From: dbriggs@zia.aoc.nrao.edu (Daniel Briggs)
Newsgroups: rec.skydiving
Subject: Which handle to pull?  (Was Re: AAD Question)
Date: 9 Apr 92 06:55:37 GMT
Article-I.D.: zia.1992Apr9.065537.779
Organization: National Radio Astronomy Observatory, Socorro NM

In article <1992Apr8.202914.11562@ichips.intel.com>
 mtimko@ichips.intel.com writes:
>I would rather deal with two canopies than ASSUME my AAD will fire
>and pull my reserve instead just in case.  I don't think you'll see 
>the USPA supporting your recommendation all too soon.  The biggest 
>reason is for those people with reserve static lines (which is 
>recommended), pulling your reserve first means you don't get a second 
>chance.  Even if you don't have a RSL, your logic would have you pull 
>a reserve that could possibly malfunction and CANNOT be cut away. If 
>you then pulled your main, it would probably get tangled in the 
>malfunctioned reserve and then your really screwed.

Ummm, maybe I'm dense, but I don't follow your reasoning.  What does an RSL
have to do with anything?  Are you assuming that the presence of an RSL
allows one to cut away lower than someone without one?  I grant you that
there probably is a slight difference here, but I but that it's less than
100' feet of altitude for an experienced jumper who's on the ball.
Certainly it's a lot less cutting away from an even half inflated canopy.

>|> If you get this low, this might be a good idea even without the AAD.
>
>NOT!!!  Without an AAD, why should altitude determine which chute you
>pull?  Your rational makes no sense in this case.  Without an AAD,
>ther is no advantage to pulling your reserve over your main below a
>certain altitude and there are quite a few disadvantages.

I think the theory here is that reserves are more carefully packed and
maintained than mains, making them more reliable.  As we all know, we're
still talking small number statistics, so it's hard to state categorically
that this is true.  (Comments, Dale?)  In addition, reserves are packed for
quick openings, often have hardware mods like bikini sliders and strong
pilot chute springs, and the fabric of the canopy might well be less porous
than an equivalent well used main.  The bottom line is that it will probably
open faster than your main.  So clearly at some altitude there has to be
a point where it makes more sense to go for your reserve.  If I'm in freefall
at 700', I'm darned well going for the shiny handle.  On the other hand,
your comments about not getting a second chance are well taken -- as long
as you're high enough to *get* a second chance.  At 1300' I'd go for the
main, since I would probably still have enough altitude to cut away from
at least some kinds of malfunctions.

BTW, as long as we're comparing safety equipment, I'll mention that I've
got an RSL but no AAD.  When I'm rich enough to afford that Sabre, I'll
give serious thought to adding a Cyprus-Expert.

-- 
| Daniel Briggs  (dbriggs@nrao.edu)                      |        USPA B-14993
| New Mexico Tech / National Radio Astronomy Observatory |            DoD #387
| P.O. Box O / Socorro, NM 87801   (505) 835-7391        |
Support the League for Programming Freedom  (info from league@prep.ai.mit.edu)