Puchaz Spinning thread that might be of interest in light of the recent accident.

I was taught this 'pause' between full opposite rudder
and stick forward and the wind 'shadow' effect was
the reason; However, since it has been proven that
even a Puchacz, which has a low(ish) tailplane, will
recover faster without the pause (Dick Johnson) and
most gliders have 'T' tails to which it doesn't apply
at all, I for one will not be teaching the 'pause'
to my students.
Rob John
Duo 'Si' K6 '350'

In a fully developed spin the tail surfaces can see
an
airflow that has a significant component coming from
underneath the tail surfaces. If the tail surfaces
are
'conventional,' (i.e. not a T-tail), and the elevator
and
horizontal stabilizer are on the fuselage, below the
rudder,
then forward stick produces a 'shadow' in this airflow
which
can block the lower portion of the rudder near the
elevator.
This 'shadow' is reduced when the stick is back. If
you
stand below the elevator and look upward (difficult,
I know)
and move the stick forward in a 1-26, for example,
this
'shadow' effect can be seen. Thus, I was told there
are
some POH's for conventional tail aircraft that recommend
using rudder *before* forward stick in the full spin
to
maximize the effectiveness of the anti-spin rudder.


At least this is what I recall as being the explanation
received from my first flight instructor. Does anyone
else
recall this 'explanation?'


Todd Pattist - 'WH' Ventus C
(Remove DONTSPAMME from address to email reply.)

Robert John wrote in message ...
I was taught this 'pause' between full opposite rudder
and stick forward and the wind 'shadow' effect was
the reason; However, since it has been proven that
even a Puchacz, which has a low(ish) tailplane, will
recover faster without the pause (Dick Johnson) and
most gliders have 'T' tails to which it doesn't apply
at all, I for one will not be teaching the 'pause'
to my students.
Rob John
Duo 'Si' K6 '350'


Then I hope you will read the revision to the AS-K 21 POH,
which updated/changed the spin recovery protocol to include the
'pause' based on flight testing, after a spinning fatality
in the K-21.
No pause, slower recovery.
Pause, more prompt recovery.
K-21 is a T-tail.

Beware broad judgments.
Please know your POH and its recommended procedures.
If you teach/deliberately enter spins, have a predetermined exit
altitude for non-responsive behavior, or don't bother wearing the chutes.

If there was on line access for the USAF Spin Eval report for the K-21,
I would make it available... but I have no electronic source.

Cindy B
www.caracolesoaring.com

The flight manual for the AS-K21 that I flew yesterday basically says
full opposite rudder, pause, and then stick forward. The manual also
had a note that some of the manual's contents had been included due
use by the USAF.

On the other hand, the flight manual for my LS-3a states to terminate
spins by "pronounced deflection of rudder opposite to spin direction
and careful pull out". I guess that means you don't have to move the
stick forward for spin recovery! Hmmm...must be magic!

Steve

Robert John wrote in message ...
I was taught this 'pause' between full opposite rudder
and stick forward and the wind 'shadow' effect was
the reason; However, since it has been proven that
even a Puchacz, which has a low(ish) tailplane, will
recover faster without the pause (Dick Johnson) and
most gliders have 'T' tails to which it doesn't apply
at all, I for one will not be teaching the 'pause'
to my students.
Rob John
Duo 'Si' K6 '350'

In a fully developed spin the tail surfaces can see
an
airflow that has a significant component coming from
underneath the tail surfaces. If the tail surfaces
are
'conventional,' (i.e. not a T-tail), and the elevator
and
horizontal stabilizer are on the fuselage, below the
rudder,
then forward stick produces a 'shadow' in this airflow
which
can block the lower portion of the rudder near the
elevator.
This 'shadow' is reduced when the stick is back. If
you
stand below the elevator and look upward (difficult,
I know)
and move the stick forward in a 1-26, for example,
this
'shadow' effect can be seen. Thus, I was told there
are
some POH's for conventional tail aircraft that recommend
using rudder *before* forward stick in the full spin
to
maximize the effectiveness of the anti-spin rudder.


At least this is what I recall as being the explanation
received from my first flight instructor. Does anyone
else
recall this 'explanation?'


Todd Pattist - 'WH' Ventus C
(Remove DONTSPAMME from address to email reply.)

Steve Pawling wrote:
...
On the other hand, the flight manual for my LS-3a states to terminate
spins by "pronounced deflection of rudder opposite to spin direction
and careful pull out". I guess that means you don't have to move the
stick forward for spin recovery! Hmmm...must be magic!
...

The stick forward is in some way implied by the "careful pull out", if
you keep the stick at the place which caused the spin, i.e. near the
back stop, the pull out would be rather agressive if not stalled.