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keithbar

rig weight

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random drunken test this evening a talon 2 with a raven 2 218 square foot reserve and a crossfire 2 169 weighted 21.6. And a 1988 talon with a safire 229.main and raven 3 249 sq rt reserve It weighed 27.4 lbs I was surprised there wasn't a wider range between those two rigs..
i have on occasion been accused of pulling low . My response. Naw I wasn't low I'm just such a big guy I look closer than I really am .


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keithbar

random drunken tinests this evening a talon 2 with a raven 2 218 square foot reserve and a crossfire 2 169 . And a 1988 talon with a safire 229.main and raven 3 249 sq rt reserve It weighed 27.4 lbs I was surprised there wasn't a wider range between those two rigs..



I'm glad you're having a good evening.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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gowlerk

***random drunken tinests this evening a talon 2 with a raven 2 218 square foot reserve and a crossfire 2 169 . And a 1988 talon with a safire 229.main and raven 3 249 sq rt reserve It weighed 27.4 lbs I was surprised there wasn't a wider range between those two rigs..



I'm glad you're having a good evening.

he couldnt ask for boobie-pics now, could he!?

:D:D:D:D:D
“Some may never live, but the crazy never die.”
-Hunter S. Thompson
"No. Try not. Do... or do not. There is no try."
-Yoda

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My cat weighs more than my rig....but my rig is only 18.9 pounds (or maybe it was 19.8 - it's been a while). Any many others are much smaller.

Yes my cat is fat...but he's a big boy orange tabby. He'd be normal at 18 and a lean machine if he could get down to 16.

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keithbar

random drunken test this evening a talon 2 with a raven 2 218 square foot reserve and a crossfire 2 169 weighted 21.6. And a 1988 talon with a safire 229.main and raven 3 249 sq rt reserve It weighed 27.4 lbs I was surprised there wasn't a wider range between those two rigs..



Well, everything is identical as far as rig, webbing, hardware, pilot chutes and number of seams goes. The only difference is a few square yards of fabric, and that stuff weighs only one ounce per sq. yd. So once you have a basic rig and canopy built, adding 90 sq. ft. (9 sq. yds.) of 1 ounce nylon doesn't change things much.

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Elisha

My cat weighs more than my rig....but my rig is only 18.9 pounds (or maybe it was 19.8 - it's been a while). Any many others are much smaller.

Yes my cat is fat...but he's a big boy orange tabby. He'd be normal at 18 and a lean machine if he could get down to 16.



That's a big freaking cat. I thought my Dlynx was fat.

-SPACE-

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A few days ago I got to jump a TonySuits Jedei Fusion (wingsuit with integrated base rig) with a Trango 205 in it.B|

I have no idea how much it weighed, I only know my stash bag will never be anywhere near as light again, and that makes me sad:(
Do you want to have an ideagasm?

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BIGUN

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and a crossfire 2 169 weighted 21.6.



So exactly how much of a lard ass are you? ;)



I always kinda wondered what fabric and stitch weight really added to wing loading, because the wing IS the fabric and stitches.
I can see lines and risers maybe, but it seems that true wing loading would be weight w/o fabric and stitches.
I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

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turtlespeed

***

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and a crossfire 2 169 weighted 21.6.



So exactly how much of a lard ass are you? ;)



I always kinda wondered what fabric and stitch weight really added to wing loading, because the wing IS the fabric and stitches.
I can see lines and risers maybe, but it seems that true wing loading would be weight w/o fabric and stitches.

No, because the wing must support *all* of the weight, not just what is slung below it.
"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

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I can see lines and risers maybe, but it seems that true wing loading would be weight w/o fabric and stitches.



The wing still has to support its own weight. You think if you lined the seams of a canopy with 20lbs of lead tape it wouldn't change the way it was loaded?

That said, I'm sure weight on the canopy doesn't affect flight behaviour in the same way as weight of jumper and rig penduluming underneath. but the, that in turn is affected by all kinds of other factors like line length.

So long story short yeah, wing weight is part of wing loading.
Do you want to have an ideagasm?

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jakee

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I can see lines and risers maybe, but it seems that true wing loading would be weight w/o fabric and stitches.



The wing still has to support its own weight. You think if you lined the seams of a canopy with 20lbs of lead tape it wouldn't change the way it was loaded?

That said, I'm sure weight on the canopy doesn't affect flight behaviour in the same way as weight of jumper and rig penduluming underneath. but the, that in turn is affected by all kinds of other factors like line length.

So long story short yeah, wing weight is part of wing loading.



Where is the line drawn?

Isn't it two different loadings? The weight of the device using itself, and air pressure to create lift, while another loading of what it supports with that lift.
I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

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Where is the line drawn?



With a parachute the line is drawn at exit weight. With other wings, such as aircraft wings, the line is drawn at Maximum Take Off Weight. You can't subtract the weight of the wing when you load your aircraft. Just try telling the FAA that you aren't overloaded because "the wing doesn't count". Same idea.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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gowlerk

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Where is the line drawn?



With a parachute the line is drawn at exit weight. With other wings, such as aircraft wings, the line is drawn at Maximum Take Off Weight. You can't subtract the weight of the wing when you load your aircraft. Just try telling the FAA that you aren't overloaded because "the wing doesn't count". Same idea.



I'm not 100% convinced that there is not a partial delineation.

Nominally yes, I get that wing loading is derived from exit weight.

My question is more about actual numbers.

Sort of like a nominal 2x4 is a 2x4, but a 2x4 is actually 1 5/8" X 3 5-8".
I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

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My question is more about actual numbers.

Sort of like a nominal 2x4 is a 2x4, but a 2x4 is actually 1 5/8" X 3 5-8".




Nominal numbers are just that, they are names assigned to aid in identifying things. Wing loading is not decided by what something is named. It is calculated by using actual weights. Of course in parachutes there is the problem that actual sizes are not always calculated in the same way. Just because a PD 170 is called a 170 does not mean that it's actual area is 170 sq. ft. So being accurate about the weight is only half of the equation. So really, in the end, wing loading calculations we use are only approximate. Go ahead and subtract the 6 lbs. that a canopy weighs if you like. The effect will be minimal.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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A quickly written opinion on all this:

======= Edited to add short version

Ultimately, all the weight matters for the wing loading. That's the total load the aerial vehicle has to support. Stitches and all.

But people can define different types of payload if it is useful to them.

And at an engineering level, yes one can vary what one includes --eg the lines don't have to carry the weight of the stitches and fabric that's above them. But that's minimal.

=========== Long version

Well you can always define various types of loads added to an aircraft.

In an airplane you can have just the weight of the passengers & baggage as payload, or also include the fuel, or also include crew and removable equipment weights. Stuff like that; one can have a bunch of different defined weights.

But ultimately, it is the total weight of the whole airplane and everything in it, just like the whole parachute system and jumper, that are the load that has to be sustained by the aerodynamic surfaces.

(Calculating the wing area to use for the wing loading on a plane is an area where one can get use different definitions and standards. Eg, assuming the fuselage does not contribute to lift other than extending the wing through the fuselage to calculate the nominal area. But issues of definition apply to parachutes too. Constructed area, bottom skin or PIA area, inflated area, inflated projected area? As long as everyone is clear on the definition used.)

If someone wanted, they could define some sort of parachute payload weight that includes only the jumper, or only from the 3 rings down, or only the links down, not including the main parachute. No problem with that as long as there's some purpose to it and everyone is on the same page.

Now if you want to get into the engineering of the whole system, then will have to look at where the weight is. Yeah, lines don't have to take the weight of the fabric above the, just everything below, although it isn't a big difference from the total system weight. On an airplane, it all matters more for the stress calculations -- Having a lot of fuel in the wings (rather than in the fuselage) or a lot of wing weight spreads the load out across the wings, decreases the bending moment and stresses at the root of the wing from the fuselage.

As for rig weights, my first instructor years back, Bob Wright, built a couple rigs for himself, in about the late 1980s, that were as light as 11 lbs. Reserve was hand deployed over the shoulder, slip-in 1" wide leg straps with no adjustments, that sort of thing. Impressive.

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Where is the line drawn?



Nowhere. There isn't a line.

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Isn't it two different loadings? The weight of the device using itself, and air pressure to create lift, while another loading of what it supports with that lift.



Why?

Part of what the wing supports is the weight of the wing. It has to be, it's not getting any 'free' lift force from anywhere else.

Again, ask youself if the wingloading changes if you somehow make the fabric of the canopy extremely heavy, to the tune of 20 or 30lbs - the answer is obviously yes. So why wouldn't the normal fabric of the canopy count? Because it's pretty light? Doesn't matter, you can apply that logic to anything.
Do you want to have an ideagasm?

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jakee

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Where is the line drawn?



Nowhere. There isn't a line.

Quote

Isn't it two different loadings? The weight of the device using itself, and air pressure to create lift, while another loading of what it supports with that lift.



Why?

Part of what the wing supports is the weight of the wing. It has to be, it's not getting any 'free' lift force from anywhere else.

Again, ask youself if the wingloading changes if you somehow make the fabric of the canopy extremely heavy, to the tune of 20 or 30lbs - the answer is obviously yes. So why wouldn't the normal fabric of the canopy count? Because it's pretty light? Doesn't matter, you can apply that logic to anything.



Can you apply it to quantum physics?

I'm not trying to change the system of easy definition to calculate, mostly safety and performance goal posts, I'm just trying to see what the actual reality is in it.

What would the actual numbers be.
I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

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I'm not trying to change the system of easy definition to calculate, mostly safety and performance goal posts, I'm just trying to see what the actual reality is in it.

What would the actual numbers be.



The actual reality and actual numbers of what?

Wing loading isn't a measure of how a canopy flies - there's way too much more going on for it to be that simple. It is only what it says it is, wing loading. And the weight of the wing itself is part of the load that the wing supports. It's that simple.
Do you want to have an ideagasm?

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turtlespeed


Can you apply it to quantum physics?

I'm not trying to change the system of easy definition to calculate, mostly safety and performance goal posts, I'm just trying to see what the actual reality is in it.

What would the actual numbers be.



Psst...Turtle:
If the weight of the wing is not included, then this would have a wingloading of zero.
"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

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ryoder

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Can you apply it to quantum physics?

I'm not trying to change the system of easy definition to calculate, mostly safety and performance goal posts, I'm just trying to see what the actual reality is in it.

What would the actual numbers be.



Psst...Turtle:
If the weight of the wing is not included, then this would have a wingloading of zero.

I was speaking specifically of canopies that are deployed and functioning in flight.

I didn't see any risers on that little toy.
I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

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I was speaking specifically of canopies that are deployed and functioning in flight.

I didn't see any risers on that little toy.



So what? As far as wing loading goes there is no difference.
Do you want to have an ideagasm?

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turtlespeed

***

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and a crossfire 2 169 weighted 21.6.



So exactly how much of a lard ass are you? ;)



I always kinda wondered what fabric and stitch weight really added to wing loading, because the wing IS the fabric and stitches.
I can see lines and risers maybe, but it seems that true wing loading would be weight w/o fabric and stitches.

"wing loading" would include the entire aircraft mass, so yes it all is included.

If we get really scientific about the physics of any aircraft in flight including a parachute, the total mass of the aircraft(parachute) being accelerated(maneuvering) would be included. This means the air inside the cells of the canopy is included. For stable, unaccelerated flight, buoyancy negates this air but it is still a part of the aircraft's inertial mass. The loading on the airfoil would even change (while maneuvering) if you have a full breath or air in your lungs or have let all the air out of your lungs.

Of course we don't care about these things because the mass of the air inside the inflated canopy is probably less than 1% of our exit weight.


Think of a 747, empty of all cargo but with fuel tanks full. It has to accelerate down the runway to takeoff, but even though it is empty of all cargo it still has ambient air (air is heavy:|) in all the voids within the aircraft not occupied by hardware. That is a lot of air. Cabin/cargo area alone is about 1000kg worth of air that has to be accelerated. Including all voids probably another 500kg. The aircraft displaces that volume + the volume of the non-air material structure and fuel, cargo, passengers, etc. All of this must be accelerated down the runway and in any maneuver that aircraft makes.

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One could have up to 10 lbs of air in a big student canopy, and something like 2 lbs in a small canopy, very roughly. (About 2.25 kg mass per cubic meter for air near sea level). Might actually be useful to include if one were modelling dynamic maneuvering.

To reinforce what Calvin said, the air mass only matters for maneuvering and not steady state flight since the air is neutrally buoyant in the air.

But lets not make this too complex Calvin, or else we'll soon be talking about what happens if the 747 taking off has a treadmill in it facing backwards, with a bunch of pigeons on it, that suddenly flap upward, while holding helium balloons in their beaks. :P

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