A new direction for an old thread: Crosswind landings

Andreas Maurer wrote:

I'm afraid that I can't be any help here.
The only thing I know about crosswind landings is to crab and (during
the flare) to align with the runway with the rudder, wings level.

I think you fly at a winch site but there's another way some tug pilots
use. On final the aircraft maintains alignment with a sideslip - so it
approaches wing-down. High wing, single-engine aeroplanes find this a
good technique because they land without levelling the wings (on one
wheel) and this makes landing simpler.

It appears from the discussion to have been carried over to gliders in
the US but since it's generally a bad idea to land a glider with a wing
down, the major benefit of the technique is lost and it's probably
inappropriate.

The explanation may lie in the widespread use of Schweizer 2-33s in the
US whose high wing allows wing-down landings - and it works even better
than a Cezzna because it only has one main wheel and it slows down
quickly. Since the technique is a bit doubtful with the more common
mid-wing, high aspect ratio gliders that many pilots will move to, it
seems silly to teach it in the first place but that's their business and
it seems to work for them. Like you, I was only ever taught crabbed
landings.

As far as I can make out, that's what this discussion is all about and
it's really not for us aliens.

To me this is such a natural maneuvre that I happen to be unable to
see why there is a need to discuss this matter - but obviously others
see things in a different way.

I see it your way. Too many words to no useful purpose. But it's
actually a private conversation, I guess.

I've yet to see a broken glider just from a crosswind landing.
Shattered egos? Yes. Broken gliders? No.

GC





Bye
Andreas

If an approach is completed successfully to touchdown, the likely
damage is minimal, save poor airmanship aims the glider as something
substantial. The discussion was not intended to focus on the safety of
the touchdown, but the thought process of the pilot while on final.
(BTW, I've seen a glider wind up on its back after a botched crosswind
landing. The only solution, however, would have been to land on another
runway!)

Why, in god's name, do otherwise competent pilots abuse the controls
while turning from base to final? The classic situation is the low
turn, the pilot trying to hurry its completion with rudder, and then an
inopportune gust inviting him to snatch up an inside dropping wing with
aileron. In fact, altitude doesn't appear to be a key issue. My own
suspicion is that visual effects play a key role (with lack of altitude
emphasizing the effects). If a pilot doesn't understand the component
elements of that turn from base to final, isn't he more likely to abuse
the controls, especially if the motion he observes doesn't match up
with his expectations? And on what does a pilot base his expectations?
Experience and a conceptual model of flight. If slipping on final,
isn't he more likely to misuse the controls as he responds to
turbulence? A slip can turn quickly to a skid as a pilot reacts to wind
shear or other turbulence. (A question to US instructors: Isn't counter
productive to teach a pilot to ignore the yaw string in the pattern?
And having taught him to ignore the yaw string, to not thoroughly
assess the ways he might wind up getting himself in trouble while
reacting to low level turbulence? When was the last time you spent
several minutes explaining how to maintain a track while slipping, and
at the same time addressing the fact that this requires occasional use
of a skid? And can you think of any good reason a pilot should skid an
aircraft in that critical altitude band below 500 feet and above 3
feet?

I agree, the problem is solved completely if you simply drop the side
slip from your vocabulary and keep the yaw string straight right to the
point of touchdown. But in the US, you will immediately shut down all
discussion if you say that a side slip has no useful purpose, and, in
fact, that a side slip may be counter productive.

One way to say just that is to get people understanding what a side
slip is and what it is for. There is no reason not to use this
technique on a wide, smooth, flat runway. However, there is absolutely
no good reason to enter the sideslip until after you've cleared the
last obtacle and you are over the selfsame wide, smooth runway. But
kudos to those who know and have stated that it is the lesser of the
two alignment options: slipping versus skidding.




Graeme Cant wrote:
Andreas Maurer wrote:

I'm afraid that I can't be any help here.
The only thing I know about crosswind landings is to crab and
(during
the flare) to align with the runway with the rudder, wings level.

I think you fly at a winch site but there's another way some tug
pilots
use. On final the aircraft maintains alignment with a sideslip - so
it
approaches wing-down. High wing, single-engine aeroplanes find this
a
good technique because they land without levelling the wings (on one
wheel) and this makes landing simpler.

It appears from the discussion to have been carried over to gliders
in
the US but since it's generally a bad idea to land a glider with a
wing
down, the major benefit of the technique is lost and it's probably
inappropriate.

The explanation may lie in the widespread use of Schweizer 2-33s in
the
US whose high wing allows wing-down landings - and it works even
better
than a Cezzna because it only has one main wheel and it slows down
quickly. Since the technique is a bit doubtful with the more common
mid-wing, high aspect ratio gliders that many pilots will move to, it

seems silly to teach it in the first place but that's their business
and
it seems to work for them. Like you, I was only ever taught crabbed
landings.

As far as I can make out, that's what this discussion is all about
and
it's really not for us aliens.

To me this is such a natural maneuvre that I happen to be unable to
see why there is a need to discuss this matter - but obviously
others
see things in a different way.

I see it your way. Too many words to no useful purpose. But it's
actually a private conversation, I guess.

I've yet to see a broken glider just from a crosswind landing.
Shattered egos? Yes. Broken gliders? No.

GC





Bye
Andreas

So, what do you want to say?

--
Bert Willing

ASW20 "TW"


a écrit dans le message de news:
...
If an approach is completed successfully to touchdown, the likely
damage is minimal, save poor airmanship aims the glider as something
substantial. The discussion was not intended to focus on the safety of
the touchdown, but the thought process of the pilot while on final.
(BTW, I've seen a glider wind up on its back after a botched crosswind
landing. The only solution, however, would have been to land on another
runway!)

Why, in god's name, do otherwise competent pilots abuse the controls
while turning from base to final? The classic situation is the low
turn, the pilot trying to hurry its completion with rudder, and then an
inopportune gust inviting him to snatch up an inside dropping wing with
aileron. In fact, altitude doesn't appear to be a key issue. My own
suspicion is that visual effects play a key role (with lack of altitude
emphasizing the effects). If a pilot doesn't understand the component
elements of that turn from base to final, isn't he more likely to abuse
the controls, especially if the motion he observes doesn't match up
with his expectations? And on what does a pilot base his expectations?
Experience and a conceptual model of flight. If slipping on final,
isn't he more likely to misuse the controls as he responds to
turbulence? A slip can turn quickly to a skid as a pilot reacts to wind
shear or other turbulence. (A question to US instructors: Isn't counter
productive to teach a pilot to ignore the yaw string in the pattern?
And having taught him to ignore the yaw string, to not thoroughly
assess the ways he might wind up getting himself in trouble while
reacting to low level turbulence? When was the last time you spent
several minutes explaining how to maintain a track while slipping, and
at the same time addressing the fact that this requires occasional use
of a skid? And can you think of any good reason a pilot should skid an
aircraft in that critical altitude band below 500 feet and above 3
feet?

I agree, the problem is solved completely if you simply drop the side
slip from your vocabulary and keep the yaw string straight right to the
point of touchdown. But in the US, you will immediately shut down all
discussion if you say that a side slip has no useful purpose, and, in
fact, that a side slip may be counter productive.

One way to say just that is to get people understanding what a side
slip is and what it is for. There is no reason not to use this
technique on a wide, smooth, flat runway. However, there is absolutely
no good reason to enter the sideslip until after you've cleared the
last obtacle and you are over the selfsame wide, smooth runway. But
kudos to those who know and have stated that it is the lesser of the
two alignment options: slipping versus skidding.




Graeme Cant wrote:
Andreas Maurer wrote:

I'm afraid that I can't be any help here.
The only thing I know about crosswind landings is to crab and
(during
the flare) to align with the runway with the rudder, wings level.

I think you fly at a winch site but there's another way some tug
pilots
use. On final the aircraft maintains alignment with a sideslip - so
it
approaches wing-down. High wing, single-engine aeroplanes find this
a
good technique because they land without levelling the wings (on one
wheel) and this makes landing simpler.

It appears from the discussion to have been carried over to gliders
in
the US but since it's generally a bad idea to land a glider with a
wing
down, the major benefit of the technique is lost and it's probably
inappropriate.

The explanation may lie in the widespread use of Schweizer 2-33s in
the
US whose high wing allows wing-down landings - and it works even
better
than a Cezzna because it only has one main wheel and it slows down
quickly. Since the technique is a bit doubtful with the more common
mid-wing, high aspect ratio gliders that many pilots will move to, it

seems silly to teach it in the first place but that's their business
and
it seems to work for them. Like you, I was only ever taught crabbed
landings.

As far as I can make out, that's what this discussion is all about
and
it's really not for us aliens.

To me this is such a natural maneuvre that I happen to be unable to
see why there is a need to discuss this matter - but obviously
others
see things in a different way.

I see it your way. Too many words to no useful purpose. But it's
actually a private conversation, I guess.

I've yet to see a broken glider just from a crosswind landing.
Shattered egos? Yes. Broken gliders? No.

GC





Bye
Andreas

Of course teaching "crabbed landing" means teaching a crab during final into
the flare, and then a last second slip. Litteral crabbed landing would be
way too expensive.

--
Bert Willing

ASW20 "TW"


"T o d d P a t t i s t" a écrit dans le
message de news: ...
Graeme Cant wrote:

I think you fly at a winch site but there's another way some tug pilots
use. On final the aircraft maintains alignment with a sideslip - so it
approaches wing-down. High wing, single-engine aeroplanes find this a
good technique because they land without levelling the wings (on one
wheel) and this makes landing simpler.

Touching down in a slip has nothing to do with making
landings "simpler." If you don't understand why a slip is
needed in a crosswind, then you don't understand the
aerodynamics involved.

The explanation may lie in the widespread use of Schweizer 2-33s in the
US whose high wing allows wing-down landings - and it works even better
than a Cezzna because it only has one main wheel and it slows down
quickly. Since the technique is a bit doubtful with the more common
mid-wing, high aspect ratio gliders that many pilots will move to, it
seems silly to teach it in the first place but that's their business and
it seems to work for them. Like you, I was only ever taught crabbed
landings.

If you only know crabbed landings, then you will land
sideways every time. That's just the reality of the
physics. In a high crosswind on a hard surface, landing
crabbed is very bad.

I seriously doubt that you were taught to land crabbed.
Most likely you were taught to use a combination of last
minute rudder to align with the runway (that ,maneuver puts
you in a slip just before touchdown) and to carefully keep
the upwind wing no higher than the downwind wing.

On Thu, 24 Feb 2005 22:51:39 +1100, Graeme Cant
wrote:

I think you fly at a winch site but there's another way some tug pilots
use.

Plenty of aerotows here, too...

On final the aircraft maintains alignment with a sideslip - so it
approaches wing-down. High wing, single-engine aeroplanes find this a
good technique because they land without levelling the wings (on one
wheel) and this makes landing simpler.

I know...
I'm using this technique in our Dimona motorglider, too.


The explanation may lie in the widespread use of Schweizer 2-33s in the
US whose high wing allows wing-down landings

Good point - I guess you are correct here.


As far as I can make out, that's what this discussion is all about and
it's really not for us aliens.

LMAO. Yup.

I've yet to see a broken glider just from a crosswind landing.
Shattered egos? Yes. Broken gliders? No.

Not even a shattered ego yet...



Bye
Andreas

And landing gears are way too expensive...
Here's the method I like and use most:
Slip to control crosswind, and about 6 feet high, wings level, start the
flare. No time for the glider to accumulate enough lateral speed (refering
to the centerline) to be a problem.
If a student (or any pilot) is not comfortable with the techniques needed to
make a safe landing in crosswinds... don't fly that day!

Jose M. Alvarez.
ASW-24 'BR'

"Bert Willing" escribió en
el mensaje ...
Of course teaching "crabbed landing" means teaching a crab during final
into
the flare, and then a last second slip. Litteral crabbed landing would be
way too expensive.

--
Bert Willing

ASW20 "TW"

Bert Willing wrote:
So, what do you want to say?

There's something amiss with the way we teach people to fly. Not in all
aspects, but certainly in some critical ones. And while we are largely
successful, I could make an argument that our failures outnumber our
successes. A widespread misunderstanding of slips is one indication.

I was an enthusiastic student, well trained, well read. I've averaged
more than 200 hours PIC per year in gliders for the past 27 years. As a
commercial ride pilot and instructor (summers in college) I would make
as many as 10 take offs and landings per day and/or watch as many
again. Over those years I noticed conflicts, in how we teach on the
ground, the materials we assign for reading, and the control use we
demonstrate and drill in the air. What we do is 99% effective. But it
can be better. And since we all subscribe to the notion that aviation
is an unforgiving business, why not make a constant effort to improve?

The most succinct advice I've seen in this thread is "Geez, just do
it!" My sentiments exactly. But not very helpful for a confused pilot.
Wouldn't we prefer that new pilots apply knowledge rather than muscle
memory?

I pointed out at the top of this thread that it is confusing to tell a
pilot that he can either "crab" or "side slip" on crosswind final. It
gives the impression that these are two separate maneuvers that produce
similar effects. And that used together, their effects are somehow
additive. They are neither similar nor additive. We should find a way
to clear this up and make it part of our methodolgy for introducing and
practicing crosswind landings.

"Slip to CONTROL crosswind."

This is confusing. How does the slip control crosswind?

Next, "wings level..." Does that mean the rudder is brought to neutral?
If so, you have introduced a crab angle. If not, then you have
inititiated a skid. Do you see why? If you disagree, please take a few
lines to explain it so I'll understand.

Ok... When the sailplane is under crosswind, it's velocity vector is altered
and it's not folowing a straight course over ground. To compensate for this
you change the direction of the lift vector sideways (rolling the wings with
ailerons) while keeping the nose pointed where you want (opposite rudder, a
slip).
This changes the velocity vector of the glider, making it follow a straight
course over ground, but a somewhat uncoordinated flight in the airmass (in a
slip, the velocity vector is not aligned with the fuselage; the glider does
not flies straight).
Wings level means... wings level... angle of bank zero, level with the
horizon, horizontal. I'm sorry I'm unable to explain better. The rudder goes
where it needs to go to keep the string centered (coordinated)
The glider is not skidding, it's just between a skid and a crab. I think
that it's flying coordinated (centered ball, centered string). You are
drifting with the wind, but only a little. The glider is close enough to the
contact point as to not be very affected by the wind in the, say, two
seconds of flight time remaining.

It would only take me a flight to explain it (to show, really) but I'm
afraid that I can't be more clear writing!
If I'm still unclear I'll try to elaborate more.


escribió en el mensaje
ups.com...
"Slip to CONTROL crosswind."

This is confusing. How does the slip control crosswind?

Next, "wings level..." Does that mean the rudder is brought to neutral?
If so, you have introduced a crab angle. If not, then you have
inititiated a skid. Do you see why? If you disagree, please take a few
lines to explain it so I'll understand.

T o d d P a t t i s t wrote:

Are you saying you land wings level in a crosswind, your
wheel is aligned with the runway AND your yaw string is
straight (coordinated flight)? It just isn't possible.

Inertia makes it possible.

Stefan