timbre

Just to make sure I understand this right -- the canopy that finally opens was his *main* and the white ball of shit was the reserve....right? I'm guessing the reserve didn't have much air to open once he pushed it out of his main lines -- so when he landed, he was trailing a ball of partially-inflated reserve? If I understand the skyhook correctly, it wouldn't have affected this situation at all. Basically the risers-side of the skyhook obviously wouldn't have done anything (the main risers still attached) and so the reserve PC would have disconnected the hook and it would have worked just like a non-skyhook rig.

When and where was there a previous PAC tail strike? . You're kidding, right? In my two years in the sport I've know of several. For example: The American Boogie, 2009. Two stalls on successive jumpruns (same group, doing large scale formation exits), tailstrike on the second. I actually talked to the jumper who'd hit the tail (can't remember his name), he was OK but pretty shaken up. The PAC may be a great airplane for DZOs, but it really isn't a great airplane for jumpers. Sure, you make the best of what you can get, but lets not all lie and pretend like there's no issue there.

Funny you should ask, I did my first hour of flight training last week. So far I haven't felt like there was much crossover -- in fact I think my time under canopy has really warped my sense of glideslope: when I think we're 'level' we're actually climbing, and when we're in a normal descent it feels to me like an incredibly steep dive. I'm sure I'll figure it all out with time but that's my very initial reaction...

Forgive my ignorance here -- but why would adding a tower have such a negative impact on skydiving operations? What issues does a tower cause?

Clicky: http://www.zoomerang.com/Survey/WEB22AGLUXXMW9

If I understand it correctly, the theory is to ensure horizontal separation even at the expense of vertical separation. Belly groups will drift further downwind (as they're in the air longer) than FFs and so you put them out first so they can't drift horizontally into the next group's space. This is all assuming an upwind jumprun, of course. Vertical separation shouldn't ever be counted on -- differences in pull heights, snivel times, and malfunctions can make vertical separation moot.

Interesting, we (my wife and I took AFF together) had the opposite experience: we did 10 minutes in the tunnel before we started AFF and it made all the difference in the world. When we did our AFF jumps we'd already done the flying and so we were able to concentrate on our gear, exit procedures, altitude awareness, etc etc, without also trying to figure out our bodies at the same time. I know it made all the difference for me, as I had that whole paralyzing fear of heights thing that monopolized my attention on my first jump. (The only part of AFF1 I consciously remember was pulling my PC....which promptly turned into a PCIT! Fortunately my instructor was still there and he gave a tug on the extended bridle to help the pin out of my container. I of course had no idea what happened until we got to the ground but it gave me nightmares for a few days once they told me about it) I've sometimes felt like the tunnel should be mandatory before AFF -- I understand the cost and access issues prohibit it -- but think about how less risky AFF1 would be if you knew your student had been in the tunnel and had already found his stable arch at least once.

Yah, my bad... Silly was the wrong word. I meant that the answer was (in my mind) pretty straightforward. If I'd really thought it a silly question, I wouldn't have bothered to write an answer.

It's really not very difficult to land on your risers, so the question is a little silly -- just drop both toggles and land on your risers. (BASE jumpers apparently practice landing with one toggle and one riser....I wouldn't try it). Practice some rear riser flares sometime (at altitude) sometime so that you've done it and know where the stall point is. Also PLF. That said, the implied "can I cut away at 1000 feet" is an interesting one....A quick search brings up a previous thread on this already: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=126353;page=1;mh=-1;;sb=post_latest_reply;so=ASC

His point might be interesting but it is wrong. Terminal is determined by the ratio of weight/surface not by surface alone. A one foot lead ball falls faster than a one foot baloon even though they have the same surface.

It may or may not be fair but remember that you will likely be jumping at this DZ for a long time - don't burn your bridges too early. AFF isn't a class, it's a wedding.

Objects ACCELERATE at 32ft/ss in a vacuum - their terminal fall rate is dictated by their air resistance. As in, they will keep accelerating until their air resistance matches gravity. Terminal velocity is proportional to mass/surface area. (IE when Fgravity = F-air you stop accelerating....F-gravity = 32*Mass, F-air is roughly surface_area * Velocity^2, solve that and you get V = sqrt(mass/surface * 32), IE proportional to mass/surface) Surface area is proportional to the ^2 (side*side) Mass is proportional to volume ie ^3 (side*side*side) So imagine two people, represented by cubes. One weighs "1" and the other weighs "8" (just to make the arithmetic easier) - A cube with mass "1" has sides of 1, and a surface area of 1....so the mass/surface = 1 - A cube with mass "8" has sides of 2, so mass/surface = 4, ie it will fall much faster than the other (twice as fast?) Since the volume increases mathematically faster than the surface (^3 vs ^2) you can generalize that heavier people have less surface area / weight, and therefore they fall faster. Note that the whole surface area / volume scaling issue is why "small" things are so different than "big" things -- it's why large animals don't lose heat as quickly - they have less surface for their bulk - and why it's more efficient for puppies to "pile" (because they have less surface to lose heat vs their mass)...it's why very small animals are so strong for their size (ants routinely pick up many many times more than their own weight), etc etc etc.

No kidding on this advice: not one but two separate PAC stall incidents today at the American Boogie in Davis -- two different planes and two different pilots, both while launching large formations...floaters ejected in both cases, one with a relatively minor (at least as minor as it gets) tailstrike. Scary stuff.

I flew base on a 10-way hybrid (6 belly, 4 hanging) yesterday for my 100th. It was a *ton* of fun...do it: http://curple.com/skydiving/Tims_100th_Jump.mov