Yaw String in a Spin

In a classic left turn traffic pattern stall spin that is caused be a
cross control attempt to rudder a turn to align the ship to final after
it breaks over the top which way is it spining and what is the proper
recovery? In a steep left turn coring a strong thermal at low altitude
the outside or high wing enters the surrounding down and the spin over
the top happens, which way is the glider spinning and what is the
proper spin recovery? No time to think correct answer please your life
depends on it.

At 19:00 16 January 2005, Greg Arnold wrote:
'Apply full rudder opposite to the direction of the
yaw string' -- what
does that mean? What is the direction of the yaw string?
If the loose
end of the yaw string is on the right side of the canopy,
is the
direction of the yaw string to the right, or is it
to the left?

Seems like there is some potentially confusing terminology
being used here that I've never heard before. I've
always been taught that the the 'direction' of the
yaw string is the side of the glider it leans to, and
so you correct by pressing the rudder on the opposite
side.

Here I think people are saying that if the yaw string
is displaced to the right side of the glider it is
'pointing' left. While I can understand how you might
naturally want the front end to be the tip of the 'pointer',
I think it's confusing to refer to 'pointing' at all
because of this left/right confusion. I prefer to
say the yaw string is 'to the left' or 'to the right'
as position is less ambiguous that the 'pointing' direction.

To be honest, I've never looked at the yaw string in
a spin as it has never been ambiguous to me which way
the world was turning - if the world is going round
and round counter-clockwise how can this not be spinning
to the right? I guess I presumed that for a spin to
persist the glider would have to stay skidding, but
in a fully established spin you might wonder, if the
yaw string was far enough forward (say in a two-seater),
whether the rotation overcomes the skid in terms of
the local flow across the canopy - apparently not given
the comments here. Boy I'd hate for that to be wrong
though.

Years ago when I was flying a Ventus A 16.6 (easy to
spin unintentionally in my experience) I taught myself
that if the inside wing in a turn ever dropped, to
push the stick forward and into the turn and to hit
top rudder. You try to make it as instinctive as possibe,
but it takes practice. The top rudder is the easiest
part - the stick movement is against most people's
instincts.

9B

It means exactly the same rudder direction you apply
in any other, non spinning, yawed condition (how could
it be otherwise as the string doesn't change its mode
of action in a spin?). The front end of a yaw string
is stuck to the canopy and if the loose end is pointing
left in a spin you apply apply right rudder.

I have never heard of anyone referring to the front
end of the yaw string being the way that it is pointing.
If they do that in the States the wording could
be changed. However, since pilots have ingrained into
thenm the wording 'full opposite rudder' for spin recovery,
I would strongly suggest retaining the word 'opposite'
and referring to the loose end of the yaw string as
the way it points.

There is nothing new to learn in what I suggest - I
just picked it up from Reichmann's book. The change
in emphasisis just that the attention is directed to
the yaw string in any case of doubt rather than to
watching the houses whirling about.

John Galloway


At 19:00 16 January 2005, Greg Arnold wrote:
'Apply full rudder opposite to the direction of the
yaw string' -- what
does that mean? What is the direction of the yaw string?
If the loose
end of the yaw string is on the right side of the canopy,
is the
direction of the yaw string to the right, or is it
to the left?

I think you mean that if the loose end of the yaw string
is on the right
side of canopy, you apply right rudder? Or the opposite
of the normal rule?




The yaw string *always* points to the inside of a
spin
(according the Reichmann and others) and modifying
the teaching to 'apply full rudder opposite to the
direction of the yaw string' would be a more certain
way of choosing the life rudder pedal rather than
the
death one at low altitude

On the same topic, I entered an unintentional stall spin for the first
time last year. I have about 1,000 hours in gliders and 450 hours in
my ASW 20. I was flying fully ballasted in a cross-country contest
task on a typical Arizona summer day with strong, turbulent thermals.
Entering a thermal, I eased into a left bank, slowing down and applying
flaps as I've done thousands of times. However, I overshot my normal
fully-ballasted zero flap setting and went to plus 1 instead.

Suddenly, I was aware that something was wrong. The air went quiet,
the controls went sloppy and suddenly the yaw string pointed left and
slightly away from me. For a moment or two, I didn't have a clue as to
what was happening. The glider then fell sideways out of the thermal.

Following the clue of the yawstring, I centered the stick, applied full
right rudder and full negative flap. The glider recovered immediately,
but lost a few hundred feet in the ensuing dive out as I recovered
airspeed. I never got any sense of rotation.

From my log file, it looks as if I overshot the center of the thermal
and entered severe outflow windshear. With the airspeed gone, aided by
a tad too much positive flap, the glider momentarily quit flying and
dropped sideways.

The yaw string was my only clue as to what was happening.

I agree with others that the experience was totally different from spin
training, in which the spin entry is expected. The problem is
recognizing what is happening and you don't have time to scan
instruments. The yaw string is the most responsive and most effective
inidicator of unusual airflow.

Mike

ASW 20 WA

John Galloway wrote:
It means exactly the same rudder direction you apply
in any other, non spinning, yawed condition (how could
it be otherwise as the string doesn't change its mode
of action in a spin?). The front end of a yaw string
is stuck to the canopy and if the loose end is pointing
left in a spin you apply apply right rudder.

I have never heard of anyone referring to the front
end of the yaw string being the way that it is pointing.

Really? I picked it up somewhere in my instruction. Something to the
effect of "Think of the yaw string as an arrow with the head attached to
the canopy. It points to the the rudder pedal you need to push to
coordinate."
Seemed very natural and simple to me.

Shawn

At 23:00 16 January 2005, Shawn wrote:
John Galloway wrote:
It means exactly the same rudder direction you apply
in any other, non spinning, yawed condition (how could
it be otherwise as the string doesn't change its mode
of action in a spin?). The front end of a yaw string
is stuck to the canopy and if the loose end is pointing
left in a spin you apply apply right rudder.

I have never heard of anyone referring to the front
end of the yaw string being the way that it is pointing.

Really? I picked it up somewhere in my instruction.
Something to the
effect of 'Think of the yaw string as an arrow with
the head attached to
the canopy. It points to the the rudder pedal you
need to push to
coordinate.'
Seemed very natural and simple to me.

Shawn

So that's the pedal you'll want to press in a spin.
Use your way of thinking about it. No dispute between
us. See Mike the Strike's posting.

John Galloway

Really? I picked it up somewhere in my instruction. Something to the
effect of "Think of the yaw string as an arrow with the head attached to
the canopy. It points to the the rudder pedal you need to push to
coordinate." Seemed very natural and simple to me.

Yes. I use this most often with transitioning power pilots who are
taught to "step on the ball" of the inclinometer ("step on the head of
the arrow"). With ab initio glider pilots I start with telling them to
add rudder on the opposite side of where the tail of the string is
pointing. If that doesn't work, I switch to the above.

Tony V.

At 23:00 16 January 2005, Shawn wrote:
John Galloway wrote:
It means exactly the same rudder direction you apply
in any other, non spinning, yawed condition (how could
it be otherwise as the string doesn't change its mode
of action in a spin?). The front end of a yaw string
is stuck to the canopy and if the loose end is pointing
left in a spin you apply apply right rudder.

I have never heard of anyone referring to the front
end of the yaw string being the way that it is pointing.

Really? I picked it up somewhere in my instruction.
Something to the
effect of 'Think of the yaw string as an arrow with
the head attached to
the canopy. It points to the the rudder pedal you
need to push to
coordinate.'
Seemed very natural and simple to me.

Yes, it is pointing into the relative wind; point the
glider toward that.

Shawn

"Nyal Williams" wrote in message
...

We should have a conversation with students specifically
about which end of the yaw string is the pointer/tail/indicator,
etc. and which foot does what to that end of the string
under discussion.

View the string as a pointer. The forward end (the point) points at the
required rudder pedal.

Duane

"Duane Eisenbeiss" wrote in message
...

"Nyal Williams" wrote in
message
...

We should have a conversation with students specifically
about which end of the yaw string is the pointer/tail/indicator,
etc. and which foot does what to that end of the string
under discussion.

The above post was incomplete. Over sensitive Send button.

View the string as a pointer. The forward end (the point) points at the
required rudder pedal to continue the turn or stop yaw. Therefore opposite
rudder in a spin would be the other rudder pedal or the top of the string.

Duane