polarbear

Again, my bad on the breaking strengths. I wouldn't expect HMA to handle sewing too well. It is so small compared to the needle and thread size. I think you are right about the finger trapping. Time will tell.

My bad on the breaking strengths of HMA and Vectran. In any case, 352 lb and 440 lb is getting low. I'm no canopy design/manufacture expert, but I would expect that weak of a line to not tolerate hard openings well.

There are no design/testing requirements for main canopies. If the damage is all on one side of the canopy, it is a good indication it was loaded unevenly in deployment. It is not hard to do...one shoulder low and you get 80% opening load on one side, 20% on the other. It may just be for a split second but that is all it takes to snap lines. Of course HMA will snap before Vectran...Vectran comes in 750 lb and 1000 lb strengths, HMA is 550 lb. When you get to extremely small HP canopies, the recommended maximums are a function of the aerodynamics of the parachute AND the material properties. As you make bigger sizes of these canopies, the aerodynamic limit goes up, but the material limit doesn't change much. Get to a BIG super HP (ie Xaos 135) and the aerodynamic limit is way over the material limit...thus a maximum wingloading of 1.9. Having said all that, I won't buy an HMA-equipped canopy...yet. I always let these things go around in the public for a couple of years. Regardless of how well a company tests a canopy, new problems always come up when you put one in the hands of the average idiot who are NOT engineers, aerodynamicisits, canopy designers, riggers, etc. Precision isn't the only company I apply this ideology to...I do the same with all of them.

It wouldn't neccessarily have to change the trim angle. You could shorten the lines without changing the trim. If you just took a line set from a 120 and threw it on a 135, then yes, it would have a flatter trim. A canopy with shorter lines will not have to throw you (the pilot) around in as a big an arc, which will result in quicker handling and recovery. The canopy will have a sharper anhedral (it won' be as spread out over your head), which may make it harder to get slowed down as much when landing. Assuming you don't change the trim angle, its hands-off natural speed should stay about the same. If you change the trim angle, the performance could feel very different.

From what I can tell, Vectran does what it is supposed to do...stay in trim.

Other way 'round. Especially if the new line set incorporates a line trim modification (ie alteration). In the end run, it depends on the manufacturer's instructions. The FAA is fairly vague about what requires a master/senior rigger. What they do say is follow manufacturer's instructions...so, if the manufacturer says it is OK for a senior rigger to do it, then there you go. It will probably require a bartack machine; most senior riggers don't have access to one of those.

The whole idea behind Vectran is that it doesn't stretch or shrink with use, meaning it doesn't go out of trim. If you jump with Vectran, keep a close eye on the lines, particularly steering lines, particularly lower steering lines. If they start getting fuzzy get worried. Like hook said, they just snap...bad thing after finishing the highest speed approach you ever did...

This is second-hand information, so take it with a grain of salt... I know somebody who had a "problem" Vengeance. When they sent it in, PD apparently test jumped a bit, scared the shit out of their test jumpers, pulled the WHOLE THING apart, re-maid it, jumped it some more, and then built a new one and sent it back. It seems like the Vengeance design may be tolerance-sensitive (on opening, anyway). At least it flies nice, once open. I would be happy flying one.

I feel like I have a pretty good perspective. In the fall-winter-spring, I jump in Illinois, at a field elevation of ~700 ft. (say on average at standard temperature). In the summer, I jump in New Mexico, at a field elevation of ~5000 ft (on average at 100 degrees). The difference? Between temperature and actual elevation, the difference is DRAMATIC. As mentioned earlier, a canopy seems to fly much smaller at the higher elevation...loses more altitude in a turn, flies faster, stalls at a higher speed, etc. It lends itself to good swoops. I find I have to start my final turn higher, start my flare higher, and be ready to run when I touch down. If you are going from a "Normal" DZ to one at high altitude and/or high elevation, be ready for a difference. Take it easy for a jump or two (at least).

7-cells typically have a lower aspect ratio than 9-cells, which means a lower glide and a more "sinking" type of flare, as opposed to a "swooping" flare. 7-cells usually roll into a turn quicker, but the ultimate turn rate will be higher on a 9-cell. 7-cells tend to exhibit more stable characteristics and malfunction less violently (one of the reasons they are used as reserves and CRW canopies). 7-cells also typically have lower pack volumes. It should be noted that number of cells is only one design variable. The other design variables can make up for the performance differences caused by number of cells. A good example is the 7-cell semi-tapered designs, like the PD spectre. This is a seven cell canopy, but because of other design characteristsics, it behaves more like a 9-cell.

I have found one with a connector link rotated 180 degrees. It probably would have opened; it MAY have caused some kind of tension know that held the slider up, or something else. I also opened one that a full 360 line twist packed into it. It also probably would have opened...to pass TSO tests, reserves have to be dropped tested with THREE full line twists, and they must be fully opened within 3 seconds of release. I have never seen one that would have certainly, or probably, malfunctioned.

Yes, I'm very glad I know how the seam of a continuous line round is supposed to be sewn. I am sure that will prove essential knowledge during my skydiving career.

Well, after a year of pretending, I am now a real rigger.

There are some good sources of information. The parachute manual has some basic information. A guy named Jerry Sobieski wrote a short thesis on the aerodynamics and piloting of high-performance parachutes...go to yahoo.com and search for "Jerry Sobieski Parachute" and you'll find it. Also, Bryan Burke wrote some good stuff on parachutes. I think you can find it on the Skydive Arizona website somewhere.

There is another issue besides riser breakage. The riser probably won't break after 400 jumps, so there are lots of people out there who never chaneg them. The issue that can happen is the dimensions on the 3-ring system can change with time, which can drastically reduce the load reduction capability of the rings and lead to a hard cutaway. 100 jumps is probably too early. Personally, unless something was obviously wrong, I would go to 300 jumps.

You should be careful about letting your suspension lines come into contact with velcro, particularly if they are spectra. The hook portion of the velcro will quickly chew up spectra suspension lines. I loop my excess through the top and put it around the stiffner on the toggle. 200 jumps like this, no problems whatsoever. My new rig has tape on the back of the riser, but there is still loose line flapping in the breeze when I stow my excess with the tape. 15 jumps with this setup and I had the excess half-hitch over my glove...managed to get it off, though.

Remember that at terminal most pilot chutes have somewhere in the vicinity of 60-70 pounds of drag force, which is the force pulling on the risers. This should be enough to cleanly seperate. If they don't, something isn't right with your cutaway system. It should require very little force. It doesn't matter if you try it at terminal or at zero on the ground. At terminal, there is still 60-70 pounds on the lines. On the ground, it will probably take much less than 60-70 pounds to separate your risers. I think billvon is right about integrity risers...they wouldn't separate if they were still laying flat against the shoulder (the rings wouldn't be able to flip through).

Legally, if the guy has a certificate, it is good for life (until specifically suspended or revoked). It has no expiration. The currency requirements are that a rigger must perform "duties under his certificate for at least 90 days out of the preceeding 12 months". In other words, it is difficult to tell if a rigger is "current". I would agree, however, that you should pick one who shows genuine interest in packing. He doesn't have to be a paid packer at the DZ; just because he doesn't pack mains all day doesn't mean he won't pack a good reserve. In fact, many paid packers I have watched obviously only know the basics. If Ram-Airs weren't so dependable, I believe that many paid packers would quickly loose business due to malfunctions. Packing a reserve to work isn't too difficult, but making it look good can be. The rigger should be willing to take the time and make it look good, no matter what type it is. He should also be willing to go back and shorten a closing loop, etc. to make it "perfect". I don't agree with the "find one who has the same type of rig you do" attitude. I currently jump a mirage (which has a beautiful pack job in it, if I do say so myself) but I have only packed a Mirage once. I have packed dozens of Javelins and Dolphins, but have never owned one. The rigger should be willing to put in the extra time to make it look good, no matter what type it is. I also don't agree with the idea of finding one who has been in the sport a while. Some of the oldest riggers I know are not as familiar with new equipment as the new riggers. Also, as someone else pointed out, if they have taken the time to get a certificate, then they *should* know everything they need to. Some of the older riggers have more of a "fuck it" kind of attitude. Find one who really cares about giving YOU a a good looking (and of course functional) pack job. Also look for a guy who inspects EVERYTHING, including the main. I have watched some riggers and have decided they are basically just reserve repackers...they pack well, but don't really inspect/service the rest of the equipment. Good riggers are patient and willing to spend the time to take care of your equipment.

FAR part 65 (it's in the SIM) explains the legal end. Basically, there are two certificates, Senior and Master. There are four type ratings; back, seat, chest, and lap (corresponding to what type of container). When you become a rigger, you have a certificate and type ratings (example Master rigger with back and seat ratings). For Senior Rigger, you have to pack 20 certificated (reserve or emergency) parachutes of one type, under supervision. Then, you have to pass a written exam that covers regulations, construction and design, packing and maintenence, etc. Then, you have to pass a practical/oral where you are required to pack a parachute of the type rating you are going for to the satisfaction of an FAA representative. For Master Rigger, you have to pack 100 each of two types of parachutes, have 3 years rigging experience, and pass a practical where two parachutes, one each of the types you are seeking ratings for, must be packed to the satisfaction of an FAA representative. Senior riggers, in short, can pack and maintain (make minor repairs). They can also pack ANY main parachute and supervise others in packing (but not maintaining). Master Rigers can pack, maintain, perform major repairs, and perform alterations. They can also supervise any of the work they are allowed to perform themselves. Both certificates only allow work on the type ratings that are included in the certificate. For example, a Master Rigger with a back and seat rating MAY NOT work on a chest-type parachute.

We all do chuteless jumps PART way to the ground .

Congratulations on your first save! I wouldn't worry too much about packing a main malfunction...I've done it once, too.n It happens. I assume you put much more care and effort into packing a reserve then you would a main. The important thing is to learn why it happened and don't let it happen again. Ultimately, if you can't have confidence in your pack jobs, I would suggest not packing reserves. That lack of confidence will scare away customers. Be CAREFUL, COMPETENT, but CONFIDENT. My first (and only) save was somebody else. It was a swift 2-pin container...the first 2-pin container I had ever packed and the first non-molar reserve I had ever packed. It took me 2 times to get the reserve in the freebag with the right bulk distribution. It took me 3 times closing the container to get the right closing loop length (it used one long contiuous loop that held both pins...the old loop was gone, so I got to guess at how long it should be). Plus, it was only my 5th or 6th pack job, so I was still pretty slow. It took me about 4-5 hours to get it all together. I never told the guy, but I was damn glad he actually used it...I put way to much effort into that one to just have it expire. The funny thing is, it ws only the second jump after my packing that he had to use it, so I got to pack it AGAIN only a couple of weeks later. It went much easier the second time. Oh yeah, the bastard still hasn't given me my booze.

Boy, this will be interesting. Post pictures/video...I'd like to see this. It should get lower surface inflation...I don't know how well it will keep it, though. The internal pressure in the cells maintains spanwise stability...without the cells, the stability might not be there. If it maintains lower surface inflation, it should get a little forward drive (due to the trim angle) but not much. It should also have a little turning capability. I would expect that if it maintains lower surface inflation, it will behave something like a modified circular. If it doesn't maintain lower surface inflation, it will fly like a ball of shit. How will it land? Hopefully without you under it. I wouldn't try landing it, even if it displayed stable flaight characteristics. You have very little lift and much less drag than a round would give...that means hard landing. Maybe too hard. Like I said, it should be interesting!

Cool picture of a water spout...I'll have to remember not to land in one of those

It is possibly covered in Mil-H-7195, which is for hardware in general. There are a lot of mil-specs out there...the ones listed in the parachute manual are all at least 11 years old. I don't think there is anything untruthful about Mirage's add.

Yes, thank you. That is really good information...the kind that is hard to come by. I hadn't thought about overlapping stitching causing unequal tension, but that makes sense.