speed and cold | http://www.speed-skydiving.com

Admin (mw)
Administrator

Posts: 178

speed and cold Oct 5, 2003 20:31:56 GMT -5

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Post by Admin (mw) on Oct 5, 2003 20:31:56 GMT -5

hey,

did anybody notice any correlation between the temperature and the speed ? the colder, thicker air should make it harder to achieve higher speed, but today's experience i had says different.

this weekend it got freaking cold in new england. it was about 0C when i woke up at the dz this morning ... it warmed up a bit but it stayed about -15C at altitude. i did 5 jumps today with my speed skydiving averages of 441, 421, 421, 442 and 428 kmh.

these are pretty high numbers for especially since i've been slaking lately

that got me thinking, do we really go slower when it's cold ? or is it just extra stuff under the suit that makes it more tight and faster ?

also on one of the jump (attached) my average for the whole jump was 407 kmh which is the highest average i've seen on my pro-track. and people said i was extra noisy in freefall today. i guess it's a crisp air

so, does anyone know about "speed and cold" ?

stan.

i didn't find how to attach files to the post ! does anybody know ? anyway, here is the pic:

harrier.itc.if.ua/~chris/keep/cold.gif

Last Edit: Oct 5, 2003 20:36:52 GMT -5 by Admin (mw)

--
it's not about defying gravity, it's how hard you can abuse it. speed skydiving it is ...

MaxMadMax
New Member

Posts: 1

speed and cold Oct 11, 2003 21:39:47 GMT -5

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Post by MaxMadMax on Oct 11, 2003 21:39:47 GMT -5

Greetings Speed Brothers & Sisters

For what ever my 2 cents worth is....It seems easier to split the tube with cold air rather than warm air. Maybe it's a laminar flow (cold) vs the warm (turbulent) air thing.

What ever it is....just let me go fast!

Thanks,
Max Mad Max

Admin (mw)
Administrator

Posts: 178

speed and cold Oct 11, 2003 22:34:25 GMT -5

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Post by Admin (mw) on Oct 11, 2003 22:34:25 GMT -5

i talked to the pilots today and i think i know what it is. altimiters should be adjusted to the ambient temperature since the gradient of the preassure change over the altitude is different when it's colder. in other words if your alitimiter shows 13k feet in winter, it's actually lower and in sumer it's higher. it's fine for the planes since they all are lower or higher but for accurate speed measurements it does mater. one of the pilots promised me he whould come up with compensation coefficient for speed and the temperature. i don't think it'll be usefull though

so we do need ideally have the speed measured from the ground.

stan.

--
it's not about defying gravity, it's how hard you can abuse it. speed skydiving it is ...