Spins, Spiral Dives and Training

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.