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Ive searched the forum but to no avail. A year or two ago I saw a table showing the number of seconds of delay you are taking vs. your freefall speed at that number of seconds vs. pilot chute size you should be using and I think there may have been smiley and frowny faces on the right telling you good choice or bad, and the height of the jump might even have been on there. There is a chance I am remembering 2 different tables, the pilot chute size one might not have had speed or something. I looked all over tonight and couldn't find it, can someone point me in the right direction? Thanks

Several sources for this:

Morpheus
Tom Aiello
Apex BASE
Lonnie
etc.

Keep looking, you will find it

I created the first one of those, with the happy faces and the skulls, for Basic Research. Todd updated it, or made me do it, I don't really remember, with happy faces and sad faces. I have a copy somewhere, I'll look for it for you.

Or, you can write Todd at Apex BASE and ask for a copy:

perrisATapexbase.com

(You know, change the AT to @)

NickD
BASE 194

Apex's PC reference chart
http://www.apexbase.com/...eference%20Chart.pdf

I've seen the freefall chart with time, distance and speed in the log books they make, but haven't seen it on their site.

Johnny Utah has one on his site :

http://www.johnnyutah.com/freefallchart1.html

Is 300' with a 42" really Black Death?

It depends what type of 300ft it is. Is it a bridge? What is the landing area like? Is it an A with clean sides.

In general, a 45in PC is better for 300ft jumps, but a 42 will also work in certain circumstance.

then we in north east Indiana are all dead......we been jump'in 42" off a couple of our 300' A's

i jump a 280 and ive jumped it with a 44 inch pilot chute from 240ft several times

>>Is 300' with a 42" really Black Death?<<

Keep in mind that chart is kinda old . . .

NickD

i have several from 300-350, stowed with 42".

Just once for me and my big ass 293 seems a bit heavy for the 42''. The ground rush was cool.

Plenty of things that work are still a bad idea.

Like a 38" PC at the Perrine for a whole week

haha, someone was doing their 5th jump or something when I was there and their mentor asked if he could borrow my 38. I said sure as I was using my 42. It was the guys first stowed jump and he asked how many seconds he should take and if he could do a stowed go and throw pretty much. The mentor responded with 'well, you can take a half second if you want, but this PC's going to take 2 or 3!'.

Dumb story, but I laughed.

well, you can take a half second if you want,
but this PC's going to take 2 or 3!

Thanks man, that was funny.

We're all dead in Cincy too. Everyone's been jumping from 280 with 42s but me and I just recently switch from 48 to 42.

Well, that's why I asked. I regularly jump 270-300' with a vented ZP 42" and do not notice a difference between that and a 48".

I realize the chart is old and was probably made up from results from different gear than what we have now, but have the fundamentals really changed?

Nick; you did the original one, how was the data obtained? Was it real world testing or just subjective information? Inquiring minds want to know.

The freefall chart for speed is not quite correct. Notice at 4 seconds it says 72 mph. It's closer to 80mph. Acceleration due to gravity for the first few seconds is 20mph per second.

A wise physicist once told me that 1 sec with a 42 will open faster than go&throw with a 48.

I don't recall the exact year but I probably made that first chart, the skull one, sometime in the early 1990s.

In those days we were still finding that line between big enough, and too big when it came to PCs. Of course we knew full well how too big degrades canopy flight performance, and how too big, too heavy, and thrown too hard could effect on-heading performance. But back then the mindset was still just get some nylon over your head and deal with whatever happens after that.

So I can't really say that chart was based on a controlled testing program. It was based on jumps we, and everyone else we knew, were doing at the time. It was based on the current conventional wisdom.

And it should be noted that every jump we made in those days was a test to some degree. Or at least it always felt that way. Gear and technique was changing at such a frenetic pace it was hard to get into a comfort zone were meaningful testing would be accurate over a large span of jumps. For awhile there it seemed like I was doing something new on every jump.

I'm not saying we didn't do testing in a big way. I don't know how many times Todd dragged us out of bed at 4:30 in the morning to go launch the hot air balloon. But most of these live tests focused on overall rig and canopy design.

And, when I hear someone say about the old daze, "Gee, who thought that was a good idea," I can smile and understand but sometimes I get they fail to see how things have changed.

And not just gear wise. The entire jump environment, envelope is probably a better word, is like night and day. We were doing, at least in our geographical area, more short delays from low stuff than anything else. The odd terminal jump, for us, meant a trip to Yosemite or some Florida/Oklahoma tower. And no one was going stowed on a regular basis. And if anything that probably had more effect on pilot chute size than anything else, at least once people did start to stow.

In the final analysis, and in hind sight, I favored too big over too small on the chart as the former may not have been optimum, but the latter might kill you.

Another aspect to consider is who was that chart for? As a gear manufacturer we dealt with both experienced and in-experienced BASE jumpers. Experienced jumpers never called me on the phone asking about which size pilot chute they needed for a particular jump. But newbies did all the time. So this was for them, and that's why it was conservative.

And we can't discount the 1980's in this discussion. Throughout those years we were using truly humongous pilot chutes. We lived (sometimes litterally) using a little mantra Mark Hewitt came up with it . . .

"May your 52 inflate for you
And in your burble
It shall't not dwell . . ."

NickD

And that's kinda my mindset as well. That second of delay only costs you about 16-18' but contributes a large increase on the pull force generated by the pilot chute.

Faster yes, but not higher !!

I know of several people that used to play a game thats aim was "collecting skulls" from that chart.....

I found that a 42 has more consistant initial inflation than a 46 or 48 with lower delays... a bunch of us experimented off 220ft with 42s and 46s, and found that there wasnt much difference in using a 42...

Saying that, I still take a 46 as a rule of thumb off that height, just because of the "head fuck" I sometimes get with a 42.... even though I know its not logical, especially as I have experienced PC hesi from that height on a 46 but never a 42

I can definatly tell a difference between using my 48 and using my 42, but my 42 is f-111 and my 48 is zp, so maybe it's not a fair comparison.

That's not actually true. When you're calculating differences in deployment height, remember that the difference doesn't add on to the top of the deployment -- it adds onto the bottom.

What do I mean? Suppose that, after you pitch, your canopy takes 1 second to deploy (which isn't at all unreasonable from most of the go-and-throw-ish footage I've seen). Then delaying one second doesn't put you at 1 second (16 feet down) vs. 0 seconds (0 feet) when you open. It puts you at 2 seconds (64 feet down) vs. 1 second (16 feet). So you lose 48 feet, not 16.

Of course, it'll open a little faster after a delay, too, but you'd make that correction from the 48 foot loss...

I have lots in the 320-350 range, stowed with 38". But then, I live in a flat country.

Ronald

And usually open at streetlight height

I missed the part of the chart that takes in consideration the shape of the country.

It's in the fine print on the EULA...

Tell this dude that a 1 sec delay with a 42 woulda been a much better idea...

http://www.youtube.com/watch?v=gIbBSgBzIwM

I really don't see what this youtube URL has to do with a 320-350 feet range. This bridge surely must be way lower then that, only 2,5 seconds canopy ride in the most optimistic case.
Ronald

http://www.youtube.com/watch?v=gIbBSgBzIwM

That is a crazy jump. One of the posts said it was 43 meters. Is that a new lowest standing freefall over hard ground? I remember a video posted on here of a guy jumping a bridge that claimed to be the lowest, think it was 146.' I can't find the link, but he had a highly modified rig with a 52pc, a 6' bridle and double the vent size on his canopy.

Yeah... Greeny

http://www.youtube.com/watch?v=GlttsWMO4F4

But he never claimed to be the lowest.....

Also he posted this "Low Freefall My thoughts":

http://www.basejumper.org/...p;t=1090&start=0

those guys are dumb

>>http://www.youtube.com/watch?v=gIbBSgBzIwM<<

>>>That is a crazy jump. One of the posts said it was 43 meters. Is that a new lowest standing freefall over hard ground?<<<

Hello hikeat,

Me, Moe and Ralph jumped "that" same bridge 20 years ago in about 1989.

It's not 43 meters. It's 85 meters or 280-feet. But the bottom changes with the amount silt that comes and goes with the water flow. It seemed about 240-feet to me. Still high by today's standards but low for back then. We were on our way to the first ever BASE crane boogie in Northern Cal when we came across it. Except boogie is a bit of a stretch considering only Moe and I made jumps from the crane.

I was totality bald then because I was receiving chemo for a bad bout of cancer. So excuse how skulled up I was dressed. I was trying to make friends with death and obviously I did, as the reaper gave me a pass that time.

The BASE rig I'm wearing is a home made job. And I built the bridle and pilot chute too. The PC was 48 inches unless you measured it twice then it came out something else. I still have that rig and sometimes I pull it out just to scare newbie BASE jumpers with.

In the vid Ralph does a direct bag first, and Moe and I figured if that worked we'd free fall it. Then I jump, and then Moe.

The second vid is me making the first jump from the crane. A PCA from about 240-feet. Moe and I both did freefalls from it later that day, but that's on another tape somewhere . . .

http://www.youtube.com/watch?v=W63prSwN70c

http://www.youtube.com/watch?v=mAQDNaC7chs

NickD
BASE 194

Nick,

Thats not the same bridge as Greeny is doing.

Gotcha, thanks . . .

NickD

Bungee Adventures John and Peter Kockelman.

Thanks for posting that video.

One day at a Gym in Santa Cruz, a guy was wearing a Boing t-shirt. It just had to be for bungee jumping so I asked him about it. He gave me a Bungee Adventures business card so the very next day, I called and made an appointment. It must have been 1990 when I made about 10 jumps from that and another crane. My 3rd bungee jump wasn't a jump, it was a negative. They hold you down and lift the basket to around 250 feet and let you go. Talk about fun... and cage rush. I went back with my brother and a few other people. One of the jumps I did 4 back flips from the rail. Doing the flips was quite the mind fuck. It took quite a while to psych myself out but finally went for it. Damn that was so fun!


Anyway, when the first bungee jumping session was over, they put up a fold out table from which to sell videos. On the table was a pamphlet for a dropzone. They had a picture of a guy doing his AFF level 1. My eyes lit up because I knew what was next. I also asked if people jumped from that crane and he said yes. It was probably you they were talking about. Small world

As long as I can remember, I wanted to skydive and after seeing that picture, I knew my first jump was going to be a free fall. Sept 15 1991 was day of my first skydive. Your video sure puts things into perspective for me because you were already BASE jumping when I did my first bungee jump.

The bridge you showed is 240. That's a fun one, dicey at times and people who haven't develped quick reflexes yet should stay away. Greeny's low bridge is close by. I'll leave that one alone

Good stuff!

Yeah, those bungee slingshot jumps are fun!!
There was a place in Panama City Beach, FL
that did great business during spring break.

Funny side note - the cage I jumped 6 times
had John 3:16 on the bottom and they were
blasting lots of Christian Rock music.

Yes, John and his brother Peter are great guys. It's cool you know them. They pretty much started the bungee craze that swept the nation at that time. In return for letting us jump the crane we taught John to BASE jump. In fact he went to Bridge Day that year and knocked out a couple of good ones . . .

NickD

so what im seeing here is nick basejumped the same crane that got tim into skydiving through bungee and eventually to base?

neato.

So I guess in a roundabout way that makes me Tim's Grand Daddy . . .

NickD

seems kind of weird when you say something like "who's your grand-daddy, who's your grand-daddy?"

Given you have less than a decade of years on me, that is pretty funny.

Well, I didn't use "Who's your Daddy" as that has a bad connotation.

What I was going for is if we could do a BASE family tree I think we'd be surprised how related some of us older guys really are.

Inbred might be a better word . . .

Sometimes directly and some times indirectly.

Mike Pelkey and Brian Schubert begat Carl Boenish, Carl begat Phil Smith, Phil begat the Harrison twins, and the twins begat, begat and begat, etc . . .

NickD