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mark last won the day on February 14 2021

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  1. No. The descent rates are measured at the maximum operating weight. See AS8015B para 4.3.7.
  2. This is unlikely to be true. As a consumer, I rely on a company's representations as to the performance of their products. If there is a secret waiver, it might allow a company to produce a product, but it will not shield them from liability for failure to meet published standards. PD and others are free to placard their canopies at less than the TSO-limited weight, but this is no different than publishing maximum weights based on experience.
  3. Atair? If so, the seams were sewn, but the fabric was an impermeable composite. The fabric was cut to size after being manufactured in sheets. The intriguing idea was that the fabric could be laid up with reinforcing strands imbedded so reinforcing tapes wouldn't have to be added later, although this would require custom lay-ups for each panel. Very hard to pack, since the sewing perforations were the only way for the air to escape.
  4. Have a look here: I think you have stuff that is not in use by civilians. Not that it couldn't be used by civilians, I just don't know of any MJs in civilian use. Equipment identical to this is in military use, except that the most likely reason it's available to you is because it has exceeded its military shelf/service life. Also, if I were a military buyer, I would reject it because I couldn't be sure of its history. In other words, the value for jumping is roughly $0. The value to a wannabe or a collector is, of course, whatever you can negotiate. -Mark
  5. What reasons did the compliance group give for its conclusions? -- Mark
  6. For FAA approval, any requirement for approved materials and traceability will be in the production certificate. Only critical materials need to be approved and traceable; exactly which these are is a matter of negotiation between the manufacturer and the manufacturer's supervising MIDO.
  7. An MC-4 canopy control line has one line continuous from toggle to canopy, and other control lines branch off from this one continuous line. Is this the same thing as "trunk and branch"? If not, how are they different? From the MC-4 manual, a close-up of the branching off from the continuous control line:
  8. The polyurethane coating is not for waterproofing. The coating adds stiffness to the fabric, so the fabric holds its shape better during manufacturing. It's the wide fabric equivalent of condition "R" tape and webbing.
  9. Gorgeous workmanship!
  10. About 10 minutes work. Freefly Bungee Loops
  11. The confusing word is "exit." For someone new to skydiving, exiting is what you do when you go through the door. For experienced jumpers, the exit is the part of the skydive when you let go of the aircraft, and it is possible to be completely outside the cabin, say, on a C182 step or rear-rear float on an Otter, and still not have exited. Instructors can use the term "flyaway" with new jumpers so there is no confusion about what part of the jump they are referring to. Jargon can come later. --Mark
  12. 70's is before acid mesh was a problem. Does the canopy even have mesh? --Mark
  13. US patent 8,074,934 B2, 13 Dec 2011. Also, French patent 2 706 855, 1993. I'm not a lawyer, and I don't know if US companies are required to honor non-US patents. I also don't know if this patent has expired. --Mark
  14. "This force evaluation is measured in exponential exertion."