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