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

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.

None of what I write here has anything to do with any accidents for
which the investigation is ongoing, analysis is incomplete, or reports
not yet published. My views have largely been made known before, at
times when no fatal accidents were in the news.

Another caveat - I am no longer a gliding instructor and my views have
no official place in the scheme of things.

First, there is now, rightly I believe, much more pre-solo emphasis on
awareness of the imminence of a stall or spin and recognition in time to
prevent it happening. I suspect even more training there would be a good
thing.

Second, I think there should be enough training in actual full spins and
recoveries that it becomes automatic to recognise it and correctly
recover. I do not think that happens generally at present.

Thirdly , I think that spin training and practice in recovery, in
suitable gliders, should continue post solo, for as long as the pilot
keeps flying, to keep the automatic recovery reflex in good nick. I am
convinced that for most, that does not happen today. The reason in part
for all three points so far, is that spinning into the ground solo, or
while pilot in command, has remained one of the top UK killers. I cannot
see how stopping spin training could reduce the incidence of such solo
accidents, and the small number while training which might be prevented
are surely likely to be more than offset by yet more inadvertent spins
if training were stopped altogether.

Fourth, note "suitable" in my third point - I would rather not have
early solo pilots doing solo spin practice in a Puchaz, for instance,
though I am willing to listen to arguments otherwise from those with
more experience.



The reason I believe that full spin training should be maintained AS
WELL AS, not instead of avoidance/recognition training, is that there
continue to be accidents originating at heights where recovery is
possible - if only the pilot would recognise it.

A typical gliding accident, though with an atypically happy ending, was
like this. The pilot's survival and hence first-hand account gives a
rare insight to one's thought processes when such an accident is
happening.

A solo glider pilot had a winch launch. Cable broke at about 4-600 feet.
Pilot heard bang and felt jerk of cable breaking, forgot all training,
and concluded tail falling off or similar. He lowered nose of glider
from climb attitude to attempt to maintain (or regain) normal attitude
and flying speed - only thing done right in the whole event.

He thought he had enough height to to an abbreviated circuit, and
initiated a turn, without checking speed was sufficient.

Observers say he did two full turns or more of a spin. He said he saw
the ground spinning which seemed to confirm to him that the glider was
out of control as tail had fallen off or whatever, so he pulled back on
the stick hoping to get the nose up. It didn't work, and he concluded he
was going to die.

He can't remember the next bit for certain, but thinks he let go of
everything and covered his face. Benign glider then recovered from spin
into steep dive. (The end result was a landing with some damage but no
major injury to the pilot.)

To me, a key element is that he saw the ground spinning but never
considered that the glider was in a spin. That can only be put down to
lack of familiarity if all the other steps in avoidance have been
missed. Yes, he also needed (imho) better cable break training, better
flight situation awareness, better recognition of onset of stall/spin,
but in the end when all those failed the one last thing to save him
might have been familiarity with a full spin and the correct reaction to
it. What actually saved him was the glider design. Not all would.

Chris N.

On Mon, 26 Jan 2004 17:40:38 UTC, Chris Nicholas
wrote:

: Thirdly , I think that spin training and practice in recovery, in
: suitable gliders, should continue post solo, for as long as the pilot
: keeps flying, to keep the automatic recovery reflex in good nick.

My club - Borders GC - insists on comprehensive spin checks for all
pilots as part of the annual checks. I rather enjoy those flights,
particularly when I can persuade a light instructor to go in the front
of a Bocian while I fly from the back...

Ian


--

I spoke today with the British Gliding Association (with Barry Rolfe, the
long serving employed full time Secretary and Administrator).

I also received a message today in reply to questions of mine to the
Department of Transport, Air Accidents Investigation Branch.

From these communications and others I have seen, my conclusion is:

No-one is yet prepared to say how or why the Puchacz crashed. In
particular, no-one will confirm that a stall-spin was involved; assumptions
that the glider was spinning are speculation and rumour.

The accident is being investigated by the AAIB, therefore when the report is
completed it will be published by them in their monthly printed report and
on-line at www.aaib.gov.uk , go to Bulletins
http://www.dft.gov.uk/stellent/group...cst?n=5254&l=2 .
The report will be included under the month and year of the date of the
report, not the date of the accident.

There have been four previous fatal accidents in the U.K. involving a
Puchacz. None of these were investigated by the AAIB, therefore the
reports are not available from the AAIB, the reports would have been
prepared by the BGA. No BGA accident reports are available on-line.

The previous 4 Puchacz accidents all involved stall/spinning.

I should mention that I personally am not, and never have been involved in
any capacity with the BGA sub-groups who deal with Accident Investigation,
Safety, Instruction or Technical matters.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Al" wrote in message
...
http://www.gliderforum.com/thread-vi...id=167&start=1

This might be of interest when discussing the Puch and its spinning.

Condolences to the family and friends of the victims of the recent crash.

Regards

Al

Hi All
Hope I'm not covering old ground on this thread and
may I start by saying since we don't know the cause
of the recent Puchacz incident, this doesn't relate
to it, but the content of the thread. I knew John.
He smiled lots.

Much good advice within indeed. My first syndicate
was a Bocian and IS29D, both of which spun at will,
the IS29 without any pre-stall buffet. I once managed
to spin the IS29 at the top of a loop which was slightly
the wrong side of exciting...

It does seem inexplicable (try as we might) that competent
folks on well proven gliders get bitten. Sure spinning
is complex and instruction invariably tries to be simple
- 'if the nose drops, ease the stick forward' etc.
With brain overload easily induced in students, it
has to be simple. Perhaps the more complex subtleties
of spinning SHOULD be introduced later as 'Advanced
spin awareness'?

One other consideration you may wish to ponder is the
British weather, with possible icing and wet wings.
This easily produces an asymetric wing:
Imagine the instructional flight. All upper air work
done well, the air's smooth and we try that old chestnut
of the 'unexpected' deeper stall in the circuit - the
one where the nose is down, grounds coming up and we
just can't resist pulling before it's 'unstuck'. Demonstrated
to me. Instructed by me. But NEVER in a wet or icy
Puchacz, Bocian, IS29. Even a gentle simple, stall
could bite very differently with wet / icy wings and
turn a benign glider into something far more interesting.

Fly safe out there.
Pete Harvey


At 15:24 28 January 2004, Robert Ehrlich wrote:
Ian Johnston wrote:

On Tue, 27 Jan 2004 12:35:43 UTC,
(Chris
OCallaghan) wrote:

: the point of my link was to show that you will not
spin from
: coordinated flight.

Tight turn. Slow speed. String in the middle. Pull
up sharply as if
another glider has just cut into the thermal. Whoops.
Well, it works
in a Bocian, anyway.

Ian
--

Another way I experienced it during my 1st flight in
an ASH25 (with
an instructor in the back seat of course). Circling
in a thermal, with
just to much aft stick than approriate. Speed slowly
decayed (slowly
beacause the hight weight and inertia of the glider),
induced roll
and yaw slowly increased, needing more and more inside
rudder and
outside stick, up to the point where a incipent spin
started, immediateley
stopped by releasing back pressure and centralizing
ailerons and rudder.
At the time of departure, stick and rudder were strongly
crossed,
but the flight was coordinated and the yaw string in
the middle.

At 09:48 31 January 2004, Arnold Pieper wrote:

The correct control input, which is to apply right
rudder to pick it up, move stick forward enough the
reduce AOA.

Sorry to pull one part of your story out for comment.

Some years ago the British Gliding Association dropped
the term incipient spin and called this 'Stall With
With Wing Drop'.

Most older instructors and pilots were taught as you
decribed to pick up the dropping wing with rudder.


The current BGA instructors manual states:-)

'When a wing drops at the stall it is essential to
unstall the glider before attempting to level the wings.
Once the glider is unstalled, level the wings with
coordinated ailerons and rudder.' Section 18 page 2

In the demonstration and practice section page 18.4.
The instructor is told

'Emphasise

the wings are levelled with coordinated use of ailerons
and rudder, BUT ONLY AFTER the glider is unstalled.'

Spinning is merely the natural consequence of failure
to understand and/or recognise the onset of the problems
caused by flying at or close to the stalling speed.
It is for this reason that students should be taught
both in theory and practice the stall symptoms and
the BGA further stalling exercises. Together with the
dangers of flying at of close to the stall speed in
any phase of their flight.

I agree that in many cases merely relaxing the back
pressure on the stick to regain flying speed can prevent
the onset of stalling the wing and it consequences.


Dave

I see Dave.

I'm courious now :
When you're teaching Stalls and a wing is low just before the stall, you
don't pick it up until AFTER the stall ?

This is not the way it's done in both countries where I fly.


"Dave Martin" wrote in message
...
At 09:48 31 January 2004, Arnold Pieper wrote:

The correct control input, which is to apply right
rudder to pick it up, move stick forward enough the
reduce AOA.

Sorry to pull one part of your story out for comment.

Some years ago the British Gliding Association dropped
the term incipient spin and called this 'Stall With
With Wing Drop'.

Most older instructors and pilots were taught as you
decribed to pick up the dropping wing with rudder.


The current BGA instructors manual states:-)

'When a wing drops at the stall it is essential to
unstall the glider before attempting to level the wings.
Once the glider is unstalled, level the wings with
coordinated ailerons and rudder.' Section 18 page 2

In the demonstration and practice section page 18.4.
The instructor is told

'Emphasise

the wings are levelled with coordinated use of ailerons
and rudder, BUT ONLY AFTER the glider is unstalled.'

Spinning is merely the natural consequence of failure
to understand and/or recognise the onset of the problems
caused by flying at or close to the stalling speed.
It is for this reason that students should be taught
both in theory and practice the stall symptoms and
the BGA further stalling exercises. Together with the
dangers of flying at of close to the stall speed in
any phase of their flight.

I agree that in many cases merely relaxing the back
pressure on the stick to regain flying speed can prevent
the onset of stalling the wing and it consequences.


Dave

A spin means both wings have too high AOA and
one wing has more AOA than the other.

If you can change the AOA of both wings so they are unstalled,
using elevator only, and the stress from the now entered spiral
doesn't make the aircraft wings twist and shatter during recovery dive,
then fine, do that.

If you can't, then it would be great to have both
wings at the same AOA, then reduce the AOA. Rudder is
a possible way to do this (make both wings have the
same AOA by making them both the same airspeed, by
countering the yawing motion). In the ensuing dive
recovery, the wings are level. In some aircraft
these stresses are different than turn/spiral stresses
and the wing structure handles them better.

I suspect this is the reasoning behind
the PARE mnemonic, where rudder is used before elevator.

Power off (for them motorglider thingies)
Aileron Neutral
Rudder Opposite
Elevator forward enough to break stall

Of course, even this mnemonic doesn't work all the
time (sometimes extra power to make the tail surfaces
more effective is better, etc.).

So results for any generalization may vary...

"Mark James Boyd" wrote in message
news:401eb7ea$1@darkstar...
A spin means both wings have too high AOA and
one wing has more AOA than the other.

If you can change the AOA of both wings so they are unstalled,
using elevator only, and the stress from the now entered spiral
doesn't make the aircraft wings twist and shatter during recovery dive,
then fine, do that.

If you can't, then it would be great to have both
wings at the same AOA, then reduce the AOA. Rudder is
a possible way to do this (make both wings have the
same AOA by making them both the same airspeed, by
countering the yawing motion). In the ensuing dive
recovery, the wings are level. In some aircraft
these stresses are different than turn/spiral stresses
and the wing structure handles them better.

I suspect this is the reasoning behind
the PARE mnemonic, where rudder is used before elevator.

Power off (for them motorglider thingies)
Aileron Neutral
Rudder Opposite
Elevator forward enough to break stall

Of course, even this mnemonic doesn't work all the
time (sometimes extra power to make the tail surfaces
more effective is better, etc.).

So results for any generalization may vary...

I did this calculation for my Nimbus 2 and found a 14 Kt. speed difference
across the 20 meter span in a normal thermalling situation with the ship
dry. (45 Kts/45 degree bank.)

Pushing the envelope a bit by slowing up and tightening the turn, I found
the typical big wing roll-off toward the low wing, but it didn't seem like a
spin departure. What I think is happening is that the inside wing is on the
back side of the polar and outside of the drag bucket, but still not
stalled. This produces a pronounced roll and yaw into the turn which
develops into a spiral dive if allowed to continue. The recovery is the
same as an incipient spin, reduce the back pressure, let the speed increase
a bit, reduce the bank and stay coordinated.

Bill Daniels