Basejumper.com - archive

hmmmm....
Take care,
space

Asshole...

Nice.
Come visit.
Take care,
space.

What is this post, anyway? MOD please delete the whole thing.

base fatalities 2013

number of fatalities so far: 23

wingsuit fatalities: 21 (91.3%)
impacts caused by instable exits: 6 (26.1%)
impacts caused by proximity flights: 12 (52.2%)
impacts caused by instable flights or unclear: 2 (8.7%)
low pull: 1 (4.3%)

slider down fatalities: 2 (8.7%)
bridle/cam hesitation: 1 (4.3%)
bridle tow/wrong gear use: 1 (4.3%)

all other slider up jumps: 0
slider up slick: NONE
slider up tracking suit: NONE

Proximity? Not as I recall the incident report.

I would classify this as a structural failure of the equipment. I would tentatively attribute it to adverse environmental conditions and pilot error in exceeding the rated flight envelope of his equipment.

It's a rather old fatality predating the current list. I'm not sure how well it was reported. It's a good lessen in the need for proper investigation and reporting of fatalities so that we may all learn from them. I suppose in some ways it might be considered the founding of the BFL. If you have any new information of this accident we would love to hear the details.

Lee

 

 
I just did some quick numbers based strictly on the density. This is using the atmospheric pressure at the bottom of the Hellas basin, one of the low points on the planet. The bitch of a thing is that the drag would go up so much when you approach the speed of sound. I don't think you could do sustained supper sonic flight. You would drop subsonic. However at higher altitudes you would be super sonic. I'm too lazy to modify my reentry program to see exactly where the transonic point would be. I'd have to dig up the rest of the planetary data.

So you would come in supersonic You could swoop the walls of the great canyon but the danger is that at some point along there you will drop through the transonic region. It would suck to have that happen while you were proxy the wall. But I have no doubt that Felix would try it if he can ever get a ticket to mars.

Lee

What do you suppose the critical mach number is, for a generic style wingsuit, anyway? Do you have any way of crunching those numbers?

No, I don't. I've got data here for my ballutes and things that I've worked on but I don't have anything here to work up the drag on some thing like this.

Lee

Who are you?
Take care,
space

Critical for what?

The point where the airflow becomes supersonic as it accelerates over the top of the wing. It's the airspeed where you start to run into some serious compressibility issues. It can cause problems, vibration in aircraft and controllability issues as it fucks up the airflow on the back half of the wing. It can happen well bellow mach 1 depending on the Cl of the wing. Wing suits fly at relatively high angles of attack and are of very low AR they would not easy shapes to look at. And would have a relatively low critical mach number.

Lee

I'm someone who didn't see the relevance of this post in the "incidents" forum.... Now it's moved I can go back to trying to use the incidents forum for its intended purpose. :)

If you dont see the relevance then you are downbound,

we should step outside if you want to fight. No probs with kluttering the forum. we may can learn from each other.
i dare you ;-)
take care,
space

Really? Looking at the first posts of this thread, the "incidents" forum seems the right place? Anyway, wasting too much time on this, picking my nose is more productive.
I like you, you're funny, so I'll kill you last :p

Sorry I don't get it.. is this about a particular incident or just meant to start a general discussion about proxy flying?

at first I thought this was an El Guapo Three Amigos allusion and I wanted to be your best friend but his quote is different.

"these are funny guys...just keel one of them!"

Great. Now my The Hangout forum is filled with these posts that have nothing to do with hanging out.... Thanks a lot jackass!!!! 

Thanks for the compliment. My point in the post was that there is a nature to not listen. Where would we be if all listened? We would never have progressed past the first conservative type of individual. Maybe my thinking is too deep after experiencing the deaths. My apologies if so.
Take care,
space

BASE 283 is old and grumpy from watching too
many of his good friends die… and well getting
old kinda makes you grumpy, damn kids with
their gadgets, use your blinker, and for God's
sake, pull up your pants!

There is a famous Greek Myth about a father
and son who are trapped, build some wings,
and plan to fly to freedom. The Dad makes
it, the Son dies from flying too close to the
sun, which makes the wax on his wings melt.

http://en.wikipedia.org/wiki/Icarus

Moral of the story - listen to your parents.
Keep in mind myths back in the day were
their form of religion, a way of explaining
nature, and teaching ideas, just like the
use of parables in the bible, or simple
little stories by Aesop.

PS: I just read the content of the link above
and according to wiki the theme was a
tragic example of hubris or failed ambition

Anyways, Spacey-Tracey probably had
a few libations and thought it would be a
very funny way of saying what Calvin said
for years, which can be summed up in
one word ---> Hopeless

Oedipus complex- kill your dad, marry your mother, have kids with her, find out about it, poke out eyes.

I'd rather be icarus than Oedipus if I'm going to suffer hubris :)

Listen to your parents, kill your parents, fuck every animal known to man... We can learn a lot from the ancients! It's all good as long as you provide for Charon. Would suck to miss the ferry, I mean.

Thanks, it was a somewhat whimsical question anyway :) I wonder if someone could even come close in the upper flight levels anyway. Anyone flown a wingsuit at FL360?

I think wingsuits have too much drag. Too much material oscillation. Bringing something like this into the trans sonic would more than likely rip it apart. Pardon, what does FL360 mean? Flight Level at 36000 ft?

As luck would have it, click here http://www.telegraph.co.uk/men/active/10438627/Wingsuit-jumper-Espen-Fadnes-in-search-of-the-perfect-flight.html. My original post had nothing to do with this but it brings a major point to life. I feel for you if you dont see this. You wont have the chance to kill me last :-P Death is necessary in evolution. Or if you are a "Creationist" Just skip to Genesis chap 1, vs 16. We couldnt be where we are without the likes of Espen, Jokke, Ludo and the rest. Next time you pack your rig, More than likely one of us had some influence on the modern gear that you jump. Thanks for the thanks.
Take care,
space

 

It could work super sonic. Inflatables have been used up to...Well I've had mine up to 2.8 and it was self inflated from vents. It can work if you do it right. If you do it wrong... If you'd like to see supersonic flutter...

http://www.youtube.com/watch?v=WXKQ0v_YPWw#t=217

That's what happen when you get your vents wrong and you have vent instability and do not achieve good inflation.

I can do the math and in the upper altitudes you would defiantly be super sonic. By the time you get down to the lower altitudes it looks like you would be subsonic. The transition through the transonic range is pretty fast. At least for us here. We're already decelerating pretty hard at that point and the transition is just a small spike on the graph. Not even close to our top forces. I thought it would be a big deal but it was remarkable unremarkable.

I'm not sure the drag would be all that bad. Depending on the suit I don't think your Whitcomb area would be all that bad. I do think you would go through the transition before you reached the ground. At least if you were landing some where low. Speaking of which do you realize how fast you would have to run on landing?

Lee

Ahhh, it is a guy? I am outta here ;-)
Take care,
space

Actually, what you read was the bastardization of the Daedalus myth.

Seriously, look it up: There is no myth of Icarus. The myth is about his father, and Icarus plays only an incidental part in it and even that part is misconstrued by most "moderns," to wit:

Daedalus not only told his son to not fly too high or the wings would melt, he told him not to fly too low because the sea would make them wet and heavy.

In other words, "Fly the middle of the envelope, son."

Which sort of circles around to Space's point, doesn't it?


44

That was my assumption, too... too many adverse forces, tearing the suit up. But then I started to wonder, well "what if."

Flight Level 360- It's the height at which actual air pressure corresponds to the air pressure you'd find at 36,000 in the standard atmosphere model. It can be hundreds to thousands of feet different than actual altitude.

Basically it would be easier for a wingsuit to hit critical mach at a high altitude than at a low altitude. Because the speed of sound decreases significantly with altitude. FL360 was just a random example comparable to a jetliner altitude where one cruises at a certain mach number. The other assumption, which I cannot judge either, is that a wingsuit would have too much drag to ever accelerate to critical mach. Unless you were Red Bull Stratos.

Application to reality? not so much. But it might be fun to know, how fast you need to fly to go trans-sonic in your wingsuit.

Velocity is what enables transsonic. The "Grand Slam" bomb was reportedly said to go near transsonic from 12,000ft. The drag of going transsonic slows one down with the increased drag. It would be relevant to surface area vs mass. If one built a high density wing suit and jumper that would be equivalent to area vs mass of the Grand Slam bomb. it would be possible at 36,000ft. it is all about terminal velocity to get in the transsonic zone in the gravity powered enviro. Compressability of the air is where things start changing.
Some flight energy is lost in compressing the air.
Get up your velocity, Hit the tropopause and have fun with the current area/mass ratio. there isnt so much differing in the atmospheric profile above the Tropopause. Yes it is warmer and therefore the speed of sound changes, but it really is not that relevant with small changes.

The speed I mean.

One would totally need to redesign a WS to have a controllable flight for transsonic same as the advance in aircraft design.

Side note: Red Bull marketing does not effect physics of fluid dynamics.

To answer your question at the end of your post, one needs to know the temp and density of the atmosphere and that will give you the precise answer. 715mph is a good working number.
Take care,
space

Hi Robin.
How can a mythical father have non mythical son? How can an island benamed after the son of a mythical father?
I appreciate your answers...
Take care,
Tracy

Is that a haiku?

I think a Haiku is a certain number of syllables per line So I cant really say because I have nothing to compare it with.
Explain more maybe.
Take care,
space

Well... not exactly, perhaps.

The wikipedia transonic page has a better description of the term than i can type out with the limited motivation that i have at 1 am.

At FL360, the speed of sound is just over 570 knots. You would go transonic at your critical mach number, which RiggerLee suggested was going to be a relatively low fraction. Drag is a major problem getting there, because it increases proportionally to the square of your velocity. My impromptu speculation was that at jet traffic altitudes, you might be high enough to have a reasonable chance of getting your wingsuit to the transonic range without filling your suit with lead (to increase your weight and thus glide speed), plus have a reasonable chance of getting a plane that can take you that high, plus not be so high that you'd require a pressure suit, etc. etc.

You are right about instabilities. Any controllability issues that you suffer once you get there are not my problem

The tropopause didn't really factor into it, from that standpoint. Other than the coincidence that the average height of the tropopause over the US happens to be in the realm of 36,000 feet above sea level.

I don't know if anyone knows how fast a wingsuit can fly at high altitudes in thin air. If someone does, please help us floundering buffoons. I am just a dumb pilot... push stick forward, houses get bigger. pull stick back, houses get smaller...

I'm making some assumptions here about the drag profile, basically I'm assuming that it will follow a similar change as my ballute, not true but it's a wag.
I come up with the transition occurring at 79,000 feet. In fact I suspect that a wing suit would be quite a bit cleaner as it went super sonic so the altitude might be a bit lower but with the increase in density happening rather rapidly it wont be by much. It's the density and the change in it that really drive the forces involved in reentry. That's why in a round earth even a small amount of lift is so important. It can keep you from... digging in to fast before you have the chance to slow down. That's why I'm so interested in inflatable lifting bodies and means to control them.

Lee

Totally off topic in this stupid thread but what ever happened to all the object strikes on opening from low slider up jumps? In the past that was the big killer and now it seems like the safest place to be.
For the record I refuse to believe that people have gotten any better at tracking or canopy control. So I can only assume that people are not surviving this stage of their progression more so than they are simply skipping it for the wingsuit.

Or now they predominantly jump from "S" where strikes are negligible before progressing to terminal tracking and wingsuit?

I highly doubt it. More likely the people that shouldn't even be tracking some walls are now simply wingsuiting them instead, shifting their fatality into a different statistical bracket.