New Speed Skydiving record

[maggyrider 10]

GoneCodFishing

I think with that graph being average speed, is it possible that the average speed increases faster than the speed itself?

The graph shows actual speed - not average speed.

Nice words are not always true - and true words are not always nice.

[DHemer 0]

The video posted above shows deployment start at around 660m (2165ft) and doing ~ 200kph (124mph).

In this video the peak speed was 587 kph.

If people are now able to go 100kph faster than a year ago I think the competition the window needs to move up.

Imagine coming out of a dive at 600+ kph, going into a bit of a track to bleed off speed, opening up flat and hearing your audible for deployment.
Pitch while going too fast can kill you or waiting will put you below what I consider a decent decision altitude.

A delay of a second or 2 after leaving the window will put you low at those speeds

[evh 22]

I think the graph shows the running average over the previous 4 seconds, which makes sense in order to smoothen out the curve and eliminate very short peaks due to turbulence, noise etc.
Even so, the difference in average speed divided by a certain time gives the average acceleration.... which in this case is physically impossible (at least based on my rusty math capabilities)

[GoneCodFishing 24]

maggyrider

***
I think with that graph being average speed, is it possible that the average speed increases faster than the speed itself?

The graph shows actual speed - not average speed.

Uh my bad. The legend that says the red line is "avg speed" got me confused.

[mathrick 2]

maggyrider

Basically yes... I think that speed skydiving given the current measurement methods is complete nonsense. I mean, just look at the deployment speeds of some curves?! Deploying at over 250km/h - that's a pull in headdown. I once had a deployment happen at the transition from sit to track and that was already painfull as f*ck. And now I should believe in curves telling me that people pull at over 250km/h on a regular base?

It shows deployment at 200km/h, which is the typical belly speed. I open at anywhere between 180 and 210km/h[1]. Also consider that it's quite possibly showing SAS ("skydiver airspeed") if they're using ProTrack, which normalises barometric altitude and speeds to 3000ft MSL at standard conditions. Thus the indicated speeds might not correspond to physical speeds exactly.

It is however indicative of the problems in speed skydiving that we're having this discussion here wondering just what the hell their measurement method is. If it were governed properly, it'd be blindingly obvious and nobody would have any doubts.

[1] My Viso is set to SAS, so that's the speed it shows, though at the deployment altitude those two are very close anyway.

"Skydivers are highly emotional people. They get all excited about their magical black box full of mysterious life saving forces."

[Amazon 7]

mathrick

***Basically yes... I think that speed skydiving given the current measurement methods is complete nonsense. I mean, just look at the deployment speeds of some curves?! Deploying at over 250km/h - that's a pull in headdown. I once had a deployment happen at the transition from sit to track and that was already painfull as f*ck. And now I should believe in curves telling me that people pull at over 250km/h on a regular base?

It shows deployment at 200km/h, which is the typical belly speed. I open at anywhere between 180 and 210km/h[1]. Also consider that it's quite possibly showing SAS ("skydiver airspeed") if they're using ProTrack, which normalises barometric altitude and speeds to 3000ft MSL at standard conditions. Thus the indicated speeds might not correspond to physical speeds exactly.

It is however indicative of the problems in speed skydiving that we're having this discussion here wondering just what the hell their measurement method is. If it were governed properly, it'd be blindingly obvious and nobody would have any doubts.

[1] My Viso is set to SAS, so that's the speed it shows, though at the deployment altitude those two are very close anyway.

Granted that is has been a few years since I competed but they used two special RED Protracks that have closer tolerances for competition. The Red Protracks are cycled among the competitors to remove having one person use one set thru the competition that might induce a perceived higher speed or lower speed for any given set if one set read a bit higher than another set of them. That would remove any chance of giving any one competitor an advantage or disadvantage.
The Official Protracks are also affixed to the main lift web near the center of gravity of the diver. Mine I put into little pouches on the side of my container that allowed them to be as far outboard of my body in clean airstream and prevent burbles that might kick me out of bounds if one read too high compared to the other. The two Protracks had to both register the speed within 18KPH ( if I remember correctly) for it to be an IN BOUNDS jump. If they read more than that difference it was OUT OF BOUNDS jump and did not count. The speed you were awarded was an average speed over the measured Kilometer and the Protracks were averaged between the two devices.

http://speed-skydiving.com/images/files/ISSAWorldSeriesRules2016.pdf

[evh 22]

Using two protracks is ofcourse better than one, but still...
The fact that both agree does not prove that the value is correct. A design flaw in the software, the electronics or the housing could have exactly that effect.

[Amazon 7]

evh

Using two protracks is ofcourse better than one, but still...
The fact that both agree does not prove that the value is correct. A design flaw in the software, the electronics or the housing could have exactly that effect.

I learned that having more the better.... I had the two on the container... but I also had two in my helmet programmed to go off at the bottom of the Measurement Zone.... when to come out of the track..... and Hard deck....

I learned also to use a full face to make sure I could hear the alarms going off... Open face helmets allow too much noise.. and you do NOT want to miss one of your pre set altitude alarms... that is how I blew up my canopy by dumping at too high a speed... because I was getting way too low.. still going WAY too fast.... highest speed on that practice dive.. 325 MPH.... I was happy with that.... I was not so happy about the opening.... or the cutaway... the DZO was sure I had broken my back from the BLAM they heard on the ground when the canopy opened explosively.

[jumpwally 0]

Specualation and uncertainty abound,,,,,,,,so what was the real speed ?

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