Eule

Besides all the sucking and blowing, there is some electrical fun too. Historically, the speed of an electric motor was determined by the local powerline frequency (60 Hz in North America; 50 Hz in Europe, etc) and how you built the motor. In the US, speeds of just under 1800 rpm and just under 3600 rpm were/are fairly common. It wasn't easy to change the speed of the motor once you built it; some motors were built with multiple windings so you could get two or three discrete speeds, but there wasn't a way to smoothly vary the speed up and down. Most speed changes were done with gearing or belts and pulleys external to the motor. Once computers and really huge transistors* got cheap enough, it became possible to build a relatively cheap "variable frequency drive" or "VFD". (Prior to this, there were some VFDs built with manual control and tubes, particularly for electric subway cars. But computers and transistors made it more practical.) Basically this lets you select whatever frequency you want to run the motor. It takes the incoming AC power and rectifies it to DC. Then the huge transistors, under control of a computer, chop the DC back into AC to run the motor. The frequency can be smoothly varied in very small steps, so you can get pretty fine control over the speed of the motor. You also get to replace several moving parts (gears or belts+pullies) with some non-moving parts (the transistors), saving maintenance and weight. When I was at SkyVenture Arizona, the VFDs were in a room off to the side of the flight chamber. The door was open and I looked in there; it was at least two or three refrigerator-sized cabinets with "Toshiba" and (if I remember right) "SkyVenture Vector Drive" logos. The basic units are probably off-the-shelf items at your friendly local industrial electric supply, and the software that comes with them probably works just fine for running one motor in a factory. If you want to coordinate four motors in a wind tunnel, you get to modify the software a little, which is probably why they had the "SkyVenture" badges on them. There are also any number of sensors scattered around the wind tunnel. Some of them are plugged into the VFD so it can shut itself down if one of the motors overspeeds or overheats; others are plugged into the operator's display so he or she can look at the temperature, pressure, airspeed, vibration in the motors, etc. Eule * OK, probably thyristors in some cases, but if you know that then you probably already know how a VFD works. PLF does not stand for Please Land on Face.

Yes! I am putting the files on this site. You can get individual files or download all of them as one folder. I updated the site a couple of hours ago. It does not yet have the ones from divinglog's post but I am working on those. Eule PLF does not stand for Please Land on Face.

The EAA had their B-17, Aluminum Overcast, at a local airport this weekend. As far as I know they don't do jumping out of it, but they do have flights (~$400) and ground tours ($6). I took the $6 one. :) One of the crew said that it burns about 50 gallons per hour per engine, or about 200 gallons an hour. The walk-up price for 100LL locally is $3.02/gallon, so that's a bit over $600 an hour. The national average for 100LL is about $3.90/gallon as I write this, so that's $780 an hour. Some things don't change, though... I watched them fuel up and they have a stick with notches on it that they put down in the tank to see how full it is, just like the 182 at the dropzone. Of course the stick for the 182 is about a foot (30 cm) long and the one for the B-17 was about four feet (1.2 m) long. I didn't ask how much oil it went through, but the oil fill hatch on each engine was stenciled "ENG OIL 37.5 GAL" (or 142 L). Airplane engine oil seems to run about $15 to $25 a gallon, depending on plain or fancy, if you buy it onesy-twosy or in cases, etc. This means that a full oil change would run around $2200 to $3800. I don't know how many hours you get on an oil change; a quick Google suggests that the engines in Cessnas have a 50-hour oil change interval, so _IF_ the (totally different) B-17 engines have a similar interval, that's another $45 to $75 or so per hour for oil. On the other hand, the radial engines on the B-17 drip so much that you might never have to actually "change" the oil; if you just keep topping it off then after awhile you've probably done the equivalent of a complete change. Hmm. The Collings Foundation (who also fly a B-17 plus some others) say theirs are tax deductible, but the EAA doesn't say anything about tax deductibility of their rides. It's probably a good idea to check with the operator of whatever you're jumping out of. Eule PLF does not stand for Please Land on Face.

The site is updated. I included the two DZs shaggio submitted. I also tried to bring a semblance of order to the naming convention, and went ahead and put the files in subdirectories by region, like I knew I should have done when I started this. There are currently 64 dropzones listed. Eule PLF does not stand for Please Land on Face.

If you do this, please make sure there is a fuse involved somewhere. A battery of 8 fresh alkaline AA cells can dump over 100 watts into a dead short, at least for a brief time. 10 freshly-charged NiCd AA cells might approach 200 watts. Fires usually suck, but fires in airplanes really suck. Eule PLF does not stand for Please Land on Face.

B-52H Stratofortress. You could do a 400-way out of one plane. Alternatively, you could load up 400 jumpers in Louisiana and take off for just about any dropzone you wanted. It'd take about an hour and fifteen minutes to get from Louisiana to DeLand, and about three and a half hours to get from DeLand to Perris. Or, it would take about seven hours to get from DeLand to Paris. One reference (from a .mil address, so you know it has to be right) says that the stall speeds vary from about 100-150 knots depending on loading, so it's maybe even conceivable that you _could_ jump from one. Eule PLF does not stand for Please Land on Face.

The site is updated. I included everything new since the last update, plus I went back and added a couple of more Australian DZs from the thread that bob.dino linked to. At the moment the naming convention is a little inconsistent as to whether it includes the name of the region and the name of the country or not. I plan to make these consistent in the next update. Eule PLF does not stand for Please Land on Face.

The "brake warning" lamp is activated by either the ABS computer throwing a code, or a float switch in the fluid res. on the master cylinder. There are two cars in my driveway right now that have neither ABS computers nor float switches on the reservoir, yet they still have brake warning lamps. One of them has a switch on the master cylinder that closes when the piston is too far off-center (in other words, one of the hydraulic circuits has failed) and the other one has a switch on the proportioning valve that does the same thing. It does tell you that your brakes have not failed in one somewhat common way. In other words, the warning light being off is necessary but not sufficient to know that your brakes are working. I agree that it doesn't tell you that something is _going_ to fail - that's hard to do. Agreed. My point was that cars are not totally devoid of safety checks, but I didn't want to say that the checks that do happen are as thorough as checking out a rig. Eule PLF does not stand for Please Land on Face.

Not very much, but here's what I think I know. As far as installing things in the airplane in general, I believe it's both easier, cheaper, and less hassle (FAA) if it's something you can just run on batteries (or maybe on the cigarette lighter; Cessnas have them but I don't know if Otters do) and is portable - nothing bolted to the airplane or permanently wired to the airplane. (Check with your friendly local airplane mechanic (A&P) for better information.) For instance, lay the receive antenna and battery box on top of the instrument panel, run the cable back into the cabin, and hang the transmit antenna from the ceiling in the middle of the cabin. The optimal place for the receive antenna is probably on top of the airplane, and you can buy active receive antennas that are designed to go there, but they start at maybe $350 and go up from there, professional installation at $100/hr not included. Looking at a couple of reviews of using the ~$50 active repeaters in cars, it looks like they _might_ work in this application. The most important thing is to install the cable and the antennae such that they can't be tripped over, get tangled with the aircraft controls, get snagged by a jumper and ripped off the wall, snag somebody's handles, etc. After that, the next thing is probably getting the receive antenna to where it has a good view of the sky. I suspect that in an Otter the antenna will be able to see slightly more sky from the cockpit than from next to the door in the back, but either place may work. Then you have to get the transmit antenna in a good location inside the cabin. "Good" in this case probably means "up high", but spacing it a bit away from the ceiling may be better than having it right on the ceiling. You could conceivably test the receive antenna locations on the ground with the engines shut down (i.e., cheaply), as long as your handheld GPS will give you a status page that shows how many satellites it can see. Park the airplane outside and pointed the same direction it usually is pointed on jump run and try your handheld GPS from both the cockpit and the door in the back. Put the handheld GPS as close as you can get it to where you might mount the receive antenna, and see how many satellites it can pick up. You might try it at different times of the day. If jump run can be lots of different directions, it might be harder to cover all the possibilities. For some background on what's going on: An antenna is basically a chunk of wire. By changing the length of the wire, you can make it so the antenna picks up some frequencies better than others. Antennas work both ways, so an antenna that is set up to receive a particular frequency well can also be used to transmit on that frequency fairly efficiently. So, you can make a simple repeater with two antennae - one outside the plane and one inside it - connected together. The GPS signals hit the outside antenna, go through a cable, and come back out on the inside antenna. This is usually called a "passive repeater", since there are no amplifiers involved. The signal picked up by a chunk-of-wire antenna is not very large. If you want to pipe it through a cable, as-is, to a GPS receiver, you need some pretty high-quality cable (read thick and expensive), and the cable usually can't be very long. To get around that, you can put an amplifier right next to the chunk-of-wire antenna to boost the signal. This boosted signal can then be fed through cheap, thin cable for a long distance, while still remaining usable at the GPS receiver. An antenna together with an amplifier in the same box is usually called an "active antenna". If you take an active antenna and connect a chunk-of-wire antenna to its output, the boosted signal will get re-radiated through the chunk-of-wire antenna and you have an "active repeater". This is what the $50 device you linked to appears to be doing. Neither of the above devices really "care" about what's going through them - they just pass along whatever happens to be in a certain band of radio frequencies. I _think_ the more-expensive repeaters that LouDiamond is talking about actually have GPS receivers in them. They receive and decode the GPS signal, then re-encode it and re-transmit it - they have a microprocessor looking at the signal, rather than a simple amplifier. As an analogy, imagine you are reading dropzone.com at work but you don't want your boss to know. You could put up a couple of mirrors so that you can sit at your desk but still see if your boss is coming down the hall - that's a passive repeater. You could point a video camera down the hall and watch the output of the camera on a small monitor at your desk - that's an active repeater. With both of these, you see everything that's happening in the hall, whether you care about it or not. Finally, you could pay a kid to stand by your door and tell you when he sees the boss coming - that's the expensive repeater, and with that one, you only get told about the one thing you really care about - is the boss coming or not. I hope this helps! Eule PLF does not stand for Please Land on Face.

One of those strange guys that actually wants to stay in the plane all the time was at Nationals and took a few photos: http://www.pbase.com/flyingphotog/eloy_uspa Eule PLF does not stand for Please Land on Face.

Something the size of a business card would be even easier to carry and pass out. There isn't as much room on it but you could print something simple on it like "Skydiver money" - the local merchants will figure it out. To get straight into a Federal crime, one could get a rubber stamp and stamp a parachute onto every single piece of currency that comes in, and offer the use of the stamp to jumpers who are going to spend money in town. Eule PLF does not stand for Please Land on Face.

Cars built before about the late 1960s that had hydraulic brakes often had a "single circuit" hydraulic system. If you got a leak anywhere in the system, you had no main brakes at all and had to use the emergency brake/hand brake/parking brake. Cars built since then have a "dual circuit" hydraulic system; if you get a leak in the system, at least half of the system usually still works. Even then, they still come with an emergency brake/hand brake/parking brake. Recent car manuals have quit calling it the "emergency" brake, but it _will_ slow you down some if you have nothing else. (Try it sometime in an empty, dry, and flat parking lot.) To get somewhat back on topic, I had this discussion with someone before I started to jump. His point was that you couldn't really "test" a parachute before you used it to make sure it was OK. He also gave the example of car brakes, pointing out that the way most cars are parked, you can't just start the engine, shift into gear, and accelerate up to highway speeds. First, you have to maneuver at low speeds to get out of the parking spot, and somewhere in this process you'll step on the brakes. If the brakes are not working correctly, it's very likely you'll notice it yet still be able to stop the car safely, so you can investigate the problem or use a different car. I agreed that you couldn't really "test" a parachute in that way, which is the reason for the inspect-canopy/pack/inspect-packed-rig for the main and the rigger inspection/pack for the reserve. Eule PLF does not stand for Please Land on Face.

Caution: Low jump numbers here, but I do have some experience in this department. Whatever your DZ says it is, minus 10 or 20 percent, unless you like being blown on the titanium breeze and becoming a target for faraway laughter. :) You also get to consider the gusts. A steady 8 mph is different than 3 mph with gusts to 13 mph. Both are within the limits but the first is (IMHO) a lot easier to deal with. It's also important to make sure that all the numbers are in the same units. The "civilian" weather report will give miles per hour, while most of the "aviation" weather reports will give knots. Some DZs have their own small weather station and these can be set to read in mph or knots. They are close but not equal - one knot is about 1.15 mph, so once you get over a couple of knots, the difference starts to be significant. Even though the book says there are no limits on winds aloft, you also probably should take those into consideration. One advantage you have as a student is that you're probably wearing the DZ's gear, so when the winds aloft are howling and you do land way out, you have a high chance of somebody coming to find you - they want to get their parachute back. :) Eule PLF does not stand for Please Land on Face.

Exactly. Puke is not just a little dirt, it's hydrochoric acid (and some other stuff). Would you pour hydrochloric acid on your rig and then jump it again? Is it common practice to replace the student half of a tandem harness once it's been puked on? Eule PLF does not stand for Please Land on Face.

I updated it last weekend and I will update it with all the additions since then on Monday the 30th. The Windoze version of Google Earth still works a little better than the Linux version, so I tend to do the updates on my Windoze machine at work. This past week they were actually making me work, so I didn't get a chance to do updates. I always change the 'Last updated' date at the bottom of the web page when I update the site. I just checked my dropzone.com mail and yes, I got it. SpeedPhreak asked about getting double labels and as jerry81 noted, this can happen if you've got a DZ in the list twice - like once in the regular list and once in 'Temporary Places', or whatever. One way to fix it is to delete one of the entries; another way is to uncheck the box at the left of one of the entries, which should remove the labels for that entry. Here is a general question for people outside of the US. In the US, it seems to be pretty common that the hangar where the plane and rigs are and the place where you jump and land are right next to each other, and that jumpers refer to the whole assembly as a 'dropzone'. If Acme Skydiving is at the Springfield airport, the plane takes off from Springfield, you jump out over that airport, and you land near the Springfield runway someplace. From a couple of the non-US entries, it seems like there are many more hangars where the plane and rigs are than there are places where you jump and land. Only the place where you jump and land is referred to as the 'dropzone'. Acme Skydiving might be at the Springfield airport and Yoyodyne Skydiving might be at the Bugtussle airport. The Iconium dropzone is at some third location - Acme's plane takes off from Springfield and flies to Iconium to drop jumpers, and Yoyodyne's plane takes off from Bugtussle and flies to Iconium to drop jumpers. Is this an accurate reflection of the situation or am I totally confused? Eule PLF does not stand for Please Land on Face.

I thought you would get way more bugs in your teeth doing AFF than doing static line, but I've never done SL so I don't know. Care to share the details of this calculation? Eule PLF does not stand for Please Land on Face.

It can potentially cost you a lot of money. From an email I wrote to a friend last summer: The DZO apparently got spanked pretty good, but landed and walked back under his own power - it wasn't like he needed medical attention. Eule PLF does not stand for Please Land on Face.

You are my new hero. :) You make my progression (passed AFF 7 on jump 46, all except for that pesky landing thing) look really fast. Eule PLF does not stand for Please Land on Face.

The first picture shows a rated motor power of 5.5 kw, which is about 7.3 horsepower (1 hp is about 0.75 kw). Some of the SkyVenture tunnels are running something like 1200 hp total. I have also heard of some older, smaller tunnels being run by DC-3 props and engines; Jane's says the DC-3 had engines of anywhere from 1000 to 1400 hp each. If they can cut you a deal on 100 or 150 fans just like that one, you'd be in business. :) Eule PLF does not stand for Please Land on Face.

"We live in the interface between radioactive molten rock and hard vacuum and we worry about safety." -- Chris Hunt First seen on Usenet 9/2001; attributed 10/2002. Eule PLF does not stand for Please Land on Face.

That might have been the party line when he went tomed school. In Poynter and Turoff's "Parachuting", there is a mention of this in the chapter on emergencies: It goes on to talk about a study done by Bruce Ogilvie at San Jose State University in 1973 of participants in high-risk sports that had some pretty positive things to say about those participants. This may or may not be exactly that study but it seems to address the same things. Since the guy is a doctor, maybe having something in "the literature" that says you aren't crazy might help. On the other hand, if the guy has lived with this assumption for 30 years, it's hard to do much to change it. Eule PLF does not stand for Please Land on Face.

Wow, it took you two posts to slam me... you'd think I was running the WFFC or something! My point was that it wouldn't cost "millions" of dollars. I am certain that the option of taking lots of digital and x-ray photos of rigs and distributing them for the TSA training classes wouldn't cost a million dollars. Hell, for US$300,000 you could buy a BRAND NEW RIG (including AAD and extra chrome plating) for every state in the US, to be used in the TSA training in that state, so getting used rigs together should cost much less than that. A lot of the posts here concerning TSA say things like "the guy didn't want to let the rig through but the supervisor came over and said it was OK" or "the guy knew it was a rig and called his co-workers over for some on-the-job training as to what a rig looks like". What I got out of that was that not that many TSA screeners have seen a rig go through the machine before. This is somewhat understandable - if you're running the TSA training class and you want to show the new recruits what a laptop or a hairdryer looks like on the X-ray, all you have to do is stroll out to the security point and wait a few minutes. If you want to show them what a parachute looks like, you'll be waiting quite a while. I was trying to come up with some inexpensive ways for the TSA trainers to be able to show the new guys what a rig looks like. And then people call the (already mostly bankrupt) airlines and say "Now that I can't take my rig, I won't be buying any more plane tickets for my skydiving trips" and parachutes magically appear on the approved list again. Cycle that through a few more iterations and you end up flying naked. Eule PLF does not stand for Please Land on Face.

34 down, 800+ to go! :) I added Palatka to the site. I have also put up a file that contains all of the individual dropzones, so you can get all of the DZs at once if you want. In many parts of the US and Canada, the weather is getting worse... a rainy, cloudy Saturday is a great time to spend 15 minutes creating an entry for your dropzone! Even if your DZ is in a "low resolution" part of the world, create an entry for it anyway. The low-res pictures are usually good enough for some basic landmarks, like the DZ's hangar, the runway, and the landing area. Because of the way Google Earth works, if Google later gets some better imagery for your area, the new images will _automatically_ appear underneath the points you've created - you don't have to do anything. A question for Quade or other greenies: would it be acceptable/worthwhile to post a pointer to this thread over in "Events and Places to Jump"? It might help get some more dropzones added to the list. Just one post that was immediately locked would probably do it. Eule PLF does not stand for Please Land on Face.

Pack up some clothes and stuff; put the bags in your car. Strap a snow shovel on the roof of your car. Start driving south; fill up every time you get down to half a tank. As soon as somebody at a gas station asks you what that thing is on top of your car, OR you come to the ocean, start looking for a dropzone. :) Welcome! Eule PLF does not stand for Please Land on Face.

All, I grabbed all the placemarks posted in this thread so far and put them here. I don't yet have the Australian ones that bob.dino linked to; those are next. Edit: I got the Australian ones added. For a couple of them I couldn't figure out the DZ or club name and just have the location. Eule PLF does not stand for Please Land on Face.