Yaw String in a Spin

In another thread Ian Strachan wrote:

'The standard recovery procedure once a full spin has
developed that
works for most aircraft is,

1. Full rudder opposite to the spin direction (make
sure it really is
opposite to the rotation, I for one have applied the
wrong rudder in a
spinning jet when I was caught by a surprise departure).'
=======================================

I have long surmised that application of the wrong
rudder in a panic situation might be a cause of failure
to recover from a spin. If it can happen to a military
test pilot of Ian's calibre then it can certainly happen
to me.

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

Slip balls do not, apparently, invariably point to
the outside of spins so they are not as certain a guide.

'Every saiplane should have a yaw string' - said Helmut
Reichmann for this reason.

John Galloway

John,

interesting thoughts. Even with strong visual cues, the more nose down
a spin, the more difficult it might be to surmise its direction. Thus,
a quick reference to the yaw string is in order. Isn't the Pooch known
for its nose down attitude while spinning?

Yet another reason to put the emphasis on stall avoidance and prompt
recovery from prestall conditions. A suprise stall and autorotation at
low altitude presents a great a risk, even for well trained, heads-up
pilots.

I agree that this is an interesting point. Even experienced, current pilots
can be caught off guard, and perhaps a better training/recognition method
might be in order. Maybe the yaw string can/should be a more integral
part of the program in terms of spin recovery training?

For what it's worth, I have had a couple of unintentional spin entries over
the last 20 years. One in particular sticks in my mind. A guy at the
local gliderport is an experienced aerobatics competitor; he owns a two
place Fox aerobatic glider. He asked me to go up with him one day, since
he was having some trouble getting the Fox to climb. He figured thermals
were a lot cheaper than 5,000 foot aerotows.

We got into a moderate thermal, and I took the controls to show him how we
"real" soaring pilots thermal. I cranked us over to 40 degrees of bank to
core the thermal. "Now, watch how I slow us up to really tighten the
circle..." I said. The owner mentioned that I ought to "be a little
careful [since] stall speed at this..." He never finished the sentence.

Departure was instantaneous. Rotation was spectacular. I recall at first
doing everything wrong. It took me at least one full revolution to realise
that the glider was spinning, and I think it was a couple of seconds more
before I figured out the direction. Fortunately, we were at least 4,000
AGL at the time, and the owner just sat back and let me figure things out.

This flight came on a day when I had been the duty instructor in the club.
I had probably done 4 or 5 incipient spin lessons earlier in the day, and I
probably had 40 hours flying in the preceeding 90 days. So, I was current
and reasonably on top of my game.

This experience just reinforced the fact that the ability to recognize a
spin, especially an unplanned one, is probably not an easy thing to teach.
The normal training mode is thoroughly unnatural, as the student is primed
and ready. The reality is a lot different, and I'm wondering if any of us
emphasize the recognition aspects of the immediate post-departure moments
enough?

Erik Mann (P3)

wrote in message
oups.com...
John,

interesting thoughts. Even with strong visual cues, the more nose down
a spin, the more difficult it might be to surmise its direction. Thus,
a quick reference to the yaw string is in order. Isn't the Pooch known
for its nose down attitude while spinning?

Yet another reason to put the emphasis on stall avoidance and prompt
recovery from prestall conditions. A suprise stall and autorotation at
low altitude presents a great a risk, even for well trained, heads-up
pilots.

I had a two turn spin in my 20 a couple of years ago at a Mifflin
contest. The ship was in a coordinated right 45 degree bank, nose on
the horizon, and I was making my third searching circle attempting to
center the strong core of a good thermal. I was stable and coordinated
in the turn when the tail pitched up violently and the ship rolled
inverted to the right. My first thought was that I got hit by another
glider ... but since my searching couldn't locate another ship, I then
thought something broke. (It's amazing how time slows down in these
situations...) Entering the second rotation, I figured I was high
enough (4000')to jump, but continued to scan outside and inside and I
happened to look at my hand ... which was holding the stick just aft of
center. What, could this be a stall/spin? Opposite rudder, stick
forward, flaps to negative ... yep, recovery ... and immediately
climbing in the thermal again. I hit the tail dump switch and made a
promise to see if I could duplicate the situation when I got home ...
which I did.

Looking back, I suspect my left outside wing went through the tight
strong thermal core, which pushed the wing up, I instinctively applied
left aileron, and of course, the inside wing stalled, and the
combination of forces kinda 'snap-rolled' the ship to the right. The
spin entry from level flight and relatively violent forces disguised
the situation and delayed my recovery ... which of course is deadly at
lower altitude. So, stall/spins don't happen the way you practice them
.... although the recovery inputs taught are correct ... you just have
to execute immediately.

I now have a rule ... or mindset ... to execute stall/spin recovery
first in any situation like this. It won't help if you do indeed have
a structural or control problem ... but it is imperative avoid an
intellectual exercise if you are really in a stall/spin. As soon as
you hear yourself saying, "What the F___" ... you should be executing
stall/spin recovery.

KK


Papa3 wrote:
I agree that this is an interesting point. Even experienced, current
pilots
can be caught off guard, and perhaps a better training/recognition
method
might be in order. Maybe the yaw string can/should be a more
integral
part of the program in terms of spin recovery training?

For what it's worth, I have had a couple of unintentional spin
entries over
the last 20 years. One in particular sticks in my mind. A guy at
the
local gliderport is an experienced aerobatics competitor; he owns a
two
place Fox aerobatic glider. He asked me to go up with him one day,
since
he was having some trouble getting the Fox to climb. He figured
thermals
were a lot cheaper than 5,000 foot aerotows.

We got into a moderate thermal, and I took the controls to show him
how we
"real" soaring pilots thermal. I cranked us over to 40 degrees of
bank to
core the thermal. "Now, watch how I slow us up to really tighten
the
circle..." I said. The owner mentioned that I ought to "be a little
careful [since] stall speed at this..." He never finished the
sentence.

Departure was instantaneous. Rotation was spectacular. I recall at
first
doing everything wrong. It took me at least one full revolution to
realise
that the glider was spinning, and I think it was a couple of seconds
more
before I figured out the direction. Fortunately, we were at least
4,000
AGL at the time, and the owner just sat back and let me figure things
out.

This flight came on a day when I had been the duty instructor in the
club.
I had probably done 4 or 5 incipient spin lessons earlier in the day,
and I
probably had 40 hours flying in the preceeding 90 days. So, I was
current
and reasonably on top of my game.

This experience just reinforced the fact that the ability to
recognize a
spin, especially an unplanned one, is probably not an easy thing to
teach.
The normal training mode is thoroughly unnatural, as the student is
primed
and ready. The reality is a lot different, and I'm wondering if any
of us
emphasize the recognition aspects of the immediate post-departure
moments
enough?

Erik Mann (P3)

wrote in message
oups.com...
John,

interesting thoughts. Even with strong visual cues, the more nose
down
a spin, the more difficult it might be to surmise its direction.
Thus,
a quick reference to the yaw string is in order. Isn't the Pooch
known
for its nose down attitude while spinning?

Yet another reason to put the emphasis on stall avoidance and
prompt
recovery from prestall conditions. A suprise stall and autorotation
at
low altitude presents a great a risk, even for well trained,
heads-up
pilots.

Since my original post today I mentioned the subject
to 2 instructors round the table at our club. One
had himself applied the wrong rudder in a spin and
he had also experienced a pupil doing the same.

When I was first taught spinning (aged 17 in 1969)
it was not immediately intuitively obvious to me which
way I was rotating without thinking back to what direction
the glider had been circling before departure - or
which wing had dropped if the instructor had started
the spin from a level stall. I confess that during
spin training, as the instructor started the spin
entry procedure, I made sure that I mentally rehearsed
in advance which rudder to apply - which rather defeated
the point I guess.

John Galloway


At 16:30 16 January 2005, Papa3 wrote:
I agree that this is an interesting point. Even experienced,
current pilots
can be caught off guard, and perhaps a better training/recognition
method
might be in order. Maybe the yaw string can/should
be a more integral
part of the program in terms of spin recovery training?

For what it's worth, I have had a couple of unintentional
spin entries over
the last 20 years. One in particular sticks in my
mind. A guy at the
local gliderport is an experienced aerobatics competitor;
he owns a two
place Fox aerobatic glider. He asked me to go up
with him one day, since
he was having some trouble getting the Fox to climb.
He figured thermals
were a lot cheaper than 5,000 foot aerotows.

We got into a moderate thermal, and I took the controls
to show him how we
'real' soaring pilots thermal. I cranked us over
to 40 degrees of bank to
core the thermal. 'Now, watch how I slow us up to
really tighten the
circle...' I said. The owner mentioned that I ought
to 'be a little
careful [since] stall speed at this...' He never finished
the sentence.

Departure was instantaneous. Rotation was spectacular.
I recall at first
doing everything wrong. It took me at least one full
revolution to realise
that the glider was spinning, and I think it was a
couple of seconds more
before I figured out the direction. Fortunately,
we were at least 4,000
AGL at the time, and the owner just sat back and let
me figure things out.

This flight came on a day when I had been the duty
instructor in the club.
I had probably done 4 or 5 incipient spin lessons earlier
in the day, and I
probably had 40 hours flying in the preceeding 90 days.
So, I was current
and reasonably on top of my game.

This experience just reinforced the fact that the ability
to recognize a
spin, especially an unplanned one, is probably not
an easy thing to teach.
The normal training mode is thoroughly unnatural, as
the student is primed
and ready. The reality is a lot different, and I'm
wondering if any of us
emphasize the recognition aspects of the immediate
post-departure moments
enough?

Erik Mann (P3)

wrote in message
roups.com...
John,

interesting thoughts. Even with strong visual cues,
the more nose down
a spin, the more difficult it might be to surmise
its direction. Thus,
a quick reference to the yaw string is in order. Isn't
the Pooch known
for its nose down attitude while spinning?

Yet another reason to put the emphasis on stall avoidance
and prompt
recovery from prestall conditions. A suprise stall
and autorotation at
low altitude presents a great a risk, even for well
trained, heads-up
pilots.

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

Since several experienced pilots have said that they have had trouble
determining the direction of the spin, I accept that it happens - and
that it can happen to me. I do not understand why. Most glider spins
happen when turning and, in the hunderds of intentional spins that I've
done (I have only one unintentional spin), the glider spins in the
direction of the turn. What am I missing? I do like the yaw string idea.

Tony V.

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.

Tony,

If the spin is unintentional, you may not have the presence of mind to
recall, at the moment of recognition, which way you were turning. The
brain is very efficient at dumping extraneous information to focus
entirely on the situation at hand. Unfortunately, this isn't always a
good thing. The whole spin training regimen is flawed, since it
presumes that you know you are entering a spin. It teaches you the
muscle memory to enter a spin, and a reflexive response once you've
entered, based almost entirely on the process of entry. As we become
more aware of the necessary steps to recognize and properly react to a
surprise spin, I think we're likely to become more interested in
improving our skill at avoiding them altogether.

Consider panic stops in an automobile as an anology. If you are on a
test track, you know exactly when you must apply the brakes on a
measured course to determine brake efficiency. A stopping distance of
100 to 140 feet from 60 mph is typical. But on the road we don't know
when we'll need to react. Response time must be added. This increases
stopping distance to over 300 feet.

In the glider we need to recognize that something is wrong, establish
what the problem is, then react properly. Intentionally entering the
spin is like taking a test with a textbook at your side, conveniently
opened to the appropriate page. But a surprise departure and
autorotation is going to require some flipping through the pages. And
getting it wrong could be devastating.

The first time I went over-the-top into a spin...it
definitely took a minute to figure out the rotation...others
experience may vary.


I was thinking about this topic and came up with this
observation....

1.) Training spin fatalities seem to happen from a
distance above earth that involves several rotations
before impact...for whatever reason, the spin developed
and could not be stopped.

2.) Inadvertant spin fatalities seem to almost always
occur so low (base to final)...that once the spin has
started, proper recovery probably would not save the
pilot.

So IMHO...are we really training for what is occuring?



At 18:00 16 January 2005, Tony Verhulst wrote:

Since several experienced pilots have said that they
have had trouble
determining the direction of the spin, I accept that
it happens - and
that it can happen to me. I do not understand why.
Most glider spins
happen when turning and, in the hunderds of intentional
spins that I've
done (I have only one unintentional spin), the glider
spins in the
direction of the turn. What am I missing? I do like
the yaw string idea.

Tony V.