Delay-Altitude-Equipment Chart

guest · November 5th, 1999, 01:52 PM

Hello Everyone,

For the folks who asked, here's a Delay-Altitude-Equipment chart that includes pilot chute size. For all of you out there with BASE web sites you are welcome to post it, we just ask that you leave Basic Research's name and contact information intact.

Please clue me if I made any massive mistakes!!!

Disclaimer, This chart is for planning purposes only and it is not guaranteed in any way!

Enjoy,
Nick_BR

***mknutson*** · January 2nd, 2012, 10:27 AM

I just created a chart that was much easier to read:

Delay Chart

**MMK** · January 2nd, 2012, 09:41 PM

These type of charts always generate some discussion. A quick glance at yours makes me wonder why 2-3s delay with a 48 from 500ft gives me a RED, yet when I take the same delay with the same PC from 600ft it suggests I am going to die.
Here is the link to the Apex chart, which lists a few more combinations and also some useful caveats when reading the chart http://www.apexbase.com/manuals/48_R...ce%20Chart.pdf

**seekfun** · January 3rd, 2012, 02:01 PM

The chart leans toward the conservative, non-experimental end of the BASE spectrum, showing which configurations are known to work well, and which configurations will most likely survive the variability we'll always encounter in BASE. In the same spirit, it may be nice to see a column for stowed vs. hand-held, as I think there are many, many, many jumpers today who go stowed not because it's the most suitable deployment method for the jump, but because it is the most suitable deployment method for proving how bad-ass the jumper is.

Flame away at me, but we've all seen the videos of the guy whose foot is one pico-meter removed from the exit point and the pilot chute is already being extracted from the BOC. In that case, what practical purpose did stowing the pilot chute serve?

**speedphreak** · January 3rd, 2012, 03:19 PM

Originally Posted by seekfun

The chart leans toward the conservative, non-experimental end of the BASE spectrum, showing which configurations are known to work well, and which configurations will most likely survive the variability we'll always encounter in BASE. In the same spirit, it may be nice to see a column for stowed vs. hand-held, as I think there are many, many, many jumpers today who go stowed not because it's the most suitable deployment method for the jump, but because it is the most suitable deployment method for proving how bad-ass the jumper is.

Flame away at me, but we've all seen the videos of the guy whose foot is one pico-meter removed from the exit point and the pilot chute is already being extracted from the BOC. In that case, what practical purpose did stowing the pilot chute serve?

I agree. I believe the basis for this chart (and other iterations of it) were designed years ago before a lot of incremental improvements to the BASE equipment environment and large amounts of experience in a wide range of jumps. No where have I seen any accommodations for vented vs. unvented pilot chutes, ZP vs. F-111, or delay time.

I feel that a better indication of pilot chute selection is delay time, not altitude. I mean really, what's the point of "properly" selecting a 38" pilot chute off of a 900' cliff if all you are going to do is go hand held with a half second delay?

**Blitzkrieg** · January 4th, 2012, 11:59 AM

also, who the hell jumps with a 45" PC?

**Blitzkrieg** · January 4th, 2012, 12:05 PM

those charts are silly... but the Apex link Mick pointed out (and what speed mentioned), the last bullet sums it up. i guarantee that i would have no problems jumping 300' stowed 38" PC with at least two of my rigs. ;^P

· The most common element of pilot chute size selection is based on airspeed/ delay. However with such a wide
range of parachute sizes available today the user must consider the weight of his parachute. Example a smaller
parachute of 200 sq. ft. might use a 38” when a larger 315 sq. ft. might need to use a 42” to get similar results at
the same airspeed.

**seekfun** · January 4th, 2012, 01:23 PM

I gave this a little thought last night, and a parallel occurred to me. In the skiing industry, binding manufacturers publish tables that indicate appropriate settings for binding tension. Binding technicians use the tables as guidelines for setting the appropriate binding tension for skiers with differing height/weight, foot size, and ability level. This is exactly the multi-dimensional dynamic that exists when we configure our BASE gear.

For ski bindings, the chart says "if your feet are this big and your ass weighs this much, then set your bindings to X. But, if you're a more aggressive skier, then you should probably bump it up a notch or two". For BASE, we could say, "if your intended delay is X, and your canopy is X square feet, then your PC should be Y, and bump it down a notch if your experience tells you that you can get away with a little less." We could also say something in the margin about reefing and we could make suggestions about density altitude adjustments...

With this in mind, I mocked up a possible presentation of BASE configuration data that addresses our most common parameters, without saying anything about object height. It mentions distance traveled and speed achieved, but does not suggest in any way how long of a delay is necessary. I also avoided density altitude for now.

NOTE 1: I am shit for artistry, so forgive me if this thing is completely uninspired and devoid of any whiz-bang.
NOTE 2: I AM NOT CERTIFYING THE DATA IN THIS CHART, I AM MERELY SUGGESTING A CHANGE TO THE DISPLAY OF THE DATA AND WHAT DATA WE INCLUDE.
NOTE 3: Please feel free to run with this concept or condemn me to the halls of BASE ineptitude, your call. Either way I'd still have fun joining you at an exit point.
NOTE 4: I attached some binding charts as examples.

Cheers,

Chris

PS - edited to make minor change to chart

**nicknitro71** · January 4th, 2012, 03:46 PM

bump it down a notch if your experience tells you that you can get away with a little less

LOL!

Experience will always concur over the laws of nature!

**seekfun** · January 4th, 2012, 05:42 PM

Good point, Nick. That was poorly stated...

I guess my perspective was that these charts should remain conservative and allow people to adjust once they're better prepared to make informed decisions about what nature will tolerate.

**airdog07** · January 4th, 2012, 06:34 PM

I have 45 ZP, 46 F-111 pc they both work fine

**speedphreak** · January 5th, 2012, 03:27 PM

I know for a fact that a 42" ZP will work for a freefall at 201' (at least it did once...).

**airdog07** · January 5th, 2012, 05:50 PM

I use a 36 for 4sec. delay once, I use a 42 on 320' many times but one time I had a tail gate hangup(I think) almost kill me or seriously injured, you can use what ever you want but you well pay the price. and the list is for beginner Gide line it's not cemented in stone. take care and don't fuck up.