Basejumper.com - archive

Has anyone had much experience with high altitude jumps and landings? I'm looking at an exit point that will put my landing in the 13-14 thousand ft (above sea level) range. There is a water landing option, but i'm wondering if that will be necessary. Thanks.

at least the water will be VERY COLD

Not to much experience but two jumps and landings above 4000 metres no diferences as usual

not quite that high, a couple landings @ 10K MSL. higher speeds with softer controls

I've landed at about 12K and it's just like landing at any high-altitude DZ: you have faster airspeed, a faster rate of descent, and less air through which to flare, so you have to flare higher than normal and expect your flare to take longer to take effect.

Your wing loading is also important; try to be no higher than .7.

A ZP topskin will also help at high altitude.

Finally, you need to have good canopy handling skills and be very confident of them because your margin for error is much smaller at high altitude.

If you have any doubt, go for the water! As the Bridge Day saying goes: You dry off faster than you heal.



44

from a technical perspective...
once your canopy stabilizes in full flight, it will always generate exactly the weight of the jumper and gear.

air density decreases with altitude. to compensate, the parachute must fly faster. of course the landings will be faster as well, if you use the same technique.

if you want to see how the parachute handles, just do a 13k hop-n-pop.

if you want to use a larger parachute, get one 1.5x larger than the one you jump at sea level. (the US Standard Atmosphere states that the air density at 13k ft is approximately 2/3 of sea level.)

if you want to fine tune your landing technique (and get familiar with faster landing speeds), practice downwind landings. OR jump a canopy 2/3 the size of the one you jump. OR carry 50% more weight.

of course, hypoxia might pose a problem. if you plan on jumping with oxygen and other gear, remember to include the gear in your weight calculations.

of course, these are not perfect comparisons. (larger canopies tend to have longer line sets, no atmosphere is "standard," Reynold's number scaling issues, etc.) the comparisons should get you closer to the high altitude reality.

YMMV

Thanks everyone for all the useful feedback. Just wanted to see what people's thoughts were. The jump itself will be a bit of a mission, it's a nice cliff pretty high up on mt. Kenya that I've been looking out. Going up the mountain tomorrow, so hopefully i'll get a better idea of what the LZ looks like. I have jumped my current canopy at around 8k ft, with a bit of extra gear, and that was fine with a no wind landing. Just wanted to see if things get exponentially worse the higher you go, or if anyone had much experience in this sort of jump. Theoretically, (unless I'm mistaken) the flare should take place at the same time it normally does, it will just be a much much faster landing due to the thinner air. With any luck i'll get some nice cold weather to make up for the altittude. :)

not that I know much about high altitude jumps(I only have one actual high altitude jump at a bit above 13,000ft off of a ~900ft wall), but I was personally more worried about a PC hesitation due to the thin air rather than flare power.

Was that in North America ?

Yep, it was in Kansas

I saw something on TV about the worlds highest DZ. People were landing at the base ov Everest. It said they had special material for the canopys? Maybe do some research on that? Where are you going? Or is it on park property,hush hush kinda thing?

Some sweet cliffs I've been looking at on Mt. Kenya. Should be fine, I've jumped in other national parks in Kenya with minimal hassle. We'll see how it goes.