riddler

When I started skydiving at Mile Hi, the owner insisted that everyone start with a tandem. Knowing that I wanted to skydive, I didn't want to "waste time" or money with the tandem, but he insisted (in a rather unfriendly way, I might add ). After doing the tandem, I was glad I did, and I now think that the DZO was right. I now help teach FJC at that same DZ. The rule about doing a tandem first is no longer enforced. I think this has to do with the fact that other DZs don't require it, so customers realize it's cheaper to go elsewhere. I now see a mix of students in the FJC - some have tandems and some do not have tandems. I see a big difference in the performance of AFF level 1 students, depending on if they have previous tandem experience. The ones that have never jumped before typically don't do as well - a lot of factors go into how well the students do, but no matter how athletic or focused a person is, I don't think anything really prepares you for that first experience. What's interesting is how some instructors factor that in. One recent student received a pass on level 1 after pulling a few thousand feet too high. The AFFI said he was more lenient because the student had never jumped before. I would think that the standards would be the same whether you do a tandem or not. But I also believe that skydiving is a very individual sport, and I think it's great that instructors can give individual assessment to each student. Trapped on the surface of a sphere. XKCD

A couple of things. The Instructional Rating Manual, explains that coaches may only teach non-method specific portions of the skydiving ground school. This does not include freefall emergencies. When I teach FJC, I am required to get an instructor to teach or supervise my teaching the emergency procedures, including freefall emergencies. I recommend checking the IRM as well as the SIM for teaching guidelines. There is no "five-second" rule in any of the manuals that I've read. That may be something they teach to AFF instructors, but it's not something I've ever read. If your AFFI came up to you and told you that they both need five seconds to get to the student, I would ask them why they don't have hold of the student in the first place? IMO, it's best to teach FJC in accordance with your DZ procedures. If your DZ has a rule that instructors are allowed 5 seconds to catch a student, and the S&TA agreed and the DZO agreed - well, if it was me, I would find a new DZ quick. Not only would I not teach there, I don't think I would feel safe jumping with those people. Don't take the word of one AFFI - ask the S&TA and the DZO. Edit for grammer. Trapped on the surface of a sphere. XKCD

It's very easy to do this. I've induced line twists using only toggles on a square canopy loaded at 1:1. Flying hard isn't necessarily the same thing as flying at the edge of the performance envelope. I'm still really learning about my canopy, but I believe the best way to learn about what your canopy can do is to find out where all the performance edges are. Flying fast and initiating fast turns can tell you about one aspect of your canopy. Flying really slow, finding your stall point, and seeing how turns develop in a stall and close to a stall is another aspect. Practicing with all eight control inputs is another aspect. There are many others, and I don't think I even know what they all are yet. Trapped on the surface of a sphere. XKCD

At the DZ I jump most often, the rule, as established by the S&TA, is to follow the first person down. But I only see that happen when the first person down lands into the wind, and the wind stays in the same direction for the rest of the jumpers. The rest of the time, everyone seems to forget the rule, and I feel bad when I take the AFF students out to the landing area after telling them the rule, and having them watch everyone land in different directions. I guess rules are only as good as their enforcement. I make an effort to follow this rule out of respect for my fellow skydivers, who's safety is important to me. If my friends expect me to follow the pattern and I do not, it may lead to unsafe conditions for all of us. A few times, there have been first-down jumpers on a long spot that elected down-wind landings in the main landing area in order to get closer to the pea gravel. After landing, I always walk over to that person and remind them of the rule. I don't necessarily think that it's safer one way or the other. What I think is UNsafe is telling everyone that this is the rule, having some people (like me) expect it, and still allowing everyone to do whatever they want. If it's a rule, it should be enforced. Jumpers should always expect the unexpected, but we shouldn't make the unexpected a rule. The rule does have an amendment that you can land in any direction you want outside of the main landing area. Because of this, the majority of my landings are outside the main landing area. When I work with students that have completed AFF, I encourage them to land outside the main landing area. It's only another 100 feet to walk, it keeps you out of the way of all the other traffic/students/tandems, and it allows you to land upwind. Trapped on the surface of a sphere. XKCD

After doing my taxes this year, I discovered that Colorado gives a state rebate to people that own Hybrid cars. I am seriously considering replacing my 5-year old F-150 with a new Prius. Also, one problem that has been noted is that dealerships often lower tire pressure below the recommended PSI for their cars. This supposedly gives the cars a smoother ride to encourage people to buy them, but it does reduce the effective gas mileage. A few people that have bought hybrids have reported seeing lower than expected gas mileage until they put the recommended air pressure in their tires, at which point, MPG went up to manufacturer claims. Personally, I work from home and live in the middle of the city, so the only time I really put any miles on my truck is when I drive to the DZ. If it wasn't for skydiving, I could live without a car completely. Considering it cost $45 on my last fill-up, it seems well worth buying a more fuel-efficient auto. Trapped on the surface of a sphere. XKCD

This sounds like a very reasonable response. I've only seen two two-out situations. One was caused by a jumper pulling low, and his AAD activated the reserve at about the same time as the main. One was cause by a jumper that had a streamer and elected to open reserve prior to cutting away because he felt too low to cutaway safely. Both situations were the result of poor judgement - the first jumper could avoid the problem by not pulling low, and the second did not follow good procedures. I'm tempted to say any two-out situation is the fault of the jumper making bad choices - equipment problems may be excepted, but jumpers should also make good equipment choices. I agree about having a larger reserve - I like the idea of having a more docile canopy in an emergency. I'll probably buy new this summer (two rigs just ain't enough ). My plan is to get a 150 main and 160 reserve. My current most-oft-used rig is a 150 main and a 143 reserve. I've seen a trend that jumpers that have a 135 main or larger tend to get a reserve about the same size, while jumpers that have under a 135 main get a reserve that is much bigger, percentage-wise. I assume that's because they don't want to swoop their reserve canopy? Trapped on the surface of a sphere. XKCD

Taken with a Canon Digital Rebel. I am really amazed at the quality of the pictures. Unfortunately, our spectator area is opposite the sun, so we get a lot of shadows on the jumpers. See ya'll in a few weeks when I get back! Trapped on the surface of a sphere. XKCD

Just want to point out to make sure you are using the latest Neptune software. I've seen that the 1.1 software can be way off in freefall speeds. 85-95 sounds like a pretty reasonable number, though. Trapped on the surface of a sphere. XKCD

Yep - just talked to a guy that says he can do them very easy. Of course, he flies a 60 square foot canopy Now I know ... Trapped on the surface of a sphere. XKCD

That's just a 360 under canopy. They aren't really turning completely upside-down. It looks upside down because of the angle. Or am I wrong? I've never heard to them referred to as barrel rolls before. Seems kinda misleading. Of course doing it that low to the ground seems fairly dangerous Trapped on the surface of a sphere. XKCD

Beg pardon. I know what a barrel roll is in freefall, but what is a barrel roll while under canopy? Trapped on the surface of a sphere. XKCD

I'm not sure that's what everyone wants, but I know I do, and I get it from great people at the DZ that sacrifice time to help out a newbie like me. Funny thing about this sport - you can be in it three years, have close to 300 jumps, and even have a coach rating and still feel like you know nothing about the sport. But I have people in my life like Skratch and DJan and Mary who all take time to try to help me improve, just because I want to. And there's people like Kaylan and Tak at the other end of the spectrum who remind me that there's more than one way to look at things, and share my passion for jumping. Just a few hours ago, the staff at Mile Hi did a memorial jump for the founder, who died in a plane crash one year ago today. It was a beautiful day and a good jump. No, it wasn't a good jump from the perspective of Airspeed, and it's probably nothing you'll see in Parachutist. But despite the fact that we didn't build the formation, we were safe and shared the most basic bonding experience you can have as a skydiver - we jumped together. Yes, I blew by the base like a man breaking out of prison , but at least I got two seconds of camera time!! And after the jump, I wasn't criticized by the other jumpers - the only concern we had was if dsbbreck was OK, because we saw his cutaway (and he got good video of it ). I realized that I have a LONG way to go before I get any good at this skydiving thing, and I may never get invited on a big-way again , but the point was the same as it always is. I had fun today jumping with my friends. Hey Riddler, err ... why were you sit-flying past the formation?

I have food grade silicon that I use to recondition the o-rings on diving lights. But I've never used it on cutaway cables. I've been told that food-grade silicon is good in a "protected" environment, but in a dirty environment (like the inside of a cutaway housing) it's more likely to attract dirt. Has anyone else heard that? For the record, I use off-the-shelf Ace lubricant. Trapped on the surface of a sphere. XKCD

You forgot the most important aspect. Looking cool! If protecs were the coolest looking helmet, everyone would wear one. Trapped on the surface of a sphere. XKCD

Out of curiosity, Bach talks in one of his books about occasionally making skydives. Just enough to keep his rating current. Anyone ever jump with him? Have to admit that he was a big part of my childhood dreams of flying. Trapped on the surface of a sphere. XKCD

People that don't ride are sometimes weird about bikes. This leads bikers to be weird right back, and gives them a reputation. I haven't ridden in a few years, but considering some of the strange situations I've been in, when I start riding again, I think I'll carry one of these. Well, you wanted to have a little fun, right??? Trapped on the surface of a sphere. XKCD

Agreed. It's worth renting, though. Watch once and say you saw it. The cool thing is, despite how old it is, many parts are still relevant to skydiving today. You have the daredevils, extra-marital affairs, wingsuits (or something like), people burning in, difficulty with local authorities, et al. Trapped on the surface of a sphere. XKCD

If it's older than 20 years, a lot of riggers will refuse to repack it. It's junk. But you might donate it to skydivers in a less fortunate country, like Russia. Trapped on the surface of a sphere. XKCD

Yeah - best thing is get ALL your money back and move to the next insurance company. They don't all treat you like that. Personally, I would be writing a letter to the local insurance regulator and letting them know what just happened with that one company. But yes, in my experience, most insurance companies draw a line between fun jumping and doing it for work. Trapped on the surface of a sphere. XKCD

I went through this too. You will have to keep trying different companies until you find one. I was routinely asked if I was an instructor for any of the "hazardous activities" I engage in. At the time, I wasn't, so it didn't affect my premium. You will have a harder time being an AFFI, but I suspect the motorcycle is more of an issue than the skydiving. Insurance companies seem to hate motorcycles. Trapped on the surface of a sphere. XKCD

It's kind of a loaded question, because the total pressure is always the water pressure plus the one atmosphere that's on top of the water, so you can't really equate the two because you can't remove that atmosphere of air that's present when diving. But to get an idea, we'll ignore that fact for now. An atmosphere of pressure, defined numerically, in pounds per square inch, is the weight of a column of air, one inch square, that goes all the way from sea level to outer space (whatever that means). The weight of that one-inch column of air all the way to space is about fourteen and a half pounds. The weight of that column if you are 13,000 feet above sea level is only about 9 pounds, since there is less air on top of you. 13,000 feet ASL is about 0.62 of one atmosphere. The weight of that one inch column of air going all the way to space is the same weight as a one inch column of water that's only 33 feet high. If you are on the surface of water, you are already under one atmosphere of pressure, from all the air on top of you. If you descend 33 feet in the water, you will be at two atmospheres, since water is a much denser fluid than air, and you now have about 29 pounds of force per square inch on your body. 66 feet, you are at three atmospheres, 4 at 99 feet, and so on. To figure pressure at depth, you can take the depth, multiply by 33 feet, divide by 14.5, and that will tell you the pressure, so to get an additional 0.62 atmospheres, you would need to descend about 20 feet in water. Or the reverse of that, since descending from .62 (13,000 feet) to 1 (sea level) is about .38 atmosphere change in pressure, then the equivalent depth of water descent would be 13 feet. So ball-park numbers, descending from 13,000 feet to sea level is about the same as submerging 12 to 13 feet in water. Just as an aside, these numbers will be different if you jump in Colorado, like I do, because our field elevation is 5,050 feet, so when we jump at 12,500 above ground level (AGL), we are really 17,550 above seal level (ASL). Also remember that it's a bit off because we removed the air pressure on top of the water. Another note is that all these numbers are not exact - they are approximations off the top of my head. If you want an exact answer, never ask an engineer Trapped on the surface of a sphere. XKCD

The majority of students that fail an AFF level do so because they are tense. Try something to get in the mode of relaxation - the key to this is subconscious, not conscious, relaxation. Get your muscles to "learn" to relax. Here's one that I did. Go to the pool at your gym and float face-down. Arch your pelvis, exhale all your air and sink to the bottom of the pool. Make sure the lifeguard knows you are not trying to commit suicide Do this several times per visit - I repeated this 20 times a day. Your body will become conditioned to relaxing when you arch and exhale. Then when you jump, your body will be more relaxed and the air will push your limbs into a symmetrical position. Trapped on the surface of a sphere. XKCD

I have small eustachian tubes, and it was worse when I started skydiving. I would get ear popping even the next two days after a jump. At the time, I worked at an elevation that was 2,000 feet higher than my house, so every day I would "practice" clearing my ears on the drive home every day, as I descended down a mountain highway, just to prepare myself for the next jump. I noticed after a few months of practicing and jumping, I had fewer ear problems after a jump. Less than six months later, I started SCUBA diving. In SCUBA, it was much harder for me to clear my ears. The relative pressures seemed to be much greater with very little descent. I took it slow on descents until I got used to it. Now, I don't have too many problems, but sometimes get a "squeeze" if I'm descending too fast and not paying attention to my ears. I don't have many problems with my ears now. They still clear a lot, but I don't think I notice it much - it's more automatic and not painful. I still clear them when I get under canopy (so I can hear other canopies), and again on the ground (so I can hear people when they ask me if that landing hurt as much as it looked ). I think SCUBA diving helped the most in conditioning my ears for pressure change. Trapped on the surface of a sphere. XKCD

First off, I've never been in a dust devil. If you find yourself in one, it may be safe to say you've already made some errors with regard to good judgement, etc. Having said that, we teach about dust devils in FJC. As been said, the best thing is to avoid them. How? They will follow the windline typically, so if you see one coming, and you have enough time, you might consider turning 90 degrees to the windline and flying out of the way. Even if you have to land crosswind, it beats an upwind landing into a fixed object or dustdevil. The problem with trying to avoid them is that you don't always see the buggers - they're only visible when they pull up dust or grass/dirt. In Eloy there's plenty of sand to make them visible. Here in Colorado, there's fewer of them, but the'ye often invisible. If you find yourself in one, I don't really think there's any procedure you can follow that's going to "save your butt". Once the devil has you, he does what he wants with you. Best advice I can offer is fight to keep your Wings Level (TM). You will have to fight, too - don't give up, and that applies to every bad situation you find yourself in while skydiving. If you make it safely to the ground, make sure to jump on your canopy to keep the devil from sucking you back up in the air again. A few people have been hurt while walking back because the wind picked up their canopies for 50 or 100 feet, then slammed them back on the ground. Trapped on the surface of a sphere. XKCD

If you are going to be a SCUBA instructor in the US, a lot of your decisions about how and where you work are tied to insurance. You can get personal liability insurance, which can be quite expensive, and work anywhere you want. But my (limited) experience is that most dive instructors in this country get group insurance with the shop they are affiliated with, and they only teach at that shop. Each instructor still typically has to pay out of his/her own pocket, but the rates are usually much less. Skydiving (also in my limited experience) does not typically share the practice of instructor liability insurance. That may lead to fewer lawsuits - I don't know. I'm not ready to make too much of this suit yet. Considering the waivers, the instructors pretty much have to do something intentional to hurt you for the lawsuit to succeed. Trapped on the surface of a sphere. XKCD