polarbear

Of course, that's right. Fluid Dynamics only works if the fluid is dynamic! "Holy s*** that was f***in' cold!"

I think I am. If the internal pressure is greater, the cell will remain inflated (remember, I am talking about the pressure across the upper and lower skin, NOT the stagnation pressure at the nose). If the external pressure is greater, it will "squeeze" the cell closed. "Holy s*** that was f***in' cold!"

You're saying that the airlock acts as a converging nozzle (forcing the air through a smaller area and thus increasing its presuure)? I hadn't thought about that, but it might be true. I don't think that is waht airlocks are specifically designed to do. I think the operating principle is just to hold air in the cell in the event the external pressure becomes greater than the internal pressure. I would agree that the Samurai is trimmed steeply...mine comes DOWN, unless I get in brakes. I don't think airlocks require steeper trim...it just so happens that the canopies that have them are steep. "Holy s*** that was f***in' cold!"

I currently jump a Samurai 150; I have about 80 jumps on it now. I have also put about 30 jumps on a Vengeance 170. I like both canopies alot. A large portion of the canopy, however, is the design parameters other than the airlocks...in other words, I don't think it is the airlocks that make them nice to fly. I do feel both canopies are a little more solid in turbulence. However, this just means they are SLIGHTLY more resistant to turbulence. They can still stop flying and drop, even if they remain inflated. Remember that stability on a ram-air canopy comes from inflation AND proper line tension. If you hit turbulence with airlocks, you may remain inflated, but you can lose line tension and your wing may still distort. Even if your wing doesn't distort, it still needs smooth air to fly, and turbulence will disrupt that. I do get bumped around in turbulence; I just notice that my wing is not doing an accordian-type movement like on non-airlocked canopies. I think it is good policy to not rely on airlocks to save you from turbulence. I also notice that the stall is different on my Samurai, both on rear risers and on toggles. On open-cell canopies, the wing will eventually bowtie if I apply enough toggle/rear riser. On my Samurai, it basically stays inflated and just starts dropping. It seems to recover from a stall less violently, perhaps bacause the wing doesn't experience as dramatic shape changes (?) As far as packing goes, I don't notice any added difficulty. The canopy does stay somewhat inflated when you land; I don't have a big problem with this. If you had to walk a long way with it on a windy day it might get old fast. As I mentioned earlier, I like both canopies a lot and have no regrets flying either. "Holy s*** that was f***in' cold!"

Well, the parachute and air do have some mass, and the air will have some stiffness. It will be highly nonlinear. I would expect the damping to also be quite strong. I don't think it will "vibrate" in the normal sense. The shedding of vortices makes the most sense, I think. The movement take4s place in the aft section between the inboard brake lines, where there are no suspension lines. In this section I would expect a low stiffness (i.e. the parachute should deflect large amounts in reaction to a shed vortex). "Holy s*** that was f***in' cold!"

You can expect the understanding from me. That is a good question...a flying parachute would have interesting mass and stiffness properties. I'm not sure what to expect in terms of vibration. It is interesting to see such a strong reaction to shedding of vortices. "Holy s*** that was f***in' cold!"

Yep. Most whuffos think the swoop artist did something wrong to get going the fast, while the slow canopy pilots making soft, on target landings impress them. It makes sense...most non-skydivers are afraid of it; they want to see it in its safest form. "Holy s*** that was f***in' cold!"

The rig is a softie and I have instructions for it. I also know the two are compatible. I just haven't worked on a C-9 before and wanted instructions for the canopy. "Holy s*** that was f***in' cold!"

I have a pilot rig I need to pack that has a C-9 canopy made by a company called reliance. Anybody know where I can get a copy of packing instructions for this canopy? "Holy s*** that was f***in' cold!"

At least they didn't waste much fabric on it "Holy s*** that was f***in' cold!"

In the case of the cypres, manufacturer's instructions allow for placing a cypres in a cypres-ready rig, but installing the pouch and channel requires a master rigger. I would agree that putting a cypres into a ready rig does alter it, but it is a pretty simple operation and the cypres manual offers clear instructions on how to do it. Sewing dive loops on risers? There are no instructions and things like stitch type, material, dimensions, etc. come in to play, plus you either have to sit down and study a riser that already has dive loops or you have to design your own scheme. It is a much more complicated process. That is why I consider it a Master rigger job. "Holy s*** that was f***in' cold!"

People. Staff, students, experienced jumpers, even whuffos...they all make or break the experience. I look for easy going, fun people that I can jump and party with. Not waiting for a plane is nice, but secondary. I usually jump out of 182's, so I'm used to it. Every once in a while I get the turbine bug and go to a bigger dropzone. That's tertiary. I like all kinds of flying, that doesn't matter too much to me. That's last. I would say that a mix is good...I think it is important(and fun!) to learn all of the disciplines. A DZ that doesn't do it all is missing out, in my opinion. Another thing I consider important to deciding on a home dropzone is how much I can get involved...do I get to actually use my rigger's ticket and help out the DZ, or I do I just jump? For deciding if I like a DZ for jumping, this isn't so important, but for my HOME DZ I like to be involved some way. A final thing would be is the DZ'z idea of safety in line with my own. "Holy s*** that was f***in' cold!"

There was a 2-part article in the April and May 1999 issues of Parachutist on landing Ram-Airs. It was part of the "Jumping the Ram-Air" series and was written by Kevin Gibson. Those two articles focus on normal, conservative, natural speed landings and are where I learned the basics of landing. I thought they were quite good. See if you can find a copy. The other suggestions given are very good, too. Having an experienced jumper video and critique your landings will help. Review the video and debrief immediately after landing, when it is still fresh in your mind. Pick an experieneced jumper who always gets soft landings. Also, practicing the flare up high is always a good. I still do it on almost every jump. "Holy s*** that was f***in' cold!"

That's all in agreement with what I've found. Following a tight stow with a loose one can spin the bag, but if all the stows are tight, there shouldn't be a problem. I stow all my lines REAL tight and never get line twists. As far as double wrapping goes, I double wrap stows regularly and have the rubber bands break. You could claim that because there are two wraps, the force is split in two and therefore the band is less likely to break. However, you have to remember that those two wraps ONLY encompass the stow...they aren't doubled down to the d-bag. When the lines unstow, there is still the same amount of rubber holding the stow to the d-bag, and it is already stretched farther because of the double-wrapping...therefore it is not any less likely to break. Pretty much everyone at my DZ double wraps at least some stows and we have yet to see a problem. "Holy s*** that was f***in' cold!"

Yeah...debating the FARs is an uphill battle . Following manufacturer's instructions is about the only clear route to legality. It also seems as if the strict interpretation of the FARs isn't enforced until an accident occurs. But, of course, then somebody's dead. "Holy s*** that was f***in' cold!"

I suppose you can make that argument. It is clear that you must follow manufacturer's instructions, which (at least the ones I have read) allow a non-rigger to perform the tasks you listed. I think you have to admit that changing brake line lengths or adding dive loops to a riser is a more difficult task than changing rubber bands on a deployment bag. And what about patching canopies? If a non-rigger can do anything to non-TSO'd gear, then that means they can patch their mains, which the parachute manual explicitly says requires a rigger. Hell, if a non-rigger can do anything, then they can replace entire panels in their mains, which the parachute manual specifies is a master rigger job. I would again point out that nowhere in the FAR's does it say that the requirements of having a rigger's ticket to perform repairs or alterations applies to TSO-d gear only, and the repair section of the parachute manual requires a rigger to perform repairs on a main. The only thing the FARs say a non-rigger can do to their equipment is pack their own main and perform simple assembly/disassembly procedures (which I think covers 3-rings, rubber bands, and closing loops). Again, it is clear that you must follow manufacturer's instructions. I'd bet if you called up the container manufacturers and asked them about sewing on dive loops, their first question would be "are you a Master rigger?" "Holy s*** that was f***in' cold!"

My second canopy was a Heatwave 170, loaded at ~1.35. I started jumping it at about 150 jumps. I was pretty happy with it. I would say it is comparable to the Stiletto. I think it has a flatter glide, lower touch down speed, and higher front riser pressure. It also oversteers more. It is a highly tapered airfoil and exhibits the characteristics associated with them. Whether or not you will be OK on it is something you and the knowledegeable people you jump with will have to decide. Generically, I would say a competent canopy pilot with 150-200 jumps should be OK, but is definitely an agressive choice. Be prepared for it. The jumper you want to buy it from should let you try it before buying. Give it a shot and see if you like it. "Holy s*** that was f***in' cold!"

Yeah...I've already had a good experience with his customer service. I was planning on talking to him at Rantoul this year. "Holy s*** that was f***in' cold!"

My thoughts are that the number one priority in skydiving is to land safely, and the number one step to take towards accomplishing that is to get a good parachute over your head. Many malfunctions are relatively simple problems, lineovers included. You might fix them, but you can lose precious time. Yes, you can lose your handles, PC, or even main canopy, but that isn't the most likely thing to have happen and it certainly isn't the most important. I've seen ~20 cutaways in my short skydiving career and the only thing lost was 2 cutaway handles, total $60 to replace. Every one of those cutaways ended with a safe landing...I'd say that $60 was a cheap price. Remember that you still have to worry about getting to a safe landing area and possibly learning to effectively flare that low-performance piece of F-111 in your reserve container. I guess in the end run it I would say provided you stay altitude conscious then trying to fix a problem might be a possibility. I personally believe it is not worth the chance of losing track of altitude and turning an easily suirvivable situation into a deadly one. Our gear is designed to save our lives with two simple operations...pull one handle, then the other. It won't work if you don't pull them. But hey, I'm a rigger, I can repack my own shit for free. "Holy s*** that was f***in' cold!"

My experience has been that the opposite is true. If tight line stows are used to stow the whole length of line, the force unstowing the lines from the bag help to slow it as it travels to line stretch. When the jumper reaches line stretch, they suddenly accelerate the bag, canopy (which is still uninflated at this point), and pilot chute back to the jumpers speed. This is called snatch force and will be significantly higher if loose line stows or fewer line stows are used. All of this can happen without line dump occurring. I experimentd with this on my old Heatwave and found the most important thing to do for a soft opening (except for getting the slider placed right) was to get the lines stows even and tight. The PD recommended 8-12 lbs of necessary unstowing forces seems about right. Flaking the canopy more or less carefully only affected how off-heading the canopy would open. It is true that some equipment set-ups use free stows or line stow pockets instead of rubber bands...these canopies are CrW, reserve, or BASE canopies that are all designed to open quickly if you have ever experienced or watched one of these openings you will see that they are not the softest. "Holy s*** that was f***in' cold!"

I've always found that by around 1000' you should know if you are going to make it back or not, and you have to remember to leave enough altitude to mesh in with traffic and get pointed into the wind. If by 1000' things don't look good, I find an out and use it. We did 2-plane formation loads this past weekend...one of them gave a long spot, 5 out of 8 of us made it back. The other 3 all landed downwind because they didn't leave altitude to get turned into the wind. All 3 of them tumbled, got real dirty, and still had to walk back anyway. A key ingredient to a good landing is finding a good landing area with enough altitude to plan and execute a landing normally. "Holy s*** that was f***in' cold!"

Thanks for the reply. I have read the owner's manual (several times) and I understand the idea behind the bump-the-brakes thing; I was just curious if other pilots had found that it really did work better. As for the wind conditions, I jump in everything from light and variable to 20+. I usually stop swooping if winds get close to 15 mph or higher. I do find that in normal flight the canopy has a steeper descent (that took a while to get used to). I was expecting a more negative recovery after a riser turn to landing. The bigger Vengeance I jumped really seemed to keep its speed up after a turn...you would return to being under the canopy (it wouldn't be pointed towards the ground) but it would keep its speed for a while untill you leveled it off. My Samurai doesn't seem to do this as much...it swings you back under and starts losing speed more quickly. It doesn't recover as strongly as a Stiletto, just stronger than I expected. I usually use the other riser to steepen the dive while I am still turning. I have found that turning high, stopping on heading, and the riding double fronts to the appropriate altitude doesn't hold speed as well. I start in brakes, let up and hold double fronts for a second, shift my weight and let up on one front riser to establish the turn, and then pull the other one back down some if I feel I'm too high. This seems to build and hold speed better. I just find I have to carry the turn down lower than I expected. I am still starting this all about 450' AGL (pretty high). Again, I was just curious if others had experienced this. As for the flare, I do get the toggles all the way down at the end, I just find it is moving quicker than other canopies. I have it set such that I can only bowtie the canopy at the very bottom of the control range...I have to push those toggles down as far as possible to make it collapse. Again, I am interested if opther pilots experienece the same thing. I have heard some say that they never have to take any steps during landing which, well, I do. "Holy s*** that was f***in' cold!"

I'm watching them. Ain't a good enough pilot to get under one of those, yet. Maybe some day. Yes, they are being front risered, and this seems to happen towards the end of the dive (when the speed is real high). I would definitely agree that when a front riser is pulled down all sorts of funky shit can happen with the distorted airfoil, especially with the higher speeds. I just don't see it happen on other canopies. "Holy s*** that was f***in' cold!"

Recently, I have noticed a couple of Icarus X-braced canopies (both FX and VX) do something a bit odd. Every once in a while during the dive to landing, the aft section of the canopy between the inboard brake lines will begin to flap around, making a great deal of noise (and probably drag). I imagine this is probably aerodynamic flutter; is this right? Has anybody else seen this? "Holy s*** that was f***in' cold!"

I've put about 50 jumps on my Samurai 150 (loaded at 1.4) and have noticed a couple of characteristics of the canopy I wanted to ask about. I am curious if other Samurai pilots experience similar personalities from their canopies. 1)Brian Germain talks about using the "bump the brakes" method to flare. This consists of making the initial toggle input fairly quickly to get the canopy planed out. This is contrary to what I had done previously. After trying both a slower, smoother flare and bumping the brakes, I haven't decided which one seems to be more efficient. What have you all experienced? 2)The recovery arc on this thing is longer than a Stiletto, but it is not quite as negative as I expected. When I come out of a front riser turn, I find that the canopy loses speed fairly quickly. It does not, however, plane itself out...it seems to return to normal flight rather than hitting a high speed, low descent type flight you'd get on a Stiletto. My brakes are long enough that the tail doesn't deflect on using the front risers. Anybody else experience this? FYI, I jumped a Vengeance 170 whose brakes were too short and it recovered less agressively than my Samurai 150. 3)This is the hardest canopy to shut down I've flown. It seems to stall at higher speeds. Being smooth on the toggles throughout the surf and the shutting down process seems to help, but it still is moving faster than other canopies when touching down. Anybody else have this problem? "Holy s*** that was f***in' cold!"