Static Line Automatic Activation Device (SLAAD) in General Skydiving Discussions September 1, 2017 I have seen the presentation at the PIA Symposium. My takeaway is thus: The military static line parachutist is in a limited time situation. And, the lower the exit, the shorter the time. (Stating the obvious) Because of this limited time, and especially at night, the soldier may be unable to determine the need to manually pull the reserve ripcord quickly enough. Not enough time to look at the situation and make that decision to pull his reserve handle. As mentioned, jumps at night make the visual recognition even harder, or even impossible. (I guess what the paratrooper would sense is that there was no opening shock within the usual time he would have felt it, based upon previous jumps?) And, by then it may be too late - time wise. Probably about 4 seconds? It is my understanding that this device senses the absence of an opening ( the absence of the deceleration) within a predetermined time and cuts the reserve loop(s). And it is designed to operate only after the paratrooper exits the plane, and it knows when the exit occurred. Possible example: The first second he falls 32 feet. The second second 64, Third 128 and the fourth 256, Add these together and he has fallen 480 feet. Four seconds. Assuming a night jump, with no visual ability to see what is wrong, the paratrooper realizes something is amiss and then makes the decision to deploy by pulling his reserve handle. Time is passing. That makes him too low and he dies. He is simply too low to react in time. This device goes quicker and it's brain is more accurate and reliable than a human. Even a well trained one. I don't know that 4 seconds is the test for this device. I just made that up based upon my static line jumps, mostly from a C -130. Since we jumped (or were supposed to) at 1250 feet, no opening in 5 seconds was the mark for for pulling the reserve handle. In SF all of our jumps were at night on T-10's. Once from a C-123 at 750 at night. Modern paratroopers probably have less time as their exit altitude is lower. This device probably uses a different elapsed time. It gives the paratrooper a chance to live. This is my understanding of it. I know the inventor can be more accurate and explanatory of what it does and how it does it. As I said, this is my takeaway. I hope I got it right. Only the inventor can actually and accurately explain it.