When does Alti record the end of a jump

[WooHoo 0]

I tend to pull at around 4000. Jumping a big old Spectre 210, when I check my audible alti it will show 3400 or + / - 100ft as the height that I came out of freefall.

Someone told me that is the height the pin was extracted, others when deployment began slowing me down, and yet others say when I was under canopy, can anyone enlighten me.

What is the point at which the NEptune or Protrack displays the second number?

Thank

[kris2extreme 0]

My neptune records pretty closely to when i'm in the saddle.

[jakee 1,593]

Certainly not when the pin is extracted - I mean, how would it know?

I would imagine that it is at some point during the snivel that deployment usually registers on the protrack, though I would be interested in knowing if it is a set vertical speed or a rough deceleration profile that causes it to 'trigger'.

For reference, I've had my Pro-track (in normal mode, not SLO) register deployment when I was going ~55mph vertical in a wingsuit.

Do you want to have an ideagasm?

[faulknerwn 38]

I once had my spinning line twists and my Pro-track never saw the deployment of my main - just my reserve...

[pilotdave 0]

I've compared my neptune's deployment altitude with the graph in paralog. Couldn't quite tell how they were choosing the deployment altitude... it's not the beginning of the sudden drop in fallrate. Been a while since I compared them, but it also doesn't seem to be the end of the deployment either. I think it must look for a large deceleration that is sustained for a certain amount of time or something before it logs an opening.

My experience checking the deployment altitude after a jump is typically that it shows the very bottom of the opening... always seems low.

Dave

[za_skydiver 0]

Quote

Certainly not when the pin is extracted - I mean, how would it know?

I would imagine that it is at some point during the snivel that deployment usually registers on the protrack, though I would be interested in knowing if it is a set vertical speed or a rough deceleration profile that causes it to 'trigger'.

Ive had a premature brake release on one toggle a few times, and the protrack only recorded the end of my freefall after i was flying level under a fully inflated canopy. (i know this because after i levelled myself off and released the other brake i checked my alti again, which was more or less the same as what the protrack displayed when i checked it on the ground).

So based on my experience, i think the "dpl. alt." on the protrack is the height where you are actually under a fully inflated and level canopy.

Some dream of flying, i live the dream...

[jheadley 0]

I check my altimeter immediately after opening, the pro track deployment altitude seems to match when in the saddle pretty accurately.