pchapman

That may or may not have been about a thread I started last year. Locally, someone with maybe 25 jumps fractured her left arm on exit. Photos show that under canopy she got both toggles from 'outside' the risers. She didn't stand up the landing on the big student canopy with her one armed flare but she said it was better than her worst student landings.

I don't know the Velstretch. As an alternative: I've got an alti with the finger loop at front and velcro wrist band at back. When I replaced the velcro band, I added in a couple inch section of elastic tape. The tape was from a fabric store and was doubled up so it wasn't too stretchy. That provides a little "give" in the whole strap.

Hey, if anyone is doing it, it would be interesting to hear on the forums. Or, Calvin, if you do talk to someone, summarize it here. Steve Curtis at least used to do such jumps. Maybe track him down at Skydive Arizona? I've only done one jump on my cutaway-only 37 canopy. (WL 4.7) It's a Stiletto 97 with 5 cells removed and trailing edge trimmed. So I'm not exactly a regular. Let's not have this thread degenerate into general warnings about the dangers of miniature canopies.

Any FAI licence should do. Repack cycles? I've never actually seen the issue come up. I don't know of any CSPA rule on foreign jumpers. We've got 180 days; if you use more, I would expect (but can't guarantee) that DZ's will be OK with it . A car helps. But Skydive Toronto (an hour NNW of Toronto) can be reached by regional bus (GO Bus), that'll get you to a village a couple miles away, and from there the DZ can pick you up. Bus runs maybe once an hour. Skydive Toronto has their Caravan running; other DZ's with turbines don't have their leased ones around until some time in May. (You didn't say when the conference is.) Not sure about Parachute School of Toronto (an hour NNE of Toronto) - they might be accessible the same way by GO Bus. Parachute School of Toronto has more organized RW going on, but until its turbine is around, only has a C-206.

Thanks for the "chapter and verse", Riggerpaul, which helps clarify the role of the reserve parachute. One might get around the need for a 3rd parachute by creating an emergency. E.g., line twist yourself with a toggle held down, causing the emergency from which you have to chop. Or hook the main up backwards and then decide you don't want to land it after all. Or try to pack a mal. All this leads to the question of whether one is allowed to deliberately (or semi-accidentally) create an emergency!

Thanks for the answers, especially Nick with the extra background not in the basic accident report. A variety of things often combine to create an accident, things which sometimes didn't seem a big deal beforehand. I didn't want to single out the owners of Perris specifically, but to see how the community handled one of the better known skydiving crashes. The accident report did state: That's interesting. Looking at a Otter panel suggests the fuel feed is usually set to "Normal" rather than "Both on AFT" or "Both on FWD". Although the report doesn't fill in the details, it suggests there's a chance the other fuel tank wasn't full of crap (maybe not having been topped up that day) and was supplying the left engine. Which suggests that if the pilot hadn't been doing as high a performance takeoff and had reacted properly to the engine loss, they might have been able to climb out OK. (Of course, with 2 engines gone it didn't need to be stalled either.) But that's supposition given that I don't know the Twin Otter fuel system at all. And it doesn't change history.

There will obviously be be some bad feelings around after an accident. I notice some are soon to commemorate the April 1992 Otter crash at Perris. How did the crash affect relations there? The Conastser's still operate the very successful DZ as far as I know. But based on the NTSB report, it suggests they owned the plane, they didn't dip the fuel storage, they didn't check the stored fuel freshly transferred to the fuel truck, they hired the pilot who didn't sump check the tanks, they hired the pilot who feathered the wrong engine and maybe stalled it out after that (no matter how many engines could still run). The pilot would be good for a lot of blame, but he died in the crash too. Did they actually have seat belts in the plane? They would have been legally required even if in that era they were rarely used by skydivers. That's the accident that changed things as I recall. Now, the basic online NTSB report doesn't go into much detail, so there may be things that weren't really the owners' fault. So it could quite well be not as simplistic as what I wrote above! But it could be a little awkward at a DZ when everyone's thinking the owners killed their friends. Plenty of other pilots have screwed up their reaction to an engine problem, but rarely does the cause seem to link back so directly to the DZ ownership.

I have a theory of what was happening to you. While I've got some evidence, I'm not sure if it applies in your case. I've got a Protrack & the Jumptrack software. It tends to sense that the jump is over when the last 6 seconds of averaged speed (which is what it uses) is dropping fast through 60-85 mph. It varies a lot, so I'm not sure what criteria it is looking at. If I do a good track, I, being light & skinny and a decent tracker, can get down to 80-90 mph easily on a sustained track. So the Protrack doesn't see a lot of speed reduction before it "clocks out" . Therefore on the graphs it may show only a few hundred feet between the first deceleration and when it marks the opening -- despite me having a small crossbraced canopy that has a reasonable modern snivel. So this might be part of the reason. I don't know whether the Altitrack really measures things differently, or whether your track is good enough at your jump numbers. Also, if you do have a good long sustained track with a slower vertical speed, you'll lose less distance anyway. How much you've actually slowed down is another matter. On a simple mathematical basis, when decelerating, a given percentage reduction in initial speed will result in a greater percentage reduction in distance. You can also start comparing the altitude you see on your alti immediately after opening to what the "opening" readout is later seen to be.

I have mixed it up on that thread about the Canadian incident I've seen DZ's do it both ways, where the instructor can call for emergency procedures, or where they can't. If they can't, they are allowed to say "Check your parachute!" as much as they like.

I think the alti in the old UPT video is a European paragliding one; probably at that time not switcheable over to feet from meters. Just a guess though. As for reserve pilot chutes, they all generally work, but it is interesting to go through some of the issues that they have. Here's a short video I shot last winter: http://blip.tv/file/3487904 It shows a spring loaded Vector pilot chute used on a main, getting caught in a jumper's burble. Of course this is only one single point of data. But it shows that a spring loaded pilot chute, with a good spring like the Vector one, can hesitate in the burble of just a single jumper. The meshless design doesn't help it as it bounces around. However, when it does pull the bridle taut, it catches air while on its side, as the design is supposed to. It is 1.37 seconds from pack opening to a taut bridle. Not ridiculous but certainly a delay.

Concerning the issue of changing the rules on older equipment -- In the gliding world there's an interesting fight going on lately. To simplify slightly: One glider manufacturer is in financial difficulty. To fly their gliders, like any certified aircraft, you have to have a copy of the current version of the manual. So now the company is producing a new manual each year, and pricing it at say $500. You don't cough up $500/yr to them, your plane is grounded. That's where the idea of "you must follow the manufacturer's instructions" starts to break down.

I'd be interested to hear more about this too. An earlier thread about downplanes and the parabatic grip is at http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3369862

The thing is, there is no 150 manual that lists a life. There are plenty of other newer product manuals that do. If there's a bulletin that specifically lifes the 150, I haven't yet seen it. Correct me if there is one. Some background info from earlier threads: Rigger "Mark": When I asked IrvinGQ/AirborneSystems they left things pretty open for the 150 even though they said what they like to see:

The pdf copy I have is also 1978, with a 1 page 1982 advisory bulletin added on front, about the optional use of ejector discs (kicker plates). Since the company was gone by '84 I would be surprised if there's anything newer. I guess the 150 wasn't in the acid mesh bulletin ... because it didn't even have mesh over its vents. I won't bug you about how ancient it is!

One DZ I'm at teaches flat packing for students, with their F-111 student canopies. Later they learn from friends how to propack when they get their own gear. All student gear has to be flat packed (even by experienced packers). The Tandem Sigmas are flat packed too. Which takes time. It is a bit of an anomaly, but the DZO clearly likes the traditional flat pack. Not that he's totally against propacking -- I've seen him propack his Parafoil 282. It's more that he sees propacking as something a bit newfangled that's too easy to mess up if done too quickly and wrong. (Counterargument: learn to do it right!)

Nice to see another pizza puke style PC. Someone once suggested the official name was the Psychedelic pattern, while there was an even busier pattern called Super Psychedelic. (Which may be what I have, as my puke PC looks different). [Edit to add:] The someone who mentioned the pattern, in a thread I started on pizza pukes, is Cosmobuddy, who is Fred Sand!

So many factors involved indeed. We haven't even gotten into spring length, spring strength, weight of the PC, weight of the cap,... Was the one that started to pull while starting on its side, a certain meshless one? Although the Vector reserve PC has been questioned about its low speed drag, I thought I heard that part of Bill's philosophy was to make it catch air well from different angles, such as on its side.

Adding an analogy to an argument always opens further arguments about the analogy.

At first look the quote seems reasonable. The quote doesn't say it, but it tends towards the idea that you aren't looking a fixed distance ahead but perhaps closer to a certain TIME ahead. Given a certain reaction time, control input time, and time to get the vehicle to react to your inputs sufficiently, that may require you to plan a certain number of seconds ahead. This may work best once on the final approach, not say while in a steep diving turn for a swoop, where there can be other factors. It is easy to oversimplify statements about landings in skydiving, especially if dealing with different landing styles. So "look at the horizon" might only apply to someone dropping in under a round who you want to not tense up too much. Or "look at where you are going to touch down" might not help on a swoop, where someone can pretty much plane out to a level attitude but still sink into the ground while at high speed if they are looking too far down the landing zone.

What the best material is for protection of the lines is an interesting question. Cotton can take more heat of friction, protecting the nylon behind it, but does that really need protecting? Would there ever be much more than the most minor heat glazing of the nylon pouch? I'm more concerned with the expensive lines. So there I'd rather have something with low friction. Would the Kevlar work better? Or something else? And if there is friction from a pouch for lines, we want to compare it not just to no friction at all, but against the normal case of lines in rubber bands. What is the friction of lines clamped tight against each other especially in double wrapped rubber bands? It might not be negligible. While the situation is different, remember how lowly little rubber bands were abrading leg straps, when they were attached to hip rings as "t-shirt tie downs". (When I get my rig from the DZ I'll have to have a look at the pouch [line stow pocket] on my rig, which I've used for about 600 jumps. Whether it added to line wear is so hard to tell if one doesn't go through identical line sets quickly.)

Not necessarily. It depends on what particular one. And a lot more on the individual. Agreed. And with a lot of such drugs, it is the initial period of adjusting to the drug, or when someone goes back off the drug, where unanticipated effects are most likely. The FAA is being extremely conservative, looking for a full year of initial grounding. Maybe it is just overprescription in today's society, but a lot of "pretty normal" people are on antidepressants these days.

I don't know if it would help, but if I told some guys with guns "don't touch it!" I'd also tell them, "But feel free to mm wave scan it, x-ray it, swab it, have drug dogs sniff it, ...."

A couple comments on reserve pilot chute drag in the wake of John Sherman's comments: 1. Drag coefficient doesn't include the effect of size. One has to multiply by the area of the canopy to get a number that is directly proportional to the actual drag. So a high coefficient is good, but it isn't the whole story. 2. The US military did one fatality report where they came out pretty strongly against the Vector's pilot chute drag at low speed. So even if John might be thought to be biased in favour of his own gear, there's some independent evidence. The accident dealt with non-extraction of the reserve after a reserve pull (without cutaway) while spiralling under a main with a problem. [Dep't of the Navy report on military fatality in Marana, AZ on 6 Mar '08] Technically, the manufacturer's name was redacted from the Freedom of Information Act document, but reading the whole doc made it fairly evident that it must have been a CPS / UPT militarized Sigma rig. Their wording was maybe a little harsh: "A drag force analysis of the [redacted] revealed that the solid nylon design; which constricts airflow through the 6-inch diameter base opening, produces minimal drag." They also wrote: "Seams used in construction of jumper pack tray reserve storage may interfere with slow deploying reserve and restrict pilot parachute from applying direct peak deployment force". I don't know if this was observed or is just conjecture. It's also unclear from the language to what degree it is talking about PC launch vs. bag extraction. The situation was different than for the USPA/PIA list, and sometimes you don't want a 2-out to happen too easily, but it still has some relevance. As for John Sherman's list of rigs in the USPA/PIA list, in some sense it is good that there's a real cross section of the industry represented, so that maybe people can get on with looking for reasons rather than just thinking it's some other rig's problem.

So what do people think about different factors affecting this problem? Different ones that have been mentioned are a full main pack tray, overstuffed containers, and tight pocketing of reserves. I wonder if the pocketing causes problems at bad angles of deployment relative to the jumper, such as some cases involving an AAD fire. (Although such cases certainly weren't all the ones in the list.) It would be nice if someone with time would go through the accident reports and find those that sound like they would be on the USPA/PIA list - if just phoning the USPA up isn't enough to obtain the list.

It would be interesting to start a table of rigs vs. freefly friendly / modern features, showing dates of introduction. I don't know off-hand who had what when. Javelins for example changed to the improved reserve pin cover in '96 I think. Vector III's, Mirages, Wings, Infinities, Reflexes, all with generally modern protection -- which hasn't changed much in over a decade -- all existed by the late 90s. Plenty of new rigs were appearing then (even if under old TSOs). At that time brand new Dolphins weren't just "simple" or "inexpensive" but seemed to show that the company was way behind on what people started to consider important safety features. So maybe I'm overemphasizing that era where they were behind for a while, but many other rigs were more freefly friendly before 2000.