markbaur

The more usual explanation is binocular vision (cats, owls) = predator, where range info is important; and monocular vision (chickens, deer) = prey, where greater field of view is more important. We do use angles in peripheral vision for speed information (the telephone poles at the side of the road whiz by faster than the mountains behind them, or the road in front of us). Mark

Replacing a Capewell with an R3 requires you to remove the long rivet that holds the slide. New R3 kits included replacement rivets, but moving an existing R3 from one rig to another will require you to find an appropriately sized rivet, which you'll have to set yourself. It's not hard to set the rivet, but you might want to buy a couple extra so you can practice. Mark

Short answer: info from the manufacturer. Long answer: About a year ago, my Digitude showed erratic readings: rapid changes in indicated altitude, display blanking, stuff like that. I sent it back to the manufacturer. He sent it back with a note saying it chambered okay -- the problem was shape of the contacts on the Energizer I'd installed, and I should switch back to a Duracell. I did, and haven't had a problem since. Mark

First think to check is the battery. Duracells work; Energizers don't. Something about slightly different contact surfaces. Mark

These guys don't want your rig. They want your money. It isn't even money laundering, since they send you a bogus check in order to get your good one. Mark

I have not used an Alti-3, but I have used a Northstar, Altimaster-2, FT-50, and Digitude. I have not observed erratic readings during freefall acceleration, including many jumps with delays in the 10-20 second range. Does the orange warning label "erratic" mean "reads higher than it should," "reads lower than it should," or "needle bounces around alot?" Is this phenomenon common to all altimeters, just mechanical ones, or just Alti-3's? I suppose you could argue that there is Venturi-type interference with the altimeter static port, but depending on the presentation to the relative wind, there could be a ram-air effect, couldn't there? How did you arrive at the 1000' foot low figure? Mark

Your voice has been heard! The fee is now $40, in line with the other initial instructor rating fees. Mark

Take a capewell, stretch it out to 4". Like a capewell, the male (riser) fitting loads inside an upper lip on the female (riser) fitting, and rotates out as the riser releases. But instead of a capewell-style slide on the front of the female fitting to keep the male lug in place, the bottom of the male fitting protrudes through the female fitting, allowing the male fitting to be pinned on the back side of the female fitting. Good points: -- All metal design. -- Cannot be assembled incorrectly. -- Simple construction: just two machined plates and a locking pin, instead of the lug, slide, rivet, covers, etc. of a capewell. Some unresolved issues: -- The stainless steel version weighs about 4 times as much as a 3-ring release (but titanium would weigh only half as much as stainless and cost about the same as the stainless). -- The pin must be pulled straight out, so alignment of the release cable housing is critical. Ask your rigger about alignment issues with old-style cones-and-pins ripcords. -- The 4" flat plate is not ergonomic; it won't conform to your shoulders like a 3-ring system does - and if a curved, shoulder-conformed model can be made for you, it may not fit me if I should borrow your gear. My prediction: this one will join the Strong Wrap, R2^2, and Chrysalis. Nice engineering, but not a serious challenge to 3-Ring. Mark

The Weekly World News, a nationally recognized newspaper of record, has reported cases of computer viruses infecting human beings. There are apparently two transmission vectors. Some viruses piggyback on photons emitted by the monitor, and enter the body through the eyes. (A photo accompanying the article depicts this happening to an actual user.) Using a filter and wearing dark glasses cuts down on the risk. The other main means of transmission is via dirty keyboards, so it's important to wash your hands before and after keyboard use. Mark

Can you tell us how you went about shopping, and how you got to be at the right place, at the right time? Thanks, Mark

With or without the boat? Mark Edit: Sorry. I was thinking parasail = towed parachute; paraglider = soaring parachute.

How do you propose to distinguish between those whose teaching experience is one-on-one or small group performance-oriented training, and those whose experience is lecturing (who think telling someone is the same as teaching them)? Mark

What is your source for this information? Thanks, Mark

(My emphasis added.) Which manufacturer allows substitution of freebag/bridle/pilot chute by anything other than its own sized and tested components? According to the Relative Workshop, which pilot chutes are approved for the Micron? Can you substitute a Mirage PC for the one in your Micron, in accordance with the manufacturer's instructions? Mark

You will not notice a problem because the loss is gradual. It happens from riding in any airplane, including the so-called quiet ones. Do yourself a favor: get your hearing tested, and start wearing hearing protection. Mark

Reserve pilot chutes and freebags are TSO'd, and are stamped with manufacturer, part number, date of manufacture, and serial number, just like the harness and container. The freebags are not interchangeable between different models of the same rig, let alone between manufacturers, because most systems depend on friction fit to stage reserve deployment. It's possible that reserve pilot chutes may be interchangeable in some cases (but not all: Vector reserve pilot chutes are significantly different than Mirage), but since the pilot chute is normally lost with the freebag, the situation rarely arises. Once you know the serial numbers, you can call the manufacturer to determine compatibility. Mark

It's never too late to start wearing hearing protection in the airplane. If you think you don't need earplugs because your ears have toughened up and you're used to the noise, all that's happened is that it doesn't hurt any more. The hearing loss continues. Mark

I'll be in the gallery for the USPA board meeting before the Symposium, then at the Symposium, and finally at the AFF standardization meeting. Mark

The test that convinced the FAA: linked in sequence, a #4 link, a #5 link, a reserve/tandem main Slink (tm), another #5 link, then a #4. In the pull-test, a hard link failed first, and two of the remaining hard links deformed to the width of the adjacent link's diameter. The Slink was undamaged. Strength is not an issue for new Slinks. They do require inspection for wear -- but conventional links require regular inspection as well. Mark

Is this your plan for drogue-up and drogue-down spins, or have you simplified your explanation for folks not familiar with tandem procedures? Mark

Drop zones in northern-tier regions like the North Central are typically closed or on winter hours at the time of USPA elections, making it difficult to organize a campaign. I'd like to see elections moved up to September or October. Rev Jim -- who's your write-in? Mark

I'm from the region where the incumbent was reelected with 43 votes. There have been challengers to unsuccessfully attempt collecting the 10% necessary to be listed on the ballot, but I don't think they tried a write-in campaign. I'm happy with the current director because he has the time and interest to visit the many small drop zones in a region 500 miles across, with a short jumping season. He does a good job representing us, and those of us who skydive a lot are grateful he is on the road instead of us. Mark

Something like the original Mirage, plus CRW flaps perhaps? The pilot chute packed underneath the flaps (like current Mirage or Vector, but the pin was on the back (like Reflex). Mark

This was true of the pre-ISP AFF program, but in the current program once a student has demonstrated acceptable survival skills (recover from unstable, maintain heading, pull at the planned altitude), he can be signed off to jump solo or with a Coach. The ISP includes canopy skills training on every jump. For example, on Category D (used to be like Levels 4 and 5), the student should be trying rear riser turns and flares. Now that the 2- or 4-sided "A" license proficiency cards are mandatory, we should see an improvement in canopy skills: rear and front riser work, braked approaches, maximum performance turns, and planned approaches considerate of other traffic are all items on the cards. BTW, fall-rate adjustment has not been part of the standard AFF program for many years. Mark

Parachutist has to balance ad pages, which pay for a substantial portion of publishing costs, against all the other pages, like articles, photos, rating course and event listings, and stuff like that. My guess is that ad pages are up because of the Parachute Industry Association Symposium later this month, and some ads might need to be run this month or not at all. For individual incidents, I think you'll find more useful information in the Incidents Forum. The annual fatality report is probably the most useful, although the report has been depressingly similar for the last several years. Mark