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Sabrekakkonen

The best glide ratio canopy

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For the thread:
It's the picky people posting now!

So "Glide Ratio" is normally defined for the aerial vehicle through the air mass. No ground, no wind, no up or downdrafts.

As far as I can tell in aviation there is no really convenient universal notation for the glide ratio "relative to the ground" or "over ground" or "with wind". One just spells that out or makes sure that it is clear from the context.

Calling it "relative glide" might be OK as an abbreviation, but one shouldn't define it as a key term as in the Parachutist article. Then one should at least call it "relative glide ratio", indicating it isn't just a pure glide ratio but relative to something else in context. (A quick look on the web shows no evidence that "relative glide" is a term that is used. Other than by the Axis Flight School, who wrote that Parachutist article. Well, at least make it clear that "glide ratio" is the proper term for the situation without winds.)

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chuckakers

Quote

Of course, the aerodynamic characteristic, and the relative performances, of the canopies don't change....



And I believe this is the only information the OP was looking for. Just a simple answer on what canopies have the best glide ratios when other factors are not considered.

In my experience the Stiletto is one of them.



On a related note, since we said that Glide Ratio doesn't change too much with WL and other "external factor" but it's more a characteristic of the canopy than anything else, it's a shame that manufacturers don't publish their glide ration or glide angle in the specs of a canopy. I'd think that to be one of the many deciding factors, or at least it'd be nice to know.
I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

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JerryBaumchen

Hi DiO,

Quote

Canopy A:
Horizontal speed: 20 mph
Vertical speed: 10 mph
Glide Ratio: 2



Don't you mean Canopy B?

Jerry Baumchen



Sorry, yes, canopy B, my bad for copying and pasting without correcting that. Thank you!

pchapman

For the thread:
It's the picky people posting now!

So "Glide Ratio" is normally defined for the aerial vehicle through the air mass. No ground, no wind, no up or downdrafts.

As far as I can tell in aviation there is no really convenient universal notation for the glide ratio "relative to the ground" or "over ground" or "with wind". One just spells that out or makes sure that it is clear from the context.

Calling it "relative glide" might be OK as an abbreviation, but one shouldn't define it as a key term as in the Parachutist article. Then one should at least call it "relative glide ratio", indicating it isn't just a pure glide ratio but relative to something else in context. (A quick look on the web shows no evidence that "relative glide" is a term that is used. Other than by the Axis Flight School, who wrote that Parachutist article. Well, at least make it clear that "glide ratio" is the proper term for the situation without winds.)


Yes, I agree, that was also the first time I saw that distinction made with those two terms, it can work or it can help make things clear, but it's not universal, generally speaking the glide ratio or glide angle are measures over the ground so, yes, they'll change in different conditions of wind. Of course, if not specified it's a 0-wind measure, but as I proved with the example, it does not, alone, define how a canopy will perform when navigating with wind so, by itself, is not necessarily a measure of how far a canopy will go "in real life", which is the reason why I was being picky.
I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

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Fundamentally the wind doesn't matter - the only two measurements that matter are the zero wind glide ratio, and forwards airspeed. Everything else is within the airmass so the windspeed becomes irrelevant (or you can work it out)

As for canopies? Well I know my Tequila4 massively outperforms my Pilot :P but I wouldn't want to take it terminal :D

Never try to eat more than you can lift

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Stumpy

Fundamentally the wind doesn't matter - the only two measurements that matter are the zero wind glide ratio, and forwards airspeed. Everything else is within the airmass so the windspeed becomes irrelevant (or you can work it out)



Yes. It's 3 variables and you need two to find the third. It could be forward and vertical, glide ratio and vertical, or, well, that's it, really.
After that, it's just adding and subtracting.
I'm standing on the edge
With a vision in my head
My body screams release me
My dreams they must be fed... You're in flight.

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On 12/22/2016 at 9:52 AM, Pobrause said:

Simple question, not so simple answer.
Depends on headwind, downwind, wingload, profile, canopy size, inputs... just to name a few.

Assuming no wind, no inputs I would bet my money on a lighty loaded biggish pulse. And of course nearly every 9cell student canopy.

Last sunday at a DZ I visited however the canopy with the best g/r was a VK75 at 3.4. Everybody else barely made any forward movement or was driving backwards.

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To absent friends
 

The wind has no effect on a canopy's glide ratio.

To your question, the Stiletto has a notoriously flat glide. It also has a very short recovery arc.

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