Spins, Spiral Dives and Training

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, 5:45*pm, Don Johnstone wrote:
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.

I think the Puchacz spin characteristics are well explained in this
report.
http://www.tsb.gc.ca/eng/rapports-re...4/a05o0204.asp

Note the paragraph where is states that after extensive testing they
found that the only way a recovery could be prevented is by holding
full back stick. It further states that the nose must be pushed to a
very steep nose down attitude, which appears from the cockpit to be
past the vertical, to get reliable recovery. They suggest that failed
spin recoveries likely result from pilots unwilling to push the nose
that far down.

The Puchacz POH can be found he
http://soargbsc.com/members/manuals/puchacz.pdf

It has two pages devoted to spins. It specifies that the ailerons
MUST be held neutral, otherwise oscillations will result. It also
says that with the CG aft of the mid point, the stick has to go
forward of neutral elevator and to expect the spin may continue beyond
one turn after anti- spin controls are applied. It also says rudder
and elevator control forces are high during the spin recovery.

It seems reasonable to say that Puchacz are spun in by pilots who are
unfamiliar with its special spin recovery characteristics - perhaps by
pilots who haven't bothered to read the POH and believe all they have
to know is the "standard spin recovery" technique.

The Puchacz is not a dangerous glider. There may be dangerous pilots
who fly them, however.

At 21:15 04 July 2009, bildan wrote: (snip)

The Puchacz is not a dangerous glider. There may be dangerous pilots
who fly them, however.

How would you describe a glider in which so many people have been killed
in spinning incidents? Unlucky? Challenging? or Misunderstood perhaps?

I fully accept the reports of the pilots who tested the glider and found
that it recovered, if it had not they would not have been able to report
that it didn't.

Of course no-one is going to design a glider that cannot recover from a
spin, and of course no-one is going to design an airliner where the doors
fall off either, causing major structural failure. I do not think that the
level of expertise found at McDonnell-Douglas exists in a glider design
facility. Design faults are found in aircraft after release to service and
mostly something is done or at least restrictions are put in place to
counteract the fault, not so with the Puchacz.
The reason why no-one has reported that a Puchacz is impossible to recover
is that if it has happened the pilots have not survived to do so. It is
easy to blame someone when they are not around to challenge that finding
and this is certainly what the Canadian report does.

Is the best explanation that anyone can come up with is that the glider
attracts more than it's fair share of dangerous pilots.

I have little doubt that the Putchacz will go on killing people while it
is permitted to continue to fly, it won't be me, I will never fly in one
again.

I have done quite a few flights in the Puchacz. It is a perfectly nice
glider, albeit with a slightly greater tendency to spin than most West
European designs. Ditto the Junior. They will both recover using the
standard spin recovery, although you may have to get the stick well
forward and hold it there until the spin stops. I personally prefer
training gliders that spin properly and require a positive recovery. With
the K13 for example, you are never quite sure whether it will go into a
spin or a spiral dive, and it will usually recover from a spin as soon as
the stick is moved off the backstop. not very realistic!

Derek Copeland


At 23:30 04 July 2009, Don Johnstone wrote:
At 21:15 04 July 2009, bildan wrote: (snip)

The Puchacz is not a dangerous glider. There may be dangerous pilots
who fly them, however.

How would you describe a glider in which so many people have been killed
in spinning incidents? Unlucky? Challenging? or Misunderstood perhaps?

I fully accept the reports of the pilots who tested the glider and found
that it recovered, if it had not they would not have been able to report
that it didn't.

Of course no-one is going to design a glider that cannot recover from a
spin, and of course no-one is going to design an airliner where the
doors
fall off either, causing major structural failure. I do not think that
the
level of expertise found at McDonnell-Douglas exists in a glider design
facility. Design faults are found in aircraft after release to service
and
mostly something is done or at least restrictions are put in place to
counteract the fault, not so with the Puchacz.
The reason why no-one has reported that a Puchacz is impossible to
recover
is that if it has happened the pilots have not survived to do so. It is
easy to blame someone when they are not around to challenge that finding
and this is certainly what the Canadian report does.

Is the best explanation that anyone can come up with is that the glider
attracts more than it's fair share of dangerous pilots.

I have little doubt that the Putchacz will go on killing people while it
is permitted to continue to fly, it won't be me, I will never fly in
one
again.

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".

On Jul 4, 12:32*pm, n7ly wrote:
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".

Hey at least we can do RTSL aborts ok!

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

On Jul 3, 7:36*pm, soarski wrote:
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

The programing myself, I meant If I had the time or the chance, to do
so before
getting incapasitated.