PLF?

[DSE 5]

Referencing the "How not to land" thread, it makes me wonder a couple things...
1. how many people have been taught the real techniques and have attempted a PLF from a running jump off a platform.

2. Why would one PLF under *those* particular circumstances when the canopy has a fair amount of horizontal airspeed? If you're downwinding, or even just under a fast canopy from a poorly executed low turn, you could be moving say...20mph, which is 29 feet per second. A PLF isn't going to do much for you, as through the minimum of 6-7 revolutions your body is going to experience, chances are pretty good that even if you tuck into a ball (which is not part of PLF), you're going to have an extremity stick out and break, if not more than one.

I've yet to hear any one advocate a sideslide, coming in on one thigh/calf/buttock so as to avoid both butt cheeks being on the ground, which will prevent compression of the spine and prevent the tail from breaking.

Another way to look at this is to drop a mannequin from a truck moving 20mph, allowing the mannequin to strike the ground feet-first. The mannequin will go ass over teakettle.

Now do the exact same thing, but drop the mannequin so that the heel and calf hit first, butt last. The mannequin *might* go ass over teakettle (ours didn't) but it doesn't have the violent flipping.
If you don't have a mannequin, do the same thing with a 55 gallon barrel. Rim first, and then side first. We've done that, just for kicks.

Am I up in the night with the thought process that a sideslide is much more current, practical, and safe than attempting to buck n' a quarter the landing, trying to roll to one side with the "impact + forward inertia not being considered in the process?

[llkenziell 0]

Never thought about it since I've never really grasped the whole PLF thing - it's always just been a save-your-ass-from-breaking-something idea, but the sideslide does sound more practical. I'll let you know next time.

"Living like fallen angels who lost their halos" - Unknown Prophets

-Love Life-

[NWFlyer 2]

Good discussion on the topic of PLFs that was started a while ago but resurrected recently ...

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2276018

And some thoughts on alternatives for downwinders:

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2430792

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[councilman24 37]

Sliding is fine, if there aren't any gopher holes or anything else to bust you up.

Going ass over tea kettle is fine, if because of the PLF your not sticking out a leg or an arm to snap.

I shattered the distal (ankle) end of the tibia badly and for awhile couldn't take a running step. I became very good at butt slide landings if I couldn't shut down the forward speed. I'd favor one cheek, tuck the other leg and pop right up just like sliding into second. An in the lawn that's not bad. In fact I got so used to landing on my butt I continued to flare low after I starting landing on my feet most of the time.

But often, if I screw up or someone else causes me a problem, dropping into a "PLF" even with forward speed keeps my limbs where they belong and allows me to go ass over tea kettle with out busting something up. If your GOOD at PLF's your NOT going to stick out an extremity.

Drop that manekin from 10 to 15 feet and see if you need a PLF. When you still have vertical velocity it's even more important.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[iamsam 0]

Quote

Never thought about it since I've never really grasped the whole PLF thing

You really should you know, and then you should practice them.

Might save you

but what do I know

[DSE 5]

I'd read both those threads, and a few others as well, but still don't grasp why the PLF is the "first go-to" for a lot of people. I know you jumped rounds, but with a round, you typically have more vertical speed than horizontal speed, or at least that's been my very limited observation. On the other hand, with a smaller square, you've almost always got significantly more horizontal motion.
My AFF instructor, old-school guy with 10K jumps, 40 years in the biz, drilled PLF into our brains. He still jumps a PC once in a while for fun, and at 60, can manage a gorgeous PLF. He was also the first experienced skydiver who answered "Because that's the way we've always done it, but it doesn't mean it's right," and then we had a lengthy discussion wherein he pulled math into the discussion and concurred with me that a side slide would be as a general rule, probably better. And believe me, we've got a *lot* of chuck holes and vole holes. One of our jumpmasters was surfing and caught one a couple weeks ago, and fractured his ankle. At the local dropzone, there isn't a blade of green grass, either. We have some buffalo grass and that's the extent of grass. It hurts when you PLF into it, but a slide works very well.
Although a proper PLF shouldn't allow your spine to be compressed, it can (and has happened hundreds of times), and does. A side slide avoids this very nicely. The spine can flex, but not compress.
For a while, I practiced PLFs under my PD 9cell, and then practiced side-slides. While a "proper" PLF (in my view anyway) includes pulling arms in, in practicality, it's not so easy because you're still trying to fly the canopy until the very end. On more than a few side slides, I was able to flare deeply enough to pop me back up to my feet.
So FWIW, after my 15 jumps of each landing practice (and a thrashed pair of camo pants in the process) I've come to the conclusion that the side slide, at least in the condition under which I practiced both PLF and sideslide, is preferable.
I guess at the end of the discussion, I'm still trying to figure out "why?" so many folks scream "PLF" vs talking about both as an alternative.
Again, I don't know that I'm right, but haven't heard any compelling evidence or discussion that I'm wrong, either.

[NWFlyer 2]

You must have me mixed up with someone else... I've never jumped a round and I'd only think about if it were over a large body of water with a rescue vessel close at hand! (Yes, old-schoolers, I'm a wuss).

I'm going to guess the reason that PLF gets pushed is that it is the method with the most "tried and true" experience, in skydiving and in other sports. I know one of the first things I learned about how to fall when I started snowboarding was to tuck up my arms and try to do something like a PLF ... to resist that natural urge to stick out an arm to break my fall (obviously, with a snowboard strapped on it's much harder to get your legs out of the way).

It's not to say that other methods might not be as good in some situations, but that the PLF has proven out to be one that works the best in most situations.

That's my theory, anyway, FWIW.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[DSE 5]

oops, my bad...I've got you confused with someone else. I "aged" you a few years, I guess.
Your explanation is as good as mine, and I guess I find it hard to accept status quo based on my own limited experience. 30 skydives divided evenly between the two options outside of running it out or sticking it if the winds are up; I'll take the slide any/every time.

[labrys 0]

I've accepted the PLF with pretty much the same idea that I've accepted the idea that practicing the same EPs over and over again is a good thing.

There's a chance that rote procedure will result in failure, but there's a bigger chance that it will result in success.

If I'm unsure how I should deal with an unexpected landing situation I'll PLF.

Owned by Remi #?

[DougH 270]

I have PLF more than once at a high rate of horizontal speed. It works great. I think there is more chances for a slide to go wrong, or to be done incorrectly.

"The restraining order says you're only allowed to touch me in freefall"
=P

[talon2 0]

PLF s certainly have earned their time in parachuting history.Consider the following.........
WW2 jumps into hostile, unprepared territory..at night..with shit hanging off you.....low to very low exit heights....800ft or lower..windspeeds in a lot of cases faster than we would jump our pocket rockets on a good day .......Gymnasts and martial artists all use a vertical conversion to horizontal roll to get up and do it again.......Slide works ONLY if you are inside your " comfort zone" ie landing on the DZ.....IMHO.......Slide if you have the knowledge/experience and know where you are landing(Case in point ,a friend who habitually slid until he encountered an unknown , unseen A/C tiedown that separated his Patella and a significant section of his scrotum and arsehole.............As an instructor I will continue to teach PLFs to my students because I believe the military got it right 1st time and it has kept them( and me ) still playing from roundies through to squares over a good few years

[BIGUN 1,402]

Mannequins and 55 gallon drums can't use their muscles to control the fall and protect the bones.

I teach the real techniques by running off a platform in every class and I've also demonstrated it from the second floor of the DZ hangar. As one of the strongest proponents of teaching PLF's properly - have also had to execute one in front of the entire WFFC going 40 mph downwind. Five perfectly executed PLFs in a row, stood up, dusted myself off and walked to the packing area.

Perhaps you'd be better off to quit trying to find the shortcuts and spend some time with an old round jumper or former Airborne to learn to do PLF's the right way.

Or come see me... I'll give you the real PLF class - no charge.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[DSE 5]

Quote

Mannequins and 55 gallon drums can't use their muscles to control the fall and protect the bones.

I teach the real techniques by running off a platform in every class and I've also demonstrated it from the second floor of the DZ hangar. As one of the strongest proponents of teaching PLF's properly - have also had to execute one in front of the entire WFFC going 40 mph downwind. Five perfectly executed PLFs in a row, stood up, dusted myself off and walked to the packing area.

Perhaps you'd be better off to quit trying to find the shortcuts and spend some time with an old round jumper or former Airborne to learn to do PLF's the right way.

Or come see me... I'll give you the real PLF class - no charge.

I guess you missed the part in my OP where I mentioned that our DZO *is* a rounds jumper, and still occasionally jumps a PC. With 40 years/10K jumps, he's not the oldest nor the highest jump #'s, but he's quite adamant about PLF. He has a few thousand jumps under rounds.
We don't jump off a second story of the hangar, but do have a platform.
As part of my search for the "right" answer (and I don't believe there is a "right" answer) I did a number of jumps alternating between the two methods. I don't believe that continually trying to find answers beyond the status quo is called a "shortcut" but rather a means of trying to understand why/if the status quo is valid.
I can continue to fly my canopy in a sideslide, but cannot do so in a proper PLF.

[edit] Talon, thanks for the answer, it makes a lot of sense when explained from your perspective.

[steve1 5]

I think one of the big problems with a PLF is that most people don't get enough practice, and never do learn how to do one properly. A side PLF is more or less a roll using your side. Anyone who has been through Army Jump School will spend weeks practicing this before making their first jump. And then there is PLF practice usually before every other static line jump after jump school.


Most skydiving first jump courses spend little time practicing PLF's, so is it any wonder many people just don't "get" how a PLF can save your bacon.

I made a low turn a couple years back. I slammed into the ground with tremendous force. I later ended up in shock, in the emergency room, from all the pain. Nothing was broken. I think what saved me was because I landed with my feet and knees together and twisted to my side on impact. If I hadn't attempted a good PLF I think I would have been carried off that field. As it was I was able to hobble to a vehicle under my own power.

So, that was one of the times a PLF has saved me from serious harm. There were several other times back in the 70's when I know it kept me from serious injury.

I now do a lot of slide in landings on windless days. I think that too is a valuable technique. So far I haven't hit any gopher holes. For some landings I agree that sliding in works better than PLFing....Steve1

[MarkM 0]

A side slide won't save you when your canopy folds up at 30 feet and you go slaming into the ground.

The solution PLFs try to solve isn't horizontal speed. Horizontal speed will bleed itself off(while snapping/bruising your extremeties in the worse case) as you tumble across the ground. It's the 30mph verticle dump into the ground that's the real worry, because all that energy goes straight into your body which will crush internal organs.

[DougH 270]

I think a roll bleeds of horizontal speed rather well.

A slide only works well if you have low traction. Some one already mentioned it (but I think it really illustrated the point): a gopher hole with really ruin your day because you catch on the ground...

A skii works awesome on slick snow slope... but a tire kicks it ass in rough terrain.

"The restraining order says you're only allowed to touch me in freefall"
=P

[riggerrob 643]

Both techniques start with the same body position: legs clamped together, knees slightly bent and arms tucked.
Direction is decided by the direction.
Twenty-five years ago, the Canadian Army Airborne Center POUNDED PLFs into me ... and I still do the occassional PLF. PLFs have allowed me to limp off of many DZs. The most amusing part is watching the shocked look on the face of the radio instructor ... who was expecting to have to phone for an ambulance!!!
Hee!
Hee!

I still do the occasional side slide when a tandem student does something stupid like refuse to lift their legs or - even worse - digs their heels in on landing. When I slide, I try to swing sideways so the large muscles in my thigh absorb the worst shock, protecting bones.

Bottom line: PLFs work best when you are landing vertically or backwards, while slides work better when most of your velocity is forward.
Since both techniques start with the same body position, it should be practiced hundreds of times to burn it into long term, muscle memory.

[BIGUN 1,402]

I did not see you OP...sorry. Really can't argue with a lot you've said. Challenging the status quo is never a bad thing. If sidesliding winds up being the thing that works for you - great. It's your skydive. I too; am just a bit "adament" about PLFs.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[fastphil 0]

I think it's the vertical speed that will seperate the sliders from the PLFers. And if you are in a high verticle speed situation you'll hope you have horizontal speed also, coming straight in has to be the hardest way to land...

[Amazon 7]

The better the PLF you can do.. the leff PFL's you will do