pchapman

Winsor wrote: Although jumpers might at times say they are basing their separation "on ground speed", in reality they may only be using observed ground speed to modify what they already know -- they're already familiar with the aircraft they are jumping and are used to the typical separation times needed, for an aircraft of that airspeed. This doesn't change the whole discussion about what is a simple but not too simple way to decide separation. But I think it makes things look a little less pessimistic about jumpers who seem to be looking at ground speed only.

Just to clarify the terminology, as used in aerospace engineering and aviation: Lift is the force perpendicular to the direction the flight vehicle is moving. Drag is the force opposite to that movement. Together, lift and drag combine to perfectly oppose weight, if the vehicle is in steady motion and not accelerating. See diagram. L=lift, W=weight, D=drag, V= velocity So a tracking jumper creates lift. Lift is contributing to keeping the jumper from falling faster, even if that lift is not from Bernoulli style flow, moving smoothly along the object's surface like on an airplane wing. In a sense the lift from a tracking jumper will be like that of drag, just a force from having a rough, non-aerodynamic, blunt object forced through the air. Since that blunt object is at an angle to the air, the force created ends up angled away from the direction the object is moving. We then represent that single overall force by the forces at right angles to each other, which we define as Lift and Drag. A 180 lb jumper in a steady track will have lift and drag combine to a 180 lb upwards force, no matter how good or bad the track is. (Indeed, it will be the same when the jumper is under canopy.) Thinking about lift and drag for skydivers is a little messier than for airplanes. For planes the angle of attack is so small that for a first approximation, one can think of drag as "towards the tail" and lift "up" relative to the airplane flying level. But for a skydiver at maybe a 0.5 glide ratio in a track, with lets guess a body angle 10 degrees head down from level, that's an angle of attack of 53 degrees. So Lift and Drag directions are not "straight up away from your back" and "towards your feet", nor "vertical" and "horizontal". No big deal, but it makes thinking about lift and drag less intuitive. In the end, when it comes to tracking: As the combination of lift and drag stays the same, the issue becomes how to achieve that combination with a lot of forward speed, or a high glide ratio, depending on your goals. A lot of drag and a lot of lift are both helpful in achieving those goals.

Given a choice I'll usually pick up my rig with the 88 in it, not the rig with the 282. Still, acccuracy approaches are a good opportunity for careful concentration & focus that are absent from many other more ordinary landings. A good challenge in other words. And Gary, perhaps you saw the thread on the PD Optimum reserve which got sidetracked into discussing how a couple PD jumpers were shooting accuracy with their Optimum 113s at the Canadian Nationals. They had to learn fast and were having a blast. (http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2910184)

At a Canadian DZ that's a little different but has a carefully thought out program: Yes, SOS for static line rigs. Keeps it simple for the vast majority who do just one jump. Then for freefall progression after static line, rigs are also SOS, with hip mounted main ripcord. (Allowing FXC AAD's both on main and reserve.) Then when students have their Canadian Solo certificate (no longer requiring direct instructor supervision), they convert to "regular" skydiving gear with TAS and BOC. Since this is a big step from their previous gear, there is a 3 jump transition program to properly teach them TAS emergency procedures and BOC main activation.

Given the car door issues, I find it funny how the Vigil's web page mentions its patented, accurate calculation method, that computes time left until activation altitude, and then activates when the right altitude is reached if the speed exceeds 35 m/s. I'm curious just what the pressure vs time graph is for a slamming car door. Exactly what kind of skydive does the Vigil think is happening? Flying along level in a plane and then accelerating downwards with a rocket attached, in order to exceed 35 m/s within a second? The whole car door pressure spike can't take very long. Maybe I'm way off base as to how messy the pressure variations are during some car door slams, but it would seem simple enough to filter that sort of thing out. Off the top of my head, the nearest kind of skydive, that could be confused with a door slam, would be a low bailout or low cutaway, where there might only be a few seconds between "OK" and "fire at 840 ft or less, and 35 m/s". If it really is so tough to deal with car door slams, perhaps Advanced Aerospace could better explain to us why it really is so, instead of having so many people be sceptical.

The songs that relate the most to skydiving do tend to get over used! A reasonable one I've found for tandem vids is "Let You Down" by Three Days Grace [edit: group name corrected], that has lyrics that are interestingly appropriate: == Trust me There’s no need to fear Everyone’s here Waiting for you to finally be one of us Come down... You may be full of fear But you’ll be safe here When you finally trust me Finally believe in me [...] == A classic is the song on Norm Kent's From Wings Came Flight: "I'm standing on the edge, with a vision in my head, my body screams release me, my dreams they must be fed"

Re my yellow helmet post: The padding on that inside face is quite thick so that there is space for the bolts without being close to touching the camera. Still, a little extra foam over them wouldn't hurt. The LANC connector isn't forced in, but if the camera moves more than I think, it can get stressed by pushing on the edge of the hole around it. You're right, a little more room around it might be good. I've also heard of people building a little extension for the LANC, so that the extension can stay in the LANC port all the time instead of plugging and unplugging every jump. Rather wear out the extension instead.

Summary: Protec with home made fibreglass helmet box for an HC-42. Camera was factory refurbished off eBay. Extra padding inside the Protec to make it fit snugly. Skysystems chin cup, Bonehead cutaway system, Cameye LANC system. Cheap, interesting project, but lots of hours to work out the details. Didn't spend enough time epoxying and sanding to make it beautifully smooth, but it's functional. How the helmet went into service: Showed up with it at the DZ for the first time. Very busy weekend and DZ low on cameraflyers. Ended up being put into the cameraflyer rotation. First jump ever with a camera helmet was a working dive, with no briefing. At the Cessna DZ, did 8 camera jumps that day. At least as a tandem instructor, I've been on the other end plenty of times so I just copied what I remember watching others do. It wasn't exactly a by-the-book initiation into camera flying… All the details: (irrelevant unless building a box oneself) The details don't matter until one has to solve the issues that are so simple in concept but messy in detail, like saying "And then you simply bolt the box to the helmet." Box built over a male mold of hard insulating foam built off the dimensions of the camera, with I hoped enough spare space for bolt heads etc intruding into the box. To some degree, nuts and bolt heads are towards the corners of the box, where the camera tends to be rounded and thus offer more free space for such things. Box was built essentially rectangular except for an extra angled face on the lower half of the side towards the helmet. That's where the helmet sides curve inwards for the ear covers. So it wasn't built to conform exactly to the complex rounded helmet shape. Box attached with 3 low profile bolts going in from the box, screwing into low profile internally threaded hardware -- essentially female Chicago screws. Therefore on the inside of the shell there are only very thin, couple millimeter thick pieces of attachment hardware; no thick bolt heads between my head and the helmet shell as I've seen on other quick homemade jobs. To align the fairly rectangular box with the rounded helmet, washers were used if needed to provide the right amount of gap at each of the three bolts. Light fibre washers were used. Each bolt also had one rubber washer between the non-parallel sides of the helmet and box, to better distribute the stress. An anti-line-snag aluminum angle was epoxied into the bottom of the box, to fill the gap between the box and helmet. The box hinge was bolted on, although I could have used rivets instead. Nuts for the hinge and closure were epoxied into the inside of the box after the basic structure was made. Box hinge is at the bottom, so that the Allen-threaded machine screw used to close the box, is at the top. Less snag hazard than the bottom mounted screw on, say, a Rawa box. Painted with Krylon spray paint for plastic. This goes on thin and needs a lot of layers, and seems to scuff easily enough. So I will soon cover it all in a final layer of epoxy for protection. Sky Systems chin cup. Seems to be good quality. Bonehead cutaway system with mods to move handle location. Basically it uses a cotter pin through the attachment pin, with a spring to push the attachment pin out when the cotter pin is withdrawn. The inside of box has a small cutout for the LANC connector to fit into the camera while in the box. The right angle LANC connector from the Cameye unit was shaved down in thickness too. (Just got rid of some insulating plastic). There's some slack in the cable inside the box so the camera can be pulled out some distance before one needs to reach in to disconnect the LANC cable. Unlike some skydiving cameras, the plastic cover over the on-camera ports was not cut off in order to expose the LANC port. Instead, a hole was drilled in the plastic cover, large enough that the LANC connector would fit through the hole, retaining the rest of the cover. The Cameye on/off button was installed as a snap fit through a hole made in the helmet. The location was chosen as one where it was unlikely to be accidentally bumped. (As it might be, say, at the center back of the helmet.) I don’t know if the location is ideal, but it is OK. The hand strap on Sony cameras can be very thick, with heavy leather-like padding. Some of this was removed and rebuilt to make the strap much thinner so that it can be left on the camera and still fit in the box. Most skydiving cameras have the strap cut off. Particularly with a non-matchbox style camera, it is nice to retain the strap. (Given the strap, heads of bolts attaching the box to the helmet, and the LANC connector, there needs to be a little extra space between the camera and the inside face of the box. So the box is a bit wider than a minimum sized box would be.) A Protec normally sits loosely on the head with quite hard foam. In order to make it more comfortable with a tight chin cup, and to keep it from shifting side to side with the weight of a camera, I had to build an additional foam liner. (Not in the photos.) The first simple version uses a number of pieces of open and closed cell foam, which were roughly sewn into a thin fabric cover. It does not fill the entire top inside of the helmet; there are gaps at places to allow for ventilation through the normal Protec ventilation holes. Some helmets' linings use a fleece cover. While comfortable, it seems like it would be warmer than necessary in summer. I'd rather have a cool helmet, so the fabric used for the liner was thin, sheer material. Direct cost was low -- about $145 US for the helmet assembly & box, excluding the Cameye as that's not part of purchased systems. Plus something for the fibreglass and epoxy, which I already had. Compare that to $395 US before shipping and taxes for a common, "inexpensive" full-box system, the Rawa.

My latest big guy was 300 lbs this past weekend. Had a standup landing with a Sigma 370 in somewhat lighter winds. (Not near zero, but definitely not medium either.) I was quite impressed! The key thing was that this fellow wasn't all flab, so was able to do good practice flares with me. Otherwise one might have to start the flare fairly early, while working hard to get the toggles down against the heavy pressure, in the meantime slowly running out of flare energy. Instead, it was possible to wait 'until the last moment' and get an aggressive 2-stage flare going. We did plan to slide it in but turned it into a standup in the end. I tend to get picked for these jobs due to being 150 lbs., tall, & having decent landing skills. Total system weight was right at the 500 lbs allowed (Or, ahem, a tiny bit over depending on our scale accuracy. We certainly wouldn't go any heavier than that at the DZ.) Still, it was entirely my choice to evaluate the student before deciding whether to allow him to go.

There's a big "Post your helmet" thread with photos and descriptions, that includes some homemade helmet systems. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1324044; I built a fibreglass box to go with a modified Protec, and I should post it in that thread some day. While inexpensive, a lot of labour hours went into it. Which was fine for me, as I wanted to work on fibreglass skills and had the time.

How much time to you spend explaining the additional risk the student is putting the tandem pair in by not arching immediately off the airplane? Best to to anesthetise and straightjacket tandem students, then just give them the video afterwards. Keeps them safer. But seriously, I find when doing a single frontloop, diving to the side from a C-182, it is fine to instruct the student to arch normally. As long as I dive rotating downwards, momentum and my body position is enough to get around. That avoids the obvious body position and timing issues for the student!

Being less sub-terminal after a few seconds might also be helping. I do tandems out of a C-182 and the DZ used to unofficially allow a frontloop if a student mentioned wanting one. I did find it was a little more work to do (rather than being easier), but perhaps more front loops would have made it more like what the original poster experienced. I thought doing a frontloop was a good practice of a tandem instructor's flying skills. Of course if "it takes more work" that somewhat implies it is less safe. Fair enough. Still, it seemed to be something an instructor should be able to handle, and that by doing it from time to time they'd be a more capable instructor in being able to take care of exits that weren't for whatever reason perfect. It might also reduce the tendency for some instructors to "get the drogue out right away" which has made for poorer drogue toss decisions, than for those who are willing to fly the student for a couple seconds longer before tossing. Allowing a front loop doesn't mean that anything goes -- the instructor still needs to be appropriately tight to the student, fly the student, and quickly deal with any tendency to get the relative wind from the side. After the DZ's firm new no-frontloop policy started, I figured I needed something for the students who really want a frontloop and want to do something cool like in the Youtube skydiving videos they've seen. First, with the head-low attidute one tends to get from some C-182 exits, especially when following a video flyer, students may think they've done some sort of flip anyway. Second, after the drogue was out I'd crank out a couple fast turns before settling down to a normal jump. They'd get impressed enough just by being spun around. One post mentioned: Ironically, some students want to be introduced to skydiving by doing a neat exit like they see real skydivers doing. What's the point of skydiving, they think, if you can't do flips and stuff...

Exactly!!! My opinion is that Tandem Progression is within the acceptable range of safety & training effectiveness of other training methods. Far greater variation can exist at any DZ with any instructional method, depending on how the DZ implements its programs. The original question: In my area of Canada, a couple DZ's have very different training philosophies, but both are well respected. One DZO chooses not to have any tandems whatsoever and only does PFF (essentially AFF) progression. Another DZO chooses only to do tandem progression. As for personal experience, I have one example of where a tandem progression program has essentially been abandoned. At a Cessna DZ I've instructed at, they never got the critical mass of PFF instructors to run a PFF program, so they had tandem progression as an alternative to beginning only with traditional static line progression. There were students who came out of the program happy & successful, but on average the program wasn't as effective as desired. The problem appeared to not be the tandem progression concept, but its implementation. Tandem progression students were handed to tandem instructors in the normal course of tandems during the day. The instructor would be expecting to gear up and go with the next student in the next 20 minutes, but suddenly be told that the student was on his 3rd tandem. For the same pay as a regular tandem, the instuctor, who might not have done a tandem progression for a couple months, would have to re-learn from the tandem progression sheet what he'd be teaching. The progression sheet was very terse so it wasn't convenient to interpret for those who didn't teach tandem progression often. And the sheet would sometimes not be updated to reflect current DZ policy. All in all, no wonder that on a per jump basis, the amount of student learning wasn't as much as desired.

Ditto! For width reduction folds, I usually use the technique of 'all down at once'. That fits with the technique Precision showed at least as far back as '91, when I learned, when the Ravens were very popular. It also matches PD, once they (years later) came up with their Pro Pack addendum. It's good enough for Aerodyne too. At times I will use some sort of microreefing without doing all the folds together. I tend to do it if the previous rigger did it that way, or in cases where volume is at a premium, especially the smallest reserves. I suspect that the individual folds might tend help allow a tighter pack job with less air in it. When I'm doing individual folds I tend to do each fold upwards, individually (with the tail wrapping around all but the nose). I've also done it with each fold individually downwards instead. For a while I was trying to be fancier, and did AB fabric upwards; BC, CD, and tail wrap downward together (ending up above the AB). I'm just not sure it really brings any advantages. With all the different methods out there, I haven't been able to pick out one method as superior. Even among BASE friends I've seen methods change, sometimes becoming more complex and then simplifying again. I'm not in tune with a lot in that world, but even they may have found limits, in that there is a point where fancier does not equal better. I do use the manufacturer's technique for what seem to be special cases, such as tandem reserves. If a rig & reserve is something ancient from the early 1980s, with no modern manuals, I certainly don't flat pack and then wrap the reserve around the closing loop(s) in some intricate manner shown by the manuals of the era. I would use more modern techniques, propacking and molar-ing the canopy. Everybody has different techniques published. Old manuals without propacks weren't always updated. PD still has propacking as an optional second way. DeWolf changed his folding from his '03 to '06 manual. Flight Concepts has the canopy propack flaked neatly, wrapped, and then laid down without going through everything again. Paratec and Performance Variable in Europe does it similarly. PD insists on clamp pull tests, FCI now specifically prohibits any clamps, and Rigging Innovation shows lots of clamps to pack a reserve. I guess in the US, the canopy manufacturer's word comes first, over that of the rig manufacturer, for canopy packing technique. But even then, where does "packing the canopy" end and "folding it into the bag" begin? For example, Velocity mentions packing the canopy according to its manufacturer's instructions. But then it still shows steps for a specific folding technique (pretty much AB up; BC,CD,tail down above the AB). And we'll all go straight to hell according to the FAA if we don't follow the manufacturer's instructions. So I like to remind people that on account of that, an Aerodyne Smart in the care of a rigger MUST be kept between 15 C and 30 C, at 15% to 70% humidity. The manual says this must be done.

I've got the IPC weight restriction table from the FAI's Canopy Piloting rules, that shows how much extra weight a competitor may carry. It's in kg and I was wondering if someone had a version translated to pounds. Can't seem to find one on the web.

Yes, my video was of one of their first practice jumps trying to sink it into the tuffet. Although the landings were quite survivable when they missed the tuffet, they soon changed to going to a full flare and trying to tap the scoring pad as they planed out and went by. They both used the Optimum 113's. Isaiah's comment on the video was that the loading was 1.8! (But there was significant wind that cut down his forward speed.) A quick count shows that between them they got scores on the 16 cm radius pad seven times out of 20 competition jumps. They also entered the just-for-fun team accuracy event and on one round used their Velocities. But one malfunctioned, so after the chop the jumper used his real Optimum 113 reserve to go for the tuffet...

Whether this refers to the video, or what I said about a single jump on an Optimum 113, you're right, it doesn't prove anything. And I don't know how another modern reserve might fare in comparison. Others may get different ideas, but I got a favourable impression out of seeing that something as small as a 113 could be flown in without it being too scary, if one for some reason weren't able to land from full flight with a proper flare. A good video of the same canopy landing with a full flare in no winds would be useful too.

Unless I'm much mistaken, I just saw the original poster at a skydiving event attended by a PD crew with demo Optimums, so she might have first hand experience now. I put just one jump on an Optimum 113 in moderately windy conditions. At 1.5:1 loading I tried sinking it in in deep brakes (about 2/3 brakes) without a flare onto grass. The descent rate was not a intimidating at all and a little roll to the side was fine to absorb the landing. A video of a PD jumper trying to sink the 113 in to a tuffet and missing also shows that the landings are quite survivable without having to have a perfect approach. The vid should be up on skydivingmovies.com any time now. The name is "Sinking in an Optimum 113.wmv".

I was also thinking that that technique may be a good place to start, although I don't have the practical experience to back the idea up. So this is just an opinion. Sometimes one will already be spinning before one can react. But other times the canopy may be flying with only a slight turn with line twists. Kicking, grabbing risers, and violently moving one's body around at that time may just make things worse. Even if the lines are fully locked in the twists and one isn't therefore making the risers uneven, all the movement can result in swinging under the canopy that can get the canopy to start turning and spiralling. Some canopies are directionally very sensitive and may tend to stay in a turn once one starts. That's in line with the reply that "You don't even need uneven risers. Do a hard riser turn after opening when breaks are still set..... The turn/dive might not stop by itself.... " The increased anhedral of a canopy, when line twists are pulling the lines inwards, is likely also making the canopy more directionally unstable.

I never found out the factory way either; they aren't always very responsive to questions. One thing I've done is just to use the same principles as building a loop for a Reflex. (That's not in the manual either but there does exist a printed sheet showing construction details. Not sure offhand if it is on parachutemanuals.com.) I also have notes from a dz.com post by someone who had contacted TSE about the Teardrop. The loop was to be built 2" from washer to finger trap, with a 1.5" long fingertrapped section. (I haven't checked the numbers out, but 1.5" is the same as used on the Reflex.) Better answers welcome.

A couple weeks ago at a drop zone in Ontario, Canada, a jumper had a minor reserve malfunction that did not result in injury or canopy damage. After a low speed cutaway from a lineover on a large canopy, the jumper activated his reserve, which was also activated quickly by the RSL. After a fast and on-heading opening, he noticed an entanglement at one front corner of the canopy. He was able to counter steer against the turn, and landed safely. The entanglement was still present after landing so the issue could be investigated. I did the informal investigation but wasn't present at the DZ where this occurred, so am relying on others' statements and photos. (I'm not highly experienced but have 600+ reserve pack jobs.) The malfunction: One line on the reserve canopy was hitched around an A-line slider stop, which on that design of canopy is at the bottom of a flare. The reserve was a Glide Path Fury, a design which continues to be built by Flight Concepts International. That canopy and others in their product line, use flares rather than direct line attachment. The line that entangled was most likely an adjacent line, either the next A-line over, or the B-line directly behind. The Fury reserve is 220 ft. sq. in size, and the jumper was perhaps 150 lbs. without gear. My conclusions: Flight Concepts knows of only one other incident where a line hitched around a slider stop (one which resulted in serious injuries). It appears to be an extremely unusual event. Both the entangling line, and the line with the slider stop, would need to be slack in order for a line to loop around a stop, either within the pack job itself, or perhaps more likely during an out of sequence deployment. The design of the Fury reserve (and others like it) with flares and no stabilizers, may in my opinion be more susceptible to such an entanglement, than a reserve which has the slider stops embedded in a stabilizer, even if the overall risk is extremely low. I would consider the incident to be largely due to chance, although it can be asked whether the pack job might not have been as neat as it could be.. Details: Picture 1 shows the line around the slider stop, as it was found after the jump. Since it is poorly exposed and focused, Picture 2 is the same but with colour added to show how the routing of the lines. Picture 3 is a re-creation using another canopy with flares, showing how such an entanglement can look when the lines are under tension. The entanglement was I believe technically a "simple hitch" -- the line just looped once around the stop. (Not quite a "half hitch", although that term is used a lot.) While it wasn't confirmed which line entangled the A-line slider stop, due to the limited amount of canopy distortion it was likely one of the adjacent lines. For Flight Concepts and Glide Path canopies like the Fury, Firelite, or Sharpchuter, there are both main and reserve canopy versions. As far as I know, all the reserve versions have no stabilizers, so the slider stops are at the bottom of flares rather than embedded in the bottom edge of a stabilizer. I hypothesize that a stabilizer's fabric and the fabric tapes around a stop, may help 'protect' a stop from having a line loop around it, even if that fabric is still flexible. While looping a line around a slider stop is simple enough in concept, even on the ground it takes some work to hitch a line and have it stay in place when tension is applied to the lines. It is still more difficult to see a way for it to have a significant chance of occurring on reserve deployment. I contacted Flight Concepts, and they said they know of only one case where a line has ever entangled on a slider stop on a Flight Concepts or Glide Path design. While minor incidents may not get widely reported, Flight Concepts noted that there have been no concerns in the industry regarding canopies like the Manta, perhaps the most popular student canopy every produced. Although the main canopies have stabilizers, they do not cover the A-line flare. (At least on some of the companies' mains. Pic 4, from another dropzone.com thread, shows an example of a Flight Concepts or Glide Path main canopy.) I personally haven't heard of similar line entanglements on other types of canopies that have stabilizers and direct line attachment. A rigger I asked at one of the major reserve canopy manufacturers had not heard of other incidents either. The one previous reported slider stop entanglement incident was a case in 2006 where a Sharpchuter reserve suffered serious damage on deployment, likely when multiple A-lines entangled around an A-line slider stop. This was reported on dropzone.com: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2171368 Ultimately the cause was unknown, but could have been more likely to occur if the pack job was not neat or the opening was not perfectly in sequence due to chance or another reason. A hitch would be more likely to happen there were slack in some lines, especially if the slider had already moved part way down the lines. One would have to imagine a scenario that could include things like a less neat pack job, the canopy at least partially dumping out of the freebag on deployment, an unsymmetrical canopy inflation, etc. A less than neat pack job would not necessarily contain an entanglement, although it could still encourage a poorer opening. The rigger who packed the reserve in the Ontario incident is a newer rigger, and was involved in the analysis of the incident. I have seen his work and have no reason to believe that he is anything but thorough in his approach to reserve packing, and he has good awareness of things mechanical. Nevertheless, maintaining canopy neatness when S-folding and squeezing it into the freebag is one of the challenges of rigging, especially for the newer rigger, so that will receive extra focus in the future. I understand that no anomalies were seen with the rest of the gear (e.g., safety stow, freebag & canopy size compatibility, etc.) Other thoughts about slider stop entanglements: One can try to imagine various scenarios for different lines of different lengths, entangling with the A-line stops. If all lines were the same length, the slider up against the stops would be very good at preventing a line (from below the slider) looping around a stop (above the slider). But with unequal line lengths from A through D, there may be more potential for lines of different lengths to interfere. The slider will help keep some lines separate from each other. The pack job method may influence the likelihood of entanglement. If the tail of the canopy is well wrapped around the canopy, right down to the bottom of the flares (that is, where the lines start), the tail material will help keep the longer lines separated from the shorter A-lines and their slider stops, when the canopy is S-folded into the bag. The two known incidents, however, seem to involve only A- and possibly B-lines. The Flight Concepts reserve packing manual does show the tail of the canopy being brought down to the bottom of the flares. Flight Concepts emphasized this when I discussed it with them, as a method of keeping the pack job organized when the S-fold is made. (However, the instructions are a little vague about wrapping the tail around to the nose. The written instructions do not explicitly mention it, but the drawings suggest that the tail is to be brought around as on a main PRO pack, although not rolled as it would be for mains.) Although riggers are to follow manufacturers' instructions on reserve packing methods (especially in the USA with the FAA), in reality I think many riggers have their own preferred method. It is possible that some riggers do not bring the tail of the canopy right down to the bottom of the flares, particularly if they are less familiar with canopies built with flares. Having a generally neat pack job, that is adequately retained in the freebag until the lines are taut during deployment, should encourage a symmetrical, well sequenced deployment, that reduces the chance of a slack line entangling a slider stop, but there are no guarantees. ============================== Any comments, corrections, additions, or opinions are welcome before I send in a report to the CSPA, USPA, and Flight Concepts.

Can someone confirm that all of the Flight Concepts or Glide Path reserves are or were built without stabilizers? (eg, Cricket, Fury, Maverick,...) I know that generally they are, but am not sure that it is that way for ALL. The main canopy equivalents generally have stabilizers that start at the B-line attachment, while the outer A-line is on its own on a flare. Does that hold true for all of Flight Concepts / Glide Path F-111 canopies? (E.g., including the good old Manta) Also, on the reserves, at least some do not use a slider stop on the B-line. (Whereas on the main some do.) Again, is this the way it is on all of those canopies? And yes I'm asking Flight Concepts too. I'm trying to understand the designs so that when I talk about them I don't make unwarranted statements about the whole range of canopies, for something that is true for only some.

I think one has to look more closely at how many jumps are involved when trading off belly vs freefly jumps. Let's say that everyone starts out with 50 jumps (or whatever) to learn the skydiving basics, and then specializes into free or belly. Perhaps most will likely agree that doing 500 belly dives (after the skydiving basics) will then make one a better belly diver than doing 250 belly and 250 freefly. There's just too much belly learning that is missed by doing all that freefly instead, even if it can teach some useful things about freefall control in general. If someone disagrees with the above, perhaps it will relate to particular skills. The 500 guy may be better at belly than the 250+250 guy, when it comes to understanding how to launch a specific formation from a specific aircraft. But what about having to do a long, steep dive down to a bigway formation base? I don't have the experience to answer that one. Will the 500 belly guy do better, or the 250+250 guy, if the freefly aspect provides a totally different but useful freefall method and set of skills for accomplising the task? Moving on: While it is perhaps less of a sure bet, I'd guess that for smaller numbers of jumps, the same relationship will exist as for 500 beating 250+250. That is, 100 belly will be better for belly than 50 belly plus 50 free. But I'll hypothesize that maybe if there are plenty of "primary discipline" jumps, then a smaller number of "secondary discipline" jumps may actually improve the primary discipline skills (for the same number of total jumps). So now compare the person who does 500 belly, vs. someone who does 450 belly and 50 freefly. The latter person won't have lost that much in belly learning, since after 450 belly, he won't be way behind on belly skills if he misses 50 more. But having just 50 freefly jumps may be enough to give the jumper some valuable additional freefall control concepts to work with, that'll make him better at belly than the other guy who never tried freefly. Whether you agree or not, this provides a more specific hypothesis to consider.

At our DZ, the standard thing to do with someone who wants to be around a tandem passenger, but isn't at all qualified to do RW with the tandem, is to have the solo jumper in the airplane next to the tandem. The solo exists first, with normal freefall separation. So at least they all get the airplane ride together. The other thing we've tried, and this seemed to be enjoyed by the friends, is to have the solo exit after the tandem (again with proper freefall separation) and pull high just like a tandem. Then the solo can fly over to the tandem under canopy. So the friends get some time "together" in the airplane and under canopy, although not in freefall. Still, as a tandem instructor I'd want to be pretty sure the friend was a heads up and disciplined jumper, before allowing this. Maybe 50 to 100 jumps experience at least??

I don't mind round reserves, but one may want to consider one's DZ environment when making the choice. My only reserve until 2002 was a round, but I was mainly jumping at a DZ that was "traditional" in that it had a lot of open fields around it. I'd think a lot more about squares if I were at a DZ surrounded by forests and subdivisions.