pchapman

Cross braced or airlocked... yes, when it comes to canopies that have been on the market, just one or the other. Brian Germain did experiment with a combination, he once said in an interview, but it was a sewing nightmare, and the additional benefits of having both features were not that big, not enough to make it worth producing. It did make a super stiff canopy though, which if you bounced off it in CRW, was like hitting an air mattress. [Ref.: interview was in an early Skydive Radio] At least that's the way I recall it.

Are all the oxygen systems in US aircraft fully legal? Or are we supposed to talk about the whole industry's oxygen systems only in hushed tones? I don't know all the rules. But are the systems that are bolted or screwed into place all approved through a 337 form or similar? Or do we maintain that they are all "temporary" and not "attached" to the aircraft, because only such things don't need approval? Some installations appear more temporary with hoses strung up only on special occasions, while others have for example aluminum distribution tubing attached by screws to the cabin walls.

I've been to a couple Canadian DZ's where a big X style arch is used for the first few seconds on PFF (AFF style) jumps. After some seconds "on the hill", when the student sees the horizon out infront and level with him, the student transitions to a box position before continuing with HARM checks etc. So the big spread arch can be used as a very stable position, before moving on to one more suited to maneuvering.

Regarding the sensitivity and 'arming' of the Vigil, I checked the manual, where it states: I think what it is saying is that a climb of 150 ft within 32 seconds is considered a takeoff, which then 'arms' the Vigil. AAD's term is 'switching to active mode'. This 150 ft active mode thing can also be the cause of Vigils not switching off all week if you leave it in a car and go up in elevation, not returning to the zero level. I'm wondering if some of the car door type incidents occur after the car has driven somewhere higher -- So that all is needed is a sharp pressure increase to fire the Vigil, rather than some oscillating fluctuation of lower pressure followed by rapidly increasing pressure. I'm not sure where into all of this one fits Vigil's "patented “permanent Left over Time Calculation” method." Whatever filtering or prediction it is doing, some spurious pressure oscillations get by it. The Vigil on Pro mode will fire anywhere from 840 ft down to 150 ft, again from the manual. But with the belly to earth burble compensation of +260 ft for firing, I guess that means the Vigil is looking for a pressure corresponding to 410 ft as the lowest at which it will fire. If that's right, it would imply that before firing, the pressure would not only have to drop 150 ft worth to go into active mode, but get up to 410 ft worth before a rapid pressure increase that actually sets the Vigil off.

Just a couple quick points: If someone is wondering what a Cypres measures, it would be worth opening up an expired Cypres 1. I did that once and posted pictures, but I didn't go through every chip's markings to try to determine what each did. Vigils, for better or worse, do tend to be more 'sensitive'. A rigger I know put a rig in a heavy duty plastic bag, twisted the mouth of the bag, then squeezed the bag to get some air out of it. Pop went the Vigil, which he had forgotten was still turned on. One way or another the Vigil thought it was airborne and ready to fire, and then fired when the air pressure suddenly went up near ground level pressure.(But he didn't run the same test with a Cypres, so it is actually unknown what it would do.)

The problem with Kroops as I see it is that the elastic strap loses strength so quickly, so one is always fiddling to adjust it shorter, or it is nearly 'stretched out' with little elasticity at all. When digging through a pile of goggles for students, the Kroops always seem to be the crappiest choice. Other types like Flexvision have a stronger bungee (although harder against the head). I personally like Skyeyes' soft silicone strap which lasts pretty long. But that's only looking at traditional skydiving goggles; many people use full face helmets (not normally for students!), or various other eyewear like sunglasses and sports goggles. Sunglasses are great for some people, but others with more sensitive eyes find that even tight fitting ones allow an uncomfortable blast of air on the eyeballs.

Huh? Have the hysterical cries about taking canopy courses now turned into ones about taking a course at least once a year??

Sometimes a DZO will use the minimum national requirements, other times they may raise the minimum somewhat. That would largely be for the vague general reason sometimes used in skydiving, that the more jumps you have, the less likely you are to screw up something simple. On a typical small helicopter used for a special skydiving event (not a large Eastern helicopter) you might be in a cramped cabin with minimal space to check gear, you need to climb out onto the narrow landing skid before the jump (and not slip), for flight safety the pilot probably wants you to step off and not push off the aircraft, and you may go unstable on exit due to the low airspeed normally used. Nothing terribly complicated but with more experience the risk of a problem might be less.

The Bureau of Land Management in the US has for many years used drogues. I don't know the details offhand. For some info on drogues, mainly in "eastern" rigs, try http://fire.ak.blm.gov/content/akjumpers/Loft/History/History%20of%20the%20drogue.pdf ("History of the Drogue"). It includes sport ram air systems with drogues -- which, who knows, might be what the O.P. would be jumping with.

I was going to mention something like that as an add-on to RiggerLee's comments! While some manuals do provide useful tips and emphasis, I've even had a new rig come packed fresh from the factory, in a way contrary to the manual. "Secret stuff" becomes like some little status contest among riggers ("I can pack that rig tighter than you can! Bet my loop was 1/4" shorter!"), rather than allowing an average but committed rigger to provide a safe pack job for the customer that doesn't unduly stress the rig.

Focus on your jump first of course! But any pics of the rig would be interesting, especially of the mechanism by which the drogue connects to the rig, and the drogue itself. Release mechanisms are always interesting as they often have to withstand a lot of force but release with little force, in this case both by a handle and a mechanical AAD. Camera electrons are cheap anyway.

If you do go through the drogue assisted progression system, get some photos of the setup! I'm familiar with the drogue system on a Russian D-6 paratrooper parachute, but most of us have no idea how the system might be set up on a sport rig.

+1 on all that

It is certainly true that making students arch hard for a long time while laying on their bellies, is very tough on them, and distracts from the other things they are learning.

The reply that was to davinciflies: No. See below. The problem is that we don't have a consistently applied definition of "line dump" in the skydiving community. Thus many say that line dump DOES NOT lead to hard openings -- because "line dump" refers only to the lines other than those in the locking stows dumping out. If the locking stows go or the canopy in any way starts coming out of the bag prematurely, that's a separate category, "bag strip". Others say line dump DOES lead to hard openings, because if the lines in one or more of the locking stows dumps out prematurely, the canopy can start inflating prematurely. Lines are lines, and anything they prematurely dump out of, including locking stows, therefore counts as "line dump". Thus much of the battle is about the definition of "line dump", not what the cause of hard openings is.

When training students on the ground to do the arch there's always the problem that they are lifting the arms and legs against gravity, rather than pressing down as if against the air. Just telling students that it is easier in the air, or putting hands on shins and telling them to press down, doesn't fix the whole problem. How common is it to instead practice the arch with the student lying upside down on an elevated, padded training stand? I've heard of it being done. Any opinions on whether it is useful? Seems like it would be better for the arm and leg forces, but more awkward to lie there, and possibly making the torso arch too easy. If the upper leg (thigh) isn't supported, then the student still has to lift their entire leg to get the right position, still putting a lot of strain on the lower back. Supporting the upper leg at a correct angle (with a sophisticated training stand) would result in having only to to lift the lower leg to the right position. It isn't easy to simulate freefall forces on the body.

Just guessing: Could it be a home modification of a common design? I haven't looked in detail, but it is somewhat close to a Mark II PC, but with a bigger central aft drive hole. Does that aspect look factory built or not? Extra holes cut out at the back can also explain a missing data panel. I've seen that before.

I looked at those ASRS / NTSB / ASAIS reports. While some do involve accidents involving jumpers hitting airport obstacles like pavement and hangars, there is no data to show that tweaking landing area sizes and shapes has much to do with it. Perhaps a greater concern is the issue of deconflicting aircraft and parachutists in the air -- it can be tough for pilots to learn exactly where jumpers will be descending and where to expect them to land on the airport. Everything is very foreign to the standard patterns and runways they are used to seeing and visualizing. That's going to be an issue any time there are parachutists near a traffic pattern including approach & departure. Some airports manage the issue better than others.

I really don't know the US situation so my opinion doesn't carry a lot of weight. But I'm guessing that the above isn't the problem. The FAA has to deal with cases where a drop zone wants to locate on a funded airport, and the airport commission or some other group says, "They can't land next to the runway, it's dangerous! Make them land in a field off the airport." The FAA has little guidance on what standards to apply, so is trying to come up with something. I could be wrong, but it doesn't sound like the FAA is upset with reports of students being dragged across taxiways in front of aircraft etc. Skydivers hitting each other under canopy may be on their radar but it doesn't seem very related to this issue. As was already noted, skydivers sometimes act as if they own the sky, or at least the patch of ground they land on.

Of course that protects just the fixed side. The side that threads through the buckle can't benefit from that fix. On the other hand, rigs nowadays used doubled-up chest strap webbing much more than they used to, when a single type 8 strap was more common.

I guess call your rigger and call SSK and see what they say about dates shipped, received, etc. Then you'll have a better idea about where the delays are taking place. I hope you recorded the serial number (or have access to a packing card that lists it) so you can identify your unit instead of just asking SSK whether they got anything in the last months from your rigger. SSK naturally wouldn't need to release any info to you about units and shipments that don't belong to you. One can also sign up for online tracking of one's Cypres with SSK, so one doesn't have to keep phoning SSK for news. But I'm not sure how that would apply in your case, or be set up if you weren't the one sending the unit in.

Here's my take: If I were buying my first AAD, for my main rig, as a really active skydiver -- I'd go for the best, a Cypres (even if I grumbled a little about the life cycle costs). If I were getting a second AAD, trying to keep costs down, I'd then buy a Vigil (even if I grumbled a little about their not quite as reliable algorithms).

I am glad to have flown aerobatics a couple times with Oscar at his glider club 20 years ago. It is interesting to see what people accomplished, who were lucky enough to survive the war. Skill helps, but luck & fate are better. A lot of German aces got second chances and more because they ended up fighting defensively, near the front lines, while American fighter pilots escorting bombers on long range missions would end up as POW's if they got hit just once. Oscar also flew the glider used in an early IMAX film -- the glide ratio apparently was rather poor with a giant IMAX camera strapped on top of the low drag glider. While Oscar did some parachute jumps out of necessity, he never got into sport parachuting, did he? I know that another glider aerobatic airshow pilot, Manfred Radius, was a skydiver, although I'm not sure that he's jumped in ages.

Yes, one wonders about the nature of the mal and how clear it was to the student, whether it was major (eg, lineover induced by asymmetric opening) or more minor (eg, closed end cells, popped toggle) -- fixable by pumping the toggles. @Loren: Limbs caught in the risers or lines happens occasionally with bad body position on a static line jump, such as if one rotates backwards so that the feet up are pointing up at the sky during opening. Bad exits are common, getting snagged is uncommon but happens. Depending on the aircraft, you'll probably need to work on stepping off the aircraft evenly without pushing off too much with the hands.

Lots of issues brought up in that post; but since I'm bored late at night I'll touch on a few of the issues. Some aspects of student gear are not about safety but are there just to accommodate multiple users -- like the extra weight & bulk of harness adjustment hardware. Some features apply to particular student training choices -- like ripcord gear (not very common these days), or a static line setup. Some things are 'safer' in a given context. A static line system will be safer for a complete novice who would tumble on an unassisted freefall, but be unnecessary for someone who knows how to fall stable. So it can have its place if other training methods are not available. It is also assumed that freefall is a very desirable part of the sport, so one wants to go beyond static lines. There can be different ways to achieve similar training goals, such as IAD vs. static line. The debate on which is better has continued over the years as there is no clear answer. IAD has in some areas won out as it allows for less specialized gear, and being able to use the same gear for different student experience levels. IAD has more potential dangers if the jumpmaster staff are less experienced, but it can also be said that training can compensate for that. There are always lots of tradeoffs. So it can be difficult to make a linear scale of the level of safety of a particular design. After being a student, you would generally get away from student gear with extra adjustment hardware, or specialized systems for particular training types like static line. Still, you can choose to use an RSL (as some experienced jumpers do), or use fairly big canopies. Maybe not as big as ab initio students, for that would get very boring very quickly, and maybe take more force to fly, and be more difficult to fly to one's target in high winds. Basically you don't want student gear. But you could still be conservative in your choices -- particularly in the size & design of canopies. A fair number of canopies can be ordered with dacron lines, if you don't care about a little bulk and want slightly improved openings. F-111 style canopies do still exist, but not many, and most modern student canopies are also ZP, at least for the top skin (hybrid). ZP is just superior for flying characteristics, and longevity, especially for anything except light wing loadings. F-111 designs have traditionally had harder openings than modern ZP canopies, but also tend not to have the very occasional slammers like ZP designs can. Still, the disadvantages of F-111 usually outdo whatever advantages they might have. You can also improve your safety a lot through choices in how to jump. That's not to say "never sitfly" or something like that, but more like, "avoid the temptation to allow a planned 2 way sitfly turn into a 6 way sitfly zoo load when your and the others' experience suggest that both safety and learning would be improved by doing a 2 way sitfly". No need to go swooping hard either. One can learn a variety of skills including mildly accelerated landings, without aggressively getting into swooping. While new jumpers often express complete satisfaction with some large canopy they are now flying, realistically, most people will get bored with them and find not quite so huge canopies much more enjoyable to fly, navigate, and land. Doesn't mean one has to get into swooping, but some degree of downsizing from student days is normal. So in the end there's a lot of gear available between the extremes of tiny swooping rigs and bulky student gear.