Forums: BASE Jumping: BASE Technical:
180s
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fbc91

Dec 23, 2020, 2:30 PM
Post #1 of 13 (1004 views)
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180s Can't Post

What causes 180's when the jumper has done everything right: pack job, body position, etc.?

Dadsy

Dec 23, 2020, 5:27 PM
Post #2 of 13 (998 views)
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Re: [fbc91] 180s [In reply to] Can't Post

During my course we packed intentional 180s and 2 of the 6 from memory came out on heading, so I don't think there is a definitive answer.

Is there footage of the body position and the PC

fbc91

Dec 23, 2020, 7:59 PM
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Re: [Dadsy] 180s [In reply to] Can't Post

In reply to:
Is there footage of the body position and the PC

Not a jumper, just curious what the theories are.

Colm

Dec 23, 2020, 8:11 PM
Post #4 of 13 (987 views)
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Re: [fbc91] 180s [In reply to] Can't Post

I have proposed the quantum theory of BASE. There is a probability distribution describing your opening heading, which is influenced by random chance, packing technique, wind integral, pilot chute symmetry, body position, state of sobriety, karma balance, and the observed angle between Jupiter and Saturn.

Like Schrodinger's cat, your parachute is literally simultaneously open facing all heading directions until you deploy it, and thus collapse the waveform by making an observation.

In other words, nobody really fucking knows, and my theory is not provably worse than anyone else's.

Dadsy

Dec 23, 2020, 8:40 PM
Post #5 of 13 (981 views)
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Re: [Colm] 180s [In reply to] Can't Post

I think this may be the most sense you have made Smile

higherground

Dec 24, 2020, 10:37 AM
Post #6 of 13 (948 views)
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Re: [fbc91] 180s [In reply to] Can't Post

- pilot chute out of trim
- winds ( meteo and relative - from a running exit )
- pc and bridle pendulum going past center
I’ve seen this mostly from a hard throw stowed with too short of a delay ( 0 to 1.5 sec with a 42 “ ) works out most of the time
- random chaos

Colm

Dec 24, 2020, 8:08 PM
Post #7 of 13 (917 views)
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Re: [Dadsy] 180s [In reply to] Can't Post

lol don't get too used to it Laugh

rendezvous

Jan 3, 2021, 11:54 AM
Post #8 of 13 (557 views)
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Re: [Colm] 180s [In reply to] Can't Post

Lol! love the collapsing wave function theory, this one will stick with me ????

Kadel

Jan 3, 2021, 3:00 PM
Post #9 of 13 (548 views)
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Re: [higherground] 180s [In reply to] Can't Post

What about bigger PC's, 46" or 48" stowed? I don't like it, but sometimes I have to do (mostly because tricky exit). But i saw two almost clear 180's at this type of jump at two different jumpers. In my opinion that was too big PC+hard pull= oscillation PC with packjob to left side..


(This post was edited by Kadel on Jan 3, 2021, 3:02 PM)

higherground

Jan 3, 2021, 6:38 PM
Post #10 of 13 (537 views)
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Re: [Kadel] 180s [In reply to] Can't Post

I’ve never done a jump with a pc over a 42”.
I wouldn’t want to introduce a possible hard pull into the mix at low altitude. For your jumps , I’d take a pca, static line or just pass altogether.
For the off headings I’ve seen with a 42 stowed short delay. It’s a hard throw to bridle extension and then the momentum of the bridle/ pc pendulum carries the pc past center to the left side of the container for the off heading. A little more airspeed from a longer delay helps to keep the pc centered. If a longer delay isn’t available, I’d go handheld.

Faraday

Jan 11, 2021, 2:45 AM
Post #11 of 13 (398 views)
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Re: [Kadel] 180s [In reply to] Can't Post

I think, it's a combination of PC size and delay in that case. I'm not sure, if there is a difference between going stowed and handheld (if body position is stable).

I noticed some kind of pattern jumping a 46'' PC based on delay. As soon as delay reaches approx. 2 sec, heading performance gets worse. No 180s, though, but 45° to 80°...

Anyway, I guess the reason is a combination of a too big PC (for the delay), resulting in to high air speed = much air spilling the PC = oscillation. I all those cases, PC thrown to the right with oscillation to the left resulting in an off-heading opening left. I think, that matches your observation.

John_Scher

Jan 11, 2021, 8:55 AM
Post #12 of 13 (381 views)
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Re: [Colm] 180s [In reply to] Can't Post

 
very clever and very funny:


Like Schrodinger's cat, your parachute is literally simultaneously open facing all heading directions until you deploy it, and thus collapse the waveform by making an observation.

In other words, nobody really fucking knows,...

taj

Jan 14, 2021, 6:46 PM
Post #13 of 13 (243 views)
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Re: [Faraday] 180s [In reply to] Can't Post

Just wondering if your 46” pc is vented or non vented ?


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