Yaw String in a Spin

At 12:00 16 January 2005, John Galloway wrote:
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



Good post, but I must point out a trap. I learned
from a student that it is easy to misunderstand which
end of the string is doing the pointing.

I always taught students to 'step on the head of the
snake.' One student could never get it right (never
been around snakes) and he was stepping on the tail
-- the aft, unattached end. I found that other students
had figured out their own way of bringing the string
into line and just ignored my comments.

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.

On the other hand, perhaps my analogies are just weird.

"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

Duane Eisenbeiss wrote:

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.

It is impossible for the forward end to "point" at anything,
since it is fixed in place by tape. The string pivots
around its stationary forward end.

Any "pointing" is of course done by the free aft end
of the string, away from the pivotal point.

Same thing as the hands of a clock. The minute hand
points "right", not left, at five past twelve.

If you give left rudder you will slip to the right
and the string will point left.

Cheers CV

CV wrote:
Duane Eisenbeiss wrote:


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.


It is impossible for the forward end to "point" at anything,
since it is fixed in place by tape. The string pivots
around its stationary forward end.

Any "pointing" is of course done by the free aft end
of the string, away from the pivotal point.

Same thing as the hands of a clock. The minute hand
points "right", not left, at five past twelve.

If you give left rudder you will slip to the right
and the string will point left.

So do you tell students that the wind sock points to where the wind is
going?
Impossible or not, by using my *imagination* early in my flying career,
I was able to simply and quickly make sense of what the yaw string was
indicating without having to think about where the relative wind was
coming from, or which pedal to push.
Jeez.

Shawn