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I am curious what sort of vertical or almost vertical drop you need before you can start flying a birdsuit. What is your glide ratio at different delays and when does it reach full glide. Maybe a chart or some kind of graph, like a freefall table, would be good. I know a lot of this is going to depend upon the experience level and type of suit being flown, lets use averages on the conservative side. How does one make a decision if a object is jumpable or not. I know you cant just drop a rock and say "looks good to me". What about the talus and other terrain further down the mountian? Does anyone use topographical maps and the calculated glide ratios to find possible sites?

Hee, hee
I've been working on a freefall table (modeling freefall with drag, no wing suit) but ran into some touble. Haven't had time to figure it out but I will. Trying to do one for wingsuits I believe would be very difficult.

i think perhaps some of the WS compagnies perhaps should jump ahead and do this job unless theres such a tabel out there;)

It's theoretically dependent on wingloading. But in practice, it seems to me to be most dependent on skill of the pilot. I've seen very good wingsuit pilots who are getting significant forward motion at 3 seconds. Personally, it takes me more like 6-7 seconds.

I think that's one of those questions that can only be answered by each person, for themslves.

Not only the person, also the condition,updraft,downdraft, in the wall have alot influence when it comes to get started, and how fast you get going! Same for tracking! It is getting so complicated as the airpressure, temperature differences from below to upstairs, how long the tallus is, which way the wind comes, from the front up tallus, from the side etc etc. It is so many variables, so if you are able to make a theory scale, it will not make any useful data for your flight!

Not to forget, what kind of wing suit flyer you are. Some are good at floating (flying at stall point), and some is good at speed (Lukas the fastest mother fucker in the walley) So I would say it is som hard to find any references that can be used except from your self.

Only by experience you will know if you will be able to fly from the place you choose, even then you can get lost!

Jumping the same object in different conditions for 100 jumps with a GPS can give you some values to make a scale?

Yo !

This is currently an art rather then a science. The variety between suits, pilots and conditions is so big that a table or a graph would be useless. A stable exit is one skill, getting a suit to fly quickly is another and reaching max glide is a third. Another major factor is a safety margin you want. You will have to figure out your personal boundaries.

A few years ago i would jump 5 sec rock drop spots, just because i could. I have screwed up countless exits since then and today won't consider anything under 7 sec. I know 2 people who jumped 4sec drops on rather positive walls and lived... i also know 2 dead people who didn't clear the ledges on longer drops. Your mileage may vary. Also important is an angle of the slope afterwards, once you got the suit flying. With L/D of 1 you can follow a 45 degree slope, L/D of 2 will open up a 30' slope and so on. Obviously, there should be a bit of clear air to get a canopy open in the end.

So in short, yes, you just drop a rock and say "looks good to me"

bsbd!

Yuri.

Hi,

i did a ws-jump with a gps plotter this summer. see the attachment for the plotted charts. on this jump i made a lousy head-down exit and lost some altitude as a result, but probably gained some of it further down, due to the increased speed. i agree with the "drop a rock and say looks good to me"-plan, but know your suit and skills before you try any tight wall. also have in mind that exit altitude might play a big role in the takeoff. i did some jumps from about 3600 m this summer, and could really feel the difference (it wasn't measured, but i'd say it was a long extra second before that flying feeling hit). my ws skills are not the best (about 30 jumps) but if i'm i doubt, i throw alot of rocks to determine the face of the wall.