Crossover and Crossunder

Richard Henry wrote:
"yunlong" wrote in message
oups.com...

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch back,
but I don't think that they do the "falling leaf." "Falling
leaf," which is named after a snowboarding maneuver, by
definition, is slipping back and forth down a steep hill
without [S]-turning--changing the edges.

I did not know that. In fact, I heard of the "falling leaf"
maneuver (and saw ski patrollers practicing it) long before I
ever saw a snowboard.

I believe there is an aerobatic maneuver called "falling
leaf", also.

Yup, it is also done by slipping, not turning.


IS

foot2foot wrote:

"VtSkier" wrote in message


By and large I agree with this stuff. I'll even let you
off the hook when you call centrifugal force a "street
term". It isn't and it's not properly the same as inertia.



Ah, I think Joe physics will agree with me.
There is no such thing as centrifugal force. There is
only inertia.



But I understand where you are coming from.

Then I like to share an observation I've made on a number
of occasions.

Some people think they can ski without instruction -OR-
they maybe think they should get "comfortable" with their
equipment before they take a lesson, or, or...

I'm often at the top at the end of the day. My job is to
try to get the skiers to vacate before patrol does TCP
(trail closing procedure). It happens that occasionally
we get a never-ever who takes the last cabin and expects
to ski a green trail (which has become very blue with
skier traffic by the end of the day) to the bottom and
enjoy the setting sun (setting sun = flat light). Someone
told him/her that by weighting the outside ski, or what
will become the outside ski in a turn, the will turn
opposite to that ski and be able to control speed down
the mountain.

This person will be bent nearly double at the waist, his/
her legs will be as straight as possible and a fairly
decent wedge is being held in this position.



And even so, they're probably not actually forward on
the skis.



Now, to get your weight on your outside ski from that
position, don't you have to move your body over that
ski?



No. From a good, solid neutral equal weight two footed
wedge position, they need to leave everything where it is,
and simply take the weight *off* the inside ski through a
lift of the tail, and then a placement of that tail next to the
outside ski tail.



Well, that's what is tried, and much of the time,
they can actually make a turn from that position. CoM
is over, and sometimes beyond over the outside ski so
that they are in fact making a turn with their weight
OUTSIDE of the outside ski.



No. Impossible, they would fall to the outside. An illusion
at best.



Well some of the time. What
usually happens is that since they are actually riding
the outside edge of the outside ski, and in a very
slow turn on very smooth terrain, it sort of works.



The pinky edge of the outside ski? They would fall to
the outside. The ski would catch. They'd go over the
handlebars.



But did I mention that the trail is not smooth? So what
usually happens is that a few turns can be made this way
and then some irregularity catches that outside edge
and a tumble results.



Not a suprise.




This completely destroys any confidence they had to begin with (they had
to have
some or they wouldn't have ridden the gondola at 4:00
in the afternoon. It's probably 4:30 or 4:45 by the
time I get to them. They are so crossed up, discouraged
and exhausted that I just call for a ride down for them.



They've never been shown four simple steps to a rough
parallel turn that will work on even advanced terrain.

It takes an hour or two for most people to learn.

Traverse to get moving, initiate the turn with a wedge,
(the same thing you do in the wedge changeups drill)
transfer the weight to the outside ski, then match the
skis with a lifting of the tail and placing it next to the
outside ski tail.

The skier must hold home position the whole time,
especially hands forward.



I used to be able to give them a BYD (brighten your day)
card for a lesson the next day.



At the present state of things, it wouldn't do a whole lot of
good for a fairly long period of time.

Show them home position, and how to make the turn
described above.

But management has


tightened up on such things. I would think it would be
worth the price of a lesson to try and keep this skier.
He/she will never be back after that experience unless
they have someone prodding them.



True enough. They needed a turn that they could learn
and use more quickly.



So, I've seen someone on skis (I won't say a skier) make
turns without crossover/under and without having their
weight/CoM to the inside of their skis. It can be done,
I don't advocate it and it ain't pretty.



Nah, You've seen someone fall unless they were crossed
over. There is no getting around inertia. You either oppose it,
or it takes you where it wants to.






Ahhhh, but there is certripital force which often makes us think we feel
the phantom force acting centrifugally. Or something like that that I
learned in Physics a long time ago. I think I could still explain it on
a chalkboard with vector lines and such.

Dave M.

yunlong wrote:
Norm wrote:

yunlong wrote:

No thanks.

Why? It is easier (less tiring) on long traverse, and
the weight on the uphill ski is already facilitating the
"early weight transfer," thus enables the skier to turn
downhill whenever he/she wants it, and slipping is safer
technique than skidding.

The "slant slipping," is faster, more stable, and more
maneuverable, so it's a much versatile technique than
simple "side slipping" or skidding.

Sounds like "falling leaf" to me. Watch a patroller with
a sled sometime. Also works great without a sled.

"Falling leaf" is a maneuver that a skier zigzags back and
forth down a steep hill without "turning," i.e. the skier
must slip backward sometimes, and to slip backward with a
sled is not just impractical but also a dangerous move,
are you sure that's how patrollers handle the run with a
sled?

You bet, see Norm's post on the same subject.

Not sure where is Norm's post on the same subject;

Immediately following yours, Yunlong, look up ^ its still
there on my server.

Not sure where your server is, neither.

Point being that if it's on Norm's server, it probably is
on your server.

nevertheless,
though they may do the zigzagging/switch back, but I don't
think that they do the "falling leaf." "Falling leaf," which
is named after a snowboarding maneuver,

Falling leaf was around and named many years before the first
snowboard appeared..

The name was around;

It was named after, um, a falling leaf, which is the action it
mimics.

nevertheless, it was snowboarders who adopted the name for that
particular maneuver, as a part of normal snowboarding.

Not being a snowboarder or a part of that culture, I have
no knowledge of the snowboarding model for falling leaf.
You best read my description of a SKIING falling leaf in
a post that came in a bit later than Norm's here.

I've know "falling leaf" since the late 1950's.

by definition, is slipping back and forth down
a steep hill without [S]-turning--changing the edges.

Slipping backward with a sled in a patroller's back is not
just impractical (the patroller has to turn facing the sled
while skis/slips backward),

Erm, No s/he has no reason to have to turn facing the sled.
Upper body faces downhill at all times, just like skiing
normally.


No way, ski on just one side of ski (edge) is not "ski normally";
unless s/he switches the edges, s/he cannot traverse the hill with the
upper body facing downhill; and if s/he switches the edges, s/he is no
longer doing "falling leaf."

Switching edges, what the hell are you talking about. Read the
description.

I don't know the rules for
flatboarding, YMMV.
Have you ever actually watched a toboggan being run? Falling
leaf is not only quite practical, in some terrain and snow
conditions it is essential for safe transport.

Yup, but it's just not practical for a "long" traverse.

There is NO traverse, read the description!

but dangerous (if the patroller's knees get
locked by an unfortunate step, say, they get bounced by a
piece of ice chunk, he is done for it; with 200~300 lbs.
average weight of the sled

A Cascade toboggan weighs about 80lbs plus rescue gear about
20lbs or less. A Traverse Rescue is about 20 lbs lighter.

Yup, the "plus" part was a mistake for "and," it was meant the whole
thing, toboggan and the person transported, and the "200~300 lbs." is
to take it on the "light" side, nevertheless, it is still a formidable
weight for a patroller to deal with when s/he is slipping backward.

Misteak noted. But note in my post what the real weight can be.
I noted upwards of 500 pounds for a sled with two people (also
common for shoulder dislocations) with one patroller driving and
no tail rope.

Talking about reckless, slipping backward with toboggan/sled in a
patroller's back is just not a safe maneuver.

Who is slipping backward. The skier/patroller is slipping/skidding
straight down the fall line with some motion, oh hell, read the
description.

Then go watch some patrol training sometime. I'm sure they have
that at the mountains you ski.

yunlong wrote:
Richard Henry wrote:

"yunlong" wrote in message
groups.com...

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch back,
but I don't think that they do the "falling leaf." "Falling
leaf," which is named after a snowboarding maneuver, by
definition, is slipping back and forth down a steep hill
without [S]-turning--changing the edges.

I did not know that. In fact, I heard of the "falling leaf"
maneuver (and saw ski patrollers practicing it) long before I
ever saw a snowboard.

I believe there is an aerobatic maneuver called "falling
leaf", also.


Yup, it is also done by slipping, not turning.

Excuse me, you're not reading very well today are you.

A one liner doesn't do it in this case since "aerobatic"
implies that your skis/board are off the snow, so how can
you be slipping and not turning?

VtSkier wrote:
yunlong wrote:
VtSkier wrote:
yunlong wrote:
VtSkier wrote:
yunlong wrote:
VtSkier wrote:

(snip)

Have you done that yourself?

It is a standard practice of flatboarding; we call it
"slant slipping."

No thanks.

Why? It is easier (less tiring) on long traverse, and the
weight on the uphill ski is already facilitating the
"early weight transfer," thus enables the skier to turn
downhill whenever he/she wants it, and slipping is safer
technique than skidding.

The "slant slipping," is faster, more stable, and more
maneuverable, so it's a much versatile technique than
simple "side slipping" or skidding.

Sounds like "falling leaf" to me. Watch a patroller with
a sled sometime. Also works great without a sled.

"Falling leaf" is a maneuver that a skier zigzags back and
forth down a steep hill without "turning," i.e. the skier
must slip backward sometimes, and to slip backward with a
sled is not just impractical but also a dangerous move, are
you sure that's how patrollers handle the run with a sled?

You bet, see Norm's post on the same subject.

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch back,
but I don't think that they do the "falling leaf." "Falling
leaf," which is named after a snowboarding maneuver, by
definition, is slipping back and forth down a steep hill
without [S]-turning--changing the edges.

Tell you what sonny,

Don't "sonny" me, unless you want to get whiplash, grand pop.

falling leaf has been done by skiers
and SKI patrollers since long before there were snowboards.
Further it was NAMED long before there were snowboards.

Falling leaf was a flying maneuver that existed before downhill skiing
was even invented. Don't chase that name, it is pedantic.


Slipping backward with a sled in a patroller's back is not
just impractical (the patroller has to turn facing the sled
while skis/slips backward),

Huh? the patroller has to turn facing the sled while he
skis/slips backward? Baloney.

Nonsense.

You obviously haven't seen it done.

Maybe you haven't seen it done closely?

A good traverse
position is essential. Skis across the fall line,

How [the skis are slanted across the fall line, i.e. is the tip higher
than the tail?]

body turned
toward the fall line, both hands securely holding onto the
sled's handle bars as if they were ski poles with the poles
both pointing up the hill (oh sorry, you don't use poles).

Both handle bars pointing up the hill?!!! How's the sled been
positioned?

Side slip down the hill with a bit of weight on the tails so
that the tips "slip",

No way, where a ski goes depends on the placement of the body weight,
when ski forward, weight on the tails, it (the skiing) skids, and
weight on the tips, it slips.

move weight forward so that tails "skid". Repeat.

Or maybe you were talking about ski/slip backward? But the "forward"
reference screws it up.

One of the advantages of this is that snow
tends not build up downhill to your skis forming a barrier.
This is the preferred method on hills too steep to snowplow.
Except for the most severe slope and conditions, our guys
don't even tail rope.

You were talking about the "forward slip," not "back slip."


but dangerous (if the patroller's knees get locked by an
unfortunate step, say, they get bounced by a piece of ice
chunk, he is done for it;

Baloney. Skis together, knees bent is the most secure position
anyone can have on the steep.

Not if you are going backward on the back-slip, you'll get caught on
the edges easily, which speeds the skis down faster than you can bend
your knees, your knees get locked by ever faster downward skis' speed.
There's no recovery from this type mishap.

A snowplow with 200 - 300 pounds
pushing you is a lot more apt to get deflected by snow snakes.

with 200~300 lbs. average weight of the sled plus the
person being transported bearing down on him, there's no
recovery).

You lack of knowledge is showing again. If a 100# female
patroller can pick up an unloaded sled to carry it to the top
of the mountain on a chair lift, it sure as hell doesn't weigh
200 to 300 pounds.

The "plus" was a mistake for "and."


2-3 hundred pounds is average loaded sled weight.

Yup, that was what I meant.

I've seen
patrollers take a sled down the hill with a SEVERELY injured
(actually dead)person. One guy driving the sled, second
patroller on the sled with the victim administering CPR DURING
THE RIDE DOWN THE HILL. That's probably 500 pounds total going
down the hill, part of it black diamond with bumps. Lots of
huge showplow (when used like that it can't be called a
wedge), some sideslip with falling leaf to give relief from
snowplow.

They may do the "sideslip" but not "back slip," which makes all the
difference.


I've hefted one around on occasion and it weighs just about
what my canoe weighs, which is 70+/- pounds.

Are you sure you want to be on that sled?

I have been on that sled. Class 4 AC separation, 3 years ago
in February. Called my own code using cell phone.

Did they ever use the "back slip"?

IS

VtSkier wrote:
yunlong wrote:
Richard Henry wrote:
"yunlong" wrote in message
roups.com...

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch
back,but I don't think that they do the "falling leaf."
"Falling leaf," which is named after a snowboarding
maneuver, by definition, is slipping back and forth down a
steep hill without [S]-turning--changing the edges.

I did not know that. In fact, I heard of the "falling leaf"
maneuver (and saw ski patrollers practicing it) long before
I ever saw a snowboard.

I believe there is an aerobatic maneuver called "falling
leaf", also.

Yup, it is also done by slipping, not turning.

Excuse me, you're not reading very well today are you.

Pardon me? Are you sure you read it right?


A one liner doesn't do it in this case since "aerobatic"
implies that your skis/board are off the snow, so how can
you be slipping and not turning?

I think that RH was talking an aerobatic [flying] maneuver.

IS

yunlong wrote:
VtSkier wrote:

yunlong wrote:

Richard Henry wrote:

"yunlong" wrote in message

egroups.com...

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch
back,but I don't think that they do the "falling leaf."
"Falling leaf," which is named after a snowboarding
maneuver, by definition, is slipping back and forth down a
steep hill without [S]-turning--changing the edges.

I did not know that. In fact, I heard of the "falling leaf"
maneuver (and saw ski patrollers practicing it) long before
I ever saw a snowboard.

I believe there is an aerobatic maneuver called "falling
leaf", also.

Yup, it is also done by slipping, not turning.

Excuse me, you're not reading very well today are you.


Pardon me? Are you sure you read it right?


A one liner doesn't do it in this case since "aerobatic"
implies that your skis/board are off the snow, so how can
you be slipping and not turning?


I think that RH was talking an aerobatic [flying] maneuver.

IS

Yes, and your reply had nothing to do with flying.

VtSkier wrote:
yunlong wrote:
Norm wrote:
yunlong wrote:

No thanks.

Why? It is easier (less tiring) on long traverse, and
the weight on the uphill ski is already facilitating
the "early weight transfer," thus enables the skier to
turn downhill whenever he/she wants it, and slipping
is safer technique than skidding.

The "slant slipping," is faster, more stable, and more
maneuverable, so it's a much versatile technique than
simple "side slipping" or skidding.

Sounds like "falling leaf" to me. Watch a patroller with
a sled sometime. Also works great without a sled.

"Falling leaf" is a maneuver that a skier zigzags back
and forth down a steep hill without "turning," i.e. the
skier must slip backward sometimes, and to slip backward
with a sled is not just impractical but also a dangerous
move,are you sure that's how patrollers handle the run
with a sled?

You bet, see Norm's post on the same subject.

Not sure where is Norm's post on the same subject;

Immediately following yours, Yunlong, look up ^ its still
there on my server.

Not sure where your server is, neither.

Point being that if it's on Norm's server, it probably is
on your server.

Point being that if there's no link, you just have to describe the
whole thing all over again.


nevertheless,
though they may do the zigzagging/switch back, but I don't
think that they do the "falling leaf." "Falling leaf,"
which is named after a snowboarding maneuver,

Falling leaf was around and named many years before the
first snowboard appeared..

The name was around;

It was named after, um, a falling leaf, which is the action
it mimics.

nevertheless, it was snowboarders who adopted the name for
that particular maneuver, as a part of normal snowboarding.

Not being a snowboarder or a part of that culture, I have
no knowledge of the snowboarding model for falling leaf.

As it (the maneuver) mimics the motion of a falling leaf, it
falls/slips from side to side, without ever changes the edge.

You best read my description of a SKIING falling leaf in
a post that came in a bit later than Norm's here.

I have only read your description on [some kind of] "slipping," not
"falling leaf." Care to refresh our memory a bit?


I've know "falling leaf" since the late 1950's.

In my SKI magazine's "Encyclopedia of Skiing," published in 1970 by
Universal Publishing and Distributing Co., has no mentioned of "falling
leaf" maneuver, in fact, the term is not even in the glossary.


by definition, is slipping back and forth down
a steep hill without [S]-turning--changing the edges.

Slipping backward with a sled in a patroller's back is not
just impractical (the patroller has to turn facing the sled
while skis/slips backward),

Erm, No s/he has no reason to have to turn facing the sled.
Upper body faces downhill at all times, just like skiing
normally.

No way, ski on just one side of ski (edge) is not "ski
normally"; unless s/he switches the edges, s/he cannot
traverse the hill with the upper body facing downhill; and
if s/he switches the edges, s/he is no longer doing "falling
leaf."

Switching edges, what the hell are you talking about. Read the
description.

Switching edges, the essential part of "turning" on skiing.


I don't know the rules for
flatboarding, YMMV.
Have you ever actually watched a toboggan being run? Falling
leaf is not only quite practical, in some terrain and snow
conditions it is essential for safe transport.

Yup, but it's just not practical for a "long" traverse.

There is NO traverse, read the description!

Huh?! The "slant slipping" for "long" traverse was topic before you
changed to the "falling leaf." Follow the thread.


but dangerous (if the patroller's knees get
locked by an unfortunate step, say, they get bounced by a
piece of ice chunk, he is done for it; with 200~300 lbs.
average weight of the sled

A Cascade toboggan weighs about 80lbs plus rescue gear about
20lbs or less. A Traverse Rescue is about 20 lbs lighter.

Yup, the "plus" part was a mistake for "and," it was meant
the whole thing, toboggan and the person transported, and
the "200~300 lbs." is to take it on the "light" side,
nevertheless, it is still a formidable weight for a
patroller to deal with when s/he is slipping backward.

Misteak noted. But note in my post what the real weight can
be. I noted upwards of 500 pounds for a sled with two people
(also common for shoulder dislocations) with one patroller
driving and no tail rope.

They need to change that procedure.


Talking about reckless, slipping backward with toboggan/sled
in a patroller's back is just not a safe maneuver.

Who is slipping backward. The skier/patroller is
slipping/skidding straight down the fall line with some
motion, oh hell, read the description.

That is no longer a "falling leaf" maneuver.


Then go watch some patrol training sometime. I'm sure they
have that at the mountains you ski.

Pedantic.

IS

yunlong wrote:


"Falling leaf" is a maneuver that a skier zigzags back and
forth down a steep hill without "turning," i.e. the skier
must slip backward sometimes, and to slip backward with a
sled is not just impractical but also a dangerous move, are
you sure that's how patrollers handle the run with a sled?


(Snip rest of crap from yunlong who is clearly making it up as he goes along
this time.)


Have I SEEN it done? Yunlong, according to my pocket log I DID it 12 times
this season. I've been doing it for 10 years now.

Trust me just a bit here.

1)Falling leaf is a required skill for any patroller, anywhere.
2)In steeper terrain with loose snow (y'know, like uh, slush powders) it is
the best way to safely handle a loaded toboggan
3)No, there is no need or reason to turn around to face the toboggan.
(Sheesh)
4)Yes you stay on the same edge. When your lead leg tires you can switch to
the other side. This is done by transitioning through a snowplow, facing
forward all the time.
5)No, of course it isn't done when traversing. By definition.

When you do your on hill test before you become a patroller you will be
required to demonstrate, with a loaded toboggan, in difficult terrain, a
falling leaf which must include at least one transition to each side. The
toboggan must continue moving straight down the fall line at all times when
demonstrating this manoeuvre.

yunlong wrote:
VtSkier wrote:

yunlong wrote:

VtSkier wrote:

yunlong wrote:

VtSkier wrote:

yunlong wrote:

VtSkier wrote:

(snip)


Have you done that yourself?

It is a standard practice of flatboarding; we call it
"slant slipping."

No thanks.

Why? It is easier (less tiring) on long traverse, and the
weight on the uphill ski is already facilitating the
"early weight transfer," thus enables the skier to turn
downhill whenever he/she wants it, and slipping is safer
technique than skidding.

The "slant slipping," is faster, more stable, and more
maneuverable, so it's a much versatile technique than
simple "side slipping" or skidding.

Sounds like "falling leaf" to me. Watch a patroller with
a sled sometime. Also works great without a sled.

"Falling leaf" is a maneuver that a skier zigzags back and
forth down a steep hill without "turning," i.e. the skier
must slip backward sometimes, and to slip backward with a
sled is not just impractical but also a dangerous move, are
you sure that's how patrollers handle the run with a sled?

You bet, see Norm's post on the same subject.

Not sure where is Norm's post on the same subject;
nevertheless, though they may do the zigzagging/switch back,
but I don't think that they do the "falling leaf." "Falling
leaf," which is named after a snowboarding maneuver, by
definition, is slipping back and forth down a steep hill
without [S]-turning--changing the edges.

Tell you what sonny,

Don't "sonny" me, unless you want to get whiplash, grand pop.

Come ski my world, we'll see who gets whiplash.

falling leaf has been done by skiers
and SKI patrollers since long before there were snowboards.
Further it was NAMED long before there were snowboards.

Falling leaf was a flying maneuver that existed before downhill skiing
was even invented. Don't chase that name, it is pedantic.

I believe you were chasing the name by saying that snowboarders
invented it and the maneuver. Yes, I have heard about the flying
maneuver called "falling leaf" but I do have to point out that
this is a SKIING newsgroup and references must be to skiing and
perhaps a bit to snowboarding, but if you come up with a flying
reference you had better define it. Also, downhill skiing has
been around a bit longer than flying, though the 12 foot long
skis used back in the middle of the 19th century probably wouldn't
work very well trying to do a SKIING "falling leaf" maneuver.

Slipping backward with a sled in a patroller's back is not
just impractical (the patroller has to turn facing the sled
while skis/slips backward),

Huh? the patroller has to turn facing the sled while he
skis/slips backward? Baloney.

Nonsense.

No, not nonsense. Read the description, go watch it
being done.

You obviously haven't seen it done.

Maybe you haven't seen it done closely?

But you do admit that I've seen it done and you haven't?

A good traverse
position is essential. Skis across the fall line,

How [the skis are slanted across the fall line, i.e. is the tip higher
than the tail?]

Skis perpendicular to fall line when not moving. Weight
forward, tails skid are more downhill than tips, skis move
backward. Weight back, tips slip are further downhill than
tails, skis move forward. Weight centered, straight side-
slip. Remember you are also moving your knees into/away
from the hill to control edging.

body turned
toward the fall line, both hands securely holding onto the
sled's handle bars as if they were ski poles with the poles
both pointing up the hill (oh sorry, you don't use poles).

Both handle bars pointing up the hill?!!! How's the sled been
positioned?

The handles of the sled are down the hill, just as the handles
of your poles (if any) would be down the hill with the points
pointing up the hill were you in a correct/conventional traverse
position.

Side slip down the hill with a bit of weight on the tails so
that the tips "slip",

No way, where a ski goes depends on the placement of the body weight,
when ski forward, weight on the tails, it (the skiing) skids, and
weight on the tips, it slips.

Like you said. No way. Your description may work for fall line
work and "flat boarding" but if your weight is back, your tail
edges will hold and your tips will "slip". The reverse is if
your weight is forward, your tip edges will hold and your tails
will "skid". Period. Go do it.

move weight forward so that tails "skid". Repeat.

Or maybe you were talking about ski/slip backward? But the "forward"
reference screws it up.

From an earlier thread you insisted that "skidding" was when
the tails of the skis move angularly more than the tips and
"slipping" is when the tips of the skis more angularly more
than the tails. I don't really have a problem with this
definition as long as it's understood going in. Since it was
your insistence, I figured you'd understand it better.

One of the advantages of this is that snow
tends not build up downhill to your skis forming a barrier.
This is the preferred method on hills too steep to snowplow.
Except for the most severe slope and conditions, our guys
don't even tail rope.

You were talking about the "forward slip," not "back slip."

No, always back and forth. Sometimes more one way than
the other. "Playing the hill" might be a way to describe it.
Imagine ice bumps. If you don't know what these are, they
are usually hard and shiny. On a competitive bump run, they
will be closer together than the length of a ski. Or more
correctly, the troughs will bend the skis to much unless
you can negotiate your way down. We're talking with a sled
here. A snowplow is often out of the question. A straight
side-slip works after a fashion, but it is a lot more
comfortable if the patroller works the hill back and forth
in a manner that keeps him on edge to slow everything down
and is avoiding overbending or bridging troughs in bumps.
This requires going back and forth in a sideslip mode to
keep control of everything. Yes forward slip AND back slip.

but dangerous (if the patroller's knees get locked by an
unfortunate step, say, they get bounced by a piece of ice
chunk, he is done for it;

Baloney. Skis together, knees bent is the most secure position
anyone can have on the steep.

Not if you are going backward on the back-slip, you'll get caught on
the edges easily, which speeds the skis down faster than you can bend
your knees, your knees get locked by ever faster downward skis' speed.
There's no recovery from this type mishap.

Gently backward, gently forward, mostly down. It's a learned
skill, especially with a sled.

You'll get caught on the edges easily, which speeds the skis
down faster than you bend your knees???? Pray tell what
does this mean.

If you "catch" and edge, you'll be on your butt with a sled
running over you. If you are "ON" your edges you will be scraping
off speed. You knees (ankles) will be bent in any case.

A snowplow with 200 - 300 pounds
pushing you is a lot more apt to get deflected by snow snakes.

with 200~300 lbs. average weight of the sled plus the
person being transported bearing down on him, there's no
recovery).

You lack of knowledge is showing again. If a 100# female
patroller can pick up an unloaded sled to carry it to the top
of the mountain on a chair lift, it sure as hell doesn't weigh
200 to 300 pounds.

The "plus" was a mistake for "and."

2-3 hundred pounds is average loaded sled weight.

Yup, that was what I meant.

Noted. Typos happen.

I've seen
patrollers take a sled down the hill with a SEVERELY injured
(actually dead)person. One guy driving the sled, second
patroller on the sled with the victim administering CPR DURING
THE RIDE DOWN THE HILL. That's probably 500 pounds total going
down the hill, part of it black diamond with bumps. Lots of
huge showplow (when used like that it can't be called a
wedge), some sideslip with falling leaf to give relief from
snowplow.

They may do the "sideslip" but not "back slip," which makes all the
difference.

I've hefted one around on occasion and it weighs just about
what my canoe weighs, which is 70+/- pounds.


Are you sure you want to be on that sled?

I have been on that sled. Class 4 AC separation, 3 years ago
in February. Called my own code using cell phone.


Did they ever use the "back slip"?

Yes, my "code" was on a natural snow, no grooming trail
with bumps. See above.

Clearly you haven't seen this done. Go back and watch
patrol training and then see if what I'm describing
isn't correct. I've done what I'm recommending you to
do. I've watched some of the best sled handlers in the
east and I've ridden shotgun on codes to be of
assistance, carry stuff, help pull across flats, you
name it.

Falling leaf, as I've described it, has been a SKIING
maneuver for at least 50 years. It is used by patrollers
bringing down sleds in the most extreme conditions of
snow quality and slope. They do slip straight down the
hill AND back and forth across the hill without turning.
NEVER face up the hill and never lose the sled.