Spins, Spiral Dives and Training

On 2 July, 20:21, Brian wrote:

I totally believe most stall spin accident soccur because the pilot is
not thinking about a stall spin and is not on the hair trigger ready
to recover, .i.e. they are distracted from this issue.

I believe that many of the spin accidents in the UK occur because most
pilots are trained ab initio in unspinnable gliders and, whatever
their instructors say, end up believing deep down that spins have to
be specially provoked in specially prepared or chosen aircraft.

What glider has killed most pilots in spins? The K21.

Ian

That is a bit unfair on the K21!. The training glider that has killed the
most pilots in spin related accidents in the UK is easily the Puchacz,
latest count about 14 I believe.

The K21 is a very safe glider in itself, but even that will do enough of a
wing drop to have you into the ground off a poorly executed low final turn.
My club still uses K13s as its basic trainer as it will just about drop
wings and spin if you force it to, but it is still more docile than many
single seaters.

You are getting into the debate about whether deliberate spin training
kills more people than accidental spins.

I know from personal experience that an unexpected spin, e.g. in a rough
thermal, can come as a bit of a shock, and it can take time to remember
what to do about it.

Derek Copeland

At 09:17 03 July 2009, Ian wrote:
On 2 July, 20:21, Brian wrote:

I totally believe most stall spin accident soccur because the pilot is
not thinking about a stall spin and is not on the hair trigger ready
to recover, .i.e. they are distracted from this issue.

I believe that many of the spin accidents in the UK occur because most
pilots are trained ab initio in unspinnable gliders and, whatever
their instructors say, end up believing deep down that spins have to
be specially provoked in specially prepared or chosen aircraft.

What glider has killed most pilots in spins? The K21.

Ian

At 11:00 03 July 2009, Del C wrote: (Snip)
The training glider that has killed the
most pilots in spin related accidents in the UK is easily the Puchacz,
latest count about 14 I believe.

And no positively identified cause, the conclusion has always been that
the spin in was caused by an error of skill by the pilot but that is
difficult to confirm. It could be that under certain loading conditions
the Putchaz is irrecoverable from a spin, we may never know for certain.
We do know that the Putchaz is a very dangerous glider, and has been
involved in more than it's fair share of accidents.

You are getting into the debate about whether deliberate spin training
kills more people than accidental spins.

There is no debate, more people are killed in deliberately induced spins
than in accidental ones and yet people still deliberately spin at
ridiculously low altitudes, and by that I mean below 2500ft.

This despite the fact that knowing the spin recovery procedure would be
unlikely to help in the most common spin, that off the final turn. The
only thing that would help there is spotting the impending spin before it
happened but little or no emphasis is placed on this in current training.
We have the situation where the most life threatening situation is not
addressed by proper training and an aspect, which gives an instructor the
opportunity to scare his pupil witless, is very well covered.
Current spin training is more about addressing the needs of the
instructors than about addressing the need of their pupils. I would
suggest that not commencing spin recovery procedure in a low spin, as off
the final turn, would be more likely to save your life than getting part
way through the recovery.

More emphasis is needed on recognition of the lead up and prevention, if
that was done properly then we might improve things. By all means teach it
but rather than checking recovery every year check the ability to recognise
and prevent. Less risk and the potential of greater benefit, it would also
reduce the need for clubs to own the potentially lethal Putchaz as the
recognition and prevention could be done in any two seater.

On 3 July, 15:45, Don Johnstone wrote:

We do know that the Putchaz is a very dangerous glider, and has been
involved in more than it's fair share of accidents.

That is a correlation, not a causation. Most Puchacz spin accidents
occur with instructors on board: perhaps the problem lies with
instructor training?

You are getting into the debate about whether deliberate spin training
kills more people than accidental spins.

There is no debate, more people are killed in deliberately induced spins
than in accidental ones...

That's meaningless unless we know how many deliberate and accidental
spins there are, what proportion result in deaths, and how many
deliberate spins those who die in accidental ones have done.

And I'm still not sure I believe it. How many of the spins of a broken
cable or at the final turn are deliberate.

Less risk and the potential of greater benefit, it would also
reduce the need for clubs to own the potentially lethal Putchaz as the
recognition and prevention could be done in any two seater.

As long as there are spinnable single seaters out there, that's just
asking for trouble.

Ian

Ian


In one message you said:

"Juniors have a complicated spin mode which is generally three turns
nose down and recoverable, three flat and unrecoverable, rinse,
repeat. If you don't recover in the first three turns (Turn 1: ****,
better get the nose up. Turn 2: why didn't that work? Turn 3: What's
spin recovery again?) you just have to sweat it out for a few hundred
feet or your current altitude, whichever is less."

and elsewhere

"You are quite right - I should have said that the oscillation is at
lighter weights / after CoGs."

So a Junior behaves strangely with an aft CofG, and in your words is
unrecoverable.
My first point is the glider should not be flying and should certainly
never have been certified under JAR if that is true, unless of course the
CofG is aft of the permitted limit.

What is really interesting is what you say about the Puchaz, which comes
from the same design shop and that is:

"That is a correlation, not a causation. Most Puchacz spin accidents
occur with instructors on board: perhaps the problem lies with
instructor training?"

In fact I cannot recall an accident where a Puchacz has spun in solo. You
are absolutely correct then when you say the accidents only occur with an
instructor on board, or more correctly when the back seat is occupied. So
we have a different loading situation in a glider which comes from the
same design shop as another glider with known spin recovery problems if
the CofG is moved aft. So is there the same problem with the Puchacz as
with the Junior, and is that problem in fact worse to the extent that
there is no recovery? We cannot know for sure but there is evidence that
points that way.

Does this not raise any concerns? I know we cannot prove that the Puchacz
will not recover under certain loading conditions any more that we can
prove that the spin ins have been caused by pilot error. The truth is that
the Puchacz has been proved to be a glider that frequently kills people. I
experienced a spin recovery in a Puchacz that was prolonged to an extent
that I thought it was not going to recover. It did eventually. It is very
easy to blame the unknown on pilot error but I suggest that we should at
least consider the possibility that there is a major problem with the
Puchacz, one which should mean that it is not intentionally spun as an
absolute minimum. We are never going to have a pilot tell us "This glider
was impossible to get out of a spin", because if that is the case he is
dead and not saying much.

My personal view is that there is sufficient evidence to show that the
Puchacz is a dangerous glider, so dangerous in fact that it should never
be flown again.

Don Johnstone wrote:

with the Junior, and is that problem in fact worse to the extent that
there is no recovery? We cannot know for sure but there is evidence that
points that way.

Yes, we can and do know. The Puchacz as well as the Junior have been
frequently flown in aerobatics contests. To my knowledge, no Puch nor
Junior has been spun into the ground during a contest. So they do
recover. More, they even do recover forseeably and precisely, otherwise
they wouldn't be flown in contests.

At 21:31 03 July 2009, John Smith wrote:
Don Johnstone wrote:

with the Junior, and is that problem in fact worse to the extent that
there is no recovery? We cannot know for sure but there is evidence
that
points that way.

Yes, we can and do know. The Puchacz as well as the Junior have been
frequently flown in aerobatics contests. To my knowledge, no Puch nor
Junior has been spun into the ground during a contest. So they do
recover. More, they even do recover forseeably and precisely, otherwise
they wouldn't be flown in contests.


Yes, but are they flown in contests with the CofG aft and in the case of
the Puchacz with the rear seat occupied with a heavier pilot? I doubt it.
I am not saying that under all loading conditions that there is a
problem. What I am suggesting is that under some loading conditions there
may well be. What has been said in previous posts tends to indicate there
might be.
Evidence from pilots who recover is unhelpful, evidence from pilots who
don't is not available.
My one experience (in a Puchacz) showed me that there was a problem and I
resolved from that day that I would never walk under one let alone fly in
one again. I assume the instructor filed a report, at the time I was not
involved with the BGA at all.

On Jul 3, 4:31*pm, John Smith wrote:
Don Johnstone wrote:
with the Junior, and is that problem in fact worse to the extent that
there is no recovery? We cannot know for sure but there is evidence that
points that way.

Yes, we can and do know. The Puchacz as well as the Junior have been
frequently flown in aerobatics contests. To my knowledge, no Puch nor
Junior has been spun into the ground during a contest. So they do
recover. More, they even do recover forseeably and precisely, otherwise
they wouldn't be flown in contests.

I can cite more than one instance where an "experienced pilot" has
spun
a "well known" design, under "normal" circumstances resulting in
"unexpected"
characteristics. There are dozens, or more, variables involved and
to assume that you have seen all the possibilities is shortsighted to
say the
least. You should not assume that you are doing everything the same
way every
time, with identical equipment. I've experienced such episodes and no
longer
will "explore" that part of a flight envelope. An appropriate phrase
for such
activity is "practice bleeding".

It will be important for Soaring pilots to know whether the recent
crashes were from a spinning or a spiraling ship..That most likely can
be determined by the type of impact.
Simply, every pilot should recognize and recover from an incipient
spin. If he or she is not sure, one should be shown in
a Blanik or similar spin happy ships.

A glider in flight should really never come close to a spiral, since
it is approaching red line fast. I feel the reason gliders get into
spirals is not only the lack of spin recognition of the pilot, but
poor flying technique. Yaw string, airspeeds, coordination.

Of course all those problems can happen to a pilot becomming sick,
passing out or similar. I have programmed myself to immidiately pull
the trim all the way back and let go of the controls. Not sure if
that would help, depends on the ship?

soarski

My personal view is that there is sufficient evidence to show that the
Puchacz is a dangerous glider, so dangerous in fact that it should never
be flown again.

Detailed 'puchy' spin analysis found he

http://www.ssa.org/members/johnson/f...72-1994-06.pdf

It's actually pronounced poo-hots BTW, but I'm not sure how it
translates in plurality... regardless, it is odd how many have drilled
into the ground with competent pilots and instructors onboard though.
Of course there's the rudder pedal theory (rear pilot's feet
obstructing mechanism's full travel...), but it's just that- a theory.

-Paul