Spinning the SZD 50-3

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.

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

Independently of the type of certification which did the Puchacz =
undergo, it has been put through a very extensive in-flight testing =
program. The SZD used to be a state runned company which in this area =
meant that the new glider has to pass a very detailed programme of tests =
almost without counting the costs (remember that it was designed in deep =
communism era where the economy rules we know didn't exist in practice).
It has to be tested thoroughly as it was intended to be full acro =
allowed two seater which was mainly designed to be a primary trainer.

Nowadays *all* Polish clubs use the Puchacz for spin training (the =
Bocians have been prohibited to spin after they reached the age of 25), =
as there are no other trainers than few (maybe 5 all) KR-03 Puchateks =
(known also as Krosno or Peregrine). For ten years I have been flying =
gliders I have never heard of any accident like this one which started =
all the recent threads on Puchacz. There were few spin fatalities =
indeed, even one in aour club, but all of them happened on the final =
leg, or in the moment of the base/final leg turn, most of them caused by =
the licensed (but not used to fly from the instructor's cockpit) pilot =
in the backseat carrying passenger in the front seat.

Regards,


--=20
Janusz Kesik

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