mark

Sunpath replaces BOC's the way folks in the field do it: use a very sharp scissors to remove the old one, then sew a new one onto the bottom flap. They don't dissassemble the pack tray from the back pad. Mark

Continuing to feed the trolls: The manufacturer coats the fabric only when it is flat. You'll have to carefully disassemble your canopy, marking each piece of tape as well as each piece of fabric, so that it can be reassembled once it is recoated. Mark

Yes, they will. The usual procedure is to replace rather than recoat the fabric, since the first coating is applied by the fabric manufacturer instead of PD. If you get a new set of lines at the same time, PD will probably throw in a new serial number for free. Mark

If you are at or below pull altitude, pulling is not a screw-up -- regardless of body position. Mark

Oops! BSRs require a functional AAD for unlicensed jumpers. I'd interpret "functional" as "on and calibrated." Mark

Okay, I'll bite. What about grapes? I'm thinking down the rows crosswind would be better than across the rows into the wind. Mark

The corn adjacent to the landing area is 8 or 10 feet tall. What should I teach my students about landing in it if Plan A (avoid it) isn't working? Would the technique be different for faster canopies, like my X-VX 93 loaded at 2.x? Mark

From a safety point of view, I don't think this is any more dangerous than side-to-side (front riser) CRW cross-connectors. I wouldn't worry much about broken neck or strangulation. I would worry more about the device catching the bottom corners of a reserve container. Mark

I was surprised to see this statement on a major manufacturer's web site. I e-mailed to ask why they recommended rotating* the rings, but received no response. Speculation? Mark *rotating... My original thought picture was rotating like you rotate your tires: take the rings off the right riser, install on the left; take the left rings and install on the right...

The thread in Gear and Rigging is now titled "Sticky cat urine on rig." Mark

I'm sorry to read this. While this thread will never have the appeal of "So you want to be a rigger," I think FrogNog asked questions many of us would like answers to. I really liked your excellent posts on binding inside and outside corners, and that leads me to believe your PM response to this query is well-written, authoritative, and informative. Can I convince you to post your PM's contents? Thanks, Mark

Isn't this guy just changing spark plugs on an endurance flight? IIRC, the in-flight refueling required flying low while a pick-up truck kept pace so fuel cans could be handed up. Do you have more pictures? Mark

Lines out of order on a connector link is a neatness/attention-to-detail issue, an indicator there might be other safety concerns, but not a safety issue in itself. The canopy will open and fly normally. As for rigging errors, the length of the repack cycle doesn't matter, as the likelihood of finding and correcting a previous error is balanced by the likelihood of introducing a new error. Mark

Two photos (at least) in Poynter's if you know where to look! Also one photo in Bill's office -- see it when he does the RWS factory tour. Mark

Sorry, just one more question. When you cock your pilot chute, does that draw the kill line up inside the bag, or does it just crinkle up the bridle outside the bag (like a tandem drogue bridle)? Mark

I suppose a bag lock wouldn't be too bad. At the other end of the spectrum, are you familiar with canopy-first deployments? Mark

My nominee: a Crossbow with floating main and reserve handles, plus both wooden main toggles trailing about 2 feet up. No malfunction, but on that jump there were 6 other folks besides me who were wondering if we seeing the beginning of one. We just kept skydiving because there wasn't anything we could do for the guy anyway. Mark

Thanks for the replies to my many questions. I wanted to be sure to eliminate all the variables so we know that the problem is in fact the pilot chute and not something else that got changed at the same time. If you are able to hang on to the base of a cocked pilot chute, the pilot chute is the problem. To confirm, try holding onto the pilot chute pud while holding it out the window of a moving car. Try slowly at first, then gradually increase speed. If you can still hold onto it at autobahn speed, the pilot chute is definitely the problem. Packing the parachute to open faster is not a solution to your problem. What skydivers think of as "opening shock" is in fact two shocks very close together. The first shock is called "snatch force" and it occurs at line stretch, when the bag/canopy/pilot chute are accelerated to your nearly freefall speed. (Of course, you are slowing down, too, but you experience a smaller change in velocity because of your greater mass). The second shock is the actual opening shock, which is when you and the canopy slow down to canopy descent speed. Packing for a brisker opening during the inflation/opening shock phase doesn't affect snatch force. What you need for a more comfortable opening is a smaller velocity difference between your speed after the snatch and the speed when opening shock occurs; in other words, more drag from the pilot chute, greater snatch force, and more deceleration from the snatch force. (For those inclined to go overboard, gigantic pilot chutes are not the answer to hard openings, since snatch force can hurt, too. It's a matter of balancing the two.) Mark

Is the pull-out the only thing new about your gear? Are you jumping the same canopy (not just the same make & model, but the same canopy) as you jumped with a throw-out? The same rig? The same jumpsuit? Is your pilot chute the one designed for your rig? Is it collapsible? Is the kill line the correct length? How do you make sure it is fully cocked? Is the pull-out pilot chute the same size as the throw-out you were using before? What do you do for those "two or three uneasy seconds" before you feel the canopy deploying? Does the pilot chute seem to launch when you start reaching for the emergency handles? Mark

Hello MEL! My bartack is also a Juki L-1900HS. I'm looking to match the bartacks PD, Precision, and Aerodyne use, figuring they've already done the R&D. Do all three use the same 7-running/32-covering/3-tying tack? Or do they use the 11/28/3 pattern? Do you know of any other center-stop patterns in common use? For example, the small tacks made at a canopy leading edge rib-skin junction look like 28-stitch patterns, and the pattern PD uses to attach lines to stabilizers looks like something else altogether. Do your chips do both 42-stitch patterns you mention, or other patterns? And would you be willing to part with any of your chips? Thanks, Mark

I own an electronic end-stop bartacker, and I plan to add a chip to do center-stop patterns. The fellow will program the chip does it stitch by stitch, so I need to know what the industry standard is, if any. That is, from the center, how many straight stitches and what direction, followed by how many zigzag stitches and what direction. I know a 42-stitch pattern is most common, but are there others (28, 36, 56, 60) in use as well, and what are the industry standards for those? Can you point me to a reference? Thanks, Mark

Sorry, not so, and the proof is from mathematics. If the parachute was straight before it was tangled, and if it was not disconnected, then when you have untangled any two adjacent lines from canopy to link(s) on straight risers, the rest of the lines will be straight as well. Mark

Bringing a canopy back to factory spec may or may not be a senior rigger task. Instead of looking at the work as an alteration, look at it as a repair: major (one which if improperly done would affect airworthiness) or a minor one (not major). Replacing the lower brake lines on a Precision main (involving just a larks-head, no sewing) would be minor, replacing a cell would be major, and in between these extremes are shades of grey. Mark

Did you talk to the supervising rigger? What did he or she say? Mark

My set includes posters of "Total", "Blown Panel", and "Horseshoe", but nothing for Mae West, streamer, or similar. Does your set have anything like that? Mark