Weathervaning

Do I fly?! Don't be a wise ass...why do you think they call it
"weathervaning"? What does a weathervane do? It turns the "weathervane"
into the relative wind. An airplane is a weathervane too and the wind can
and does turn an airplane into the relative wind. Definition:
"weathervaning".

Kobra

"CASK829" wrote in message
...
The tail does not know what direction the wind is blowing if the airplane
is in
the air. So therefore it DOES NOT push the nose into the wind.
Do You fly?



It's from the wind striking the vertical stabilizer and pushing the nose
into the wind.

Kobra

"Robert Moore" wrote in message . 7...
(Koopas Ly) wrote

You'd also use some right rudder to keep the nose straight and
prevent it from "weathervaning".
Is this "weathervaning effect" caused by your leftward relative
motion due to the left bank OR by the rightward crosswind
ITSELF?

There is NO weathervaning effect until the wheels touch the ground.
Banking an airplane (putting a wing down) causes it to turn. You
use opposite rudder simply to keep it from turning due to the bank.

It's sort of the opposite of weathervaning. The vertical stab will normally keep the
tail in line with the aircraft (coordinated flight). Using the rudder will
force it out of line (and in alignment with the direction of travel on the ground).

"Roger Long" om writes:

As far as the plane is concerned, there is no such thing as wind until the
wheels touch the ground.

Unless the wind changes too fast (i.e. sudden gusts, wind shear, etc.).


All the best,


David

Robert Moore writes:

There is NO weathervaning effect until the wheels touch the ground.
Banking an airplane (putting a wing down) causes it to turn. You
use opposite rudder simply to keep it from turning due to the bank.

In flight and on the ground (even tied down), the aircraft tries to
weathervane into its relative wind, which is aircraft-referenced
rather than ground-referenced. That's why the plane turns when you
bank the wings (the vstab makes the plane weathervane towards the
sideslip).

Only when the plane is not moving or moving very slowly on the ground
is the relative wind from roughly the same direction as the (static)
wind that the windsock sees.


All the best,


David

"Peter Duniho" writes:

Actually, in some aircraft, banking an airplane causes it to turn in a
direction *opposite* of the bank. Rudder is necessary in a turn, to make
sure the turn is coordinated and is as efficient as possible. Many
airplanes, without the use of rudder, will simply slip sideways without any
change in heading at all.

That would require extremely draggy ailerons. I know that some planes
turn sloppy without rudder, but what planes don't change heading at
all? Gliders?


All the best,


David

David Megginson wrote:

That would require extremely draggy ailerons. I know that some planes
turn sloppy without rudder, but what planes don't change heading at
all?

Maules, for one. Give mine aileron and no rudder, and she will quite happily
fly sideways on the same heading. Something about "adverse yaw"?

George Patterson
If you're not part of the solution, you can make a lot of money prolonging
the problem.

That's what I said. Did you read the whole thing?
--
Roger Long

David Megginson wrote in message
...
"Roger Long" om writes:

As far as the plane is concerned, there is no such thing as wind until
the
wheels touch the ground.

Unless the wind changes too fast (i.e. sudden gusts, wind shear, etc.).


All the best,


David

"G.R. Patterson III" writes:

Maules, for one. Give mine aileron and no rudder, and she will quite
happily fly sideways on the same heading. Something about "adverse
yaw"?

At what bank angle, and for how long? With very draggy ailerons, I
can imagine that there might be one bank angle where drag from the
aileron on the high wing exactly counteracted the weathervaning
tendency of the plane, but it would be amazing if that were true of
every bank angle up to 30 deg (for example).


All the best,


David

"Roger Long" om writes:

That's what I said. Did you read the whole thing?

I thought I had, but I missed that part. Apologies.


All the best,


David

"Peter Duniho" wrote

Of course there is. There is "weathervaning" any time the
relative wind is not parallel to the longitudinal axis.

But I think that the discussion was weathervaning into the
actual wind, not the relative wind. If I bank away from the
wind, does the airplane then weathervane into or away from
the wind? The only thing that can cause the airplane to
weathervane into the actual wind is for the wheels to be in
contact with the ground. Without the pivot, a weathervane
doesn't weathervane.

Bob