I'm just really trying to understand how quicker reaction by 1-2 sec could make it any worst
It can't. Who ever came up with that idea in the first place is wrong.
Any amount of brake input will create drag, which will eat some of the energy built up in the dive, energy which the jumpers body won't be using to leave a divot in the LZ.
Additionally, by impacting at a more shallow angle, more of the remaining energy will go into skipping the jumper across the ground, as opposed to pile driving the jumper straight down (as demonstrated in the video).
To anyone who had any doubt - flare your canopy as much as possible before you hit the ground in any unusual circumstance. As much as you can. Really.
Only 1-2 seconds earlier on this particular jump would have generated a huge amount of forward speed at a very low altitude, resulting in a feet/legs, head, feet legs landing, IMHO.
A huge amount of forward speed at a low altitude is otherwise known as a swoop! They don't always end in tumbles. I'm sorry, but you're still not making sense to me. If I had to make the choice, I'd take digging out late over digging out very late any day of the week.
In reply to:
10 seconds earlier would have been a run out with a PLF at the end probably.
I agree with the flare hard when all else fails. However we are speaking of this incident only. 1-2 seconds earlier he stabs the brakes it would have created drag, thus swinging his body forward at an increasing speed. My point is that-on this jump, 1-2 seconds earlier would have put him into a high speed angle right into a flip through his lines. Unfortunately I have witnessed it many times. The way he impacted he should also have been more severly injured. Sometimes we can't just beat dumb luck. Maybe he would have pounded in with no injuries if he stabbed them a second or two sooner, but I really doubt it. The moral of the story, don't hold front risers down until 20ft.
He was on his fronts through a left hand turn until you see him release from what I was told.
From the video he drops fronts and starts flaring at about 2.5 seconds, and impacts (at most) a second later. You will have to work very, very hard to convince me that 3 seconds worth of dig is worse than <1 second of dig.
I also doubt that 10 seconds earlier was the first point at which he could have usefully flared. If it was just a 90 he was doing I'd be surprised if he'd even started the turn at that point.
I agree with you about flaring earlier and having 3 seconds of flare instead of nearly none. I also agree that 10 seconds earlier wasn't the earliest he could have usefully flared. My point was that for his ability level he should have released his fronts 10 seconds earlier. The other point is that stabbing his brakes only 1-2 seconds sooner would "probably" have put him into that high speed angled impact that I have witnessed over and over. I'm amazed he made it through with "only" a broken back.
1-2 seconds earlier he stabs the brakes it would have created drag, thus swinging his body forward at an increasing speed.
Yes, he would swing forward at a higher speed, but that higher speed is only relative to the speed at which he was already swinging forward under his canopy. The increase in speed would be only along the arc he is traveling under his canopy, and would not represent a higher speed of the entire canopy/pilot system in relation to the ground.
In truth, that higher speed along that arc would only serve to pitch the nose of the canopy up that much faster (aka shortening up the recovery arc). The more your canopy can pitch up before impact, the more you shift your energy from the vertical to the horizontal component. More skipping/sliding, less impacting and crushing.
I think the last thing you can control in this type of situation is your exact body position at impact. There are too many variables, and things happen too fast. The one thing you can alwys count on is the reflex action to stab those toggles (if you have that reflex, something you need to develop before trying to go fast with a parachute) and the overall loss of energy that will provide.
Best case scenario would be to do both, apply full toggle input, and manage your body position at impact.
Isn't this the cause of the accident. Its not really about downsizing or jump numbers, its about changing from a canopy with a short recovery arc to one with a long recovery arc. If I hold the risers on my safire II to 20' before releasing them I get a nice swoop and don't need any toggle input to level out.
What would the result be of going for the rears instead of the toggles on a canopy like that when he realized he was in trouble?
Crashing the ground with even high speed and or high speed stall....
I never really gave it much number crunching but my canopy feels like it recovery quicker on rears than brakes. Not like a sabre2 has a long recovery arc anyway. What canopy would you need to have the strength to go directly from a dive to a stall on rears?
What would the result be of going for the rears instead of the toggles on a canopy like that when he realized he was in trouble?
Crashing the ground with even high speed and or high speed stall....
I never really gave it much number crunching but my canopy feels like it recovery quicker on rears than brakes. Not like a sabre2 has a long recovery arc anyway. What canopy would you need to have the strength to go directly from a dive to a stall on rears?
-Michael
Strength? Not much strength needed to get a high-speed rearriser stall
Here's an example of a guy trying to bail out on rears, now imagine if that were grass instead of water: 3:20 into this video. At 3:46 there's another guy bailing waaaay to low
What would the result be of going for the rears instead of the toggles on a canopy like that when he realized he was in trouble?
Crashing the ground with even high speed and or high speed stall....
I never really gave it much number crunching but my canopy feels like it recovery quicker on rears than brakes. Not like a sabre2 has a long recovery arc anyway. What canopy would you need to have the strength to go directly from a dive to a stall on rears?
-Michael
What is your range on brakes? About your full reach? You got about 20-25 cm with rears before you stall. Rear risers are not tools for saving your arse. You might have some early signs before you stall with breaks, there are less signs with rears.
I never really gave it much number crunching but my canopy feels like it recovery quicker on rears than brakes.
Nope, and you're fooling yourself if you think it does. Your toggles have a greater range, not just in motion, but in terms of the stall speed compared to rear risers. You throw out more drag, slow down more, and enact more change to your canopy with the toggles.
The decreased range of the rears, combined with the stall characteristics make them a very bad choice for an emergency situaiton. It is much easier to over control, and induce a high speed stall with your rears.
Additionally, the toggles are already in your hands, where you have to reach for the rears. You eat up valuable recovery time just making the reach, and god help you if you miss one or both of them.
billvon (D 16479)
Moderator
Feb 2, 2009, 2:06 PM
Post #65 of 69
(602 views)
Shortcut
> 1-2 seconds earlier he stabs the brakes it would have created drag, thus >swinging his body forward at an increasing speed.
Correct. When done close to the ground, that maneuver is called a flare and is used to reduce vertical speed. It is essential to start the flare as soon as possible during a botched landing attempt to get the most possible time for the canopy to scrub off its vertical speed, thus reducing impact forces. If the canopy then recovers to a normal glide angle/speed at a significant altitude, the toggles can be let back up to some degree to let the canopy fly before the final flare.
Bottom line - under NO CONDITIONS should a jumper who has botched a low turn hesitate to add brakes to begin the recovery. Ideally, he should flare and level the wing at the same time; the wing does its best job when it is above the jumper instead of off to one side.
