chute could actually be slower than with a well chose pc size.

BSBD,
Robert

[guest]

<center><font size="1" color="#ff0000">LAST EDITED ON Oct-02-99 AT 11:28&nbsp;AM (EST)</font></center>

I have done some experimentation with different pilot chutes while doing repeated jumps(26 jumps) from the same 300ft. object. I now use a new zero-p 46" for low stuff (250 to 350), a 43" F-111 or zero-p for medium stuff (350 to 700) and a 36" zero-p with my slider up for all higher objects. My videos of the low jumps show better openings and less canopy distortion with the 46" Zero-p than with the 50" and the 55" that I tried. This is only my opinion, not gospel.

[Nick]

This is why we invented the Multi. The Multi eleminates center cell stripping. There is more information here:

http://www.delphi.com/basicresearch/start/

Nick-BR