mark

That is a curious turn of phrase. There is a difference between "tested to the standards of TSO C23(b)" and "approved under TSO C23(b)." PA's wording doesn't answer the question you asked. Mark

"TSO" is two parts: initial testing, then quality control system to ensure production articles are the same as test articles. "Tested to the standards of TSO C-23b Low Speed Category" meets the first part, but doesn't address the second part. The manual section entitled "Test Standards" does NOT make the claim that the Airforce reserve is approved under TSO C-23b, just that it was tested and that it can be marked with Australian markings (but not U.S. markings). What is the exact phrase in their email regarding the Airforce and TSO? Thanks, Mark

mdrejhon: Do you think this phenomenon is confined to ram-air skydiving canopies, or might it extend to other air vehicles as well? For example, would round canopies tend also to turn downwind? How about para-gliding canopies? Would it matter if the vehicle was powered (like a Para-Plane) or unpowered (like a fiberglass sailplane?) Also, would the canopy turn downwind faster in stronger wind? Or is the rate of turn solely a result of the turbulence? Finally, if the wind speed increases as your canopy descends, would that make any difference to the rate of turn? Thanks, Mark

If that is the same as Skydive Perris Valley, That is great news. Skydive Paris, Tennessee, is not the same as Perris Valley Skydiving, California. Mark

Like this? Mark

Jump pilot: less training = higher risk. Requiring more experience is a way of compensating for the lack of formal training and supervision. Also, most jump pilot time is PIC almost from the start. Commuter/regional: formal training program + better supervision = lower risk. And you start out as SIC. Mark

[Edited to clarify my response to Mark Klingemeyer's post. Edits in italics.] The complete phrase is "duties under his certificate." Change your own closing loop? Doesn't require a rigger ticket. If it did, owners couldn't do it and it wouldn't be on the USPA A License Proficiency Card. Change your own rubber bands? Doesn't require a rigger ticket. So just jumping and repacking your own main is not "rigging work." Gear check? Doesn't require a rigger ticket. Pack a main? Packing your own doesn't require a rigger ticket; packing someone else's does. Inspections and repairs? Yep, that's rigger work. Helping or teaching another person to pack? Maybe, if the helper or teacher is going to take responsibility for the pack job. Otherwise, doesn't require a rigger ticket. If people pack for just themselves and a couple friends, they can rationalize the currency requirements. After all, skydivers aren't falling out of the sky because of poor rigging. They're unlikely to be called on it. They're still just rationalizing, though. Mark

Are you mixing up PACKING ONE RIG in the last 90 days, or working 90 days out of 365 in the industry??? I think it is the first, but you think it is the second. Please find your source and quote it, as this is a new one to me... Here you go: FAR 65.129 Performance standards. No certificated parachute rigger may-- (a) Pack, maintain, or alter any parachute unless he is rated for that type; (b) Pack a parachute that is not safe for emergency use; (c) Pack a parachute that has not been thoroughly dried and aired; (d) Alter a parachute in a manner that is not specifically authorized by the Administrator or the manufacturer; (e) Pack, maintain, or alter a parachute in any manner that deviates from procedures approved by the Administrator or the manufacturer of the parachute; or (f) Exercise the privileges of his certificate and type rating unless he understands the current manufacturer's instructions for the operation involved and has-- (1) Performed duties under his certificate for at least 90 days within the preceding 12 months; or (2) Shown the Administrator that he is able to perform those duties. Mark

I am a rigger who always uses a scissors to cut seal thread. I don't think hand-breaking is a reliable method of testing whether a thread meets strength requirements. A 5.25-pound break wouldn't feel a lot different than a 4.75-pound break, even though only the latter would be acceptable. No rigger I know tries to re-use scraps of threads once they are cut off the spool or bobbin. I don't go rooting around on the floor near the sewing machines looking for a piece of thread long enough to seal a pack, especially since I don't sew anything with seal thread. Most riggers I know do not own a spool of red E-thread, and those that do do not keep their sewing machine thread in the same place they keep their seals, press, and seal thread. E-thread comes in 8- and 16-ounce sizes wrapped around a plastic spool, much larger than the 1- or 2-ounce seal thread size wrapped around a cardboard spool, so it is not hard to tell the difference just by the appearance of the spool. I have heard of E-thread being used instead of seal thread, but I can only imagine a rigger who was confused about that difference would be confused about a lot of other things, too. BTW, nothing in the regulations requires an owner to keep his rig sealed, though long-standing custom (in the US) would lead you to believe a seal is mandatory throughout the life of a pack job. Mark

Oops! The center lines are, well, center lines. Crown lines go from the uppermost part of each radial seam to the pilot chute attachment point. Thanks for this continuing series. I'm looking forward to the next one! Mark

Post the errors here or PM me. If you have a proposed change, include it. I'll be seeing the author next week. Thanks, Mark

Widespread use of whole-airframe parachutes would not necessarily result in net lives saved. BRS advertises a 182-compatible parachute for a little less than $18,000 before installation. It weighs about 85 pounds. Given that most airplane accidents where a parachute might be useful are related to maintenance or fuel, you would be better off investing the money in an engine monitor and oil analysis program, and you would be better off carrying the 85 pounds as fuel. Additionally, the BRS parachute for a 182 is about 2' x 2' x 3', which reduces cabin room by about 1 skydiver. Mark

Aerodyne lists most line sets at $210. PD prices are similar for Spectra line sets ($195), cheaper for Dacron ($155). Those are the prices for the line sets themselves, what you would pay if you were buying a set for your local rigger to install. The prices do not include links ($25 for Slinks™). I didn't see where Aerodyne listed the price of a reline. PD lists reline with Spectra at $245, which does not include the mandatory $20 inspection fee. You'd also be responsible for shipping and insurance both ways (about $40), and you'd still have to assemble it on your risers when it comes back. After taking all costs into account, it's only slightly less expensive for the manufacturer to do major repairs (the difference for an installed line set would be around $10 - $30), mostly because the folks doing the work aren't being paid master rigger rates even though they are very competent. What you get by taking your work to a local rigger is prompt service. It takes me a couple hours to do a reline, including the inspection and assembly on your risers. That means you can jump your parachute all weekend, drop it off on Sunday night, and expect to have it ready the next time you come to the dz. Plus, if I have the opportunity, I'll put a test jump on your canopy! Mark

Dan Tarasievich: Chrysalis. Mark

If the webbing has taken a set, rotating the rings won't change that. If the rings have elongated, you need new rings -- and you need to let the rest of us know so we can get the other substandard rings out of (ahem!) circulation. Mark

Type 17 webbing rated for 2500 pounds. Stitch pattern good for about 900 pounds. 1" quick fit adapter rated for 500 pounds. What will fail first? RiggerRob is right: the reason for two layers of Type 17 is to reduce slippage, not to add strength. Mark

I agree that a single layer of Type 17 is probably strong enough -- the weak point is the friction adapter -- but I disagree about the bartacks becoming a formality on a Javelin chest strap. There is only one layer of Type 17 around the chest ring, and it ends just beyond the 3-bartack pattern, which also secures the other end of the webbing. The only load-bearing overlap is at the bartacks. Mark

Can you share who the supplier is? And what sorts of stiffener materials he or she has available? Thanks, Mark

Care to explain your math here. +300 feet means just that. 300 feet above the preset to 300 feet below the preset. That would be the kind of math I do when I type faster than I think. What I meant to write was that at the lowest allowable setting of 1000 feet, actual firing could be as low as 700 feet for a unit within calibration limits. Sorry. Mark

Pulley ring is installed upside down. Otherwise, an outstanding diagram. Hey, you asked! Mark

"Skydiving in Northern Michigan" would be Skydive Harbor Springs, a USPA member dz run by a couple guys with a 182 and a few rigs. They used to split their year between Michigan and southern California. I don't know if the Arizona operation is instead of California, or in addition. Mark

Descent rate faster than 65 fps (approx 45 mph) MUST fire. Descent rate slower than 40 fps (approx 27 mph) MUST NOT fire. Between 40 and 65 fps may or may not fire. Allowable firing range + 300 feet, so may fire as low as 700 feet below the preset altitude and still be within calibration limits. (I'm guessing you set the altitude to 3000 or 4000 feet so you wouldn't have to worry about spiralling through 700 feet.) The + 300-foot range also applies to the freefall speed test, 175 fps (approx 119 mph). Mark

Absolutely! Grounding a rig is not one of the privileges of a rigger. Mark

One of the privileges of my rigger ticket is to decline to pack a rig for any reason I choose. I exercise that privilege from time to time. Mark

Don't forget to add some seam allowance. Uh, are canopies cut and sewn together without a seam allowance these days? Mark