wwarped

another possible option would be to introduce a variable link between the brake line and the cascades. collect the cascaded lines in a loop. terminate the upper brake line in a loop. feed a new line (with loops at both ends) through the upper brake line loop. secure both free ends of this new line to the cascade loop via a Slink, or similar. having several sets of these "connector lines" would permit rapid changing, and repeatable settings. just ensure the correct length is installed. (you can even color coat matching pairs.) the single brake settings would move up or down the lines. the toggles could be shifted accordingly (to maintain a consistent flair stroke). all parts could be made at the factory. no need for sewing to create new brake settings. unfortunately, I don't have the tools, material, or bridge to experiment with this concept... DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

I played the BD04 DVD during my parents' last visit. surprising reaction. my mother called it exciting. I also had to pause the DVD when I stepped onto the platform. they wanted to be called back into the room...

thanks for starting this thread. Tom deserves all the accolades. but the thread title made me nervous. what would be your first take to these threads? "JeNnEjEnN...hmmm....", "KMonster...hmmm....", or "Rhonda Lea...hmmm...." DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

true. but don't overlook easier design, development, and manufacture as well. (i.e. cheaper) DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

another reason: simplicity. one center cell implies an odd number of cells. for example: a seven cell canopy has 8 sets of lines. 4 sets of lines to each riser. to have 2 center cells, you'd have a parachute with an even number of cells, and an odd number of lines (or some novel configuration). while I'm sure it's possible, is it worth the extra headaches?

just read a thread mentioning someone with 650+ BASE jumps. it got me wondering... what is a good year, in terms of number of jumps? DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

from the lack of official pre-requisites, Miles' FJC seems like a bad idea. (then again, so did jumping off an object in the first place.) a couple posts indicate he is still being selective. if he carefully selects his students and customizes training for his clients, he will be seen as an innovator. it seems MD is testing a new theory. if the concensus here is correct, it will quickly prove faulty. hopefully it doesn't damage our access.

yet another poor role model... jump #1 - S jump #2 - E jump #7 - A jump #13 - B DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

first, I don't know Miles or near enough to train anyone. but I have two quick questions to those who feel Miles is being unfairly attacked... has he taught YOU much regarding the sport? would you feel comfortable having Miles train one of your family? DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

ooohhh! video.

V = at is invalid. it only works when acceleration is constant. since your acceleration is changing as the drag increases, you can not use this equation. I believe the correct method is to integrate your acceleration as a function of time. remember, once you reach terminal, you are in a "steady state" condition. i.e. the forces of gravity = the forces of the air. therefore, since a = 0 and V = at, then V = 0. now that would be WAY cool... DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

it may be a bit off topic, but at the moderator's request... I pulled out my first textbook regarding aerodynamics. (Introduction to Flight by John D. Anderson, Jr. 1978, McGraw-Hill) section 4.3 on pages 69-73 discuss momentum along a streamline. (a stream line is the path along which an infinitesimally volume of air flows.) mass: the volume of the piece of air is dx dy dz. therefore it's mass = ro(dx dy dz) (ro is the density of air) acceleration: a = dV/dt = DV/dx dx/dt = DV/dx V (V is velocity, t is time) Newton: F=ma -dp/dx (dx dy dz) = ro(dx dy dz)V dV/dx (p is pressure) (pressure x area = F = ma) dp = -ro V dv (Euler's equation) or dp + ro V dV = 0 integrating it along a streamline yields p + 1/2 ro V^2 = constant (Bernoulli's equation) (static pressure + dynamic pressure = total pressure = constant) static pressure is the pressure as measured perpendicular to the airstream. dynamic pressure is the pressure resulting from the motion of the air. assumptions: -gravity is insignificant -frictionless air -the formula is for any point on the same streamline -incompressible flow (i.e. ro is a constant) "if all the streamlines have the same value of p and V far upstream, then the constant in Bernoulli's equation is the same for all streamlines." ------ air cannot flow into a solid object. at best it will flow parallel to the surface. thus the pressures affecting a wing, and creating lift, are STATIC pressures. freefalling bodies will feel TOTAL pressures. otherwise the following statements conflict: “the faster air over the top of the wing results in a lower pressure.” “the faster you fall the ‘harder’ the air becomes.” we would be better served if we prefaced “pressure” properly… (side note: aircraft use pitot tubes to determine airspeed. these devices compare the pressure parallel to the airstream with that perpendicular to the airstream.) ----- as far as pilot chutes go... it is a very complicated situation. at the risk of committing over-simplification, obviously, the airflow within the pilot chute is less than the flow outside. Bernoulli thus states that the static pressure within the pilot chute is greater than that without. but, an uninflated pilot chute can not support a load. any hint of pressure differences will cause the fabric to move. therefore, the phrases “the air inside an inflating pilot chute pushes the fabric out” or “the air flowing by the inflating pilot chute pulls the pilot chute out” are equally valid. DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

I pulled out the most basic book on aerodynamics on my shelf and created a response. Bernoulli's equation is fairly easily derived from Newton. too bad I did not see an e-mail address listed in your profile, otherwise I'd PM you. don't think the forum wants to see THAT much detail... btw, my background is in Aeronautical/Astronautical engineering and I too have worked for NASA. DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse

previously: uh. no. Bernoulli and his predecessors don't deserve such abuse. Bernoulli's principle describes how total pressures balance and are a sum of static and dynamic pressures. fortunately for us, surfaces respond primarily to the static pressure. wings, or canopies, have relatively high pressure on the lower surface and relatively lower pressure across the upper surface. lift is generated. period. describing it as "air sucking the wing up" or "air pushing the wing up" are both valid. the inflating pilot chute does not contain a vacuum. to inflate, air molecules MUST find there way inside and stay there. thus the air inside the pilot chute is constrained and impeded (i.e. captured). it can not flow readily. with less airflow, the dynamic pressure is lessened, and the static pressure is higher. the converse is true on the exterior of the pc. increased airflow results in increased dynamic pressure, lessening the static pressure. pilot chutes inflate simply because the static pressure inside the pc is greater than the static pressure outside the pc. it doesn't matter if you say "the air inside pushes the fabric out", or "the air outside sucks the fabric out." both are correct. DON'T PANIC The lies in learning how to throw yourself at the ground and miss. sloppy habits -> sloppy jumps -> injury or worse