Spinning the SZD 50-3

I love to spin. It's exciting. I took aerobatic training with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden. This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front, I spun it while
sitting in the back seat more than a dozen times. The CG was within
the published range and I didn't have any trouble with simple
recovery- stick centered and forward and rudder away from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than I am now, but
still in the published range for the plane.
During the training towards my instructors rating, I spun the Puch
twice with my instructor. The first 2 or so rotation spin I was able
to recover normally, no sweat. The second manuver was quite different.
I was asked to let the spin develop a little deeper for the second.
After 4 or so rotations, the nose seemed to float up and the rotation
*seemed* to slow considerably. I remember thinking that this is cool!
Kind of like floating. When it was time for the recovery I applied the
control inputs I'd been taught (as specified above) and much to my
surprise, nothing different happened.....for a long time. I estimate
that we completed another 5+ rotations nose high before it broke,
rolled over and recovered. I had the stick centered and against the
front stop with the rudder also pegged away from the rotation. We
recovered with several (4 or 5) thousand feet under us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the grumpy bar for
at least an hour. I (and he) decided to never spin the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that it was from
operation outside of the design envelope. Apparently I was wrong.
John Shelton probably said it best: "On my own as a test pilot, I will
certainly get killed". I felt like a dumb-ass for quite a while (more
than usual) after that.

Tim Shea wrote:
I love to spin. It's exciting. I took aerobatic training with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden. This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front, I spun it while
sitting in the back seat more than a dozen times. The CG was within
the published range and I didn't have any trouble with simple
recovery- stick centered and forward and rudder away from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than I am now, but
still in the published range for the plane.
During the training towards my instructors rating, I spun the Puch
twice with my instructor. The first 2 or so rotation spin I was able
to recover normally, no sweat. The second manuver was quite different.
I was asked to let the spin develop a little deeper for the second.
After 4 or so rotations, the nose seemed to float up and the rotation
*seemed* to slow considerably. I remember thinking that this is cool!
Kind of like floating. When it was time for the recovery I applied the
control inputs I'd been taught (as specified above) and much to my
surprise, nothing different happened.....for a long time. I estimate
that we completed another 5+ rotations nose high before it broke,
rolled over and recovered. I had the stick centered and against the
front stop with the rudder also pegged away from the rotation. We
recovered with several (4 or 5) thousand feet under us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the grumpy bar for
at least an hour. I (and he) decided to never spin the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that it was from
operation outside of the design envelope. Apparently I was wrong.
John Shelton probably said it best: "On my own as a test pilot, I will
certainly get killed". I felt like a dumb-ass for quite a while (more
than usual) after that.

Anyone else spin the Puch for more than three turns? What happened
(obviously you survived)? I've heard that some other aircraft also have
a flatter spin mode that after several turns that is hard to recover
from. Any knowledge of why this happens? (Now where's my copy of Stick
and Rudder?)

Shawn

If you were within the permitted CoG range, and used
the standard recovery method, the spin behaviour you
described is definitely non-compliant with JAR 22 certification
rules. JAR22.221 states that a sailplane certificated
for intentional spinning must be able to recover from
a fully developed spin (5 turns) within 1 turn after
recovery action is done. This has to be demonstrated
in several loading and control conditions.

Additionally, this paragraph states that it must be
impossible to obtain uncontrollable spins with any
use of the controls.

The Puchacz may not have been certificated to JAR 22,
but possibly to the older OSTIV rules. However, I very
much doubt that this type of behaviour would have been
acceptable under older certification rules, although
the verification/testing requirements might have been
less strict in earlier days.

Geir

At 01:00 28 January 2004, Tim Shea wrote:
I love to spin. It's exciting. I took aerobatic training
with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden.
This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front,
I spun it while
sitting in the back seat more than a dozen times. The
CG was within
the published range and I didn't have any trouble with
simple
recovery- stick centered and forward and rudder away
from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than
I am now, but
still in the published range for the plane.
During the training towards my instructors rating,
I spun the Puch
twice with my instructor. The first 2 or so rotation
spin I was able
to recover normally, no sweat. The second manuver was
quite different.
I was asked to let the spin develop a little deeper
for the second.
After 4 or so rotations, the nose seemed to float up
and the rotation
*seemed* to slow considerably. I remember thinking
that this is cool!
Kind of like floating. When it was time for the recovery
I applied the
control inputs I'd been taught (as specified above)
and much to my
surprise, nothing different happened.....for a long
time. I estimate
that we completed another 5+ rotations nose high before
it broke,
rolled over and recovered. I had the stick centered
and against the
front stop with the rudder also pegged away from the
rotation. We
recovered with several (4 or 5) thousand feet under
us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the
grumpy bar for
at least an hour. I (and he) decided to never spin
the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that
it was from
operation outside of the design envelope. Apparently
I was wrong.
John Shelton probably said it best: 'On my own as a
test pilot, I will
certainly get killed'. I felt like a dumb-ass for quite
a while (more
than usual) after that.

"Shawn Curry" wrote in message
link.net...
Tim Shea wrote:
I love to spin. It's exciting. I took aerobatic training with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden. This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front, I spun it while
sitting in the back seat more than a dozen times. The CG was within
the published range and I didn't have any trouble with simple
recovery- stick centered and forward and rudder away from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than I am now, but
still in the published range for the plane.
During the training towards my instructors rating, I spun the Puch
twice with my instructor. The first 2 or so rotation spin I was able
to recover normally, no sweat. The second manuver was quite different.
I was asked to let the spin develop a little deeper for the second.
After 4 or so rotations, the nose seemed to float up and the rotation
*seemed* to slow considerably. I remember thinking that this is cool!
Kind of like floating. When it was time for the recovery I applied the
control inputs I'd been taught (as specified above) and much to my
surprise, nothing different happened.....for a long time. I estimate
that we completed another 5+ rotations nose high before it broke,
rolled over and recovered. I had the stick centered and against the
front stop with the rudder also pegged away from the rotation. We
recovered with several (4 or 5) thousand feet under us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the grumpy bar for
at least an hour. I (and he) decided to never spin the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that it was from
operation outside of the design envelope. Apparently I was wrong.
John Shelton probably said it best: "On my own as a test pilot, I will
certainly get killed". I felt like a dumb-ass for quite a while (more
than usual) after that.

Anyone else spin the Puch for more than three turns? What happened
(obviously you survived)? I've heard that some other aircraft also have
a flatter spin mode that after several turns that is hard to recover
from. Any knowledge of why this happens? (Now where's my copy of Stick
and Rudder?)

Shawn

OK, this is speculation.

Remember the old spin-the-hammer trick from freshman physics? It seems
solid objects don't like to spin around their long axis - they prefer to
spin about their shortest. Imagine a glider with the CG in the middle of
the allowed range but the mass distributed far away from the CG in heavy
wings and long fuselage with a heavy load in the cockpit balanced with a
weight in the tail. Might it tend to flatten and spin about the vertical
axis?

BTW, any time I feel a glider hesitate to recover from a spin, I'm going to
throw full aileron into the spin. (As per the POH of most Eastern European
gliders.)

Bill Daniels

Bill Daniels

You shouldn't spin more than 3 turns unless you're practicing for aerobatic
flight.

In a case as you describe, application of full PRO-SPIN controls for a few
seconds should have been performed prior to a second attempt at recovery.
And recovery should be rudder and stick at the same time (as recomended by
Dick Johnson after his testing) or with the Rudder leading the recovery by 1
second or so (as recomended by the Puchacz's POH).
Commencing recovery with the Stick first is not recomended, and it may in
fact retard recovery significantly.

Also, chances are that you didn't have the stick and/or rudder against the
stops, for simple reasons such as Trim not being Neutral (as recommended by
the manual), or the Ailerons might not have been Neutral (as they should),
or the CG may have been slightly off-limits.
The same things would cause similar behaviour in any other modern training
glider.

In a regular spin, with 3 or less rotations, some of these things are less
of an issue, but they have to be observed anyway.

Recovery however has to be the same way in a fully developed spin :
-Anti-spin rudder to the stop
-After 1 second or less, release back pressure on the stick or even move it
forward, all-the-way if you have to.
Rotation should stop.
If it doesn't, apply full pro-spin controls, verify the ailerons in neutral
(stick not in any of the sides) and trim in neutral, then repeat recovery.



"Tim Shea" wrote in message
m...
I love to spin. It's exciting. I took aerobatic training with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden. This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front, I spun it while
sitting in the back seat more than a dozen times. The CG was within
the published range and I didn't have any trouble with simple
recovery- stick centered and forward and rudder away from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than I am now, but
still in the published range for the plane.
During the training towards my instructors rating, I spun the Puch
twice with my instructor. The first 2 or so rotation spin I was able
to recover normally, no sweat. The second manuver was quite different.
I was asked to let the spin develop a little deeper for the second.
After 4 or so rotations, the nose seemed to float up and the rotation
*seemed* to slow considerably. I remember thinking that this is cool!
Kind of like floating. When it was time for the recovery I applied the
control inputs I'd been taught (as specified above) and much to my
surprise, nothing different happened.....for a long time. I estimate
that we completed another 5+ rotations nose high before it broke,
rolled over and recovered. I had the stick centered and against the
front stop with the rudder also pegged away from the rotation. We
recovered with several (4 or 5) thousand feet under us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the grumpy bar for
at least an hour. I (and he) decided to never spin the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that it was from
operation outside of the design envelope. Apparently I was wrong.
John Shelton probably said it best: "On my own as a test pilot, I will
certainly get killed". I felt like a dumb-ass for quite a while (more
than usual) after that.

In article ,
Geir Raudsandmoen
om wrote:

If you were within the permitted CoG range, and used
the standard recovery method, the spin behaviour you
described is definitely non-compliant with JAR 22 certification
rules. JAR22.221 states that a sailplane certificated
for intentional spinning must be able to recover from
a fully developed spin (5 turns) within 1 turn after
recovery action is done. This has to be demonstrated
in several loading and control conditions.

Fine.


Additionally, this paragraph states that it must be
impossible to obtain uncontrollable spins with any
use of the controls.

But how on earth can that be demonstrated? No matter *what* you do, you
can't get into an uncontrollable spin? But there are an infinite number
of possible things you *might* do with the controls. They can't ALL be
tested.

-- Bruce

Shawn Curry wrote in message hlink.net...
Tim Shea wrote:
I love to spin. Anyone else spin the Puch for more than three turns?

What happened
(obviously you survived)? I've heard that some other aircraft also have
a flatter spin mode that after several turns that is hard to recover
from. Any knowledge of why this happens? (Now where's my copy of Stick
and Rudder?)

Shawn


The Puke will usually recover quickly within the first 3 or so turns,
but it does go int a more stable, nose higher-type rotation after
maybe 4 or 5.
I've spun both the 55 and the 59 out of wave, maybe 15 turns or so,
and experianced what Tandem Tim described. I also got into this mode
in the 103 once, believe it or not, spinning it up over 17K. I believe
it has most to do with the gyroscopic inertia that builds after a few
turns.
SInce I was plenty high, ( in each case) my first thought was to
loosen the belts & lean forward, but I wanted to try control input
first. I held full opposite rudder, and centered & full forward stick.
In each case, they dropped through & recovered, but you had to sit
through a few rev's just holding those inputs and Believe that it will
eventually work. I was ready to try other options & inputs, but I
wanted to see if the hold-it & wait method would work.
It was a bit unnerving, the 103 went on for maybe 3 turns, the Puch
maybe 4, and the 59 maybe 5 or 6. (I don't remember if I had the tips
on) and I would never enter that mode again without 2 miles between me
and the nearest planet, and a rented plane.
If you instruct to fully developed rotation, start recovery in the
Puch as soon as it falls through, or within 1 turn, and don't stick
yer toes under the back seat pedals.
I fully agree with putting the emphasis on incipiant recovery, tho I
think there's value in training a pilot to remain calm & methodical in
an unexpected emergancy event, when the world is spinning way faster
than it should.
For those up to it, it does a nice snap at 55~60, nose up a little, &
full rudder, elevator & aileron. If you hold it all the way through,
it comes around a second time with the nose real high. (Flame suite on
for the safety nazis)

Remember to live live at your own risk,
Choose your level of involvement to be just under your ability, and
remember...
You've gotta be tough...
If you're gonna be stupid.
-Dan

The Puchacz WAS certified to JAR 22. When it was first
imported into the UK I repeated the tests, prior to
the BGA granting it certification. The testing included
five turns spins with the C of G at the manufacturers
aft limit; recovery was normal in well under one turn.

Having said that:

1. I once had a similar experience to the one described,
when flight testing the Grob Twin II for BGA certification.
Earlier spins at mid-range C of G had been typically
Grob - self recovery after less than a turn. I expected
that it would be just possible to hold it in at aft
C of G. In fact the spin started to flatten after
about two turns. I initiated recovery immediately,
it took three turns to recover (I was considering abandoning
the aircraft at that point).

After lots of phone calls to the manufacturer (who
said it had never happened in their testing), we resumed
testing (Cautiously) and approached the aft C of G
in small increments. Eventually we got to the C of
G position at which I had had the problem - the spin
was perfectly normal! So far I was aware, I had used
exactly the same spin entry technique in both cases.
Clearly there must have been some small difference
(ailerons not quite central, or some such) that made
an important difference. Whatever the cause, I couldn't
get it to repeat, all subsequent spins were unremarkable.

Rogue spins can happen, IN ANY TYPE.

2. The Puchacz described may have had some repair,
or equipment change, that moved the C of G further
aft, and this failed to get into the aircraft's records
(appalling, I know, but it has happened).

3. The elevator deflections may have become mis-set,
allowing greater upward deflection, and less downward.
This can happen unintentionally, I don't know how,
but it would very likely produce the result described.


At 01:36 28 January 2004, Geir Raudsandmoen wrote:
If you were within the permitted CoG range, and used
the standard recovery method, the spin behaviour you
described is definitely non-compliant with JAR 22 certification
rules. JAR22.221 states that a sailplane certificated
for intentional spinning must be able to recover from
a fully developed spin (5 turns) within 1 turn after
recovery action is done. This has to be demonstrated
in several loading and control conditions.

Additionally, this paragraph states that it must be
impossible to obtain uncontrollable spins with any
use of the controls.

The Puchacz may not have been certificated to JAR 22,
but possibly to the older OSTIV rules. However, I very
much doubt that this type of behaviour would have been
acceptable under older certification rules, although
the verification/testing requirements might have been
less strict in earlier days.

Geir

At 01:00 28 January 2004, Tim Shea wrote:
I love to spin. It's exciting. I took aerobatic training
with Wayne
Handley and was taught spin recoveries by him.

I have direct experience spinning the Puchacz at Minden.
This is what
I remember from my experience. Your mileage may vary.
With friends (usually lighter than me) in the front,
I spun it while
sitting in the back seat more than a dozen times. The
CG was within
the published range and I didn't have any trouble with
simple
recovery- stick centered and forward and rudder away
from the
direction of rotation. Worked great.
I should mention that I used to be 50 lbs heavier than
I am now, but
still in the published range for the plane.
During the training towards my instructors rating,
I spun the Puch
twice with my instructor. The first 2 or so rotation
spin I was able
to recover normally, no sweat. The second manuver was
quite different.
I was asked to let the spin develop a little deeper
for the second.
After 4 or so rotations, the nose seemed to float up
and the rotation
*seemed* to slow considerably. I remember thinking
that this is cool!
Kind of like floating. When it was time for the recovery
I applied the
control inputs I'd been taught (as specified above)
and much to my
surprise, nothing different happened.....for a long
time. I estimate
that we completed another 5+ rotations nose high before
it broke,
rolled over and recovered. I had the stick centered
and against the
front stop with the rudder also pegged away from the
rotation. We
recovered with several (4 or 5) thousand feet under
us (we'd been
playing at cloudbase at about 15K).
Once on the ground, we discussed this incident in the
grumpy bar for
at least an hour. I (and he) decided to never spin
the Puch again. I
didn't. I doubt he did either.
I had heard of this happening before. I assumed that
it was from
operation outside of the design envelope. Apparently
I was wrong.
John Shelton probably said it best: 'On my own as a
test pilot, I will
certainly get killed'. I felt like a dumb-ass for quite
a while (more
than usual) after that.

Reading of these brave souls who have been testing the Puchaz spinning
characteristics with multi-turn spins at high altitudes reminds me of an
anecdotal rumour which reached me about at least one other glider type,
and I think also some power aircraft, which similarly misbehaved until
many turns/it got lower. It made me wonder a few things:

At the heights people here have been writing about - 10 to 17 thousand
feet - what is the true airspeed at which it enters the spin on command
and how does that differ from the lower altitude airspeed used for
certification tests? Bear in mind also one poster's comments that a
glider does not instantly cease forward motion and go instead into
vertical motion with a rotational component - in the absence of infinite
forces, the first is subject to some deceleration taking time and space,
and the second some vertical acceleration taking time and height.

Similarly, what is the true vertical velocity at onset and when stable
in the spin?

What is the ratio of those two velocities compared with the ratio at
test air densities?

Does the rotation rate remain identical, whether at height (lower air
densities) or at lower altitude (higher density)?

Does all that have an effect on true angle of attack?

Could such things account for high altitude spins when fully developed
requiring more turns to recover?

I wonder if the people who conduct these high altitude tests were in a
regime not tested by the maker or the certification test pilots such as
Chris Rollings?

Chris N.

On Wed, 28 Jan 2004 00:56:12 UTC, (Tim Shea)
wrote:

: After 4 or so rotations, the nose seemed to float up and the rotation
: *seemed* to slow considerably. I remember thinking that this is cool!
: Kind of like floating. When it was time for the recovery I applied the
: control inputs I'd been taught (as specified above) and much to my
: surprise, nothing different happened.....for a long time. I estimate
: that we completed another 5+ rotations nose high before it broke,
: rolled over and recovered.

I am told that a Junior oscillates nose up and down while spinning,
and that recovery is much much snappier nose down.

Ian