pilotdave

A ground loop is caused by instability of a tail dragger on the ground because the CG is behind the main landing gear. He was comparing that to what might happen if the CG was out of whack in a canard aircraft. Just like a bump on the ground could suddenly cause the tail to swing around, a bump in the air could cause the same thing, though along the lateral axis. It was just an analogy. In this case I don't agree... but picture a plane with the vertical tail mounted ahead of the CG.... what would happen when distubed in yaw?

I think you're on the right track. I believe it's not the center of pressure/lift, but rather the aerodynamic center of the wing that you're talking about. I don't believe it would "ground loop" in the air... you'd have an unstable aircraft, but not ncecessarily uncontrollable. What you'd have is a pitching moment that would increase with an increase in angle of attack. A stable plane (in pitch) has a very constant negative pitching moment. At stall the pitching moment should increase like crazy in the negative direction. Otherwise you wouldn't be able to recover from a stall. There are multiple reasons to sweep the wings on a canard pusher design. One is what you basically said... move the aerodynamic center of the wing farther back. It's gotta go way back because the rear engine gives a far rear CG. Another reason is to put the tails as far back as possible, for yaw stability and control. And it looks freaking cool.

A DZ I used to jump at drove me nuts with a boogie. I was there to jump. It was a nice summer saturday and I was happy doing soloes or whatever (I probably had 50 jumps or so). Showed up at the DZ, had to get my gear inspected, fill out a new waiver, pay a registration fee ($25) when I knew I wasn't gonna be staying late, and buy new jump tickets even though i had a few regular ones with me. I didn't participate in any organized jumps (they were too big for me), didn't get the free freefly coaching (wasn't interested), and didn't drink or eat anything. I was pretty pissed my home DZ wouldn't cut me any slack on the registration fee or jump tickets. And other than an RW organizer (a local) and a freefly coach, there was nothing special about the day. Dave

What's gonna happen when there are a whole lot of people using 5-10 year old slinks? Do properly inspected rapide links ever fail? Can a slink be damaged by being stepped on? What other questions does nobody even know to ask yet about them? Did anyone realize that a manufacturing defect in a grommet could cause an entaglement before it happened? Rapide links are not as strong as slinks, but they are well proven and well understood. They are prone to failure when not properly cared for/inspected, right? What'd the downside of slinks going to turn out to be? Maybe nothing... but how sure are you? Dave

Come on... slinks are newer. If you have failure rate information that would be meaningful. Number of failures is not an equal comparison. Even failure rates are probably very skewed since I'm guessing no slinks have ever failed. Doesn't mean they never will. Not saying you're wrong that slinks are better though. Dave

I also use a GPS with my laptop. It's great for long trips when i'm alone, but I can't really use it if anyone's in the passenger seat. Mine also takes too long to set up before getting on the road to use for most short trips. Dave

http://www.eecs.wsu.edu/paint.net/index.html. Basically MS Paint on steroids. Not quite up to photoshop standards, but for free it looks pretty good. Dave

I'll be happy to take it off your hands if I don't have to pay for shipping.

The tunnel won't hurt. If you don't mind spending the money, definitely go for the tunnel. If it meant waiting 6 months to jump or something maybe not, but there's no reason not to go get a few minutes in the tunnel to build your confidence (and even learn a thing or two). I'll be in the tunnel next wed and thurs. Can't wait! Dave

There's a picture in the Square1 ad in the latest parachutist. Looks just like a Z1. Dave

Eww... that's way worse than this: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=800112. Dave

I also think they'd be a lot less likely now (probably for good reason) to publish pictures of things they consider dangerous. Can you imagine this on the cover now?: http://manifestmaster.com/parachutist/1979_07.jpg. But yeah, I don't blame USPA for boring covers. I'm not sending them anything better... Dave

I was looking at doc john's parachutist cover site (http://manifestmaster.com/parachutist/years.html) the other day and was noticing that some of the older covers were much more creative than most of the recent ones. I was also pleasantly surprised by the january cover (which I actually saw for the first time on that site). Dave

My brother had the same problem on his laptop. I found some post in a forum somewhere suggesting that a bios update had fixed the problem for someone else. Problem was I couldn't keep the thing running long enough to get the bios update to complete. Eventually I bought him some canned air. Sprayed it into the fan exhaust and intakes, sprayed a ton of dust out, and the problem was solved. A friend had the same thing happening on his desktop. He could keep it running only by leaving the case open and aiming a big fan right at his processor. Somebody suggested he should upgrade his power supply. I didn't believe it would help, but I installed a bigger power supply for him and again, problem solved. Dave

The MH-60S is sort of a combination of the blackhawk and seahawk. It's a multimission aircraft, designed to replace the Navy HH-60s and CH-46s. It's already in service, being used for VERTREP (dropping shit off on ships without landing). In development now are 2 mission kits, each consisting of actually a whole bunch of different configurations. One mission is to detect and kill mines using some really freaking cool stuff. The other one, that I work on, is called Armed Helo. It will do a few different missions, and can be outfitted with .50 caliber guns and hellfire missiles for one of the missions. When it's not busy blowing shit up, it can be set up for Plane Guard/SAR, CSAR, and a mission to drop off special operations guys on enemy ships by fastrope. Most of those changes are just different seating/gun configurations. Sadly, no mission to drop me off from 10,000 feet. I'm working on sneaking that into the spec.

A "Plane Guard" helicopter launches before anything else from an aircraft carrier. But yeah, they are just flying in case anything goes wrong near the ship (within ~100 miles), not hundreds of miles away where the combat is. The helicopter in my avatar pic will be taking over the Plane Guard and CSAR missions, among others, in the future, the MH-60S. And it'll do it safely if I do my job right. Dave

I have no idea about that material, but you have bigger problems if the kill line shrinks than if it breaks. It's easy to check for a shrunken kill line, but not everybody does. I didn't till I had a PC in tow. Dave

I'd love to see someone try to do a 35,000 foot jump with a pet racoon. Do you have a problem with it?

How much do your reserve and hook knives weigh? Just be extra careful...you'll be fine! Dave

Over $3000 in jump tickets... plus 2 trips to the tunnel, new gear, LOTS of gas, a few hotel rooms, a tandem for a friend, etc. Not gonna even think about what all that adds up to. Going to the tunnel twice next week, then a boogie, then back to the tunnel again twice the week after. At least my bank account has had a couple months of rest... sort of. Dave

I love my Toshiba laptop. It's a Tecra M2. It's too slow for most new games (1.5 GHz), but plenty of fast for everything else. Size is great... can't remember the specs but I think it's under 5 lbs. Quality is very good. I really didn't like any of the Satellites I looked at (too big, too heavy, and cheap looking). The Tecras are meant for corporate use I guess, but you can buy em online straight from Toshiba. Battery life is very good... Firewire for video, IR port for the Neptune, SD port for digital cameras, S-video to hook up to a TV, built in 802.11g wireless, bluetooth, etc. Everything I wanted in a laptop. Also comes with Microsoft OneNote which is a kinda nice program for taking notes in meetings or whatever. I'd definitely recommend it as a second computer.... probably not powerful enough for a primary computer unless you don't play any games or do high end video editing (although it's as powerful as anything was just a few years ago). I bring it to the DZ to show videos during weather holds, update Neptunes, etc. I sometimes use it for photoshop when I just NEED to mess with someone's face and I'm not at home. Dave

I totally agree with you but I'm just wondering about the possibilty of breaking a slink with a burred slider grommet (or any other grommet that it might contact). Slinks ARE stronger in tension. But I'd guess they are much less cut resistant. How about long term wear? Canopy lines wear out and can break right? Obviously the answer to that is just looking at them every once in a while... but how do I know that the wear will be obvious/visible? How prone are slinks to manufacturing flaws? Those concerns are probably more realistic for main slinks, not reserve slinks. I'm just curious what your opinion is. Slinks are stronger, but they're also newer and it's possible that not every failure mode has been seen yet. Dave

Do rapide links spread the opening forces out more than slinks? I don't get your point about spreading forces or what spinning malfunctions have to do with it. Dave

That wasn't the nail I was aiming for, but I'm glad I hit one anyway!

I THINK you're saying that a rapide link can open up and bend, but still hold the lines, and a slink is most likely to release completely if it fails, right? Is that a positive though (on a main)? What if that bent rapide link decides to let go when you hit some turbulence on final? I think I'd prefer to have my slink break on opening than suddenly let go at 200 feet. But on a reserve of course a broken slink would be fatal where a bent rapide link could be survivable. The failure of each one has a probability and a severity. Since a bent rapide link MIGHT still hold the lines, I'd say it has a slightly lower severity. But what about probability? My understanding is that a bent rapide link is far more likely to occur than a broken reserve slink. If the probability of a bent rapide link is sufficiently higher and the severity is not sufficiently lower, the risk associated with a bent rapide link is higher than the risk associated with a broken reserve slink. Now that may not be true.... it's just the way I'm understanding it. And I do use both main and reserve slinks on my rig. Cause they're new and cool. And stronger than rapide links, and easier to maintain, and don't require slider bumpers, and pack neater, and don't stick into my back when packed. Dave