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skydiverek

Are PD mains bigger than advertised, just like PD reserves?

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do they, and other skydiving manufacturers measure projected, or flat area? Im assuming flat cause that would make a lot more sense, but Im curious because my speedflying wing says both in the manual, and i'm not sure which size to use to compare to skydiving mains that Ive flown as well.

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I think it was agreed here that PD reserves are in reality bigger than their advertised square footage. For instance, a PDR 176 will be approximately 190 square when measured.

Does the same applies to PD main canopies?



PD explains their measuring method for canopies (part I). Keep in mind that actual size, even when measured with the same method, isn't the complete story, neither on canopy performance nor pack volume.

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OK, I found the PIA sheets - see attachments. Same measuring method was used (PIA). So, for examle, by this method, a PD-Reserve 176 is actually 189 square feet. And Micro Raven 150 is 150 square feet.

That's what I meant. When using a common denominator (=same measuring method), PD reserves have more square footage than they advertise. Some competitors have the SAME area as advertised.

So, is Spectre 190 also bigger than 190 square feet? That was my original question.

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There are several different methods to measure canopy area, but let's limit this discussion to the two most popular methods: PIA and PD.

The PIA method was written back when Para-Flite was the leading manufacturer of ram-air canopies. Since Para-Flite licensed several of their canopies to Parachute Industries of Southern Africa, PISA adopted the PIA method.
The PIA method measures chord from the top leading edge - in a straight line - to the trailing edge. Chord is measured six inches back from the top leading edge.

Performance Designs still measures chord the same way, but measures span across the bottom skin. This results in reported area 10% or 15% smaller.
IOW PD canopies are reported to fly "bigger" than their advertised area.

Just to mess with you, Icarus changed from the PIA method to PD's method circa 2001.

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>Just to mess with you, Icarus changed from the PIA method to PD's method circa 2001.

And to mess with you even more, for a while they measured their Safires differently than all their other canopies. I have a Safire1 129 that is equivalent to a modern Safire2 119.

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To directly answer your question, 'Yes'.

However, I don't think it's wise to try to game the differences in canopy sizes. It would be foolish, for example - to say to yourself that it's "safe" to jump a canopy one size smaller, because the manufacturer measures differently.

I hope that's not why you're asking. That'd be foolish.

_Am
__

You put the fun in "funnel" - craichead.

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OK, I found the PIA sheets - see attachments. Same measuring method was used (PIA). So, for examle, by this method, a PD-Reserve 176 is actually 189 square feet. And Micro Raven 150 is 150 square feet.

That's what I meant. When using a common denominator (=same measuring method), PD reserves have more square footage than they advertise. Some competitors have the SAME area as advertised.



Sort of, but it would be equally valid to say that PD/Icarus and others have the same area that they advertise, while other manufacturer's canopies have less area than they advertise.
Do you want to have an ideagasm?

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Im curious because my speedflying wing says both in the manual, and i'm not sure which size to use to compare to skydiving mains that Ive flown as well.



I wouldn't compare the two -Unless you're comparing either a GLS / GLX / Ballistic type wing that has a similar skydiving style planform and input characteristics to a skydiving wing.

They're made with different characteristics and don't really compare that well due to the large differences in handling.

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by this method, a PD-Reserve 176 is actually 189 square feet. And Micro Raven 150 is 150 square feet.

Most people agree that a PD-143R is much safer than a Raven Micro 150, for other reasons -- even though the area is roughly the same.

Me and a friend of mine, replaced our Micro Raven 150's last year with a different reserve, and mine is a PD143R, the biggest that would fit my container without paying a fortune for a PD160R Optmium.

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