markbaur

I'm looking for insurance for my home-based rigging business. I'd like coverage for: -- Fire/theft/etc. for my sewing machines and supplies -- Fire/theft/etc. for the rigs I'm working on -- Premises liability for customers and visitors ("slip-and-fall"). I'd accept partial coverage for any one or all of the above. I'd settle for a homeowner's policy that allowed the business to continue, but just excluded business claims. If your insurance company knows you are doing business as a parachute rigger at home, and thinks that's okay, could you tell me how to get in touch with them? PM is fine. Mark

It is clear to me, but may not be so clear to 45*-angle proponents, that the jumpers start above the 45-line then descend below it (almost immediately), instead of being "blown back" from below the line to above it, as the 45-degree method mistakenly asserts. That's a point worth emphasizing. Mark

As well they should. They share the same street address, phone number, and web site. Go to the Relative Workshop contacts page to see where to send email inquiries. Mark

In 1835, the American balloonist John Wise twice allowed his balloon to collapse upward into the retaining netting, converting it to a kind of round parachute. The fact that he did it twice means he had at least one acceptable descent. Mark

Not so. As Prof Kallend has already pointed out, as long as the airplane TAS is less than a skydiver's descent rate, the 45-degree angle cannot be reached. It takes a jumper about a minute to travel the 2 vertical miles from altitude to opening. During that same minute, an 80-knot jumprun will take the jump plane about 1-1/2 miles horizontally. Draw a picture or do the math: the angle between the airplane and the jumper at pull time is less than 45 degrees. If you were serious about using the 45-degree angle method, you would allow as little time as possible between groups; it is only immediately after exit that a jumper's vertical speed is less than the aircraft horizontal speed. I'm so disappointed. Mark

I'll try to be graceful! An unmodified T-10 has the lift vector exactly perpendicular to weight, but doesn't have a very good flare. On a ram-air canopy, the landing flare converts forward speed to lift; the forward speed comes from tilting the lift vector forward. Perhaps what you are suggesting is that making the lines progressively longer as you go from center to outside allows less anhedral, so more of the lift vector is up and less is to the side than in a conventional all-lines-the-same square canopy like a Sabre. That would make a more efficient wing, but there's a trade-off: you need some sideways "lift" to keep the canopy spread open. Otherwise instead of a little cathedraling between the lines, you'll get a lot, and the individual cells won't be as efficient. Cross-braces (and to some extent the valves on air-locked canopies) help reduce the cathedraling of individual cells. Mark

"Lone Star Parachutes" is correct; late 70's or early 80's as I remember. One of the Minneapolis-area riggers has one, in original (not yet sewn) condition, which he has declined to sell. I don't recall any ad, but perhaps there was a classified in a Parachutist of the time. Mark

The Sailwing was a three-lobed gliding parachute, but not square, nor a ram-air. From Poynter's: Jalbert made a literally square parachute in 1952, but it was a decellerator (like a round), not a gliding wing. Poynter continues: "Jalbert devised the multicell glide canopy in 1962, which was triangular in shape and flew nose forward. In 1964, he developed the ram air inflated wing which he named the 'Para-Foil.'" The accompaning diagram for the triangular model shows what looks like ram-air inflated cells. The photos of early Para-Foils in flight show trailing pilot chutes, indicating they were jumped, not towed. Before they was used for skydiving, ram-air wings were used as kites. Do I recall reading of one truly gigantic one (~3000 square feet?) was used to lift instrument packages into the upper atmosphere? Mark

These figures do not seem correct to me. How are they arrived at? What assumptions are made about initial price, battery replacement, and the cost of periodic maintenance (including shipping and insurance)? Mark

FXC 12000 requires 2-year checks @ $130 plus shipping, and chambering at each repack ($37 is advertised price at Action Air). The life-cycle costs are roughly the same as Cypres. Mark

I used to teach: "Tuck, cutaway, pull, punch." The airborne tuck puts you in a back-to-earth position, better for chest-mount deployment. Cutaway was a reasonable option for R-3 equipped rigs, and some folks thought it worked okay for shot-and-a-halves, too. Pull is self-explanatory. Punch: sometimes the reserve container would stay closed after the ripcord was pulled, so after pulling the ripcord with your right hand, it helped if you punched the reserve container with the left. I don't recall similar drills for folks who didn't believe in cutaways. If you had a partial malfunction, the procedure was to open the reserve container, pull out as much canopy and line as you could, and hand-deploy it by throwing it down and in the direction of spin. So are you planning a nostalgia jump soon? Mark

I've had openings like you describe on my FX99 and VX93, before and after x-mods on both. Like Hook, I've found that popping the rear risers fixed it when it happened. Unlike Hook, it's happened when I pack (all the cells fully exposed) and when others have packed (various degrees of rolling nose and tail). Mark

I have a ZP canopy that got road salt on it because of a winter jump. The canopy got a little wet at the time, but it's dry now. I'd like to get the salt out because I'm concerned about sharp crystalline edges degrading the fabric, but I'm also am concerned about repeated fresh-water rinses increasing the porosity, shrinking the tapes and fabric, and allowing the colors to bleed. Suggestions? Mark

The arming altitude for Cypres is 1500 feet. If the airplane hasn't made it to that altitude, the Cypres will not fire. On the other hand, if the emergency started at 2000 feet and the airplane has been descending then you're right -- you will have a higher chance of a Cypres fire with a low exit. You'll still need to accelerate to firing speed, though, so you might still be better off going for the handle you've pulled a zillion times before, instead of the new handle. Gets kinda complicated, doesn't it? Mark

Having slogged through 18 pages of NPRM, I'm not sure it will have any significant impact on skydiving. The summary says the FAA wants to "expand the approval functions of FAA organizational designees..." But USPA has no organizational designees, the way Part 121/135 operators have designated check pilots, or Part 141/142 flight schools have their own examiners. Designated Parachute Rigger Examiners are not USPA employees. "[T]he proposed rule would allow designated organizations to issue airman certificatges or authorizations under 14 CFR parts 61, 63, and 91..." But noticeable by omission is Part 65, which covers parachute riggers. "[T]he proposed rule would allow designated organizations to find compliance or conduct functions leading to the issuance of certificates or authorizations for -- Parachute jumping operations under 14 CFR Part 105..." But Part 105 only requires certificates of authorization in connection with demonstration-type jumps, and for jumps in designated airspace, although that authorization is more in the nature of "notification" rather than "asking permission." Since ATC is unlikely to cede any control over airspace, the FAA is talking at most about allowing USPA (or ICAS) to approve demo jumps. So could USPA simplify the approval process for demos? I'd be surprised if they could, but my knowledge is limited. ... I find it interesting that the other GA folks most affected by the NPRM are all flight operations (rotorcraft external load, ag, flight schools), and there is no proposal to change our flight operations. Sorry, diverdriver. The NPRM does apply to Part 21, which covers production and which includes TSOs. I'd be interested in learning what kind of QC system the manufacturers have, what kind of FAA oversight they have, and how this NPRM might affect them. Mark

Yes, it's legal. +3 months means a unit due in May can be used through August. Remember that batteries are separate issue: no + leeway when they're due. If the batteries will expire in less than 120 days, an entry on the packing card noting when the batteries (and the pack job) expire will do the trick. Mark

Really? 90 mph winds. Jump-run speed 90 mph, jumper terminal velocity 120 mph, jump altitude 13K, opening around 3K. At opening, the jumpers have fallen about 2 miles in 1 minute. At the same time, they've drifted backward 1-1/2 miles relative to the plane. The angle from airplane to jumper at opening time is thus less than 45 degrees, and will not increase to 45 degrees until the jumper's vertical speed is less than the aircraft forward speed, that is, until after deployment. Thus the 45-degree angle method says that on 90-mph-wind days, you should wait for the previous group to open before you jump. Mark

Really? No-wind day. Jump-run speed 90 mph, jumper terminal velocity 120 mph, jump altitude 13K, opening around 3K. At opening, the jumpers have fallen about 2 miles in 1 minute. At the same time, the aircraft has flown forward 1-1/2 miles. The angle from airplane to jumper at opening time is thus less than 45 degrees, and will not increase to 45 degrees until the jumper's vertical speed is less than the aircraft forward speed, that is, until after deployment. Thus the 45-degree angle method says that on no-wind days, you should wait for the previous group to open before you jump. Mark

Must be a CNN thing. Yesterday's story said the height is 4'9" (145 cm); today's says it's 4.9 feet. Mark

Yup. The same story (attributed to AP) appeared in this morning's newspaper, but without the screwy conversion. Mark

From the CNN website this evening: My emphasis added. The previous conversion error was really expensive. Mark

I read FAR 65.131(b) as requiring records to be kept for only two years. A prudent rigger might keep records longer than that, but is there a requirement to keep records until an article is no longer in service? Mark

These are usually "twin needle" machines, with two threads on top and a single thread on the bottom. You get the decorative appearance of double seam, but without its strength. A true double-needle has two bottom threads. Many canopies have been made on single-needle machines, even where it appears a double-needle has been used. You might consider a single-needle machine like a Singer 20U which you can use in other applications as well. Mark

No. We all know of or can imagine reasonable situations where an alternative might be better. But rather than treat each situation as unique, requiring time (and altitude) for analysis and response, we still need general rules that apply to most situations. Mark

My reference for the do-not-cutaway-below altitude is SIm Section 4, Category A, subsection H (equipment emergency procedures). Mark