Pilot Chute size and deployment speeds?

[Bolas 5]

Hypothetical:
Two collapsible ZP pilot chutes are identical in construction except for size, one is 24 in, the other is 28 in. Which would open the same canopy in the same container faster possibly causing a harder opening? Let's pretend it is one opening where the only thing that changes is the PC size. Everything else is identical
My thinking is that the 28 in. one causes more drag and will pull the canopy out quicker. I've heard arguements that the 28 in. PC will slow you down more than the 24 in. one.
What's the correct answer?

Stupidity if left untreated is self-correcting
If ya can't be good, look good, if that fails, make 'em laugh.

[diablopilot 2]

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My thinking is that the 28 in. one causes more drag and will pull the canopy out quicker.

I agree the 28 inch will get the canopy to linestrech faster. If it is a properly designed kill line then it will not affect the opening once the canopy is out of the bag.

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I've heard arguements that the 28 in. PC will slow you down more than the 24 in. one.

There is a decelerative effect in both directions (i.e. to the canopy and the jumper) but it's impact on the jumper (larger mass) is neglegible.

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You're not as good as you think you are. Seriously.

[mjosparky 4]

The larger PC will have some effect on the felt snatch force but none on opening shock.
Sparky

My idea of a fair fight is clubbing baby seals

[base283 0]

Weight of the canopy and deployment speed versus drag of the PC are the factors along with your geared up weight are the that will determine the outcome. However, A slow deceleration from an undersized PC can cause very hard openings because the time from bag opening to canopy stretch can take too long and the canopy can start to inflate before the tension is applied directly throughout the system due to insufficient separation speed giving you an out of sequence deployment resulting in an already somewhat open canopy hitting terminal(?) velocity airspeeds. have fun,
take care,
space

[3ringheathen 0]

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Hypothetical:

My thinking is that the 28 in. one causes more drag and will pull the canopy out quicker. I've heard arguements that the 28 in. PC will slow you down more than the 24 in. one.
What's the correct answer?

It's not quite that cut and dry. Here's another thread that discusses the factors:

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=822267#822267

Note that PD, the manufacturer of your main, disagrees with at least one answer you've been given here.

FWIW, I tend to agree with you. The larger pilot chute will extract the canopy faster. Depending upon a lot of other factors, it may or may not make a significant difference in the overall opening process.
-Josh

If you have time to panic, you have time to do something more productive. -Me*
*Ron has accused me of plagiarizing this quote. He attributes it to Douglas Adams.

[ChasingBlueSky 0]

Bill Booth at the Expo this weekend mentioned there is a sweet spot number for how fast the bag should be extracted...I don't recall that number, but I do remember him saying that 0.6 seconds is the sweet spot from letting the PC go to the canopy leaving the bag..... .7 and higher can cause hesitations and .5 and lower can cause faster openings.

Anything from the size of the PC, the size of the canopy and the construction of the PC can have an impact on this.

_________________________________________
you can burn the land and boil the sea, but you can't take the sky from me....
I WILL fly again.....

[slotperfect 7]

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Here's another thread that discusses the factors:

Clicky

Arrive Safely

John