How much difference does DZ altitude make when it comes to landing your canopy?

[grue 1]

I recently was talking to someone who expressed surprise that I was transitioned to a 230sqft canopy (about a 1:1 wingload) for jumps 7, 8, and 9... but not because of the actual wingload by itself.

He was more surprised that I was jumping a roughly 1:1 at my DZ, which has an altitude of 1,400' or so. How much of a difference is it to be jumping a 1:1 at 1,400' MSL than it would be to land at a DZ at sea level?

cavete terrae.

[flyangel2 2]

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my DZ, which has an altitude of 1,400'

That's nothing, come to Colorado were we have a field altutude of 5,500. Talk about fast landing.

May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view. May your mountains rise into and above the clouds. - Edward Abbey

[grue 1]

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my DZ, which has an altitude of 1,400'

That's nothing, come to Colorado were we have a field altutude of 5,500. Talk about fast landing.

But I -like- my legs! :)

Would the 1,400 between here and sea level actually make that much of a difference though?

cavete terrae.

[GreenLight 8]

You won't see much of a difference between those two altitudes. Landings at lower altitudes are easier than higher ones. The air is fatter lower but between 1400 and 0 it is not really that noticeabel... Now if you go to Skydive Tahoe you'll probably carve a nice ditch into the ground....

Green Light
"Harry, why did you land all the way out there? Nobody else landed out there."
"Your statement answered your question."

[tdog 0]

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That's nothing, come to Colorado were we have a field altutude of 5,500. Talk about fast landing.

I think it is the other way around. Sea level; talk about a slow landing... I have on video my first sea level landing. I gave it a strong mile high flare and all of a sudden I was way above the ground, thinking, s&^%, where did all that power in the wing come from. My sea level friends laughed so hard at me as I was popping back up going for a ride when I should have been landing.

[BenHall 0]

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That's nothing, come to Colorado were we have a field altutude of 5,500. Talk about fast landing.

I think it is the other way around. Sea level; talk about a slow landing... I have on video my first sea level landing. I gave it a strong mile high flare and all of a sudden I was way above the ground, thinking, s&^%, where did all that power in the wing come from. My sea level friends laughed so hard at me as I was popping back up going for a ride when I should have been landing.

How much different is it? I've only jumped in CO at 5'5 (and a few at 6'5), but I'll be jumping much closer to sea level this summer. I don't want to make the same mistake! Is the difference really that much?

[johnny1488 1]

When I went to eloy this past winter I definetly noticed it a lot. I was haulling ass around the corner on every jump.

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

[tdog 0]

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How much different is it? I've only jumped in CO at 5'5 (and a few at 6'5), but I'll be jumping much closer to sea level this summer. I don't want to make the same mistake! Is the difference really that much?

Ya, I really felt it a lot... But, I tip toed the landing after popping up, so the "mistake" was completely within a safe landing... I think the bigger "danger" is going up to 5,500 for the first time ever or after a few day trip to sea level... That is where I found myself landing hard and thinking all of a sudden things were going much faster... I.E. coming home sucked until I re-dialed it in.

Kind of like when you drive cross country... When you go 75MPH for a while, it feels normal... Then you get a cone-zone and have to go 55MPH. That feels slow for a while, then feels normal... Once you get back to 75MPH - you feel like you are going real fast, until you get used to it... That is what it felt like for me to go back and forth... Just add a PLF or two at the higher altitude.

[quade 4]

Both altitude and temperature combined play a part and are called "Density-Altitude".

For a breakdown, some rules of thumb how they relate to your canopy and how it will affect your landings; http://futurecam.com/densityAltitude.html

Oh, and don't let people fool you into thinking 1,400 feet is "nothing" (sorry Mar). 1,400 feet MSL combined with 110°F is nothing to be trifled with if you initially learned how to skydive at a sea level airport in a cooler climate.

quade -
The World's Most Boring Skydiver

[Kwoo 0]

Ahhh, That first landing in Eloy on a crisp cool morning right after they watered the grass. Yeehaw!
Under the right conditions 1400 feet can make a difference.

[JohnMitchell 16]

The air at 5000 feet is only 80% as dense as a sea level, so you could WAG that the difference is about 4% per thousand feet. Temperature affects density altitude enormously as well. Hot days can have really hard landings. I think 1:1 loading is a little brisk for a student, but I tend to be prety conservative on that subject.

Ask a pilot about density altitude. They can give you a lot of numbers on all thatl

[kelpdiver 2]

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Oh, and don't let people fool you into thinking 1,400 feet is "nothing" (sorry Mar). 1,400 feet MSL combined with 110°F is nothing to be trifled with if you initially learned how to skydive at a sea level airport in a cooler climate.

As I found at Perris and Elsinore last August. The kill line PC might also have contributed, but definitely was a bit faster.

[RkyMtnHigh 0]

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my DZ, which has an altitude of 1,400'

That's nothing, come to Colorado were we have a field altutude of 5,500. Talk about fast landing.

Tell me about it! Now that I'm adjusted to sea level soft landings, I'm chicken to go back and jump at MileHi, plus I slightly downsized since I was there.

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[jose 0]

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Would the 1,400 between here and sea level actually make that much of a difference though?

Yes, there is a difference. I was there canopy training with Clint Clawson, dialing in my HP set-up and when I got home to sea level, I have had to adjust my turn initiation altitude. I was coming out high if I did my 90 at 320 like I was at Perris, so now I make the turn at around 280. But there are other factors as well to take into consideration when jumping at other DZ's.

Air density is much different in the desert as it is here at Vancouver BC, so I had to adjust for that as well. Wind directions coupled with the above 2 can make a big difference. If your landing area only allows a N2S or S2N (just for example) you might be getting a crosswind landing with either direction.

Now jumping in Moab at 4500ft, with no moisture is sure a hell of alot of fun, but meant that I had to add around 250 feet to my 270's. So in some cases is a huge difference, and rather small for others.

[wingnut 0]

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I've only jumped in CO at 5'5 (and a few at 6'5), but I'll be jumping much closer to sea level this summer. I don't want to make the same mistake! Is the difference really that much

yes!!! i went from 4500ft in utah to abot 1200 here in ohio and i am way slower, it is very noticable, the turns i do here onto final would put me in a helicopter on the way to surgery if i was to do them at the same altitude back in utah..... nothing like landing a canopy loaded at 1.4:1 in 100+ weather at a field elevation of 4,500ft msl.... ah some things i really won't miss about utah!!!!

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"i have no reader's digest version"

[adamsr 0]

i went to a boogie at a dz that was 2000 feet above sea level, and it was noticably faster, and harder to time the flare.

pretty much everyone was messing up their landings a bit, but by the second or third day everyone had got used to it, and it felt normal. so it does make a difference but once you have adjusted it's fine. Just like going down a canopy size, it takes a while to adjust.

[riggerrob 643]

Oh joy!
I only have a couple of jumps on my recently re-lined Stiletto 135, at sea level and tomorrow I will jump it at 3,000 MSL (Beiseker, Alberta).

Note to self: conservative approach.

[adamsr 0]

i'm sure you'll be fine, it's not as if you're short of experience!!

I only had 80 jumps at the time so wasn't fantastic at canopy control anyway!

[ryoder 1,590]

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Tell me about it! Now that I'm adjusted to sea level soft landings, I'm chicken to go back and jump at MileHi, plus I slightly downsized since I was there.

You? Or the canopy?

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[RkyMtnHigh 0]

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Tell me about it! Now that I'm adjusted to sea level soft landings, I'm chicken to go back and jump at MileHi, plus I slightly downsized since I was there.

You? Or the canopy?

Both.

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[Spizzzarko 0]

When jumping up in colorado, your canopy will act a size smaller. That's about the easiest way to explain it.

[DrewEckhardt 0]

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He was more surprised that I was jumping a roughly 1:1 at my DZ, which has an altitude of 1,400' or so. How much of a difference is it to be jumping a 1:1 at 1,400' MSL than it would be to land at a DZ at sea level?

Speed increases 2% for every 1000 feet of density altitude which is what you'd get if you shrunk your canopy by 4%.

We go really fast in Colorado.