markbaur

Can you give more details? Do you think there aren't enough rating courses, or is it that the standards are too high, or is the problem something else? Mark

USPA SIM 3-1, paragraph C sub-paragraph 2: Jumps for license and rating qualfications must be signed by another licensed skydiver, a pilot, or a USPA National or FAI Judge who witnessed the jump. sub-paragraph 3: Jumps to meet skill requirements must be signed by a USPA Instructor, Instructor Examiner, Safety & Training Advisor, or a member of the USPA Board of Directors. Mark

The unintended consequence of these pull priorities is an association between pulling and stability. Many students who can correctly recite the 3 pull priorities will in the next breath tell you that if they are unstable at pull time, they'll arch to get stable, then pull. How about this pull priority: If you are at or below pull altitude, pull. Mark

Preferable to throw down and in the same direction as the spin. An R-3 uses the load-bearing part of the canopy release, but replaces the metal cover and thumb loop with a piece of light webbing held in place by velcro. There are still a few of these in use. They require very little maintenance compared to 3-ring, and if you have to cut away, you don't have to go looking for a cut-away handle. Mark

The first three sections are identical to the print version. The Category A portion of Section 4 [ISP] is missing only "Category at a Glance." I've spot checked the other sections as well, and what I've checked is identical to the print version. The license and award applications (Appendix C: Forms) are missing from the on-line version. Bottom line: the on-line version is as complete as most of us need, and in some ways is in a more convenient format as well. Mark

You can get a rough idea by using a glide ratio of 3:1. At 14 mph of forward speed, that's a little less than 5 mph down, or about 7 fps. You'll get a better number if you take a stopwatch and your Digitude that measures altitude in 10-foot increments. 14 mph seems really slow. At that speed and 3:1 glide ratio, you should be able to stand up easily in 14-mph winds without flaring! What do you mean by "rated at around 14 mph"? Mark

Statistically, the more tickets you buy, the more money you are likely to lose. If you bought every ticket in a particular game, you'd get back about 50 cents on the dollar (more or less). The best way to increase your odds of winning is to buy no tickets at all. I don't want you to do this, though, because every time you buy a ticket, my taxes go down: I win! Mark

Fair enough. But this sort of anecdote is only meaningful by comparison to the alternative. During that same period of time, were there any incidents attributable to out-of-sequence handle pulls, for students trained on a 2-handle system? (I say student because there have been tandem incidents involving out-of-sequence handle pulls.) Mark

I like SOS for students. It simplifies emergency procedures for students. Don't like the canopy you've got? Pull the red handle! No need to decide if this is a one-handle or two-handle malfunction, no possibility of pulling handles out of sequence. [Like most AFF instructors, I've seen plenty of students do normal PRCTs, then attempt a cross-pull at pull time. I don't know what handle sequence they would try under the stress of a high-speed malfunction.] The immediate consequence of simplified emergency procedures is that there is more room in the FJC student's brain for detail in other FJC topics, like canopy control and landings. (Please don't suggest I make my FJC longer. Once their brains are full, any extra info, no matter how important, just overflows.) The obvious drawback is the higher-risk period when the student transitions to a two-handle system, around jump number 10 or 15. Since most students make exactly one jump, and most of the rest make fewer than ten, that's a trade-off I'm willing to make. Mark

My guess is that the most common rigging error would be to pass both right-side cables through both ends of the right-side loop (or both left-side cables through both ends of the left-side loop), requiring both handles to be pulled in the normal sequence. In most cases, you'd be no worse off than you'd be with the standard handle configuration. In a properly designed and assembled SOS system, the 3-rings release before the slack is out of the reserve ripcord cable, so there is no additional ripcord pull force. The 3-ring cable jam issue is more serious, but these dual-handle systems are found on student rigs, typically with standard (not mini) rings, where even spinning malfunctions are relatively low-g. The likelihood of a cable jam on a dual-cutaway rig has to be balanced against the likelihood of an out-of-sequence handle pull on a standard system. Have there been reports of cable jams on student rigs? Mark

This is exactly correct. Like a two-handle drogue release, risers on this student system have 3-ring loops that can be released at either end. What you get: no harm from out-of-sequence emergency procedures. If the student pulls the cutaway handle, then the reserve ripcord, that's good. But if he pulls just the cutaway handle, the RSL is there as a back-up. And if he pulls in the wrong order, the reserve ripcord is actually a 3-cable SOS handle, which releases the other ends of the main riser 3-ring loops before deploying the reserve. What you give up: like any SOS system, what you have at 1000 feet is what you'll land with. Pulling just silver still gets you a cutaway first. Sunpath offers this option on its student Javelins, and I expect most manufacturers will, too. Mark

The issues involved may be similar, but the FAR requirement for a tug check-out is just three tows, actual or simulated, plus some ground training. I'm with diverdriver -- whoever does the checkout needs to be more thorough than the minimum required by regulation. Mark

Two points: First, I need to know what curriculum you have in mind before suggesting who the instructor should be. Second, a tail-wheel sign-off requires a CFI, but jump pilot training is more like aerobatic training, where the instructor need not have any pilot rating at all, as long as the student is rated and current in the aircraft. Mark

Dan: Is there a reason (besides comfort level and liability) why you'd use a certified altimeter instead of an uncertified one? Some of the newer uncertified digital ones are more accurate than certified analog ones, and are much cheaper, too. Also, I notice you didn't include a VSI. The last time I checked, many years ago, VSIs were TSO'd, but there were no calibration standards, even for IFR use. I think using an uncalibrated instrument (the VSI) in tandem with a calibrated one (the alti) gives an uncalibrated result. You'd be able to verify firing altitude, but not the 40 fps no-fire, or 65 fps always-fire. Mark

Skydive Twin Cities has about 15, used on student rigs, and I saw a few on student rigs in East Troy last summer, but the other 10 or 15 DZs I've visited in the last couple years have all used Cypres on their student gear (some student models, some expert models). On the plus side, the FXC 12000 doesn't turn into a door stop after 12 years, and it can be turned on and off and on again in the aircraft. On the minus side, it requires a 2-year factory check instead of a 4-year, and there's that pesky requirement to chamber them at every repack. Action Air is advertising $37.50 for a chamber check, which seems like a lot until you figure out how many tests it takes to cover the $5500 price for an FXC chamber. Mark

I need an FXC altitude test chamber. The FXC Corporation list price is over $5500, but the company says that other versions can be used for the functional test as long as they're able to measure altitude and descent rate. Can anyone suggest a source for a used FXC test chamber, or another commercially produced test chamber, or a home-built version? Please do not suggest using a plastic bag over the sensor. It's not a substitute for a functional test, and anyway, the only thing the plastic bag test shows is if the unit will fire if you're going fast enough at impact. Mark

Uhhh... did you use a calculator, or just estimate? Mark

Recent posts assume that soaring ram-airs are sufficiently like skydiving ram-airs that techniques used for one type can be used for the other. I am not so sure, but I have no experience with soaring ram-airs. What are the significant design differences between the two, and especially, how do their angles of attack compare? Mark

Huh? I asked a question. What's to disagree with? So the difference is that it's different? Mark

How was what he did different from what fighters in the Lincoln Brigade did in the Spanish Civil War? Mark

Not exactly. I made 10 or 15 jumps on a Sabre 135 before going to the 107. Before anyone gets the idea that this would be a good transition program in general, I need to point out that at the time I had 2000 jumps, including a bunch on my own experimental designs, as well as 4000 hours piloting a variety of aircraft. BTW, the fabric is F-111 (not F1-11), named after the Air Force swing-wing fighter-bomber. George Harris also made a heavier fabric he called B-1, but there was never a big demand for it since F-111 did the job with lighter weight. George was a pretty nice guy, former airborne trooper in the 101st. Mark

USPA no longer has a "Jumpmaster" rating. USPA instructional ratings are: Coach (without specialty like SL, IAD, AFF), Instructor (SL, IAD, AFF, Tandem), and I/E (SL, IAD, AFF, Tandem). Perhaps the profile options could be changed to reflect this. Apologies to all the instructors who hold non-US ratings (like PFF) -- perhaps the profile options could be expanded to include those ratings as well. Mark

I owned an FX107 for about 350 jumps, a transition canopy from my PD-210 to the FX99 I've had for almost 900 jumps. My back-up canopy is a VX93, which I've jumped nearly 500 times. All three were or are Precision-made models. No problems with structural integrity. Easy to pack. No malfunctions, not even a hint. I'm working on wearing out the 99 so I can buy a Xaos, but I figure I've got 1000 jumps to go. Mark

You don't say what the differences are, so I'm guessing: Loading farther forward, in general: longer dive, heavier front riser pressure, less surf, more stable. Loading farther aft, in general: shorter dive, lighter front riser pressure, more surf, less stable. How am I doing? Mark

Would it be correct to restate Dan's claim as, "The center of gravity hangs below the center of lift"? And would it be correct to restate Chris's reply as, "The angle between the chord and the CG-CL line is determined by the line set"? If both of these restatements are correct, then Dan's and Chris's claims are complementary, not contradictory. I'd be interested in hearing more. Mark