andyhughes

Buckle looks identical to the Paragear ones I've used in other applications. The pull-test figures are engraved on the reverse of the buckle, mine say 9KN. I would add that i use the adjustable ones, whereas the hi-res photo looks like it is non-adjustable. I don't know if the pull-test would be the same for both, but i would imagine it is very close (if not the same).

Thanks for the info guys - that is what i needed to know.

Worry not, I wouldn't going anywhere near a parachute with this kind of thing. This question relates strictly to non-flying things such as waterproof coats/tents/bags etc. I'm asking here as I'm sure some people will have some knowledge of appropriate products (brands, products, retailers etc).

Quick question: what kind of tape is good for making water/air tight seams (i.e. the type of thing used on weather proof coats/bags etc.)?

The way i understand it, there are three main reasons for this: 1. Even if the flow over the airfoil becomes turbulent (say) 30% along the chord, doesn't necessarily mean no lift will be generated by the wing (the efficiency will depend on how turbulent the air is). So the airfoil will still produce lift towards the rear of the wings. 2. After the flow has transitioned from laminar to turbulent air, it can "reattach" to the airfoil, in effect causing a bubble of separated (turbulent) air. This is one of the advantages of operating at low Reynolds numbers. 3. Even if the shape of the butt deflector isn't producing lift, it is still going to vastly reduce the turbulent air behind the blunt (bottom) edge of the rig, resulting in reduced drag on the entire system.

Google for "ridge lift".

Ok, so there haven't been to many replies, so I'm going to try to throw this open a bit more... Does anyone have any ideas/guesses/opinions on the types of foils used on modern canopies? This could be in terms of the actual shape, or the flight characteristics.

Well, that could be argued about planform design too, but the manufactures aren't reserved about that. And from what i've seen, the parachute industry is less concerned with IPR than industries such in technology or engineering for example. I've always assumed it was because foil design principals are not very accessible to the general public, whereas with planform design and line trim etc is much easier to understand. Marketing canopies (or anything for that matter) in a way that potential customers can't easily understand is always going to be a non-starter. Anyway, not to digress into IPR discussions or marketing strategy banter... back to airfoils design...

Planform design and line trim are always discussed when people talk about canopy choice and flight characteristics. This is helped by the amount of information the manufacturers publish for each of their canopies (e.g. aspect ratio, planform area, number of cells, line trim, line placing, leading edge taper, trailing edge taper, and more recently stabilizer design). The shape of the airfoil is pretty much always overlooked, even though it is at least as important as planform design, and details are not published by the manufacturers (for one reason or another). I'm interested to hear what foil designs are used, what specific characteristics (such as reflex etc) make a good parachute foil, and how skydiving canopy foils differ from paraglider and ram-air kite foils. The "PD foil" has been mentioned on here a few times, and Ive seen discussions about Precision foils (mainly the Xaos) and Big Air Sportz designs, but there has been little or no mention of the exact foil shapes used. I guess what I'm hoping for is a little inside knowledge, and hopefully there are people here that can help out with this or offer some suggestions regarding the design of parachute foils.

N/A

When I hit the link on the sidebar, i get: "User Uploads are not currently available."

Anyone know what the deal is with the upload page on skydivingmovies.com? It hasn't been working for a few weeks and there is very little info about what's up on the website.

It sounds like some of the problems related to back-surge on vented/valved canopies could perhaps be counteracted by some Airlock-esque design features on the nose. In effect dampening the effects of relative wind on DBS settings?

that makes sense. so when the RSL guide ring is used with the skyhook it is required to misroute the skyhook lanyard to get a reserve total. that wasn't clear from the manual - hence the confusion. thanks for the clarification.

According to the manual, if an RSL guide ring is used with an skyhook, it is possible that reserve total may occur. After spending some time thinking about this, I am having trouble understanding exactly why this is the case. Why is it exactly that this would cause a total with a skyhook but not when a standard RSL is installed? It would seem that (from a few rough sketches), even if there was a mechanical lock trapping the RSL caused by the ripcord not detaching from the reserve pin (thus not allowing it to pass through the ring), the red lanyard would still release when the PC catches some air. This seems to be the case from both a manual reserve deployment and when the opening sequence begins with the main risers leaving the harness. What am i missing here?

Most people call it Empuria, but many refer to it as Ampuria. The DZ sign says Empuria, whereas the race track next-door spells it Ampuria... Anyone know what the deal is here?

is there one? strange that we hear so much about head-down records and pretty much nothing about the head-up/mixed ones.