tso-d_chris

Have you been sniping golf balls off the fairway again, Dave? The golfers are tired of taking the penalties.

I'm not sure why this is a problem. I've seen more than one highly experienced swoopers (PD test jumpers making fun jumps), on many occasions, hang out up high until everyone has spiralled down before landing. It serves the same purpose of ensuring that they land at a different time or place than everyone else. The nice thing about cross-braced canopies is they tend have a larger performance envelope than their non-cross braced counterparts. An experienced pilot can make it fly pretty slow, with a flat glide. What am I missing? For Great Deals on Gear

Is there a flare in volved in the TSO test? (I don't know; that's why I'm asking.) For Great Deals on Gear

Thanks, Amazon, Skybytch and DiabloPilot. Feedback is always appreciated. It's not very practical for me two order myself two new, nearly identical containers for myself to make a comparison. For Great Deals on Gear

Sorry, I wasn't meaning to yell at you. Initially, I would have been more accurate if I had said: A canopy will not maintain a heading all by itself. It has a preferred orientation relative to the positive acceleration of the airmass in which it is flying. However, the canopy can only change heading on its own during periods of time in which the airmass is actually accellerating. Does that sound better?

Sounds reasonable.

Good advice. Even at the end of the month, it is usually not the best idea to buy on the same day you first look at the vehicle.

Or its chord. Same forces, coming from a different direction. Same result about the vertical axis. For Great Deals on Gear

Agreed, but so is the sealed battery that the Vigil has. Unfortunately, we can't have it both ways, at least at this point in time. For Great Deals on Gear

True, but this change will not occur instantaneously, and that is the key in this scenario. The "flies at a constant velocity relative to the airmass" theory is only completely true if the airmass has a constant velocity. Change the velocity, and you intoduce new forces to the system. Of course, with a conscious jumper these forces are going to cause minute changes that are easily corrected without toggles. But without any pilot input, those minute changes will accumulate, and could substantially affect heading over the course of the descent. And, to clarify, I WAS WRONG ABOUT IT ALWAYS PREFERRING A DOWNWIND HEADING. There are factors of the canopy design which will affect whether a canopy "prefers" a downwind or into the wind heading. I initially failed to take all these factors into consideration. The fact remains, however, that an asymetrical surface area of the airfoil profile + stabilizer will result in predictable heading changes in known, changing wind conditions.

Feel free to elighten us. If there is no reference to the ground, you have no way of knowing whether your claim is true or not. All you experiment shows is that the canopy maintains a constant position relative to the jumper. Kindly explain, then, exactly how the myth was dispelled. What experiments were conducted? How were they conducted? Were people used to fly the canopy, or dummy weights? How many different canopy models were used? How many jumps per canopy? How were the wind conditions changing? What was the air density observed for the experiments? Variables, variables, variables. Forget to keep track of any of them, and things which aren't random will appear to be. For Great Deals on Gear

The bowling balls are on fire, right?

Let me try this from a different approach... Why is there a necessity for auto pilot on commercial jets. Why can't the pilot just take of from LA, point the plane towards New York, and then go catch the inflight movie? Or... Why won't you jump on the front of a storm? Is it not because the extreme accelerations of the air that you are flying in will make your canopy do some really effed up things? Now, imagine that same turbulence, with the intensity turned way, way down, such as might be found on a typical summer day. If the winds are increasing, then the second derivative of a function modeling the position of the air molecules relative to the earth is going to be positive. If the winds are decreasing that same second derivative will be negative. The important point is that, in both cases, the second derivative of the position function, aka accelleration, is not zero. The reason this is important is because it implies that at any given time, the velocity of the canopy relative to the airmass in which it is flying, is constantly changing, either in direction or magnitude. This is do to the jumper/parachutes inertia, and the asymetrical surface area being exposed to any crosswind component. This asymetrical surface are allows the force of the air molecules that are colliding with the canopy to be applied diferentially, which will change the heading ever so slightly. So slightly that any input on the part of the pilot is going to be huge by comparison. But, the scenario at hand does not allow any pilot corrections. That is what makes the tiny heading changes accumulate predictably. She'll be probably be able to do a better job than me. Sounds like you area justifiably proud papa. For Great Deals on Gear

Without getting into a PD Reserve versus a MicroRaven discussion, should the different criteria for TSO C-23c vs TSO C-23d give any indication of possible differences in flight characteristics of the two reserves? For Great Deals on Gear

Your friend jumped an F111 seven cell rectangular canopy at 1.5:1, well over manufacturer's recommended max suspended weight, and then blames the poor landing on the canopy? Jumping any reserve outside its performance envelope is just asking for problems. It should therefore come as no surprise to the pilot when the problems manifest. It is certainly not the fault of the canopy. For Great Deals on Gear

And excellent workmanship! For Great Deals on Gear

That is how I understood the swoop mode as well when I saw the Argus. It will give people another choice, with some different features that other brands don't offer. While it will probably be competitive, I don't expect it to dominate the AAD market. Some of the new features will be seen as improvements by some people. Others will likely view them as steps backwards. The bad news (for US jumpers) is the price will be, like the CYPRES, based on the Euro/dollar exchange rate. For Great Deals on Gear

Here's the minimalist approach. (Requires Quick Time)

I'm not responding specifically to Amazon. I'm curious as to how many people have the means to make a fair comparison between hip rings and no hip rings. The high time jumpers I've talked to specifically about this subject who have hundreds or more jumps on rigs equal in all other respects, don't place much importance on hip rings outside of freestyle. However, this subject doesn't often come up, so I would be interested in hearing input from anyone with lots of jumps with and without on the same brand custom harness. A custom harness is going to be pretty comfortable with or without hip rings. On the other hand, This post leads me to beleive that stainless hardware might be more than just a cosmetic option. It might have greater longevity than standard hardware. If you will be doing a lot of freestyle, go I recommend the hip rings. For anything else, the stainless is probably the better option. Regardless of which option you choose, you will love your Infinity. Velocity Sorts Equipment builds an outstanding container. For Great Deals on Gear

I've noticed lot's of differences, actually. I didn't use the term weathervane first, but I have to admit it is sure a lot easier to type than "find its preferred orientation relative to the Earth due to the second derivative of the position of the air molecules, amongst which the canopy flies, relative to the Earth." (Even if a weathervane only gives us information about the air molecules' position's first derivative.) Even without being fixed to the earth, the jumper plays the same role in keeping the canopy fixed on two axis while allowing freedom of movement on a third axis as the fixed shaft of a weather vane.

By and large, you are correct. But we are talking about zero pilot input. In effect, the things that on any other jump have effects so small we can counter them by leaning a tiny amount, actually make up the majority of the forces at hand controlling heading. Thus, they become significant. BTW I was wrong about it always being downwind. But weathervaning will be consistent, all else being equal (which it never is). Of course, the liklihood of thinking about any of this under such rare conditions is slim to none. Except for the fact that its been raining nearly every day here for several weeks now, there's no real world purpose for the discussion.

What kind of skydiving will you be videoing? SONYSONYSONYSONYSONY

Have you tried VLC or MPlayer? both are great freeware (or shareware?) media players that will handle most anything thrown ot them. They don't play everything though, so it is still necessary to keep QT and WMP on standby. Rarely should you have to use them, though. For Great Deals on Gear

I have used both, and I would not say that. PCs are clearly better than Macs for gaming. Apple is improving, but still has tremendous ground to make up. Macs are clearly better for internet use. There are no known viruses for OS X. You would be incorrect to assume it was from their small marketshare. One DZ.commer even posted this challenge. By contrast, Windows machines have a fifty percent chance of being comprimised within twelve minutes of going online, if not properly patched. It's fair to say that anyone reading this forum uses the internet. Total cost of ownership tends to be lower for Macs. The cost of maintenence for the internet concession at one local drop zone went down by about $10,000 annually by replacing four PCs with four macs. And I doubt that it is any coincidence that the fastest/cheapest (per processor) cluster supercomputers are Mac or Power PC chip based. So, no, I don't think they are both 100% workable solutions. Depending on your application, you may have two good options, or maybe only one (other OSs notwithstanding) good one. Nor am I saying that Macs have no issues. They do; they are just Mac issues instead of PC issues, and are much easier to deal with in my experience.

Fly with the wind line, then turn 45 degrees. Your canopy does not change its velocity instantaneously, it has to take the time to accellerate. During that time, the relative wind is not coming from straight ahead. It is during these times that any weathervaning is going to occur. An positive average accelleration implies that the wind accellerations will not balance to zero, so neither can the weathervaning.