there was a guy who cutaway the skyhook cutaway rig at about 150 ft or so. i don't think i would try that, but i can tell you that it gets your reserve out quick. i was recently under a spinning mal, and before my cutaway hand was fully extended i was under a perfectly square reserve.
Should have attending Bill Booth's lecture at Skydive Chicago this weekend. He gave the figure of 100'. He showed two base jumpers doing it, which they estimated between 90-100'. One actually had time to unstow his toggles, the other not so much but he had an inflated canopy over his head! He also mentioned that a malfunctioning main and a fully inflated main will take the same amount of time and altitude to get a good reserve over your head, which was quite a shock to me!
Don't be a dumb ass... Remember what your AFF JM's told you.. Don't cutaway below 1000'. Just fire the reserve. Go back to basics man, they will save your ass one day. Besides, other than a canopy colision why should you be cutting away that low? I had a friend die last summer from cutting away from line twists low. He impacted the earth at about the same time his reserve freebag did. Just because some new safety device comes out on the market, doesn't mean we can all go and lower our decision and cut away altitudes. Don't get me wrong, I really am impressed with the skyhook, but use it as a last resort.
Didn't mean to imply that you were, but some of us who have been around for awhile, have just seen to much shit, and if we can prevent another Femur, Spinal, Compound, ECT ECT ECT we are going to do our best to do that.
It doesn't just hurt you, when you break yourself, it hurts the whole sport. It makes it hard to make close freinds when then people you associate with can get hurt badly and possibly killed. It doesn't help when those people dont listen to other people telling them that they are fucking up by the numbers.
So the moral of the story is to not do stupid things.
The idea of either cutting away below 1000' or firing the reserve into a malfunctioning main below 1000' scares the crap out of me and I hope I never need to do either one. But is firing the reserve without cutting away truly safer (say above 500') than cutting away with a skyhook-equipped rig? Sure the device is new and not well proven in the real world, but if it works properly, aren't ya better off cutting away? You lose the entaglement risk, and your reserve will open faster. There's definitely the possibility the skyhook will fail. But is that probability higher than the probability of an entanglement or slow reserve deployment?
I understand that the purpose of the skyhook is not to lower our hard deck, but rather to add to our safety margin. But under 1000', all bets are off. It's a question of what option has the highest probability of keeping me alive. I still don't know what that is though.
Personally I dont see the problem in asking what is the lowest you could theoretically cut away with a skyhook. Knowing that it could still save your ass as low as 100' gives me more confidence in my equipment, it doesnt mean for a second that I would delay a cutaway because I know it will open faster.
I like to know the limits and tolerances of all my gear and dont feel that inquiring about them deserves flippant answers like 1001' or Dont be a dumb ass
This includes cars, motorcycles, skydiving equipment, scuba gear, or whatever. If I pay extra $$ for extra functionality, I have every right to know what that extra expense purchased.
If I'm cutting away, I'm trusting my reserve system with my life, no matter what equipment I have. The skyhook is still fairly new. Is that the only reason NOT to trust that it will work as reliably as the rest of my reserve system?
Yeah, it's an RSL. It can fail for a lot of different reasons. I was taught not to trust it, or my Cypres, and always pull my reserve. But if I was LOW and couldn't land my main, I'd either take the risk that my reserve will entangle with my main or not fully inflate, or that my RSL will fail. Assuming my reserve really opens in 300 feet or less, I'd still have a shot after cutting away to get it out. Wouldn't wanna try that, but is it truly less safe than just firing the reserve without cutting away? Lets assume it's a nasty spinning malfunction caused by a suddenly damaged canopy.
The first thing the Skyhook does is get your reserve to line stretch in about 1/2 a second. This is considerably faster than any pilot chute can do it. How many feet you will fall between cutaway and life saving reserve depends on how fast you were descending before the cutaway, and how fast your particular reserve opens. With most sport reserves, from a fully open main, far less than 100 feet is required.
The other (probably more important) thing the Skyhook does is put your reserve right where your main just was, or exactly in line the with the vertical axis of your body. This yields beautifully straight and even line groups at line stretch. A pilot chute, however, always deploys your reserve with the relative wind. This becomes a very important difference when you breakaway from a spinning malfunction. Without the Skyhook, you must "get stable" and align your body into the relative wind before it is safe to deploy your reserve, because if you deploy with the relative wind at an angle to your body, you risk entanglement with the deploying reserve, and you will have "unequal" reserve line lengths at line stretch, risking a spinning reserve opening with line twists. So, depending on the severity of your "spinner", just getting set up for a stable reserve deployment make take many hundreds of feet, and that's before you even pull the reserve ripcord. This means that you will have to deploy your reserve at, or near, terminal velocity (ouch). Add in a little pilot chute hesitation, and all this could eat up the better part of 1,000 feet. (Remember, the faster you are falling, the more altitude your reserve will take to open.) That's why most people recommend cutting away above a grand.
With the Skyhook however, reserve deployment starts immediately, and at line stretch, your reserve will be aligned perfectly with your body, with equal line lengths, even if you started with a spinning malfunction. And no pilot chute hesitation is possible. The difference here could be seven of eight hundred feet...and, you will be at the lowest possible airspeed. Fastest possible opening...lowest possible airspeed...highest possible altitude to avoid obstacles on the ground. What's not to like?