hackish

These is a lot of advice on buying gear immediately. Generally you will read that it's better to gain some experience on large rental rigs so you can buy a canopy and then use it for a long time before you will be ready for a downsize. The appropriate canopy for you with 2 jumps is probably not the same as when you have 50. From 50 on you might jump the same thing for 200-400 or more... Certain types of canopies such as a Manta or a Navigator are designed to be docile. Your instructors will probably be able to give you the best advice on what canopy would suit you with your style and skills. -Michael

Fred, have a search around and see if you can find a copy of the 2 out report. In that the test jumpers found that in a 2 out situation they were best behaved if the canopies were not extremely mismatched as far as size goes. This should be part of the safety consideration when sizing these things. If billvon is able to fly a 103 then a 143 is likely to feel like the goodyear blimp. It's all perspective. My 170 felt very slow after trying out a 135. I still prefer the 170 mind you but the difference is significant. The other important thing to consider and I know it's been mentioned many times here is that some older reserves do not behave very well when heavily loaded. Just another part of the size evaluation. -Michael

Hey that's a really cool idea. I might have to wait for a thesis to be completed before I can do that. Turned out to be OK with the kids. Got a few who were like "Hey my grandfather did that" or "hey my daddy did that." Got one parent who asked "is that thing real?" He looked me in the eye and said "you're crazy". -Michael

My better half joked about me doing that one. I was thinking of looking around for one of those pink naked suits you can buy but damn-it. I got home from work with 30 minutes to spare - 5 of which I just used up here :) -Michael

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Just wondering how many people are going to take the easy way out and dress up as a skydiver? Since we're hosting a Halloween party I think I'm considering it. Just as long as everyone with beer stays away... On the other side most know I'm a skydiver so I suppose it's an interesting opportunity to peek interest. -Michael

Side note: Maybe this thread should be split into trapdoors... I assume reducing the trapdoor would make an opening more comfortable because your actual deployment speed should be lower because you have no chance to accelerate when the drogue is released. On our eclipse and vector tandems the drogue release lets go of the 3 ring. The scrunched up bridle section immediately before the pin. Does anyone have a picture of a strong? I've watched tandems deploy more than once but I've never thought to look up at the drogue to see what it was doing. -Michael

Sorry, I misread this as the drogue doesn't collapse at all. How do they delay collapsing the drogue until the canopy is open? All I could think of was having the kill line attached to the MLW so the canopy must be out of the bag before it can travel... I suppose the trapdoor thing is really only a safety issue for the video guy but I suppose the opening on a strong is probably more comfortable. I've done a few tandems as the checkout dummy and I've always found them to be "brisk". -Michael

Trust me this wasn't an extremely slow pull and that's why I used a 42" long "pin". The only real difference in speed is the amount of inertia your hand has. Although kinetic friction does change with V it doesn't change a lot in this situation. The dept of aerospace may be willing to let me use some of their equipment to prove the real life situation. The guy I spoke to said that it's nearly impossible to calculate the kinetic friction so you just have to measure it. He concurred with my evaluation that you should end up with on average the kinetic force required plus the ultimate strength of the sealing thread * the number of strands. -Michael

You are wrong. Did some quick testing last night. Took a grommet in a vise, ratcheted a piece of cypress cord down down on a pece of 3/32 polished stainless wire until it was at 20 pounds of pull force. Believe it or not this is a lot of force! Then I measured the static and kinetic friction. 2 pounds different. Once it was moving I reduced the force until it stopped. Stopped at just under 18. I didn't have a sealing thread around but applying 20 pounds of pull force would have applied at maximum 2 pounds on the sealing thread whether it had been tight or not. -Michael

Makes sense. How well does the strong fly with a giant drogue inflated behind? To have the best of both worlds you'd almost need the kill line attached via a cascade to the main risers. Don't think every canopy manufacturer would mod their stuff for that! -Michael

Any insight into why the strong doesn't have a trapdoor effect? We only have eclipse and vector rigs at my DZ and they're pretty much identical except the vector has velcro tabs instead of tuck tabs. Do the strong rigs have the same sort of drogue release or is there something that prevents the drogue from collapsing before linestretch? Although I've been practising 30 or so jumps with a tandem the people here shit all over you if you don't have an F license and 5000 jumps to do anything but fly a manta 288. Advice given in person has always been vastly different than advice given on the interweb. I agree with a lot of comments - sometimes the TI is all over the place and I spend a lot of time and effort chasing them all over the sky. The local DZ wants to see a B license before I do tandem video but I don't think I could do one good enough that someone would pay for it. Maybe after 100 more practise jumps :) -Michael

I was going to get a soft reserve handle for fashion but decided it was better to retain my gold ring (previous owner did it). If you ended up with a piece of jumpsuit covering the metal ring I find it easier to locate. I also find it easier to apply a lot of force to the ring given a few emergency scenarios - dislocated/broken left arm/shoulder? I just think a soft reserve handle is a bad idea. -Michael

Something that may contribute about 1/3 of the pull force you may feel. I don't know. What will I ask the engineer? How to best determine the static versus kinetic friction, if they are usually significantly different or not. I'll go to the aerospace lab because it tends to pique their interest when you ask questions for something that flies. I also know they have instruments that are much better than my "Made in China" fish scale. -Michael

On my last one I think I remember feeling the thread but it could just be all up in my head. I'm going to ask an aerospace engineer what they think about the kinetic friction thing tomorrow. Since it peeks my curiosity I'm sure I'll do some more study and see what I find. -Michael

I'm not an instructor so I'll just describe my experience. We have similar weights. I started jumping a 170 sabre 2 at about 40 or so jumps. I did about 20 jumps on a Sabre 210 as a transition. I'd have to check my logbook to be sure. As with any canopy there exists a real chance that you could injure or kill yourself and if you don't know what you're doing on a sabre2 170 the chance is greater. People here said I'd kill myself people at my local DZ said I'd be fine with a good briefing. Ultimately I did ok - took a canopy control course in Deland and it helped a lot as well. What I did was not for everyone and I'm sure there are lots with more talent than me. What I suggest from my experience is to learn everything you can and get as much personal advice from instructors who know you. Get video of your landings everyone will be able to make suggestions so you can improve. Take a canopy control course. Ultimately it should be an instructor you get the advice from but who says you can't educate yourself. People on the interweb don't know you from a hole in the ground so if you're crazy talented or an accident waiting to happen there is no way to know. -Michael

If you read back to the posts I made you will see that I clearly state many times that the worst case is 22+the breaking strength of 2 strands of thread. I am however interested in seeing what the thread actually contributes. Maybe when things slow down this winter I will build a test fixture and apply weights to see what the real pull force is with a moving pin. Is the kinetic friction like 5% or 40% lower? I'll bet it's more like 5%. -Michael

I'm a packer and people frequently ask me to pack theirs when I can. I usually have enough time to pack 2 tandems and have 3-4 minutes before they land and bring me 2 more. If I want to do 2 tandems and a sport rig I have to bust my ass. I remember someone got me an iced cappuccino instead of a tip. That was far more valuable to me than a few extra bucks in my pocket. Do tippers get preferential treatment? Not really but it does make me feel appreciated. -Michael

Just tossing around ideas. I called lodi because their website sucks so bad. $5 for a hop & pop, hard to beat that but their weather in December isn't the best. Are there any other places around that have good weather in December and cheap hop & pops out of a turbine? I'd like to see if I could get 15+ loads a day all week long. -Michael

A few months ago I was reading an article about threads. I believe you will find that spectra is also more UV resistant. Besides expense the reason they don't use it is probably consistent with the comments above. -Michael

Whenever I do a repack I open it very carefully and look at how the last job was done. I've seen a few neat little tricks others have used and added them to my repertoire. If a rigger were so inclined I suppose a small piece of paper, similar to a fortune cookie could be placed in the tail that said "last packed by ...". If that comes out after repacking someone elses repack then it's a smoking gun. I think the best thing to do is just give the rigger a call and tell them that your rigger feels it was pencil packed. See what the response is but leave it at that. You might otherwise be shooting an innocent person. If it was pencil packed then they'll probably think twice about doing it again. -Michael

You know something was hard when everyone on the ground was wondering if hunting season had started... Part of a slider's operation is that it plays a tug of war against the spreading lines and the wind from your downward travel. For every inch down it travels I could see more than an inch of spread available to the canopy. Starting with the slider down a few inches may give the canopy enough of a head start that it wins the tug of war too fast and BANG. A few other points - rolling the cone nice and tight gives it more time before the nose starts to catch and inflate. I've found making a tight cone and camera packing the nose on my sabre2 170 gives me very nice smooth openings. I can always tell when someone else packs it. -Michael

A good point and probably an explanation as to why my test measurement did not work out to closer to the theoretical result. I think I remember having this discussion with you in the past about the thread and we both agreed that they have a history of working. As long as everything is within the specs it has a history of working as expected. Poynter details a test done (I think in Australia) where they sampled the strength of a number of male and female subjects and found that 22lbs was well within their ability. -Michael

I took a rig that was up for repack. There was about 1/2" of slack in the seal. I did a pull test as I normally would with my finger on the pin to see when it starts to move. I held the number of pounds that allowed the pin to move and it stopped when the sealing thread became taunt. I then applied more force until the thread broke and it popped. This happened very fast but the second number was the last place I saw indicated before the pilot chute was in the air. There will probably be a few repacks to do before people head off to winter boogies so when I get those I can repeat the tests as well. The results make sense to me. If you consider that it takes 16lbs of overcome the resistance of the pin/closing look and grommet. You apply 16.5 lbs then stopping the pin from moving should require 0.5lbs in the other direction. The sealing thread is therefore applying it's breaking strength worth of additional resistance. -Michael

Yeah, I got my rating after being in the sport for 6 months. It just took a lot of extra work and study to fill in facts that some would have through experience. Not a workaholic. Not a workaholic. Had 2 saves so far as well. PS I bought my beer for getting the rating but fortunately haven't been pied on my 100th. -Michael