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What can i expect

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I'm going to be travelling to CO soon and will be heading to Mile Hi, the elevation is considerably high ten my home dz (500'MSL)
So i understand (froma website application) that at Mile hi i will be jumping my 135 Stiletto at an apparent wing load of 1.7psf, I currently load it at 1.5ish. (200pounds out the door on a 135).
So what can i expect when i get to Colorado?
More speed, what else?
You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?

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More speed, more dive and some bomber swoops.

I bumped my turn 100' on my first jump there and found that I needed 125' for my typical 270. That's just me, though. YMMV.

Be careful and bail if you have to. Remember that the "power" in your toggles coming out of the dive if you have to dig will be less.
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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I've been competing at Mile Hi since 2005 and train at sea level. I find my canopy feels about 1 size smaller than at sea level.

More importantly than bumping up your turn, is bumping up your roll out sight picture. Most people start turning higher, but keep turning till it 'looks right'...so, in CO it should look a little high but won't really be.

Treat it like a new canopy - do a straight in, then slowly work back to your usual turn - this time of year it's getting cold so DA will be less of a factor and you'll just be dealing with the altitude about sea level.

In a nutshell, be prepared to be low - if you're low, be prepared for it to take longer to respond. Basically, don't go balls to the wall right away :)
Blues,
Ian

Performance Designs Factory Team

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Yes and no.

The response from the toggles would be quicker, but the reaction of the canopy will take more altitude (as in it will take more altitude to bail from a turn and you'll burn more altitude in any other maneuver). Thus shortened to "you'll have less power" when referencing a save your butt maneuver.

Atleast that's my understanding and what I felt like was going on. Please correct me if otherwise.
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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Don't let jumping in Colorado freak you out. It's not like you are going to be there in the middle of the summer on a hot 100+ degree day where the density altitude is maxed out. Sure things will likely be a little faster than you may be used to, but just take the first few jumps easy and try not to induce too much extra speed until you get used to the area. Plus don't forget to finish your flare.


Try not to worry about the things you have no control over

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Cameron, from the aussie national team, was out last weekend and found it not too be that big of a difference compared to what he's heard about the place. he said he raised his altitudes about 70'. it's pretty cold right now so like the others said raise your altitudes but it won't be as big of a difference from what it is during the summer.
Slip Stream Air Sports
Do not go softly, do not go quietly, never back down


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Actually, I believe he's correct. The relative wind flowing over the wing is the same.

Pilots taking off at high elevations experience this - their ground speed is far higher than they're used to but the aircraft hasn't achieved the required take off airspeed (which is the same).

Blues,
Ian
Performance Designs Factory Team

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no, less atmosphere does not = less velocity.

A fixed foil (canopy, wing, rotor, etc.) requires "X" unit volume of Earth's atmosphere flowing to remain in flight, and since air density (volume of Earth's atmosphere) decreases with increasing altitude, the only way to maintain the required volume is to increase velocity (air speed). You have the same volume of air flowing over your wing at a given altitude, but at a higher velocity. This is why your canopy will have a higher stall speed at higher elevations.

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I'm going to be travelling to CO soon and will be heading to Mile Hi, the elevation is considerably high ten my home dz (500'MSL)
So i understand (froma website application) that at Mile hi i will be jumping my 135 Stiletto at an apparent wing load of 1.7psf, I currently load it at 1.5ish. (200pounds out the door on a 135).
So what can i expect when i get to Colorado?
More speed, what else?



it is different, but it is not as different as you expect it to be.

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wouldn't there be more power in the toggles because of the higher speed?



No because there are fewer air molecules.

You get the speed of a canopy 1-2 sizes smaller (depending on when you come; in the summer we're a lot hotter than standard conditions at 5000 feet and end up with 8000-10000' density altitudes) but not the control responsiveness.

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I'm not saying less atmosphere=less velocity.
Your velocity in relation to the air is the same; same amount of air molecules flowing over wing.
Velocity in relation to the ground is greater. Stall speed is higher in relation to ground speed.
When you are flying the relative wind hitting your face will feel the same no matter what altitude, It's when we look at the ground that we feel we are going faster, and we are in relation to our movement over it.

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We don't need to be getting into this sort of thing folks. Let's go back and read what the OP was asking. Myself and several others have already mentioned that the OP shouldn't freak out too much about jumping in CO. Sure his landings may be a little faster than he is used to, but you know what? He may actually enjoy the added speed. The vast majority of my jumps are at altitude in Colorado (this is where I first started jumping), so I learned to swoop in that environment. But in 2005 when some of the best swoopers in the world came to Colorado to enjoy what we knew all along, they too enjoyed the added speed of swooping at altitude and the vast majority of them didn't have any major issues adjusting. Set up a tad higher, a tad further back and try and come out of the turn a tad higher than normal and he should be fine.

Like anyone who wants to swoop, the OP just needs to be smart and not go too big on the first few jumps in CO until he gets used to the environment. But chances are, he will be fine and he may just find that he enjoys jumping in CO.


Try not to worry about the things you have no control over

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nope, your moving faster through the air as well. Airplanes have a higher stall speed at altitude, stall speed is only measured in air speed, and ground speed is irrelevant.

Air is liquid. think of it this way, if air was molasses your canopy would have a harder time pushing through it. now if it was water it would move through it faster (less viscosity) with the same amount of energy being put in to the system. The amount of energy (gravity) being put in will be the same, but because the atmosphere is thinner, you will be moving faster through it.

The phenomenon that you describe sounds like the difference between landing into the wind and landing downwind. the column of air that the canopy operates in is stationary in relation to the pilot, but moving in relation to the earth, thats why the amount of air you feel on your face (air speed) is the same if you point your canopy into the wind, or if your are running with it, but you will have a very different ground speed. I can assure you the two are unrelated.

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Just a pilot's quick post:

With IAS (Indicated Air Speed) remaining constant (i.e. under canopy flying straight and level), TAS (True Air Speed), which is the airspeed that we are actually travelling through the volume of air, goes up as you increase altitude. As a result, ground speed will go up (considering no wind) as you increase altitude. Increasing temp has the same affect.

As an example on a bigger scale, Flying in the Citation X at 45,000' ish, our indicated airspeed will be approx. 250 kts, but our TAS will be approx. 560 kts (.92 Mach).

I will now continue lurking.



"I promise, I will never die."

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