PC Sizes

[link1 0]

as a side note...what are the two most popular (useful ) sizes of pilot chutes to have? I currently have a 42" and will be adding another with my new rig purchase. Thanx.

[Faber 0]

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what are the two most popular (useful ) sizes of pilot chutes to have? I currently have a 42" and will be adding another with my new rig purchase.

What do YOU preffere to jump/jump most?
my 2 most popular pc´s are 42 and 46

Stay safe
Stefan Faber

[TomAiello 25]

I've split this off from the "Drag Table" thread, a it appears to be a separate, and useful, discussion.

When I was learning to BASE jump, my mentor said something like this:

You will need three PC's:

1) Really big one, for low stuff.
2) Small one, for terminal stuff.
3) A 42", for everything else.

Which is more important (very big or very small) is going to be for you to decide, based on what you plan on jumping.

If you are planning on doing big stuff (terminal towers, or a big wall trip to Norway, or something similar), get a smallish PC. My two favorite small PC's are the BR 36" F-111, and the CR 32" A/V. In terms of deployment characteristics (primarily orbiting and oscillation), I slightly prefer the F-111. But the ZP on the A/V will last far longer (two or three times as many jumps). If you are planning on keeping it forever (i.e. several hundred terminal jumps), I'd go with the CR 32" A/V. If you are only going to do a few terminal jumps a year, I'd go with the BR 36" F-111.

If you are going to be doing low stuff close to home, you'll want to get a big PC next. My favorite big hand held PC is the BR 48" ZP. I prefer it because it has nothing on the apex, yielding less potential for hesitation and overall faster and more consistent inflation.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[andy2 0]

you prefer no vents tom for really low stuff and for everything else vents? I thought vents sacrificed a little speed in the deployment but much less oscilliation? I remember reading on here something about a vented PC will have a smaller margin of error than a nonvented PC. Such as a nonvented PC might deploy much faster one time but much slower the next whereas a vented PC is much more stabile. Isn't this stability would be what you are shooting for doing low low stuff? What do you think about that?

Thanks (sorry if I asked you a million questions at once ).

---------------------------------------------
let my inspiration flow,
in token rhyme suggesting rhythm...

[TomAiello 25]

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you prefer no vents tom for really low stuff and for everything else vents?

It depends on your definition of "really low". I'd prefer an unvented PC for some very low stuff that required specialized techniques. I'd prefer a small vent (like the BR 48 vented PC's that DW had, I'm not sure if they'll sell them to mere mortals like me, though) for the "general purpose" ultra lows in the 180-220 range.

However, given a choice between the everyone else's vented 46's and BR's unvented 48 (the choice most of us are faced with), I'd probably go with BR's unvented 48.

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I thought vents sacrificed a little speed in the deployment but much less oscilliation?

True.

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I remember reading on here something about a vented PC will have a smaller margin of error than a nonvented PC. Such as a nonvented PC might deploy much faster one time but much slower the next whereas a vented PC is much more stabile.

I think you misremember. That discussion was about hand held v. stowed PC's. rather than vented v. unvented. The vented v. unvented difference (in terms of reliability) is pretty marginal, but probably falls (slightly) in favor of the unvented PC.

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Isn't this stability would be what you are shooting for doing low low stuff?

Are you asking about stability of the PC, or reliability of inflation times (i.e. resistance to random hesitations)? These are two different things, with vented (or F111) PC's being far better at the former, but marginally (or more in the case of F111) worse at the latter.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[link1 0]

Does canopy size have any relationship to PC size? For instance, say jumping an ACE 310 or equivalent...would that put me into a bigger PC range?

[TomAiello 25]

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Does canopy size have any relationship to PC size? For instance, say jumping an ACE 310 or equivalent...would that put me into a bigger PC range?

Yes, but...

I've seen the max size canopies jumped with undersized (by delay) PC's, with no ill results.

The only times when I would really worry about upsizing the PC to match a big canopy is on an ultra low jump (200' or less), or a low pull (loosely defined as more time in freefall than under canopy).

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[czechbase 0]

Some guys I spoke to said for real low stuff they use a 52", ain't that a bit too big????

Who makes 52" pcs now anyway?

www.motavi.com

[Faber 0]

i guess it rely on the person.

I freefall 180ft whith a 46´zp av pc from CR,which does the job werry well.

Other groups of Europaeans(The hardcore Belgiancrew) freefall 150ft whith a 46´zp pc,and smoke 42´zp pc down to 180ft freefalls.. i think some of their 150ft freefalls are at their site.I dunno if they post here but if they do,they might answer this...

Stay safe
Stefan Faber

[BASE813 0]

I tried to ask this (sort of?!?!) in another thread about the drag differences and opening distances with different PC's - but no one responded................. then I decided to look into this myself with 689's handy XL spreadsheet..... thanks 689!

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=729814#729814


Be safe always.............

[link1 0]

well I won't be worried about doing anything near 200' anytime in the foreseeable future...thanx for the info.

[Faber 0]

i never saw a 52´ but i saw a 48 and that is one BIG pc

Stay safe
Stefan Faber

[TomAiello 25]

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Some guys I spoke to said for real low stuff they use a 52", ain't that a bit too big????

In general, yes. DW used to use a 52 for his super low jumps, but it was a custom made 52 with almost no weight on the topskin.

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Who makes 52" pcs now anyway?

I think that you'd have to get a 52 built custom, currently. Gravity Sports Limited used to make them as a stock size, but they had a cap on the apex, which I wouldn't recommend.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[andy2 0]

whats the function of the cap then? What was their reasoning for having one? What's your reasoning for not wanting to jump a PC that big with a cap on the end? Adds unnessecary weight to the PC - slows down inflation?

---------------------------------------------
let my inspiration flow,
in token rhyme suggesting rhythm...

[TomAiello 25]

The cap is intended as a handle to facilitate easier "grabbing" of the PC when stowed. It was developed as an alternative to PVC and hacky handles, which are not safe to use on a hand held PC. The cap is a sort of happy medium, which is meant to allow the PC to be used hand held or stowed.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[TomAiello 25]

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Adds unnessecary weight to the PC - slows down inflation?

Any additional weight on the top of the PC will slow down (and make less consistent) the inflation.

I've recently decided that this is a bigger deal than we all previously thought, after discussions with a friend, and review of the photos on this thread. If that PC is sideways at terminal, imagine how much effect the weight of the handle will have at 6 seconds.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[andy2 0]

ok now Im confused, tom.

Who is going stowed on a jump that requires a 52" PC!?!?

---------------------------------------------
let my inspiration flow,
in token rhyme suggesting rhythm...

[base587 0]

Hey Tom

Just to add a little to the big PC debate....

I've got a custom made 52" (true diameter measurement) ZP no-cap, unvented PC which I have only used ONCE.

It was TOO big!!!!

[245 Fox 'vented only' v-tec, 0.70 wingloading, single bridle attachment.]

It created so much drag it impeded inflation and did not allow for full flight. I had very little forward speed and a whole lot downwards. I hit the ground very hard with what felt like 'half' a canopy over my head.

For low stuff I've stuck with a BR 48" ZP (46" true diameter) with good success.

I was thinking I could still use the big 52" PC for low freefalls with a roundie into H2O. I don't think it would affect flight characteristics. Any thoughts?

[jalisco 0]

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If that PC is sideways at terminal, imagine how much effect the weight of the handle will have at 6 seconds.

Does that follow? Would any pilot chute really inflate at anything short of bridle stretch? Seems like until there is some sort of pull at the bridle attachment point, a pilot chute is just a floppy bit of fabric.

Now, at your 6 seconds, I probably would want the pilot chute to follow me as little as possible, so reducing the weight of the thing (for a given size) as much as safely possible is, I'm sure, an excellent plan.

I'm just saying that the orientation of it prior to bridle stretch is probably a bit uncertain in any case. In the pictures to which you refer, it seems to me like the bridle and pilot chute are just dancing limply together in the the jumper's burble (until bridle-stretch).

[TomAiello 25]

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ok now Im confused, tom.

Who is going stowed on a jump that requires a 52" PC!?!?

Someone doing a double gainer.

Which, in practice, means pretty much no one.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[TomAiello 25]

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Would any pilot chute really inflate at anything short of bridle stretch? Seems like until there is some sort of pull at the bridle attachment point, a pilot chute is just a floppy bit of fabric.

I disagree. I believe that a ZP PC will begin to inflate as soon as it leaves your hand. It will be at least partly inflated well before it reaches bridle stretch.

An F-111 PC, on the other hand, will generally inflate at bridle stretch. This is the reason for the "popping" sound that you hear when an F-111 PC hits bridle stretch. It's doing all of it's inflating right then. ZP, of course, doesn't do this.

If you take an F-111 PC on a load with people who've only used ZP PC's, you can almost always freak them out. "What was that noise your PC made? Is it ok? It didn't tear, did it?"

-- Tom Aiello

[email protected]
SnakeRiverBASE.com